Science.gov

Sample records for steel catenary risers

  1. Fatigue analysis of steel catenary risers based on a plasticity model

    NASA Astrophysics Data System (ADS)

    Dong, Yongqiang; Sun, Liping

    2015-03-01

    The most critical issue in the steel catenary riser design is to evaluate the fatigue damage in the touchdown zone accurately. Appropriate modeling of the riser-soil resistance in the touchdown zone can lead to significant cost reduction by optimizing design. This paper presents a plasticity model that can be applied to numerically simulate riser-soil interaction and evaluate dynamic responses and the fatigue damage of a steel catenary riser in the touchdown zone. Utilizing the model, numerous riser-soil elements are attached to the steel catenary riser finite elements, in which each simulates local foundation restraint along the riser touchdown zone. The riser-soil interaction plasticity model accounts for the behavior within an allowable combined loading surface. The model will be represented in this paper, allowing simple numerical implementation. More importantly, it can be incorporated within the structural analysis of a steel catenary riser with the finite element method. The applicability of the model is interpreted theoretically and the results are shown through application to an offshore 8.625″ steel catenary riser example. The fatigue analysis results of the liner elastic riser-soil model are also shown. According to the comparison results of the two models, the fatigue life analysis results of the plasticity framework are reasonable and the horizontal effects of the riser-soil interaction can be included.

  2. Critical top tension for static equilibrium configuration of a steel catenary riser

    NASA Astrophysics Data System (ADS)

    Athisakul, Chainarong; Klaycham, Karun; Chucheepsakul, Somchai

    2014-12-01

    This paper aims to present the critical top tension for static equilibrium configurations of a steel catenary riser (SCR) by using the finite element method. The critical top tension is the minimum top tension that can maintain the equilibrium of the SCR. If the top tension is smaller than the critical value, the equilibrium of the SCR does not exist. If the top tension is larger than the critical value, there are two possible equilibrium configurations. These two configurations exhibit the nonlinear large displacement. The configuration with the smaller displacement is stable, while the one with larger displacement is unstable. The numerical results show that the increases in the riser's vertical distances, horizontal offsets, riser's weights, internal flow velocities, and current velocities increase the critical top tensions of the SCR. In addition, the parametric studies are also performed in order to investigate the limit states for the analysis and design of the SCR.

  3. Cross-flow VIV-induced fatigue damage of deepwater steel catenary riser at touch-down point

    NASA Astrophysics Data System (ADS)

    Wang, Kun-peng; Tang, Wen-yong; Xue, Hong-xiang

    2014-03-01

    A prediction model of the deepwater steel catenary riser VIV is proposed based on the forced oscillation test data, taking into account the riser-seafloor interaction for the cross-flow VIV-induced fatigue damage at touch-down point (TDP). The model will give more reasonable simulation of SCR response near TDP than the previous pinned truncation model. In the present model, the hysteretic riser-soil interaction model is simplified as the linear spring and damper to simulate the seafloor, and the damping is obtained according to the dissipative power during one periodic riser-soil interaction. In order to validate the model, the comparison with the field measurement and the results predicted by Shear 7 program of a full-scale steel catenary riser is carried out. The main induced modes, mode frequencies and response amplitude are in a good agreement. Furthermore, the parametric studies are carried out to broaden the understanding of the fatigue damage sensitivity to the upper end in-plane offset and seabed characteristics. In addition, the fatigue stress comparison at TDP between the truncation riser model and the present full riser model shows that the existence of touch-down zones is very important for the fatigue damage assessment of steel catenary riser at TDP.

  4. Experimental investigation on vortex-induced vibration of steel catenary riser

    NASA Astrophysics Data System (ADS)

    Fan, Yu-ting; Mao, Hai-ying; Guo, Hai-yan; Liu, Qing-hai; Li, Xiao-min

    2015-10-01

    Steel catenary riser (SCR) is the transmission device between the seabed and the floating production facilities. As developments move into deeper water, the fatigue life of the riser can become critical to the whole production system, especially due to the vortex-induced vibration (VIV), which is the key factor to operational longevity. As a result, experimental investigation about VIV of the riser was performed in a large plane pool which is 60 m long, 36 m wide and 6.5 m deep. Experiments were developed to study the influence of current speed and seabed on VIV of SCR. The results show that amplitudes of strain and response frequencies increase with the current speed both in cross-flow (CF) and in-line (IL). When the current speed is high, multi-mode response is observed in the VIV motion. The amplitudes of strain in IL direction are not much smaller than those in CF direction. The seabed has influence on the response frequencies of riser and the positions of damage for riser.

  5. Multiaxial fatigue analysis on reeled deepwater steel catenary risers with girth weld defects

    NASA Astrophysics Data System (ADS)

    Yang, He-zhen; Ding, Jin-hong; Li, Qing-quan; Li, Hua-jun

    2014-12-01

    In the present study, we simulated the reel-lay installation process of deepwater steel catenary risers (SCRs) using the finite element method and proposed multiaxial fatigue analysis for reeled SCRs. The reel-lay method is one of the most efficient and economical pipeline installation methods. However, material properties of reeled risers may change, especially in the weld zone, which can affect the fatigue performance. Applying finite element analysis (FEA), we simulated an installation load history through the reel, aligner, and straightener and analyzed the property variations. The impact of weld defects during the installation process, lack of penetration and lack of fusion, was also discussed. Based on the FEA results, we used the Brown-Miller criterion combined with the critical plane approach to predict the fatigue life of reeled and non-reeled models. The results indicated that a weld defect has a significant influence on the material properties of a riser, and the reel-lay method can significantly reduce the fatigue life of SCRs. The analysis conclusion can help designers understand the mechanical performance of welds during reel-lay installation.

  6. Multiaxial fatigue analyses of stress joints for deepwater steel catenary risers

    NASA Astrophysics Data System (ADS)

    Zheng, Wen-qing; Yang, He-zhen; Li, Qing-quan

    2012-12-01

    In the present study, the dynamic and fatigue characteristics of two types of stress joints are investigated under ocean environmental condition. Connected with the riser and the platform, stress joint at the vessel hang-off position should be one of the main critical design challenges for a steel catenary riser (SCR) in deepwater. When the riser is under a high pressure and deepwater working condition, the stress state for the joint is more complex, and the fatigue damage is easy to occur at this position. Stress joint discussed in this paper includes two types: Tapered Stress Joint (TSJ) and Sleeved Stress Joint (SSJ), and multiaxial fatigue analysis results are given for comparison. Global dynamic analysis for an SCR is performed first, and then the local boundary conditions obtained from the previous analysis are applied to the stress joint FE model for the later dynamic and multiaxial fatigue analysis. Results indicate that the stress level is far lower than the yield limit of material and the damage induced by fatigue needs more attention. Besides, the damage character of the two types of stress joints differs: for TSJ, the place where the stress joint connects with the riser is easy to occur fatigue damage; for SSJ, the most probable position is at the place where the end of the inner sleeve pipe contacts with the riser body. Compared with SSJ, TSJ shows a higher stress level but better fatigue performance, and it will have a higher material cost. In consideration of various factors, designers should choose the most suitable type and also geometric parameters.

  7. The Catenary as Roulette

    ERIC Educational Resources Information Center

    Sanchez-Reyes, Javier S.

    2012-01-01

    The focus of a parabola rolling without sliding along a straight line traces a catenary. We give some historical notes on this classical kinematical construction, observe that it was rediscovered in a recent article, and give a simpler and more geometric alternative derivation.

  8. Catenaries in viscous fluid

    NASA Astrophysics Data System (ADS)

    Hanna, James; Chakrabarti, Brato

    2015-11-01

    Slender structures live in fluid flows across many scales, from towed instruments to plant blades to microfluidic valves. The present work details a simple model of a flexible structure in a uniform flow. We present analytical solutions for the translating, axially flowing equilibria of strings subjected to a uniform body force and linear drag forces. This is an extension of the classical catenaries to a five-parameter family of solutions, represented as trajectories in angle-curvature ``phase space.'' Limiting cases include neutrally buoyant towed cables and freely sedimenting flexible filaments. Now at University of California, San Diego.

  9. NASA CPAS Drogue Textile Riser Feasibility Study

    NASA Technical Reports Server (NTRS)

    Hennings, Elsa J.; Petersen, Michael L.; Anderson, Brian; Johnson, Brian

    2015-01-01

    Steel cable was chosen for the lower end of the drogue and main parachute risers on NASA's Orion Multi Purpose Crew Vehicle Parachute Assembly System (CPAS) to protect the risers from extreme temperatures and abrasion should they contact the crew module during deployment, as was done for Apollo. Due to the weight and deployment complexity inherent in steel, there was significant interest in the possibility of substituting textile for steel for the drogue and main parachute risers. However, textile risers could be damaged when subjected to high temperature and abrasion. Investigations were consequently performed by a subset of the authors to determine whether sacrificial, non-load-bearing textile riser covers could be developed to mitigate the thermal and abrasion concerns. Multiple material combinations were tested, resulting in a cover design capable of protecting the riser against severe riser/crew module contact interactions. A feasibility study was then conducted to evaluate the performance of the textile drogue riser cover in relevant abrasive environments. This paper describes the testing performed and documents the results of this feasibility study.

  10. TLP marine riser tensioner

    SciTech Connect

    Peppel, G.W.

    1988-03-08

    A riser tensioner for use in maintaining a tension on a marine riser from a tension leg platform, the tension leg platform moving relative to the marine riser and the marine riser having a center line is described comprising: (a) an elastomeric assembly, adjustably deformable in pad shear, for maintaining the riser in tension during vertical movement of the platform relative to the riser, the elastomeric assembly having upper and lower ends; (b) a gimbal assembly for pivotally connecting the upper end of the elastomeric assembly to the tension leg platform to accommodate misalignment between the riser and the tension leg platform; (c) a base ring to which the lower end of the elastomeric assembly is secured; and (d) a collar, securely mounted on the riser, for resting within the base ring to connect the lower end of the elastomeric assembly to the riser.

  11. The Hyperbolic Sine Cardinal and the Catenary

    ERIC Educational Resources Information Center

    Sanchez-Reyes, Javier

    2012-01-01

    The hyperbolic function sinh(x)/x receives scant attention in the literature. We show that it admits a clear geometric interpretation as the ratio between length and chord of a symmetric catenary segment. The inverse, together with the use of dimensionless parameters, furnishes a compact, explicit construction of a general catenary segment of…

  12. Orion Parachute Riser Cutter Development

    NASA Technical Reports Server (NTRS)

    Oguz, Sirri; Salazar, Frank

    2011-01-01

    This paper presents the tests and analytical approach used on the development of a steel riser cutter for the CEV Parachute Assembly System (CPAS) used on the Orion crew module. Figure 1 shows the riser cutter and the steel riser bundle which consists of six individual cables. Due to the highly compressed schedule, initial unavailability of the riser material and the Orion Forward Bay mechanical constraints, JSC primarily relied on a combination of internal ballistics analysis and LS-DYNA simulation for this project. Various one dimensional internal ballistics codes that use standard equation of state and conservation of energy have commonly used in the development of CAD devices for initial first order estimates and as an enhancement to the test program. While these codes are very accurate for propellant performance prediction, they usually lack a fully defined kinematic model for dynamic predictions. A simple piston device can easily and accurately be modeled using an equation of motion. However, the accuracy of analytical models is greatly reduced on more complicated devices with complex external loads, nonlinear trajectories or unique unlocking features. A 3D finite element model of CAD device with all critical features included can vastly improve the analytical ballistic predictions when it is used as a supplement to the ballistic code. During this project, LS-DYNA structural 3D model was used to predict the riser resisting load that was needed for the ballistic code. A Lagrangian model with eroding elements shown in Figure 2 was used for the blade, steel riser and the anvil. The riser material failure strain was fine tuned by matching the dent depth on the anvil with the actual test data. LS-DYNA model was also utilized to optimize the blade tip design for the most efficient cut. In parallel, the propellant type and the amount were determined by using CADPROG internal ballistics code. Initial test results showed a good match with LS-DYNA and CADPROG

  13. Riser and tendon management system

    SciTech Connect

    Devlin, P.V.

    1992-02-18

    This patent describes a riser and tendon management system. It comprises means to set nominal conditions for the risers and tendons; means to measure actual riser and tendon conditions; means to compare the actual and nominal conditions of the risers and tendons; and means responsive to a differential between the actual and nominal riser and tendon conditions, which difference exceeds specified limits, and recommending corrective action to bring the risers and tendons back to within nominal conditions.

  14. RELIABLE RADIOGRAPHIC INSPECTION OF FLEXIBLE RISERS FOR THE OIL INDUSTRY

    SciTech Connect

    Almeida, Romulo M.; Rebello, Joao Marcos A.

    2010-02-22

    Flexible risers are composite tubular structures manufactured by the concentric assemblage of cylindrical polymeric and helically wound metallic layers employed to convey pressurized fluids such as oil, gas and water in the ocean environment. The metallic layers account for the flexible risers' structural strength and are dimensioned according to the static and dynamic loads. They are usually installed in a free hanging catenary configuration and are subjected to the direct action of waves and marine currents and wave induced motions from the oil production platform. The fatigue rupture of wire armours in the end fitting or within the riser segment protected by the bend stiffener is an object of major concern. Integrity models have been developed, however inspection techniques are mandatory to ensure that failure is detected. Gammagraphy has been used as a common inspection technique in all regions of the flexible riser, mainly with the single wall-single view method. On the other side, there is not any qualified radiographic procedure to this kind of structure. Radiographic simulation was adopted and its validation with actual gammagraphies and establishment of radiographic parameters to complex radiation geometries were done. Results show the viability of the radiographic inspection analyzing the armour wires' rupture and the displacement between wires.

  15. Reliable Radiographic Inspection of Flexible Risers for the Oil Industry

    NASA Astrophysics Data System (ADS)

    Almeida, Rômulo M.; Rebello, Joao Marcos A.; Vaz, Murilo A.

    2010-02-01

    Flexible risers are composite tubular structures manufactured by the concentric assemblage of cylindrical polymeric and helically wound metallic layers employed to convey pressurized fluids such as oil, gas and water in the ocean environment. The metallic layers account for the flexible risers' structural strength and are dimensioned according to the static and dynamic loads. They are usually installed in a free hanging catenary configuration and are subjected to the direct action of waves and marine currents and wave induced motions from the oil production platform. The fatigue rupture of wire armours in the end fitting or within the riser segment protected by the bend stiffener is an object of major concern. Integrity models have been developed, however inspection techniques are mandatory to ensure that failure is detected. Gammagraphy has been used as a common inspection technique in all regions of the flexible riser, mainly with the single wall-single view method. On the other side, there is not any qualified radiographic procedure to this kind of structure. Radiographic simulation was adopted and its validation with actual gammagraphies and establishment of radiographic parameters to complex radiation geometries were done. Results show the viability of the radiographic inspection analyzing the armour wires' rupture and the displacement between wires.

  16. A fresh look at the catenary

    NASA Astrophysics Data System (ADS)

    Behroozi, F.

    2014-09-01

    A hanging chain takes the familiar form known as the catenary which is one of the most ubiquitous curves students encounter in their daily life. Yet most introductory physics and mathematics texts ignore the subject entirely. In more advanced texts the catenary equation is usually derived as an application of the calculus of variations. Although the variational approach is mathematically elegant, it is suitable for more advanced students. Here we derive the catenary equation in special and rectangular coordinates by considering the equilibrium conditions for an element of the hanging chain and without resorting to the calculus of variations. One advantage of this approach is its simplicity which makes it accessible to undergraduate students; another is the concurrent derivation of a companion equation which gives the tension along the chain. These solutions provide an excellent opportunity for undergraduates to explore the underlying physics. One interesting result is that the shape of a hanging chain does not depend on its linear mass density or on the strength of the gravitational field. Therefore, within a scale factor, all catenaries are copies of the same universal curve. We give the functional dependence of the scale factor on the length and terminal angle of the hanging chain.

  17. A Classroom Investigation into the Catenary

    ERIC Educational Resources Information Center

    Staples, Ed

    2011-01-01

    The quest to find the equation of a catenary makes an ideal investigation for upper secondary students. In the modelling exercise that follows, no knowledge of calculus is required to gain a fairly good understanding of the nature of the curve. This investigation is best described as a scientific investigation--a "hands on" experience that…

  18. Deepwater production riser

    SciTech Connect

    Panicker, N.N.; Yancey, I.R.

    1983-05-01

    A deepwater production riser design developed by Mobil Research and Development Corporation is presented. The riser consists of a lower rigid section terminated about 200 feet below the sea surface with a tensioning buoy assembly and a flexible upper section made of a bundle of flexible pipes. It is designed to be compliant to waves, currents and vessel motions and applicable to both mild and severe environments. Design, analysis, testing, and installation method are discussed.

  19. Deepwater production riser

    SciTech Connect

    Panicker, N.N.; Yancey, I.R.

    1984-08-01

    The design of a deepwater production riser is described. The compliant riser design consists of a lower rigid section terminated about 200 ft (60 m) below the sea surface with a tensioning buoy assembly and a flexible upper section made of a bundle of flexible pipes. It is designed to be compliant to waves, currents, and vessel motions and applicable to both mild and severe environments. Design, analysis, testing, and installation are discussed.

  20. Solar radiation on a catenary collector

    NASA Astrophysics Data System (ADS)

    Crutchik, M.; Appelbaum, J.

    1992-07-01

    A tent-shaped structure with a flexible photovoltaic blanket acting as a catenary collector is presented. The shadow cast by one side of the collector produces a shadow on the other side of the collector. This self-shading effect is analyzed. The direct beam, the diffuse, and the albedo radiation on the collector are determined. An example is given for the insolation on the collector operating on Viking Lander 1 (VL1).

  1. Solar radiation on a catenary collector

    NASA Astrophysics Data System (ADS)

    Crutchik, M.; Appelbaum, J.

    A tent-shaped structure with a flexible photovoltaic blanket acting as a catenary collector is presented. The shadow cast by one side of the collector on the other side producing a self shading effect is analyzed. The direct beam, the diffuse and the albedo radiation on the collector are determined. An example is given for the insolation on the collector operating on the martian surface for the location of Viking Lander 1 (VL1).

  2. D Catenary Curve Fitting for Geometric Calibration

    NASA Astrophysics Data System (ADS)

    Chan, T.-O.; Lichti, D. D.

    2011-09-01

    In modern road surveys, hanging power cables are among the most commonly-found geometric features. These cables are catenary curves that are conventionally modelled with three parameters in 2D Cartesian space. With the advent and popularity of the mobile mapping system (MMS), the 3D point clouds of hanging power cables can be captured within a short period of time. These point clouds, similarly to those of planar features, can be used for feature-based self-calibration of the system assembly errors of an MMS. However, to achieve this, a well-defined 3D equation for the catenary curve is needed. This paper proposes three 3D catenary curve models, each having different parameters. The models are examined by least squares fitting of simulated data and real data captured with an MMS. The outcome of the fitting is investigated in terms of the residuals and correlation matrices. Among the proposed models, one of them could estimate the parameters accurately and without any extreme correlation between the variables. This model can also be applied to those transmission lines captured by airborne laser scanning or any other hanging cable-like objects.

  3. Conceptual baseline design developed for a 13,200-ft riser system for OMDP

    SciTech Connect

    Jocobs, R.P.; Homer, S.T.

    1982-01-25

    This report describes the development of the riser system, which consists of a 17-in. ID, high-strength steel riser with 4-in. ID integral choke and kill lines and an air can buoyancy system. A free-standing bouyant riser feature permits the vessel to be disconnected from the riser in the event of severe storms. The development of riser design criteria is discussed. Vertical vessel and riser motion during installation, retrieval, and storm disconnect dominate the riser's structural design and require a variable buoyancy system. This report recommends that improved computer codes be used to further optimize the design of the riser, particularly in the suspended mode, and the development of critical system components be initiated as early as possible during the preliminary design phase. The program's general design criteria called for a vessel capable of performing drilling and coring operations with riser and well control equipment in 4,000-m (13,200-ft) water depths with a total drillstring length of 10,000 m (33,000 ft). The conceptual baseline riser system described here represents a feasible, cost-effective solution to one of the critical technical issues facing the OMDP. The system utilizes existing, field-proven technology wherever possible. Design Criteria for the OMDP riser system are presented. 2 refs.

  4. 20. VIEW OF CATENARY, FEEDER TOWERS AND COS COB POWER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. VIEW OF CATENARY, FEEDER TOWERS AND COS COB POWER PLANT (CENTER BACKGROUND) LOOKING WEST FROM THE NORTH SIDE OF THE MIANUS RIVER BASCULE BRIDGE. NOTE THAT THE CATENARY ENDS AT BRIDGE 313. TRAINS ARE CARRIED ACROSS THE BASCULE BRIDGE BY THEIR OWN MOMENTUM AND PICK UP THE CATENARY ON THE EAST SIDE OF THE RIVER. THE FEEDER LINES CARRY POWER ACROSS THE RIVER ABOVE THE LEVEL OF THE OPENED BASCULE ON THE TOWERS TO THE LEFT AND RIGHT. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

  5. Marine riser connector

    SciTech Connect

    Hampton, J.

    1982-05-18

    A marine riser is disclosed including a uniquely designed three element connection structure and associated connecting and releasing means for the inhibiting of fatigue failure caused by moments and axial loads resulting from relative motion between the fixed ocean bottom and a floating drilling platform or ship, such as a semisubmersible rig. The system includes a preloaded connection including a female member and a male member coaxially aligned and held in compression by a nut placed in tension. The connection holds riser pipe sections together. The connection is preloaded through a tool to a degree such that when a load equal to the yield strength of the pipe section material is applied to the pipe sections joined by the connector, the compressed faces of the male and female members do not separate from each other. The degree of preload would be sufficient to maintain the contact between the compressed faces under expected working loads of the pipe sections. The tool operates in conjunction with lugs located on the nut and a flange or platform with mounting holes located on the male member. A lock is provided on the nut to prevent the disengagement of the male and female members after they are brought into compression by the nut. The position of the lock relative to the nut lugs determines the sustained preload of the connection. Seals are provided between the male and female member to prevent leakage of fluid between the interior of the riser connector and the surrounding environment. The connector also includes provision for the support and connection of sections of kill and choke lines.

  6. 4. OBLIQUE VIEW, AUTOMATIC BLOCK SIGNAL, EASTBOUND ON CATENARY BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. OBLIQUE VIEW, AUTOMATIC BLOCK SIGNAL, EASTBOUND ON CATENARY BRIDGE 486 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  7. 3. REAR VIEW, AUTOMATIC BLOCK SIGNAL, EASTBOUND ON CATENARY BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. REAR VIEW, AUTOMATIC BLOCK SIGNAL, EASTBOUND ON CATENARY BRIDGE 486 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  8. 1. FRONT VIEW, AUTOMATIC BLOCK SIGNAL, EASTBOUND ON CATENARY BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. FRONT VIEW, AUTOMATIC BLOCK SIGNAL, EASTBOUND ON CATENARY BRIDGE 486 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  9. 5. DETAIL, HOME SIGNAL, WESTBOUND ON CATENARY BRIDGE 518, FRONT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. DETAIL, HOME SIGNAL, WESTBOUND ON CATENARY BRIDGE 518, FRONT VIEW - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  10. 12. FRONT VIEW, DETAIL, DWARF SIGNAL, EAST ON CATENARY BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. FRONT VIEW, DETAIL, DWARF SIGNAL, EAST ON CATENARY BRIDGE 522 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  11. 13. OBLIQUE VIEW, THREE DWARF SIGNALS, EAST OF CATENARY BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. OBLIQUE VIEW, THREE DWARF SIGNALS, EAST OF CATENARY BRIDGE 522 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  12. Engineering report for simulated riser installation

    SciTech Connect

    Brevick, C.H., Westinghouse Hanford

    1996-05-09

    The simulated riser installation field tests demonstrated that new access ports (risers) can be installed safely, quickly, and economically in the concrete domes of existing underground single- shell waste storage tanks by utilizing proven rotary drilling equipment and vacuum excavation techniques. The new riser installation will seal against water intrusion, provide as table riser anchored to the tank dome, and be installed in accordance with ALARA principles. The information contained in the report will apply to actual riser installation activity in the future.

  13. TLP production risers for 1200-m water depth

    SciTech Connect

    Delgado, J.H.; Erb, P.R. ); Moe, G. )

    1988-11-01

    A number of technically feasible alternative riser systems exist for tension leg platform (TLP) production systems in deep water. These include conventional steel, steel with added buoyancy, titanium, and carbon-fiber composite. The last three of these options provide substantial reductions in required riser tension for a 1200-m (3,935-ft) depth. For a minimum-size TLP, these reduced tensions translate into substantial reductions in fabricated steel weight. Replacing conventional top tensioners with a hard-mount or gimbal arrangement requires a relatively small increase in top tension, which would be balanced out by weight savings on the tensioning equipment. Operational concerns related to pressure and temperature changes must be addressed to ensure feasibility of the hard-mount or gimbal approach.

  14. Catenary optics for achromatic generation of perfect optical angular momentum.

    PubMed

    Pu, Mingbo; Li, Xiong; Ma, Xiaoliang; Wang, Yanqin; Zhao, Zeyu; Wang, Changtao; Hu, Chenggang; Gao, Ping; Huang, Cheng; Ren, Haoran; Li, Xiangping; Qin, Fei; Yang, Jing; Gu, Min; Hong, Minghui; Luo, Xiangang

    2015-10-01

    The catenary is the curve that a free-hanging chain assumes under its own weight, and thought to be a "true mathematical and mechanical form" in architecture by Robert Hooke in the 1670s, with nevertheless no significant phenomena observed in optics. We show that the optical catenary can serve as a unique building block of metasurfaces to produce continuous and linear phase shift covering [0, 2π], a mission that is extremely difficult if not impossible for state-of-the-art technology. Via catenary arrays, planar optical devices are designed and experimentally characterized to generate various kinds of beams carrying orbital angular momentum (OAM). These devices can operate in an ultra-broadband spectrum because the anisotropic modes associated with the spin-orbit interaction are almost independent of the incident light frequency. By combining the optical and topological characteristics, our approach would allow the complete control of photons within a single nanometric layer. PMID:26601283

  15. Diffusion of innovations dynamics, biological growth and catenary function

    NASA Astrophysics Data System (ADS)

    Guseo, Renato

    2016-12-01

    The catenary function has a well-known role in determining the shape of chains and cables supported at their ends under the force of gravity. This enables design using a specific static equilibrium over space. Its reflected version, the catenary arch, allows the construction of bridges and arches exploiting the dual equilibrium property under uniform compression. In this paper, we emphasize a further connection with well-known aggregate biological growth models over time and the related diffusion of innovation key paradigms (e.g., logistic and Bass distributions over time) that determine self-sustaining evolutionary growth dynamics in naturalistic and socio-economic contexts. Moreover, we prove that the 'local entropy function', related to a logistic distribution, is a catenary and vice versa. This special invariance may be explained, at a deeper level, through the Verlinde's conjecture on the origin of gravity as an effect of the entropic force.

  16. Catenary optics for achromatic generation of perfect optical angular momentum

    PubMed Central

    Pu, Mingbo; Li, Xiong; Ma, Xiaoliang; Wang, Yanqin; Zhao, Zeyu; Wang, Changtao; Hu, Chenggang; Gao, Ping; Huang, Cheng; Ren, Haoran; Li, Xiangping; Qin, Fei; Yang, Jing; Gu, Min; Hong, Minghui; Luo, Xiangang

    2015-01-01

    The catenary is the curve that a free-hanging chain assumes under its own weight, and thought to be a “true mathematical and mechanical form” in architecture by Robert Hooke in the 1670s, with nevertheless no significant phenomena observed in optics. We show that the optical catenary can serve as a unique building block of metasurfaces to produce continuous and linear phase shift covering [0, 2π], a mission that is extremely difficult if not impossible for state-of-the-art technology. Via catenary arrays, planar optical devices are designed and experimentally characterized to generate various kinds of beams carrying orbital angular momentum (OAM). These devices can operate in an ultra-broadband spectrum because the anisotropic modes associated with the spin-orbit interaction are almost independent of the incident light frequency. By combining the optical and topological characteristics, our approach would allow the complete control of photons within a single nanometric layer. PMID:26601283

  17. Design analysis and full scale prototype testing of Auger TLP`s 9-5/8 inch TLP production riser weld-on connector

    SciTech Connect

    Fox, S.A.; Smith, J.D.; Asbill, W.T.

    1995-12-31

    The design, analysis, and full-scale prototype testing of a special threaded connector for use on the Auger TLP 9-5/8 inch x 0.435 inch wall production risers is summarized in this paper. A flush-bore production riser connector with internal and external metal-to-metal seals, a resilient seal between the external metal-to-metal seal and the external torque shoulder, radial thread interference, and high resistance to fatigue was developed. Finite element analyses and full-scale static, sealability, and fatigue tests verified that the connector satisfied all design requirements. The full-scale fatigue tests verified that the design fatigue curve and fatigue life prediction procedure used yield conservative results and that the fatigue life of the connector greatly exceeds the girthweld. Consideration of manufacturing methods and tolerances along with gauging, in the early stages of the design, resulted in a cost effective connector. The threaded connector was designed for the Auger Tension Leg Platform production risers. However, it is envisioned that the connector will be easily scalable to other riser diameters and wall thicknesses for other TLP`s and has applicability to catenary and top-tensioned risers and subsea flowlines. In addition to resulting in an efficient long life production riser connector design, the design process illustrated the Importance of interaction, between the designers, quality control personnel, machinist, gauge manufacturer, and end user, during the design. All made significant contributions to the success of the design.

  18. UNIDENTIFIED CATENARY SUSPENSION BRIDGE WITH TRUSSED OBELISK TOWERS ON STONE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    UNIDENTIFIED CATENARY SUSPENSION BRIDGE WITH TRUSSED OBELISK TOWERS ON STONE PIERS, SHOWING HOWE PIPE TRUSS RAILING AND TRUSSED DECK BEAMS TYPICAL TO BRIDGES BUILT BY FLINN-MOYER COMPANY. 3/4 VIEW FROM BELOW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

  19. Flexible dynamic riser for floating-production facility in the North Sea

    SciTech Connect

    Pettenati, C.; Dumay, J.M.

    1983-09-01

    When considering the production riser aspect of a floating-production facility project, two systems can be generally envisaged: - The rigid steel, tensioned multiple riser. - The flexible, dynamic riser. Although this last one was successfully introduced in Brazil as early as 1978, and since then has proved to be an extremely reliable solution in several other parts of the world as well, for other major operators, the industry in general was still recently expressing some concern about its introduction in an extreme-weather environment such as the North Sea. A more classic and well-known technique such as the steel tensioned riser was generally favoured by companies operating in this hostile context. (Ex: Argyll, Buchan). This paper describing what can be considered as a typical development involving flexible, dynamic risers in the North Sea, presents evidence that this concern, although understandable, is mostly unfounded and that on the contrary, the flexible, dynamic riser represents a very considerable improvement in the reliability and efficiency of a floating-facility offshore development.

  20. Magnetic non-destructive evaluation of ruptures of tensile armor in oil risers

    NASA Astrophysics Data System (ADS)

    Pérez-Benitez, J. A.; Padovese, L. R.

    2012-04-01

    Risers are flexible multilayered pipes formed by an inner flexible metal structure surrounded by polymer layers and spiral wound steel ligaments, also known as armor wires. Since these risers are used to link subsea pipelines to floating oil and gas production installations, and their failure could produce catastrophic consequences, some methods have been proposed to monitor the armor integrity. However, until now there is no practical method that allows the automatic non-destructive detection of individual armor wire rupture. In this work we show a method using magnetic Barkhausen noise that has shown high efficiency in the detection of armor wire rupture. The results are examined under the cyclic and static load conditions of the riser. This work also analyzes the theory behind the singular dependence of the magnetic Barkhausen noise on the applied tension in riser armor wires.

  1. Structural analysis of multiport riser 5A installation on tank 241SY101

    SciTech Connect

    Strehlow, J.P.

    1994-09-16

    The Tank 101-SY multiport riser assembly in the 241-SY-101 waste tank will replace the existing 42 inch riser with four smaller ports. Each smaller port can be used independently to access the tank interior with equipment and instruments needed to mitigate the concentration of hydrogen in the tank. This document provides a design report on the structural evaluation of the multiport riser assembly as well as its anchorage. The multiport riser assembly is a steel structure installed directly above the 42-inch riser and sealed at the existing riser flange. The assembly is structurally supported by the concrete pad placed around the 42 inch riser. The multiport riser assembly will provide two 8-inch penetrations, one 12-inch penetration and one 24-inch penetration. Each penetration will have a shielding plate. These penetrations will be used to insert equipment such as a sonic probe into the tank. In addition to normal loads, non-reactor Safety Class 1 structures, systems and components are to withstand the effects of extreme environmental loads including Design Basis Earthquake (DBE), Design Basis Wind (DBW), Design Basis Flood, Volcanic Eruptions and other abnormal loads considered on a case by case basis. Non-reactor Safety Class 2, 3 and 4 structures, systems and components are those that are not Safety Class 1 and are respectively specified as onsite safety related, occupational safety related and non-safety related items. The 241-SY-101 tank is considered as a non-reactor Safety Class 1 structure. The multiport riser assembly is considered as a non-reactor Safety Class 2 structure since it serves to contain the radioactive and toxic materials under normal operating conditions. However, the pressure relief doors provided on the assembly are considered as Safety Class 1 structures.

  2. Active control strategy on a catenary-pantograph validated model

    NASA Astrophysics Data System (ADS)

    Sanchez-Rebollo, C.; Jimenez-Octavio, J. R.; Carnicero, A.

    2013-04-01

    Dynamic simulation methods have become essential in the design process and control of the catenary-pantograph system, overall since high-speed trains and interoperability criteria are getting very trendy. This paper presents an original hardware-in-the-loop (HIL) strategy aimed at integrating a multicriteria active control within the catenary-pantograph dynamic interaction. The relevance of HIL control systems applied in the frame of the pantograph is undoubtedly increasing due to the recent and more demanding requirements for high-speed railway systems. Since the loss of contact between the catenary and the pantograph leads to arcing and electrical wear, and too high contact forces cause mechanical wear of both the catenary wires and the strips of the pantograph, not only prescribed but also economic and performance criteria ratify such a relevance. Different configurations of the proportional-integral-derivative (PID) controller are proposed and applied to two different plant systems. Since this paper is mainly focused on the control strategy, both plant systems are simulation models though the methodology is suitable for a laboratory bench. The strategy of control involves a multicriteria optimisation of the contact force and the consumption of the energy supplied by the control force, a genetic algorithm has been applied for this purpose. Thus, the PID controller is fitted according to these conflicting objectives and tested within a nonlinear lumped model and a nonlinear finite element model, being the last one validated against the European Standard EN 50318. Finally, certain tests have been accomplished in order to analyse the robustness of the control strategy. Particularly, the relevance or the plant simulation, the running speed and the instrumentation time delay are studied in this paper.

  3. UNIDENTIFIED CATENARY SUSPENSION BRIDGE ON RIVETED METAL PIERS, SHOWING HOWE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    UNIDENTIFIED CATENARY SUSPENSION BRIDGE ON RIVETED METAL PIERS, SHOWING HOWE PIPE TRUSS RAILING AND TRUSSED DECK BEAMS TYPICAL TO BRIDGES BUILT BY FLINN-MOYER COMPANY. TRIPODAL PIPE TOWERS RESEMBLE CLEAR FORK OF THE BRAZOS SUSPENSION BRIDGE’S TOWERS PRIOR TO ENCASEMENT IN CONCRETE. NOTE COLLAPSED TRUSS IN RIVER. ELEVATION VIEW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

  4. UNIDENTIFIED CATENARY SUSPENSION BRIDGE WITH TRIPLE PIPE TOWERS, SHOWING HOWE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    UNIDENTIFIED CATENARY SUSPENSION BRIDGE WITH TRIPLE PIPE TOWERS, SHOWING HOWE PIPE TRUSS RAILING AND TRUSSED DECK BEAMS TYPICAL TO BRIDGES BUILT BY FLINN-MOYER COMPANY. NOTE THAT TOWER PIPES LIE IN ONE PLANE, UNLIKE TRIPODAL ARRANGEMENT AT CLEAR FORK OF THE BRAZOS SUSPENSION BRIDGE. ELEVATION VIEW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

  5. A photovoltaic catenary-tent array for the Martian surface

    NASA Technical Reports Server (NTRS)

    Colozza, Anthony J.; Appelbaum, J.; Crutchik, M.

    1993-01-01

    To provide electrical power during an exploration mission to Mars, a deployable tent-shaped structure with a flexible photovoltaic (PV) blanket is proposed. The array is designed with a self-deploying mechanism utilizing pressurized gas expansion. The structural design for the array uses a combination of cables, beams, and columns to support and deploy the PV blanket. Under the force of gravity, a cable carrying a uniform load will take the shape of a catenary curve. A catenary-tent collector is self shading which must be taken into account in the solar radiation calculation. The shape and the area of the shadow on the array was calculated and used in the determination of the global irradiance on the array. The PV blanket shape and structure dimensions were optimized to achieve a configuration which maximizes the specific power (W/kg). The optimization was performed for three types of PV blankets (silicon, gallium arsenide over germanium, and amorphous silicon) and two types of structural materials (carbon composite and arimid fiber composite). The results show that the catenary shape of the PV blanket corresponding to zero end angle at the base with respect to the horizontal results in the highest specific power. The tent angle is determined by optimizing the specific mass and the output power for maximum specific power. The combination of carbon fiber structural material and amorphous silicon blanket produces the highest specific power.

  6. A photovoltaic catenary-tent array for the Martian surface

    NASA Astrophysics Data System (ADS)

    Colozza, Anthony J.; Appelbaum, J.; Crutchik, M.

    1993-05-01

    To provide electrical power during an exploration mission to Mars, a deployable tent-shaped structure with a flexible photovoltaic (PV) blanket is proposed. The array is designed with a self-deploying mechanism utilizing pressurized gas expansion. The structural design for the array uses a combination of cables, beams, and columns to support and deploy the PV blanket. Under the force of gravity, a cable carrying a uniform load will take the shape of a catenary curve. A catenary-tent collector is self shading which must be taken into account in the solar radiation calculation. The shape and the area of the shadow on the array was calculated and used in the determination of the global irradiance on the array. The PV blanket shape and structure dimensions were optimized to achieve a configuration which maximizes the specific power (W/kg). The optimization was performed for three types of PV blankets (silicon, gallium arsenide over germanium, and amorphous silicon) and two types of structural materials (carbon composite and arimid fiber composite). The results show that the catenary shape of the PV blanket corresponding to zero end angle at the base with respect to the horizontal results in the highest specific power. The tent angle is determined by optimizing the specific mass and the output power for maximum specific power. The combination of carbon fiber structural material and amorphous silicon blanket produces the highest specific power.

  7. Operating a drilling riser in deep water

    SciTech Connect

    Warriner, R.A.

    1984-05-14

    The purpose of a drilling riser is to provide a conduit from a floating vessel to the seafloor through which drilling operations are conducted. The primary components of a riser system, as shown include the gimbal connection to the drill vessel, the slip joint, riser tensioners, an upper ball joint (if required), riser joints, and the lower ball joint. The gimbal connection (usually a ball joint) of the slip joint inner barrel to the drill vessel isolates the riser from the pitch and roll motions of the vessel. Similarly, the slip joint allows for relative vertical motion (heave) between the drill vessel and riser. Riser tensioners provide a pull at the top of the slip joint outer barrel sufficient to maintain tension throughout the riser string. Tension is maintained nearly constant by pneumatic/hydraulic tensioners that compensate for relative motion between the vessel and the slip joint outer barrel. An upper ball joint immediately below the slip joint is sometimes employed if high bending stresses are expected in the wave zone. Its function is to reduce bending stress. A lower ball joint provides the necessary flexible connection between the lower end of the riser and the BOP stack.

  8. Deep water riser system for offshore drilling

    SciTech Connect

    Potts, H.L.

    1984-05-15

    A buoyant riser system for use in a deep water offshore drilling environment is anchored by a system of compliant guys below the active weather zone of the sea. A controllably buoyant housing of the system is submerged at a depth that is readily accessible to divers and includes a blow-out preventer (BOP) from which a suspended sub-riser leads to a well bore to which the sub-riser is coupled. Above the housing, a riser suspended from a floating drill rig is coupled to the BOP thereby communicating the drill rig directly with the well bore for drilling and well completion operations.

  9. A photovoltaic catenary-tent array for the Martian surface

    NASA Astrophysics Data System (ADS)

    Crutchik, M.; Colozza, Anthony J.; Appelbaum, J.

    1993-08-01

    To provide electrical power during an exploration mission to Mars, a deployable tent-shaped structure with a flexible photovoltaic (PV) blanket is proposed. The array is designed with a self-deploying mechanism utilizing pressurized gas expansion. The structural design for the array uses a combination of cables, beams, and columns to support and deploy the PV blanket. Under the force of gravity a cable carrying a uniform load will take the shape of a catenary curve. A catenary-tent collector is self shadowing which must be taken into account in the solar radiation calculation. The shape and the area of the shadow on the array was calculated and used in the determination of the global radiation on the array. The PV blanket shape and structure dimension were optimized to achieve a configuration which maximizes the specific power (W/kg). The optimization was performed for four types of PV blankets (Si, GaAs/Ge, GaAs CLEFT, and amorphous Si) and four types of structure materials (Carbon composite, Aramid Fiber composite, Aluminum, and Magnesium). The results show that the catenary shape of the PV blanket, which produces the highest specific power, corresponds to zero end angle at the base with respect to the horizontal. The tent angle is determined by the combined effect of the array structure specific mass and the PV blanket output power. The combination of carbon composite structural material and GaAs CLEFT solar cells produce the highest specific power. The study was carried out for two sites on Mars corresponding to the Viking Lander locations. The designs were also compared for summer, winter, and yearly operation.

  10. A photovoltaic catenary-tent array for the Martian surface

    NASA Technical Reports Server (NTRS)

    Crutchik, M.; Colozza, Anthony J.; Appelbaum, J.

    1993-01-01

    To provide electrical power during an exploration mission to Mars, a deployable tent-shaped structure with a flexible photovoltaic (PV) blanket is proposed. The array is designed with a self-deploying mechanism utilizing pressurized gas expansion. The structural design for the array uses a combination of cables, beams, and columns to support and deploy the PV blanket. Under the force of gravity a cable carrying a uniform load will take the shape of a catenary curve. A catenary-tent collector is self shadowing which must be taken into account in the solar radiation calculation. The shape and the area of the shadow on the array was calculated and used in the determination of the global radiation on the array. The PV blanket shape and structure dimension were optimized to achieve a configuration which maximizes the specific power (W/kg). The optimization was performed for four types of PV blankets (Si, GaAs/Ge, GaAs CLEFT, and amorphous Si) and four types of structure materials (Carbon composite, Aramid Fiber composite, Aluminum, and Magnesium). The results show that the catenary shape of the PV blanket, which produces the highest specific power, corresponds to zero end angle at the base with respect to the horizontal. The tent angle is determined by the combined effect of the array structure specific mass and the PV blanket output power. The combination of carbon composite structural material and GaAs CLEFT solar cells produce the highest specific power. The study was carried out for two sites on Mars corresponding to the Viking Lander locations. The designs were also compared for summer, winter, and yearly operation.

  11. Center vortices, area law and the catenary solution

    NASA Astrophysics Data System (ADS)

    Höllwieser, Roman; Altarawneh, Derar

    2015-12-01

    We present meson-meson (Wilson loop) correlators in Z(2) center vortex models for the infrared sector of Yang-Mills theory, i.e. a hypercubic lattice model of random vortex surfaces and a continuous (2 + 1)-dimensional model of random vortex lines. In particular, we calculate quadratic and circular Wilson loop correlators in the two models, respectively, and observe that their expectation values follow the area law and show string breaking behavior. Further, we calculate the catenary solution for the two cases and try to find indications for minimal surface behavior or string surface tension leading to string constriction.

  12. Subsea choke and riser pressure equalization system

    SciTech Connect

    Shanks, F.

    1980-07-01

    A description is given of a subsea choke and riser pressure equalization system comprising, in combination: a section of riser pipe; a choke conduit line mechanically supported by said riser pipe; a variable choke valve having an inlet port and a discharge port; a gate valve having an inlet port and a discharge port; a gate valve having an inlet port conected in fluid communiction with the choke line and an output port connected in fluid communication with the inlet port of the variable choke for permitting diversion of fluid from the choke line to the variable choke; and, means connecting the discharge port of the variable choke in fluid communication with the interior of the riser section, said means including a discharge conduit extending from said choke valve in inclined relation with respect to the axis of said riser, whereby fluid diverted from said choke conduit is discharged into said riser in counterflow relation with respect to the upward flow of drilling fluid through said riser.

  13. Nonlinear analysis of wind-induced vibration of high-speed railway catenary and its influence on pantograph-catenary interaction

    NASA Astrophysics Data System (ADS)

    Song, Yang; Liu, Zhigang; Wang, Hongrui; Lu, Xiaobing; Zhang, Jing

    2016-06-01

    The wind-induced vibration of the high-speed catenary and the dynamic behaviour of the pantograph-catenary under stochastic wind field are firstly analysed. The catenary model is established based on nonlinear cable and truss elements, which can fully describe the nonlinearity of each wire and the initial configuration. The model of the aerodynamic forces acting on the messenger/contact wire is deduced by considering the effect of the vertical and horizontal fluctuating winds. The vertical and horizontal fluctuating winds are simulated by employing the Davenport and Panofsky spectrums, respectively. The aerodynamic coefficients of the contact/messenger wire are calculated through computational fluid dynamics. The wind-induced vibration response of catenary is analysed with different wind speeds and angles. Its frequency-domain characteristics are discussed using Auto Regression model. Finally, a pantograph model is introduced and the contact force of the pantograph-catenary under stochastic wind is studied. The results show that both the wind speed and the attack angle exert a significant effect on the wind-induced vibration. The existence of the groove on the contact wire cross-section leads to a significant change of the aerodynamic coefficient, which affects largely the aerodynamic forces applied on the catenary wires, as well as the vibration response. The vibration frequency with high spectral power mainly concentrates on the predominant frequency of the fluctuating wind and the natural frequency of catenary. The increase in the wind speed results in a significant deterioration of the current collection. The numerical example shows that a relatively stable current collection can be ensured when the wind flows at the relatively horizontal direction.

  14. Experimental investigation of deep sea riser interaction

    SciTech Connect

    Huse, E.

    1996-12-31

    In future deep sea field developments the drag force and corresponding static deflections of the risers due to current can become quite large. The prevention of mechanical contact (collision) between the risers will need more careful evaluation than in moderate water depths. The paper describes a series of model experiments in a Norwegian fjord to determine criteria for on-set of collisions between the risers of a deep sea TLP. The current was modeled using the natural tidal current in the fjord. Results from the tests are summarized and used for verification of numerical calculations of collision criteria.

  15. Offshore production riser with flexible connector

    SciTech Connect

    Blomsma, E.C.; Holtslag, P.T.

    1981-06-16

    A central pipe riser support structure is connected to an underwater offshore base member by means of a gimbal joint. Vertical flow lines run parallel to the central riser and are supported by support means connected thereto. The lowermost support of each flow line is formed by a guide sleeve allowing at most a 3/sup 0/ deviation between the central axis of the guide sleeve and the central axis of the flow line.

  16. The Effect of a Soap Film on a Catenary: Measurement of Surface Tension from the Triangular Configuration

    ERIC Educational Resources Information Center

    Behroozi, F.; Behroozi, P. S.

    2011-01-01

    A chain assumes the well-known shape known as a catenary when it hangs loosely from two points in a gravitational field. The correct solution of the catenary was one of the early triumphs of the newly invented calculus of variations at the end of the 17th century. Here we revisit the catenary and show that, for a chain hanging from a horizontal…

  17. Reconstruction of Twist Torque in Main Parachute Risers

    NASA Technical Reports Server (NTRS)

    Day, Joshua D.

    2015-01-01

    The reconstruction of twist torque in the Main Parachute Risers of the Capsule Parachute Assembly System (CPAS) has been successfully used to validate CPAS Model Memo conservative twist torque equations. Reconstruction of basic, one degree of freedom drop tests was used to create a functional process for the evaluation of more complex, rigid body simulation. The roll, pitch, and yaw of the body, the fly-out angles of the parachutes, and the relative location of the parachutes to the body are inputs to the torque simulation. The data collected by the Inertial Measurement Unit (IMU) was used to calculate the true torque. The simulation then used photogrammetric and IMU data as inputs into the Model Memo equations. The results were then compared to the true torque results to validate the Model Memo equations. The Model Memo parameters were based off of steel risers and the parameters will need to be re-evaluated for different materials. Photogrammetric data was found to be more accurate than the inertial data in accounting for the relative rotation between payload and cluster. The Model Memo equations were generally a good match and when not matching were generally conservative.

  18. Progressive fracture of composite offshore risers

    SciTech Connect

    Chamis, C.C.; Minnetyan, L.

    1995-08-01

    Structural durability/damage tolerance characteristics of a pressurized fiber composite tube designed as an offshore oil production riser is investigated via computational simulation. The composite structure is made of graphite/epoxy angle plies and S-glass/epoxy hoop plies. An integrated computer code that accounts for all possible failure modes is utilized for the simulation of composite structural degradation under loading. Damage initiation, growth, accumulation, and propagation to structural fracture are included in the simulation. Results show the structural degradation stages due to pressurization of a composite riser and illustrate the use of computational simulation for the investigation of a composite tube.

  19. An approach to monitor railway pantograph-catenary interaction with fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Bocciolone, Marco; Bucca, Giuseppe; Collina, Andrea; Comolli, Lorenzo

    2010-09-01

    With the increase of the speed in the railway operation, a particular care has to be addressed to the interaction between pantograph and catenary: the variation of contact force and, consequently, the contact loss probability increases. The contact between pantograph and catenary is an electromechanical contact and when a contact loss occurs electrical arcing phenomena arise. One of the most important effects of arcing phenomenon is the increase of wear for both contact wire and contact strip. The monitoring of contact force between pantograph and catenary in the high frequency range (up to values greater than 100 Hz) should be useful to put in evidence problems on the pantograph-catenary interface. In this work the use of fiber optic strain gauges, with FBG technology, to measure the pantograph-catenary contact force is discussed. This solution is insensitive to the electrical disturbances caused by the sparks and can be safely used in-line. Starting from a static and dynamic validation of the sensors, using as a reference traditional electrical strain gauges, a method to estimate the contact force was developed and tested.

  20. Early Risers. What Works Clearinghouse Intervention Report

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2012

    2012-01-01

    "Early Risers" is a multi-year prevention program for elementary school children demonstrating early aggressive and disruptive behavior. The intervention model includes two child-focused components and two parent/family components. The Child Skills component is designed to teach skills that enhance children's emotional and behavioral…

  1. ROV recovers riser from 500-ft depth

    SciTech Connect

    Not Available

    1984-10-01

    A Scorpio ROV was used recently to remove a collapsed marine riser, disassemble the upper blowout preventer connector and re-establish the wellhead equipment. It was the first time such a procedure had been undertaken by an unmanned vehicle. The performance of the ROV is described.

  2. Modeling and simulation of vortex induced vibration on the subsea riser/pipeline (GRP pipe)

    NASA Astrophysics Data System (ADS)

    Raja Adli, Raja Nor Fauziah bt; Ibrahim, Idris

    2012-06-01

    This paper presents the research work conducted to investigate the dynamics characteristics of the offshore riser pipeline due to vortex flow and to develop a model that could predict its vortex induced responses. Glass-fiber reinforced plastic (GRP) pipe is used for this study which has smaller density from the steel. A two-dimensional finite element computational method is implemented to describe the dynamic behavior of the riser. The governing equation of motion was based on Hamilton's principle, consists of the strain energy due to bending and axial deformation, kinetic energy due to both riser and internal fluid movement and also external force from currents and waves. A direct integration method namely Newmark integration scheme is proposed to solve the equation of motion. A MATLAB program code was developed to obtain the simulation results. The natural frequency and damping ratio are presented for each mode. Dynamic response of riser is shown in time-domain and the numerical results are discussed. Several parameter effects are used to investigate dynamic responses and the results show an agreement with the theory. Vortex shedding phenomenon also has been discussed in this paper. As a conclusion, the simulation results have successfully shown the vortex induced vibration responses for GRP pipeline.

  3. Flexible Riser Monitoring Using Hybrid Magnetic/Optical Strain Gage Techniques through RLS Adaptive Filtering

    NASA Astrophysics Data System (ADS)

    Pipa, Daniel; Morikawa, Sérgio; Pires, Gustavo; Camerini, Claudio; Santos, JoãoMárcio

    2010-12-01

    Flexible riser is a class of flexible pipes which is used to connect subsea pipelines to floating offshore installations, such as FPSOs (floating production/storage/off-loading unit) and SS (semisubmersible) platforms, in oil and gas production. Flexible risers are multilayered pipes typically comprising an inner flexible metal carcass surrounded by polymer layers and spiral wound steel ligaments, also referred to as armor wires. Since these armor wires are made of steel, their magnetic properties are sensitive to the stress they are subjected to. By measuring their magnetic properties in a nonintrusive manner, it is possible to compare the stress in the armor wires, thus allowing the identification of damaged ones. However, one encounters several sources of noise when measuring electromagnetic properties contactlessly, such as movement between specimen and probe, and magnetic noise. This paper describes the development of a new technique for automatic monitoring of armor layers of flexible risers. The proposed approach aims to minimize these current uncertainties by combining electromagnetic measurements with optical strain gage data through a recursive least squares (RLSs) adaptive filter.

  4. Riser, pipelines installed in Griffin field

    SciTech Connect

    Not Available

    1994-05-23

    A mooring riser and flow lines along with a 67-km, 8-in., gas-export pipelines have been installed offshore Australia for BHP Petroleum's Griffin field development. The 66-km gas line will carry Griffin field gas to an onshore gas-processing plant. Completing the projects ahead of schedule was Clough Stena Joint Venture (Asia), Perth. BHP awarded the contracts in early 1993; the project was completed in January this year. The paper describes the contractor, pipeline installation, and handling equipment.

  5. Dynamic analysis of a circulating fluidized bed riser

    SciTech Connect

    Panday, Rupen; Shadle, Lawrence J.; Guenther, Chris

    2012-01-01

    A linear state model is proposed to analyze dynamic behavior of a circulating fluidized bed riser. Different operating regimes were attained with high density polyethylene beads at low and high system inventories. The riser was operated between the classical choking velocity and the upper transport velocity demarcating fast fluidized and transport regimes. At a given riser superficial gas velocity, the aerations fed at the standpipe were modulated resulting in a sinusoidal solids circulation rate that goes into the riser via L-valve. The state model was derived based on the mass balance equation in the riser. It treats the average solids fraction across the entire riser as a state variable. The total riser pressure drop was modeled using Newton’s second law of motion. The momentum balance equation involves contribution from the weight of solids and the wall friction caused by the solids to the riser pressure drop. The weight of solids utilizes the state variable and hence, the riser inventory could be easily calculated. The modeling problem boils down to estimating two parameters including solids friction coefficient and time constant of the riser. It has been shown that the wall friction force acts in the upward direction in fast fluidized regime which indicates that the solids were moving downwards on the average with respect to the riser wall. In transport regimes, the friction acts in the opposite direction. This behavior was quantified based on a sign of Fanning friction factor in the momentum balance equation. The time constant of the riser appears to be much higher in fast fluidized regime than in transport conditions.

  6. Flexible riser configuration for a FPSO in deep waters

    SciTech Connect

    Karunakaran, D.; Leira, B.J.; Olufsen, A.; Nordsve, N.T.

    1995-12-31

    Throughout the world development of oil and gas fields in deep and ultra deep waters is being considered. Floating systems offer an efficient alternative for development of such fields. Flexible risers will in general form an important part of such floating production system. Presently, the flexible risers are designed by application of factor of safety, which is based on experience from laboratory tests, theoretical pipe mechanics and engineering know-how. Generally, it is not based on reliability calculations and risk assessment. Hence it is very important to assess the safety level in current design practice and to aim at a rational and safe design procedure. In this paper, a reliability analysis procedure for flexible riser systems based on a response surface methodology and FORM/SORM methods is outlined. It is applied to a deep water riser system. In this case only a failure criterion at the top end is considered. This location is critical for this riser with respect to Ultimate Limit State (ULS). The results indicate a sufficient safety level for the top end of the riser. However, it is emphasized that this is not a conclusive result with respect to riser safety in general. A more comprehensive study is required to assess the overall safety level for flexible riser systems. Such a study should include a number of different riser configurations and limit states, specifically FLS criteria, to arrive at more general conclusions.

  7. The Stability of the Catenary Shapes for a Hanging Cable of Unspecified Length

    ERIC Educational Resources Information Center

    Mareno, A.; English, L. Q.

    2009-01-01

    It has long been known that when a cable of specified length is hung between two poles, it takes the shape of a catenary--a hyperbolic cosine function. In this paper, we study a variation of this problem. First, we consider a cable hanging between two poles in which one end of the cable is fixed to one pole; the other end of the cable runs over a…

  8. Dynamic response of a riser under excitation of internal waves

    NASA Astrophysics Data System (ADS)

    Lou, Min; Yu, Chenglong; Chen, Peng

    2015-12-01

    In this paper, the dynamic response of a marine riser under excitation of internal waves is studied. With the linear approximation, the governing equation of internal waves is given. Based on the rigid-lid boundary condition assumption, the equation is solved by Thompson-Haskell method. Thus the velocity field of internal waves is obtained by the continuity equation. Combined with the modified Morison formula, using finite element method, the motion equation of riser is solved in time domain with Newmark-β method. The computation programs are compiled to solve the differential equations in time domain. Then we get the numerical results, including riser displacement and transfiguration. It is observed that the internal wave will result in circular shear flow, and the first two modes have a dominant effect on dynamic response of the marine riser. In the high mode, the response diminishes rapidly. In different modes of internal waves, the deformation of riser has different shapes, and the location of maximum displacement shifts. Studies on wave parameters indicate that the wave amplitude plays a considerable role in response displacement of riser, while the wave frequency contributes little. Nevertheless, the internal waves of high wave frequency will lead to a high-frequency oscillation of riser; it possibly gives rise to fatigue crack extension and partial fatigue failure.

  9. Ultrasonic inspection of risers -- a new and simple approach

    SciTech Connect

    Agthoven, R. van

    1998-12-31

    A riser forms the connection between the top side of an off-shore platform and a pipeline on the sea-bed. Such pipeline systems may be equipped with launch and receive facilities for cleaning and general intelligent pigging of the entire pipeline. The riser may be of different material or of heavier wall thickness, making self contained intelligent pigging of the riser difficult, less effective or cost prohibitive. Today, offshore operators are strongly committed to protect the environment and pigging and riser inspection will assist in determining the condition of the installation and the riser in particular. In this description a new approach for a detailed ultrasonic inspection of the risers only is explained, based on the application of a compact umbilical (cable, tether) operated tool. This requires that the riser is bled down and liquid filled. The inspection tool provides on-line presentation of results for immediate evaluation. The system uses straight beam ultrasonic sensors for general corrosion survey in the pipe material and a novel ToFD (Time of Flight Diffraction) technique for additional inspection of the circumferential weld area.

  10. Mass transfer effects in a gasification riser

    SciTech Connect

    Breault, Ronald W; Li, Tingwen; Nicoletti, Phillip

    2013-01-01

    In the development of multiphase reacting computational fluid dynamics (CFD) codes, a number of simplifications were incorporated into the codes and models. One of these simplifications was the use of a simplistic mass transfer correlation for the faster reactions and omission of mass transfer effects completely on the moderate speed and slow speed reactions such as those in a fluidized bed gasifier. Another problem that has propagated is that the mass transfer correlation used in the codes is not universal and is being used far from its developed bubbling fluidized bed regime when applied to circulating fluidized bed (CFB) riser reactors. These problems are true for the major CFD codes. To alleviate this problem, a mechanistic based mass transfer coefficient algorithm has been developed based upon an earlier work by Breault et al. This fundamental approach uses the local hydrodynamics to predict a local, time varying mass transfer coefficient. The predicted mass transfer coefficients and the corresponding Sherwood numbers agree well with literature data and are typically about an order of magnitude lower than the correlation noted above. The incorporation of the new mass transfer model gives the expected behavior for all the gasification reactions evaluated in the paper. At the expected and typical design values for the solid flow rate in a CFB riser gasifier an ANOVA analysis has shown the predictions from the new code to be significantly different from the original code predictions. The new algorithm should be used such that the conversions are not over predicted. Additionally, its behaviors with changes in solid flow rate are consistent with the changes in the hydrodynamics.

  11. Dynamic analysis of marine risers with vortex excitation

    SciTech Connect

    Nordgren, R.P.

    1982-03-01

    The basic equations for nonplanar transverse vibrations of marine risers are derived from the theory of elastic rods. A numerical method is developed for solution of the equations by time integration. Spatial discretization is accomplished by a hybrid finite element method. Vortex excitation is modeled by the coupled wake oscillator proposed by Iwan and Blevins. The vortex oscillator equations are integrated numerically in time along with the riser equations. By way of example, several typical riser problems are analyzed including forced vibration and vortex-induced vibration.

  12. Camera-based measurement for transverse vibrations of moving catenaries in mine hoists using digital image processing techniques

    NASA Astrophysics Data System (ADS)

    Yao, Jiannan; Xiao, Xingming; Liu, Yao

    2016-03-01

    This paper proposes a novel, non-contact, sensing method to measure the transverse vibrations of hoisting catenaries in mine hoists. Hoisting catenaries are typically moving cables and it is not feasible to use traditional methods to measure their transverse vibrations. In order to obtain the transverse displacements of an arbitrary point in a moving catenary, by superposing a mask image having the predefined reference line perpendicular to the hoisting catenaries on each frame of the processed image sequence, the dynamic intersecting points with a grey value of 0 in the image sequence could be identified. Subsequently, by traversing the coordinates of the pixel with a grey value of 0 and calculating the distance between the identified dynamic points from the reference, the transverse displacements of the selected arbitrary point in the hoisting catenary can be obtained. Furthermore, based on a theoretical model, the reasonability and applicability of the proposed camera-based method were confirmed. Additionally, a laboratory experiment was also carried out, which then validated the accuracy of the proposed method. The research results indicate that the proposed camera-based method is suitable for the measurement of the transverse vibrations of moving cables.

  13. Mud handling improved with a constant-volume riser

    SciTech Connect

    Baker, R.J. )

    1990-09-24

    Marine risers currently deployed by floating drilling units incorporate a telescopic joint to accommodate vessel movement, primarily heave. This vertical telescopic movement changes the internal volume of the riser and causes fluctuations in the return-mud flow rate. Flow fluctuations make accurate measurement of the return mud difficult. The significance is that these measurements are vital for the early detection of well bore influx or downhole mud losses. Erratic mud flow also adversely affects the efficiency of the solids-removal equipment and potentially increases the risk of discharging whole mud to the environment. To overcome these adverse effects, a design for a telescopic joint is proposed (constant volume riser or CVR) in which the internal riser volume remains constant, irrespective of movement, thus permitting a uniform flow rate of mud returns.

  14. Differential thread riser coupling for TLP and platform tieback applications

    SciTech Connect

    Williams, M.R.; Chen, L.Y.

    1983-05-01

    This paper presents the design concept and principle of operation for a new threaded riser coupling called a ''Differential Thread Connector'' (DTC). Connector designs are presented for several TLP (tension leg platform) and platform tieback riser applications. The new connectors have several features which make them particularly well suited for subsea riser service: Mechanical interlock (prevents couplings from backing off under reverse torque loads) Non-rotating, gall-resistant, metal-tometal seals High strength and fatigue life Small Outside Diameter Fast running/retrieval time The DTC's performance has been confirmed via extensive finite element analysis and full-scale prototype testing. These new connectors offer several functional advantages and promise high performance/reliability for demanding subsea riser applications. They also promise significant cost benefits through reductions in rig time (faster running and retrieving), elimination of welding costs, and reductions in connector renovation costs.

  15. Single-shell tank riser resistance to ground test plan

    SciTech Connect

    Kiewert, L.R.

    1996-03-11

    This Test Procedure provides the general directions for conducting Single-Shell Tank Riser to Earth Measurements which will be used by engineering as a step towards providing closure for the Lightning Hazard Issue.

  16. Deep water drilling risers in calm and harsh environments

    SciTech Connect

    Olufsen, A.; Nordsve, N.T.

    1994-12-31

    The overall objective of the work presented in this paper is to increase the knowledge regarding application of deep water drilling risers in different environmental conditions. Identification of key parameters and their impact on design and operation of deep water drilling risers are emphasized. Riser systems for two different cases are evaluated. These are: drilling offshore Nigeria in 1,200 m water depth; drilling at the Voering Plateau offshore Northern Norway in 1,500 m water depth. The case studies are mainly referring to requirements related to normal drilling operation of the riser. They are not complete with respect to describe of total riser system design. The objectives of the case studies have been to quantify the important of various parameters and to establish limiting criteria for drilling. Dynamic riser analyses are also performed. For the Nigeria case, results for a design wave with 100 years return period show that the influence of dynamic response is only marginal (but it may of course be significant for fatigue damage/life time estimation). The regularity of the drilling operation is given as the probability that jointly occurring wave heights and current velocities are within the limiting curve.

  17. Computer simulation of FCC riser reactors.

    SciTech Connect

    Chang, S. L.; Golchert, B.; Lottes, S. A.; Petrick, M.; Zhou, C. Q.

    1999-04-20

    A three-dimensional computational fluid dynamics (CFD) code, ICRKFLO, was developed to simulate the multiphase reacting flow system in a fluid catalytic cracking (FCC) riser reactor. The code solve flow properties based on fundamental conservation laws of mass, momentum, and energy for gas, liquid, and solid phases. Useful phenomenological models were developed to represent the controlling FCC processes, including droplet dispersion and evaporation, particle-solid interactions, and interfacial heat transfer between gas, droplets, and particles. Techniques were also developed to facilitate numerical calculations. These techniques include a hybrid flow-kinetic treatment to include detailed kinetic calculations, a time-integral approach to overcome numerical stiffness problems of chemical reactions, and a sectional coupling and blocked-cell technique for handling complex geometry. The copyrighted ICRKFLO software has been validated with experimental data from pilot- and commercial-scale FCC units. The code can be used to evaluate the impacts of design and operating conditions on the production of gasoline and other oil products.

  18. Theoretical performance of cross-wind axis turbines with results for a catenary vertical axis configuration

    NASA Technical Reports Server (NTRS)

    Muraca, R. J.; Stephens, M. V.; Dagenhart, J. R.

    1975-01-01

    A general analysis capable of predicting performance characteristics of cross-wind axis turbines was developed, including the effects of airfoil geometry, support struts, blade aspect ratio, windmill solidity, blade interference and curved flow. The results were compared with available wind tunnel results for a catenary blade shape. A theoretical performance curve for an aerodynamically efficient straight blade configuration was also presented. In addition, a linearized analytical solution applicable for straight configurations was developed. A listing of the computer program developed for numerical solutions of the general performance equations is included in the appendix.

  19. Comparison of optical and electrical measurements of the pantograph-catenary contact force

    NASA Astrophysics Data System (ADS)

    Bocciolone, Marco; Bucca, Giuseppe; Collina, Andrea; Comolli, Lorenzo

    2010-09-01

    In railway engineering the monitoring of contact force between pantograph and catenary gives information about the interaction between the two systems and it is useful to check the status of the overhead line. Indeed the failure of the catenary is one of the main causes of out of order problems. This study was conducted in a test campaign on an underground train instrumented with sensors able to monitor the line status. One of the more important measured quantities is the pantograph contact force, and two measurement systems were implemented: one optical and another electrical. The optical one was based on FBG sensors applied on the pantograph collector strip; the electrical one was based on two load cells positioned at the sides of the collector strip. The in-line measurements show that the optical solution is very promising, providing very reliable results that can be successfully used in the monitoring application, allowing the determination of the critical point in the line. The thermal compensation of any FBG sensors is a known problem and here is no exception: a thermal compensator was used to get also mean value measurements and the results are discussed.

  20. Stripwise discrete vortex method for VIV analysis of flexible risers

    NASA Astrophysics Data System (ADS)

    Sun, L.; Zong, Z.; Dong, J.; Dong, G. H.; Liu, C. F.

    2012-11-01

    This paper presents a stripwise discrete vortex method (SDVM) to study the vortex-induced vibration of flexible risers. The discrete vortex method is employed to calculate the vortex-induced vibration (VIV) of each strip, and the finite volume method and increment method are used to compute the 3-D dynamics of the flexible riser. To verify the discrete vortex method for a single cylindrical strip of the entire flexible riser, a cylinder with elastic supports exerted by a 2-D uniform flow with a high Reynolds number is investigated. The 1-D transverse motion, 2-D transverse motion and 2-D stream-wise motion, as well as their influences on the wake shapes, are considered. Comparisons are made between the transverse amplitudes for the single degree of freedom and two degrees of freedom elastic-mounted systems. The relations between the lift coefficients and response amplitudes of the different mass ratios and reduced velocities are further discussed. The characteristics of the motion responses of the cylinder for different mass ratios and degree of freedoms are also discussed. Finally, the present numerical model is employed to calculate a 3-D flexible riser exerted by the uniform current, and the analysis of the numerical results shows the characteristics of the vortex-induced vibration of a flexible riser.

  1. Analysis of dynamic interaction between catenary and pantograph with experimental verification and performance evaluation in new high-speed line

    NASA Astrophysics Data System (ADS)

    Lee, Jin Hee; Park, Tae Won; Oh, Hyuck Keun; Kim, Young Guk

    2015-08-01

    Understanding the dynamic interaction between the catenary and pantograph of a high-speed train is the one of the most important technical issues in the railway industry. This is because the catenary-pantograph system plays a crucial role in providing electric power to the railway vehicle for stable operation. The aim of the present paper is to estimate the current-collection performance of this system by using numerical analysis, in particular, the flexible multibody dynamic analysis technique. To implement large deformable catenary wires, an absolute nodal coordinate formulation is used for the cable element. Additionally, an efficient contact element and an interactive model for the catenary-pantograph system are introduced. Each developed model is then used for analytical and experimental verification. Actual on-line test results of existing high-speed railway vehicles are presented and used to verify the analysis model. Finally, the performance characteristics of a new 400 km/h-class high-speed line are estimated and evaluated on the basis of international standards.

  2. Transient Characterization of Type B Particles in a Transport Riser

    SciTech Connect

    Shadle, L.J.; Monazam, E.R.; Mei, J.S.

    2007-01-01

    Simple and rapid dynamic tests were used to evaluate fluid dynamic behavior of granular materials in the transport regime. Particles with densities ranging from 189 to 2,500 kg/m3 and Sauter mean size from 61 to 812 μm were tested in a 0.305 m diameter, 15.5 m height circulating fluidized bed (CFB) riser. The transient tests involved the abrupt stoppage of solids flow for each granular material over a wide range gas flow rates. The riser emptying time was linearly related to the Froude number in each of three different operating regimes. The flow structure along the height of the riser followed a distinct pattern as tracked through incremental pressures. These results are discussed to better understand the transformations that take place when operating over various regimes. During the transients the particle size distribution was measured. The effects of pressure, particle size, and density on test performance are also presented.

  3. Design, test and commercialization considerations of OTEC pilot plant riser cables

    SciTech Connect

    Garrity, T. F.; Eaton, R.; Dalton, T.; Pieroni, C.; Walsh, J. P.

    1980-01-01

    Discussion addresses riser cable system development for OTEC pilot plants transmitting power in the range of 10 to 40 MW. Specifically, design, testing and status of riser cable system development are reviewed. Further discussion encompasses unique technical, hardware and operational considerations associated with the commercialization of riser cable systems.

  4. Vortex-induced vibration of two parallel risers: Experimental test and numerical simulation

    NASA Astrophysics Data System (ADS)

    Huang, Weiping; Zhou, Yang; Chen, Haiming

    2016-04-01

    The vortex-induced vibration of two identical rigidly mounted risers in a parallel arrangement was studied using Ansys- CFX and model tests. The vortex shedding and force were recorded to determine the effect of spacing on the two-degree-of-freedom oscillation of the risers. CFX was used to study the single riser and two parallel risers in 2-8 D spacing considering the coupling effect. Because of the limited width of water channel, only three different riser spacings, 2 D, 3 D, and 4 D, were tested to validate the characteristics of the two parallel risers by comparing to the numerical simulation. The results indicate that the lift force changes significantly with the increase in spacing, and in the case of 3 D spacing, the lift force of the two parallel risers reaches the maximum. The vortex shedding of the risers in 3 D spacing shows that a variable velocity field with the same frequency as the vortex shedding is generated in the overlapped area, thus equalizing the period of drag force to that of lift force. It can be concluded that the interaction between the two parallel risers is significant when the risers are brought to a small distance between them because the trajectory of riser changes from oval to curve 8 as the spacing is increased. The phase difference of lift force between the two risers is also different as the spacing changes.

  5. Design review report for multiport riser final design review

    SciTech Connect

    McWethy, L.M.; Sheen, E.M.

    1994-05-01

    This design review examined the design documents contained in a notebook prepared for the final design review of the multiport riser assembly. This assembly will support the Hydrogen Mitigation Test program for mitigation of safety issues for Hanford Waste Tank 241-SY-101. The purpose of the Multiport Riser is to provide multiple access ports of several diameters in a single 42 inch riser for simultaneous access of test and support equipment. The notebook was titled: {open_quotes}Multiport Riser Final Design Review.{close_quotes} The review was conducted using a database comment registration system whereby the reviewer comments were entered into the database and each comment was given a unique identifier. During the review, each comment was referred to by its identifier. Changes to comments, responses, and actions needed were made with the agreement of the committee and the reviewers at the formal design review meeting held March 1, 1994. When the structural analyses were available, they were distributed for review which allowed closure of all design review comments. Approval of the design was achieved and supporting documents are included in this report.

  6. Kennedy Space Center (KSC) Pad B Catenary Capability Analysis and Technical Exchange Meeting (TEM) Support

    NASA Technical Reports Server (NTRS)

    Wilson, Timmy R.; Kichak, Robert; Rakov, Vladimir; Kithil, Richard, Jr.; Sargent, Noel B.

    2009-01-01

    The existing lightning protection system at Pad 39B for the Space Shuttle is an outgrowth of a system that was put in place for the Apollo Program. Dr. Frank Fisher of Lightning Technologies was a key participant in the design and implementation of that system. He conveyed to the NESC team that the catenary wire provision was put in place quickly (as assurance against possible vehicle damage causing critical launch delays) rather than being implemented as a comprehensive system designed to provide a high degree of guaranteed protection. Also, the technology of lightning protection has evolved over time with considerable work being conducted by groups such as the electric utilities companies, aircraft manufacturers, universities, and others. Several accepted present-day methods for analysis of lightning protection were used by Drs. Medelius and Mata to study the expected lightning environment for the Pad 39B facility and to analyze the degree of protection against direct lightning attachment to the Space Shuttle. The specific physical configuration directly affects the vulnerability, so cases that were considered included the RSS next to and rolled back from the Space Shuttle, and the GOx Vent Arm both extended and withdrawn from the ET. Elements of the lightning protection system at Pad 39B are shown in Figure 6.0-1 and consist of an 80 foot insulating mast on top of the Fixed Support Structure (FSS), a catenary wire system that runs from the mast in a North/South direction to grounds 1000 feet away on each side of the mast, the RSS which can either be next to or away from the Space Shuttle, and a GOx vent that can either be extended or retracted from the top of the ET.

  7. Stress analysis of the subsea dynamic riser baseprocess piping

    NASA Astrophysics Data System (ADS)

    Ju, Xuanze; Fang, Wei; Yin, Hanjun; Jiang, Ying

    2014-09-01

    Thesubsea dynamic riser base (SDRB) is an important piece of equipment for the floating production platform mooring system. One end is connected to the rigid pipeline, carrying a rigid pipeline thermal expansion load and the other end is connected to a flexible riser, carrying the dynamic load of the flexible riser, so its function is a transition connection between the flexible riser and the rigid pipeline which fixes the flexible riser on the seabed. On the other hand, as a typical subsea product, the design will satisfy the requirements of the standards for subsea products. By studying the stress analysisphilosophy of the topside piping and subsea pipeline, a physical model and procedure for piping stress analysis of the SDRB have been established. The conditions of the adverse design load have been considered, and a combination of the static load from the rigid pipeline and the dynamic load flexibility has also been optimized. And a comparative analysis between the AMSE, DNV and API standards for piping stress with the checking rules has been done. Because the SDRB belongs to the subsea pipeline terminal product, the use of DNV standards to check its process piping stress is recommended. Finally, the process piping stress of the SDRB has been calculated, and the results show that the jacket pipe and the carrier pipe stress of the SDRB process piping satisfy the DNV standards as a whole.The bulkhead cannot be accurately simulated by the AutoPIPE software which uses the FEA software ANSYS in the detailed analysis, but the checking results will still meet the requirements of the DNV standards.

  8. Program for catenary-pantograph analysis, PrOSA statement of methods and validation according EN 50318

    NASA Astrophysics Data System (ADS)

    Finner, Lars; Poetsch, Gero; Sarnes, Bernhard; Kolbe, Michael

    2015-03-01

    DB Systemtechnik is a high-performing, customer-driven service provider that, as well as authoritatively serving the Deutsche Bahn Group by dint of its specialist knowledge is also increasingly active on the global railway market. Development and testing of pantograph models and catenary systems have been part of the company's essential activity fields from the beginning. Therefore, an efficient and high-performing simulation tool is indispensable. That is why DB Systemtechnik spent high efforts to develop the program PrOSA in cooperation with the Heinz-Nixdorf-Institut (HNI) of the university Paderborn to simulate the interaction of pantograph and catenary. This article gives an overview of the most relevant properties of PrOSA. Furthermore, it is described how the benchmark requirements were implemented and processed.

  9. Analysis of Current Harmonics in 3kV DC Catenary Caused by Specific Current Harmonics of an Asynchronous Motor

    NASA Astrophysics Data System (ADS)

    Lewandowski, Mirosław

    2010-01-01

    The mathematical model of vehicle supply system as well as the mathematical model of main circuit of locomotive with asynchronous motors have been described in this article. The necessity of analysis of disturbances caused by distorted current run of drive motors emerged together with the introduction of high power vehicles with power electronic converters. Analysis of the compatibility of traction high current circuits with circuits of the signal and traffic control systems requires the knowledge of current spectrum in a catenary, which has been taken by a vehicle. The author has described the algebraic method of calculating of the spectrum amplitudes in a catenary. It does not require laborious and time-consuming simulations of a system, which considerably decreases preliminary costs of designation and dimensioning of a vehicle drive system.

  10. Experimental study and modelling of overheating of electrical catenary-pantograph interface for trains supplied with power in station

    NASA Astrophysics Data System (ADS)

    Bausseron, Thomas; Baucour, Philippe; Glises, Raynal; Verschelde, Sylvain; Chamagne, Didier

    2015-06-01

    For railroads and trains, there have been many incidents involving catenary overheating at the contact with the pantograph when a train is supplied with power while standing still. The overheating of the catenary-pantograph interface can sometimes cause the contact wire to break. In order to anticipate the occurrence of such costly problems, the FEMTO-ST Institute has carried out theoretical and experimental studies in collaboration with the French National Railway Company (SNCF) to better understand this phenomenon. First, a 2D transient electrical model was developed for the contact wire. This allows the current distribution in the wire to be estimated to obtain an accurate measure of the internal heat generation. The heat produced by the interface was considered and split between the catenary and pantograph with an analytical model. Finally, the heat transfer equation for the wire under particular boundary conditions was solved for the entire finite difference network based on Euler's implicit method. The transient modelling results of the wire heating were compared with earlier experimental values, and a parametric study was performed.

  11. ALARA plan for the Old Hydrofracture Facility tanks contents removal project at Oak Ridge National Laboratory, Oak Ridge, Tennessee. Amendment 1 for Appendix B: Install flex-pipe on tank riser spools

    SciTech Connect

    1998-05-13

    This amendment to Appendix B contains the specific ALARA evaluations for installing flex-pipe on riser spools to accommodate ventilation duct connections to the north risers of each tank. The work will be a routine task that is part of the Equipment Installation and Mobilization phase of the project. The dose rates were estimated using the recent Radiological Surveillance Section radiological survey: SAAS-97-063S. Task B-6 has been added to the OHF Project ALARA review process to address a field decision to modify an approach to installing the tank ventilation system. The revised approach will incorporate 12-in. diameter, 36-in. long, stainless steel flex-pipe connected to each north riser spool to address the problem of pipe fitting multiple bends and turns expected with the 12-in. PVC duct. This improved approach will reduce the time necessary to install the duct system between the tanks and the ventilation skid. However, the task includes opening the 12-in. riser spool connections to replace the currently installed blind gaskets. Since a riser spool for each tank will be opened, there is a potential for significant personnel exposure and spread of contamination that will addressed through this ALARA review process.

  12. A nonlinear vortex induced vibration model of marine risers

    NASA Astrophysics Data System (ADS)

    Liu, Juan; Huang, Weiping

    2013-03-01

    With the exploitation of oil and gas in deep water, the traditional vortex induced vibration (VIV) theory is challenged by the unprecedented flexibility of risers. A nonlinear time-dependent VIV model is developed in this paper based on a VIV lift force model and the Morison equation. Both the inline vibration induced by the flow due to vortex shedding and the fluid-structure interaction in the transverse direction are included in the model. One of the characteristics of the model is the response-dependent lift force with nonlinear damping, which is different from other VIV models. The calculations show that the model can well describe the VIV of deepwater risers with the results agreeing with those calculated by other models.

  13. Remote installation of risers on underground nuclear waste storage tanks

    SciTech Connect

    Jackson, J.P.; Gessner, R.F.

    1988-03-01

    The West Valley Demonstration Project was established to solidify 2120 m/sup 3/ (560,000) gallons of high-level nuclear waste generated during six years of commercial nuclear fuel reprocessing. This liquid will be processed to remove radioactive elements which, with the remaining sludge, will be combined with glass formers and be converted into borosilicate glass. Risers were installed on the high-level tank for installation of pumps which will be used to remove the liquid and sludge. The extensive use of remote technology was required to install the risers and to minimize operator exposure to high levels of radiation and contamination. The riser installation required remotely: drilling through two feet of concrete shielding; installing pump access pipes which are welded to the tank top; and cutting holes in tanks located 3658 mm (12) feet below ground. These operations were successfully completed 13 times without exposing personnel to high-level radiation or contamination. Specially designed remote equipment was developed for each step of this operation. Extensive operator training in the use of this equipment was performed on a tank with low radiation prior to work on the high-level tank. This paper discusses the application of remote technology that assured a quality job was safely accomplished. 3 refs., 18 figs., 2 tabs.

  14. Behavior of unbonded flexible risers subject to axial tension

    NASA Astrophysics Data System (ADS)

    Ren, Shao-fei; Tang, Wen-yong; Guo, Jin-ting

    2014-04-01

    Owing to nonlinear contact problems with slip and friction, a lot of limiting assumptions are made when developing analytical models to simulate the behavior of an unbonded flexible riser. Meanwhile, in order to avoid convergence problems and excessive calculating time associated with running the detailed finite element (FE) model of an unbonded flexible riser, interlocked carcass and zeta layers with complicated cross section shapes are replaced by simple geometrical shapes (e.g. hollow cylindrical shell) with equivalent orthotropic materials. But the simplified model does not imply the stresses equivalence of these two layers. To solve these problems, based on ABAQUS/Explicit, a numerical method that is suitable for the detailed FE model is proposed. In consideration of interaction among all component layers, the axial stiffness of an eight-layer unbonded flexible riser subjected to axial tension is predicted. Compared with analytical and experimental results, it is shown that the proposed numerical method not only has high accuracy but also can substantially reduce the calculating time. In addition, the impact of the lay angle of helical tendons on axial stiffness is discussed.

  15. Jet penetration into a riser operated in dense suspension upflow: experimental and model comparisons

    SciTech Connect

    Shadle, L.J.; Ludlow, C.J.; Spenik, J.L.; Seachman, S.M.; Guenther, C.P.

    2008-05-13

    Solids tracers were used to characterize the penetration of a gas-solids jet directed toward the center of the 0.3-m diameter, circulating fluidized bed (CFB) riser. The penetration was measured by tracking phosphorescent particles illuminated immediately prior to injection into the riser. Photosensors and piezoelectric detectors were traversed across the radius of the riser at various axial positions to detect the phosphorescent jet material and particles traveling in the radial direction. Local particle velocities were measured at various radial positions, riser heights, and azimuthal angles using an optical fiber probe. Four (4) variables were tested including the jet velocity, solids feed rate into the jet, the riser velocity, and overall CFB circulation rate over 8 distinct test cases with the central, or base case, repeated each time the test series was conducted. In addition to the experimental measurements made, the entire riser with a side feed jet of solids was simulated using the Eulerian-Eulerian computer model MFIX.

  16. A CFD study of gas-solid jet in a CFB riser flow

    SciTech Connect

    Li, Tingwen; Guenther, Chris

    2012-03-01

    Three-dimensional high-resolution numerical simulations of a gas–solid jet in a high-density riser flow were conducted. The impact of gas–solid injection on the riser flow hydrodynamics was investigated with respect to voidage, tracer mass fractions, and solids velocity distribution. The behaviors of a gas–solid jet in the riser crossflow were studied through the unsteady numerical simulations. Substantial separation of the jetting gas and solids in the riser crossflow was observed. Mixing of the injected gas and solids with the riser flow was investigated and backmixing of gas and solids was evaluated. In the current numerical study, both the overall hydrodynamics of riser flow and the characteristics of gas–solid jet were reasonably predicted compared with the experimental measurements made at NETL.

  17. Flow Regime Study in a High Density Circulating Fluidized Bed Riser with an Abrupt Exit

    SciTech Connect

    Mei, J.S.; Shadle, L.J.; Yue, P.C.; Monazam, E.R.

    2007-01-01

    Flow regime study was conducted in a 0.3 m diameter, 15.5 m height circulating fluidized bed (CFB) riser with an abrupt exit at the National Energy Technology Laboratory of the U.S. Department of Energy. Local particle velocities were measured at various radial positions and riser heights using an optical fiber probe. On-line measurement of solid circulating rate was continuously recorded by the Spiral. Glass beads of mean diameter 61 μm and particle density of 2,500 kg/m3 were used as bed material. The CFB riser was operated at various superficial gas velocities ranging from 3 to 7.6 m/s and solid mass flux from 20 to 550 kg/m2-s. At a constant riser gas velocity, transition from fast fluidization to dense suspension upflow (DSU) regime started at the bottom of the riser with increasing solid flux. Except at comparatively low riser gas velocity and solid flux, the apparent solid holdup at the top exit region was higher than the middle section of the riser. The solid fraction at this top region could be much higher than 7% under high riser gas velocity and solid mass flux. The local particle velocity showed downward flow near the wall at the top of the riser due to its abrupt exit. This abrupt geometry reflected the solids and, therefore, caused solid particles traveling downward along the wall. However, at location below, but near, the top of the riser the local particle velocities were observed flowing upward at the wall. Therefore, DSU was identified in the upper region of the riser with an abrupt exit while the fully developed region, lower in the riser, was still exhibiting core-annular flow structure. Our data were compared with the flow regime boundaries proposed by Kim et al. [1] for distinguishing the dilute pneumatic transport, fast fluidization, and DSU.

  18. Guided-waves technique for inspecting the health of wall-covered building risers

    NASA Astrophysics Data System (ADS)

    Tse, Peter W.; Chen, J. M.; Wan, X.

    2015-03-01

    The inspection technique uses guided ultrasonic waves (GW) has been proven effective in detecting pipes' defects. However, as of today, the technique has not attracted much market attention because of insufficient field tests and lack of traceable records with proven results in commercial applications. In this paper, it presents the results obtained by using GW to inspect the defects occurred in real gas risers that are commonly installed in tall buildings. The purpose of having risers is to deliver gas from any building external piping system to each household unit of the building. The risers extend from the external wall of the building, penetrate thorough the concrete wall, into the kitchen or bathroom of each household unit. Similar to in-service pipes, risers are prone to corrosion due to water leaks into the concrete wall. However, the corrosion occurs in the section of riser, which is covered by the concrete wall, is difficult to be inspected by conventional techniques. Hence, GW technique was employed. The effectiveness of GW technique was tested by laboratory and on-site experiments using real risers gathered from tall buildings. The experimental results show that GW can partially penetrate thorough the riser's section that is covered by wall. The integrity of the wall-covered section of a riser can be determined by the reflected wave signals generated by the corroded area that may exit inside the wall-covered section. Based on the reflected wave signal, one can determine the health of the wall-covered riser.

  19. Deep-water riser fatigue monitoring systems based on acoustic telemetry

    NASA Astrophysics Data System (ADS)

    Li, Baojun; Wang, Haiyan; Shen, Xiaohong; Yan, Yongsheng; Yang, Fuzhou; Hua, Fei

    2014-12-01

    Marine risers play a key role in the deep and ultra-deep water oil and gas production. The vortex-induced vibration (VIV) of marine risers constitutes an important problem in deep water oil exploration and production. VIV will result in high rates of structural failure of marine riser due to fatigue damage accumulation and diminishes the riser fatigue life. In-service monitoring or full scale testing is essential to improve our understanding of VIV response and enhance our ability to predict fatigue damage. One marine riser fatigue acoustic telemetry scheme is proposed and an engineering prototype machine has been developed to monitor deep and ultra-deep water risers' fatigue and failure that can diminish the riser fatigue life and lead to economic losses and eco-catastrophe. Many breakthroughs and innovation have been achieved in the process of developing an engineering prototype machine. Sea trials were done on the 6th generation deep-water drilling platform HYSY-981 in the South China Sea. The inclination monitoring results show that the marine riser fatigue acoustic telemetry scheme is feasible and reliable and the engineering prototype machine meets the design criterion and can match the requirements of deep and ultra-deep water riser fatigue monitoring. The rich experience and field data gained in the sea trial which provide much technical support for optimization in the engineering prototype machine in the future.

  20. Failure assessment of aluminum liner based filament-wound hybrid riser subjected to internal hydrostatic pressure

    NASA Astrophysics Data System (ADS)

    Dikshit, Vishwesh; Seng, Ong Lin; Maheshwari, Muneesh; Asundi, A.

    2015-03-01

    The present study describes the burst behavior of aluminum liner based prototype filament-wound hybrid riser under internal hydrostatic pressure. The main objective of present study is to developed an internal pressure test rig set-up for filament-wound hybrid riser and investigate the failure modes of filament-wound hybrid riser under internal hydrostatic burst pressure loading. The prototype filament-wound hybrid riser used for burst test consists of an internal aluminum liner and outer composite layer. The carbon-epoxy composites as part of the filament-wound hybrid risers were manufactured with [±55o] lay-up pattern with total composite layer thickness of 1.6 mm using a CNC filament-winding machine. The burst test was monitored by video camera which helps to analyze the failure mechanism of the fractured filament-wound hybrid riser. The Fiber Bragg Grating (FBG) sensor was used to monitor and record the strain changes during burst test of prototype filament-wound hybrid riser. This study shows good improvements in burst strength of filament-wound hybrid riser compared to the monolithic metallic riser. Since, strain measurement using FBG sensors has been testified as a reliable method, we aim to further understand in detail using this technique.

  1. Numerical scheme for riser motion calculation during 3-D VIV simulation

    NASA Astrophysics Data System (ADS)

    Huang, Kevin; Chen, Hamn-Ching; Chen, Chia-Rong

    2011-10-01

    This paper presents a numerical scheme for riser motion calculation and its application to riser VIV simulations. The discretisation of the governing differential equation is studied first. The top tensioned risers are simplified as tensioned beams. A centered space and forward time finite difference scheme is derived from the governing equations of motion. Then an implicit method is adopted for better numerical stability. The method meets von Neumann criteria and is shown to be unconditionally stable. The discretized linear algebraic equations are solved using a LU decomposition method. This approach is then applied to a series of benchmark cases with known solutions. The comparisons show good agreement. Finally the method is applied to practical riser VIV simulations. The studied cases cover a wide range of riser VIV problems, i.e. different riser outer diameter, length, tensioning conditions, and current profiles. Reasonable agreement is obtained between the numerical simulations and experimental data on riser motions and cross-flow VIV a/D . These validations and comparisons confirm that the present numerical scheme for riser motion calculation is valid and effective for long riser VIV simulation.

  2. An optimized FBG-based fatigue monitoring strategy on deepwater risers

    NASA Astrophysics Data System (ADS)

    Li, Xuan; Ren, Peng; Zhou, Zhi; Ou, Jinping

    2014-11-01

    For the sake of the increasing demands of oil and gas essential, scientists and engineers have exerted great efforts in obtaining natural resources deposited in the deep water. Risers, as the channel between platform and wellhead, play a key role in oil and gas transportation. Subjected to coarse environmental conditions and uncertain loading patterns, risers would display complex dynamic behaviors which could result in severe fatigue damages. Recently, riser response is commonly measured using passive and durable Fiber Bragg Grating (FBG) strain sensors for industry safety, especially for Integrity Management (IM). However, for technique difficulties as well as economical consideration, it is impossible to execute distributed fatigue monitoring on the whole riser, which makes it essential to find out an optimized method utilizing the least number of sensors and reconstruct the global response of risers. This paper propose a method which combines H2 norms and Kalman filter to give optimal state estimation of risers based on limited FBG-based dynamic strain information. The H2 norms are used to give guideline for optimized sensor placement. Meanwhile, Kalman filter realize the global response reconstruction of risers as well as minimize the environmental disturbance. The accuracy and efficiency of the method has been verified by a numerical case. This study provides an FBG-based early warning technique for industry application of deepwater risers in future.

  3. Turbulent gas-particle flow in vertical risers

    SciTech Connect

    Dasgupta, S.; Jackson, R.; Sundaresan, S. . Dept. of Chemical Engineering)

    1994-02-01

    The riser reactors used for the catalytic cracking of gas oil use a transported solid catalyst, and their performance can be predicted with confidence only if the physical mechanism that determines the cross-sectional distribution of the catalyst can be identified and modeled. Understanding this mechanism is, therefore, of central importance in predicting the behavior of any system in which solid particles are transported through a duct by fluid, and this is the problem addressed here. Many experimental studies on the cross-sectional distribution of particles in vertical risers have revealed marked segregation of particles. These flows are inherently unsteady with large fluctuations in suspension density. In this article, the authors have analyzed the time-smoothed equations for the motion of dense suspensions to demonstrate the role of these fluctuations on the occurrence of segregation. It is shown that the particles will congregate in regions where the kinetic energy of fluctuations associated with the particles is small. In the context of transport of small particles such as FCC, a simplified model based on the mixture velocity can be constructed. A speculative K-[epsilon] model based on this velocity is analyzed to illustrate the extent of segregation of particles afforded by unsteady fluctuations.

  4. Gas-liquid two-phase severe slugging in a pipeline-riser system with S-shaped flexible riser: Experiments and modeling

    NASA Astrophysics Data System (ADS)

    Li, Nailiang; Guo, Liejin; Li, Wensheng

    2013-07-01

    The objective of the present work is to investigate the air-water two-phase flow patterns in pipeline-riser system with an S-shaped flexible riser. The test loop with 50 mm ID consists of a horizontal pipeline with 114 m in length, a downward inclined section with 16 m in length, and an S-shaped flexible riser with 24 m in height when downward section inclined at -2° with respective to the horizontal. The inclination angle of the downward section varied from -2° to -5°. The liquid superficial velocity ranged from 0.03 to 1.5 m/s, and the gas superficial velocity from 0.4 to 6.0 m/s. Identification and characterization of flow regimes were attained by pressure at riser-base and liquid holdup at riser top. Severe slugging I, severe slugging II, transition flow and stable flows are observed to exist. Flow pattern maps for each declination are presented and the transition criteria are proposed. It's found that as higher liquid and gas velocity is required for the transition of the flow in the pipeline from stratified to intermittent with increasing the declination angle, severe slugging was observed to occur over a wilder range of flow conditions. The effect of riser geometry and separator pressure on the occurrence of the flow patterns was also examined. It shows that the S-bend tends to suppress the initiation of severe slugging.

  5. Experimental study on response performance of VIV of a flexible riser with helical strakes

    NASA Astrophysics Data System (ADS)

    Gao, Yun; Fu, Shi-xiao; Cao, Jing; Chen, Yi-fan

    2015-10-01

    Laboratory tests were conducted on a flexible riser with and without helical strakes. The aim of the present work is to further understand the response performance of the vortex induced vibration (VIV) for a riser with helical strakes. The experiment was accomplished in the towing tank and the relative current was simulated by towing a flexible riser in one direction. Based on the modal analysis method, the displacement responses can be obtained by the measured strain. The strakes with different heights are analyzed here, and the response parameters like strain response and displacement response are studied. The experimental results show that the in-line (IL) response is as important as the cross-flow (CF) response, however, many industrial analysis methods usually ignore the IL response due to VIV. The results also indicate that the response characteristics of a bare riser can be quite distinct from that of a riser with helical strakes, and the response performance depends on the geometry on the helical strakes closely. The fatigue damage is further discussed and the results show that the fatigue damage in the CF direction is of the same order as that in the IL direction for the bare riser. However, for the riser with helical strakes, the fatigue damage in the CF direction is much smaller than that in the IL direction.

  6. Two-riser system improves drilling at Auger prospect

    SciTech Connect

    Gonzalez, R.; Marsh, G.L.; Ritter, P.B.; Mendel, P.E. )

    1992-02-10

    This paper reports on a two-rise system (TRS) for drilling deepwater development wells which eliminates some of the limitations of conventional subsea technology and allows flexibility in well programs. Shell Offshore Inc.'s deep exploratory wells in Garden Banks 426 and 471 have encountered drilling problems that were attributed to limitations in casing sizes imposed by conventional subsea drilling systems. These problems are not uncommon in exploratory deepwater, deep well drilling in the Gulf of Mexico. Reservoir depths of up to 19,500 ft true vertical depth (TVD) and 7-in. production casing requirements led to potentially troublesome and expensive well plans. Because of the constraints placed on the development drilling program by completion requirements and directional drilling, a two-riser system was designed and fabricated. Solving such significant drilling problems has reduced overall development costs.

  7. Engineering study - installation of new risers in Single-Shell Tanks

    SciTech Connect

    Magruder, W.J.

    1994-08-01

    A sampling program is being developed to characterize the 149 underground SSTs on the Hanford Site. The sampling effort will require access to the tank interior in a minimum of two locations per tank. Some of the risers suitable for sampling are either unavailable or are not in locations for proper characterization of the tank contents. Additional risers will be required in the SSTs to support the tank characterization sampling program. The purpose of this engineering study is to review alternatives for installation of new riser in the SSTs.

  8. Riser tensioning wave and tide compensating system for a floating platform

    SciTech Connect

    Heeres, C.J.; Larsen, C.H.

    1980-09-16

    A riser tensioner cylinder is provided with a hollow piston rod which forms a second cylinder in which a ram is reciprocated. The free end of the ram is connected to a link which in turn is connected to the end of the riser for providing tension on the riser. The ram reciprocates in the second cylinder under constant pressure to compensate for wave action on the floating platform and the second cylinder is automatically positioned within the first cylinder for adjustment for tide, vessel offset or other infrequent but variable factors.

  9. Effect Of Drill String Rotation On The Dynamic Response Of Drilling Risers

    NASA Astrophysics Data System (ADS)

    Major, I. E.; Big-Alabo, A.; Odi-Owei, S.

    2015-08-01

    The effect of the rotation of a drill string on the response of a drilling riser has been studied. A governing equation for the flexural response that incorporates the effect of the drill string rotation is developed from first principles, and the resulting differential equation is found to have a variable coefficient, which is a function of the drill string rotational speed. Results simulated for the free vibration response show that the drill string rotation reduces the natural frequency and increases the amplitude of vibration of the drilling riser. The implication of these findings is that neglecting the effect of rotation of the drill string leads to under-estimation of the deflection and over-estimation of the natural frequency. Further analysis reveals that for a drilling riser of given dimensions, a drill string rotational speed exists at which the natural frequency of the drilling riser is theoretical equal to zero, and this rotational speed is the threshold rotational speed.

  10. Strain monitoring of drilling riser in deepwater based on fiber Bragg gratings

    NASA Astrophysics Data System (ADS)

    Jiang, Yajun; Yang, Dexing; Wang, Jun; Xu, Jian; Qin, Chuan; Liao, Wei; Zhao, Jianlin; Wang, Haiyan; Jiang, Shiquan

    2011-11-01

    It is very important to monitor the lateral and axial strains of drilling riser for evaluation its health in deepwater. An optical fiber strain sensing system based on optical fiber Bragg gratings (FBGs) used for monitoring the strain of drilling riser is presented. The optical fiber strain sensors are made by embedding FBGs into thin columned fiber reinforced polymer which protect FBGs from seawater corrosion. Four optical fiber strain sensors are installed parallel to the riser axis and arranged at 90° angles around the riser by a home-made metal belt, at the same time, twelve resistance strain gauges are pasted near the sensors around the drilling riser at 30° angles as reference sensors. A scaled drilling riser about 1 meter long and 0.245m diameter is pressed in the lateral and axial direction in the range of 0-400KN, the experimental results show that the relative error between optical fiber strain sensors and resistance strain gauges is less than 6%.

  11. Frequency domain response of a parametrically excited riser under random wave forces

    NASA Astrophysics Data System (ADS)

    Lei, Song; Zhang, Wen-Shou; Lin, Jia-Hao; Yue, Qian-Jin; Kennedy, D.; Williams, F. W.

    2014-01-01

    Floating Production, Drilling, Storage and Offloading units represent a new technology with a promising future in the offshore oil industry. An important role is played by risers, which are installed between the subsea wellhead and the Tension Leg Deck located in the middle of the moon-pool in the hull. The inevitable heave motion of the floating hull causes a time-varying axial tension in the riser. This time dependent tension may have an undesirable influence on the lateral deflection response of the riser, with random wave forces in the frequency domain. To investigate this effect, a riser is modeled as a Bernoulli-Euler beam. The axial tension is expressed as a static part, along with a harmonic dynamic part. By linearizing the wave drag force, the riser's lateral deflection is obtained through a partial differential equation containing a time-dependent coefficient. Applying the Galerkin method, the equation is reduced to an ordinary differential equation that can be solved using the pseudo-excitation method in the frequency domain. Moreover, the Floquet-Liapunov theorem is used to estimate the stability of the vibration system in the space of parametric excitation. Finally, stability charts are obtained for some numerical examples, the correctness of the proposed method is verified by comparing with Monte-Carlo simulation and the influence of the parametric excitation on the frequency domain responses of the riser is discussed.

  12. failure of a fluid catalytic cracker riser line bimetallic weld

    SciTech Connect

    Schult, J.T.

    1983-05-01

    A weld of Inconel 182 to 1 1/4Cr-1/2Mo failed after less than 5000 hours of service in a fluid catalytic cracker riser line. The weld was found to have a unique fracture mode with both fusion line and weld metal separation, but no evidence of base metal rupturing. Poorly documented weld procedures obscured the thermal history, but laboratory simulation and comparision of heat-affected-zone depths inferred that a 600 F preheat was used. It is theorized that high preheat led to amperage reduction, greater first pass base-to-filler metal ratio, poor mixing, and high residual stress in the weld. Stress analysis of the field repair indicated that residual shear stresses would eventually cause creep rupture of the base metal and also demonstrated sensitivity to post-weld heat treatment (PWHT) variables. Of the options of using a second, higher temperature PWHT or a lowered operating temperature, the latter was chosen, and was implemented by removing insulation and adding shielding. This paper reviews the metallurgical aspects of this experience.

  13. First riser drilling in Scientific Ocean Drilling history, Observatory drilling and casing in the Nankai Trough (IODP Exp 319)

    NASA Astrophysics Data System (ADS)

    Toczko, S.; Eguchi, N. O.; Takahashi, K.; Araki, E.; Byrne, T. B.; McNeill, L. C.; Saffer, D. M.

    2009-12-01

    IODP Expedition 319 (“Riser and Riserless Observatory-1”, NanTroSEIZE Stage 2) was the first time in IODP history that scientific riser operations were conducted. As part of this groundbreaking advance in scientific drilling, other technologies and sampling methods were also introduced: scientific mud-gas monitoring, drilling cuttings collection and analysis, MDT, and VSP (walk-away and zero-offset). Although the goals and achievements for Expedition 319 were modest, we will describe the operational portions of these technologies, and also discuss the potential and benefits of future riser drilling operations. JAMSTEC’s Center for Deep Earth Exploration (CDEX), the Japanese Implementing Organization and operator of the riser drillship Chikyu, this year performed the inaugural riser drilling expedition for IODP, as part of NanTroSEIZE Stage 2, Expedition 319, “Riser and Riserless Observatories”. Riser drilling is a typical method of drilling in industry, since it helps prevent loss of petroleum while drilling at sea, and also allows for deeper drilling depths, when compared with the usual non-riser drilling. The system aboard Chikyu is an industrial design riser system, which has just completed drilling operations in the Kumano Basin, drilling and casing a riser hole, Hole C0009A, to 1607.3 mBSF in water 2054 m BSL deep. The riser drilling system maintains a connection between the riser pipe suspended from the drillship to the sea floor blowout preventer (BOP), which makes a seal between the riser pipe and well head, and below to the cased intervals of the borehole below the seafloor. This allows the drilling mud to circulate down through the drillpipe, out the bit, and back up the casing and riser pipe to the drillship. This cools the bit, clears the borehole of cuttings (recovered aboard ship in the shale shakers) and allows real-time mud-gas monitoring. Mud weight can be more carefully controlled and adjusted, improving the quality of mudcake on the

  14. Flow Mapping in a Gas-Solid Riser via Computer Automated Radioactive Particle Tracking (CARPT)

    SciTech Connect

    Muthanna Al-Dahhan; Milorad P. Dudukovic; Satish Bhusarapu; Timothy J. O'hern; Steven Trujillo; Michael R. Prairie

    2005-06-04

    Statement of the Problem: Developing and disseminating a general and experimentally validated model for turbulent multiphase fluid dynamics suitable for engineering design purposes in industrial scale applications of riser reactors and pneumatic conveying, require collecting reliable data on solids trajectories, velocities ? averaged and instantaneous, solids holdup distribution and solids fluxes in the riser as a function of operating conditions. Such data are currently not available on the same system. Multiphase Fluid Dynamics Research Consortium (MFDRC) was established to address these issues on a chosen example of circulating fluidized bed (CFB) reactor, which is widely used in petroleum and chemical industry including coal combustion. This project addresses the problem of lacking reliable data to advance CFB technology. Project Objectives: The objective of this project is to advance the understanding of the solids flow pattern and mixing in a well-developed flow region of a gas-solid riser, operated at different gas flow rates and solids loading using the state-of-the-art non-intrusive measurements. This work creates an insight and reliable database for local solids fluid-dynamic quantities in a pilot-plant scale CFB, which can then be used to validate/develop phenomenological models for the riser. This study also attempts to provide benchmark data for validation of Computational Fluid Dynamic (CFD) codes and their current closures. Technical Approach: Non-Invasive Computer Automated Radioactive Particle Tracking (CARPT) technique provides complete Eulerian solids flow field (time average velocity map and various turbulence parameters such as the Reynolds stresses, turbulent kinetic energy, and eddy diffusivities). It also gives directly the Lagrangian information of solids flow and yields the true solids residence time distribution (RTD). Another radiation based technique, Computed Tomography (CT) yields detailed time averaged local holdup profiles at

  15. Modeling of the formation of under-riser macrosegregation during solidification of binary alloys

    SciTech Connect

    Diao, Q.Z.; Tsai, H.L. )

    1994-05-01

    The formation of macrosegregation in a rectangular ingot with reduced cross section from the riser to the casting, chilled from the bottom, has been studied numerically. In addition to positive inverse segregation occurring near the chilled surface, very severe negative segregation around the under-riser region and moderate positive segregation near the top comers of the casting were found. Although large circulating vortexes are created by natural convection in the under-riser region during the early stage of solidification, the fluid flow in the mushy zone is dominated by solidification shrinkage. As a result, the final solute distribution in the casting is determined by the flow of solute-rich liquid in the mushy zone owing to the combined effects of solidification shrinkage and change of cross section from casting to riser. Detailed explanations regarding the effect of different flow phenomena on the formation of the segregations are provided. The effects of riser size and cooling condition at the bottom of the ingot on the formation of macrosegregation also were studied. The predicted negative and positive macrosegregations in the casting compared very well with the available experimental data.

  16. Study and Test of a New Bundle-Structure Riser Stress Monitoring Sensor Based on FBG

    PubMed Central

    Xu, Jian; Yang, Dexing; Qin, Chuan; Jiang, Yajun; Sheng, Leixiang; Jia, Xiangyun; Bai, Yang; Shen, Xiaohong; Wang, Haiyan; Deng, Xin; Xu, Liangbin; Jiang, Shiquan

    2015-01-01

    To meet the requirements of riser safety monitoring in offshore oil fields, a new Fiber Bragg Grating (FBG)-based bundle-structure riser stress monitoring sensor has been developed. In cooperation with many departments, a 49-day marine test in water depths of 1365 m and 1252 m was completed on the “HYSY-981” ocean oil drilling platform. No welding and pasting were used when the sensor was installed on risers. Therefore, the installation is convenient, reliable and harmless to risers. The continuous, reasonable, time-consistent data obtained indicates that the sensor worked normally under water. In all detailed working conditions, the test results show that the sensor can do well in reflecting stresses and bending moments both in and in magnitude. The measured maximum stress is 132.7 MPa, which is below the allowable stress. In drilling and testing conditions, the average riser stress was 86.6 MPa, which is within the range of the China National Offshore Oil Corporation (CNOOC) mechanical simulation results. PMID:26610517

  17. Damage localization of marine risers using time series of vibration signals

    NASA Astrophysics Data System (ADS)

    Liu, Hao; Yang, Hezhen; Liu, Fushun

    2014-10-01

    Based on dynamic response signals a damage detection algorithm is developed for marine risers. Damage detection methods based on numerous modal properties have encountered issues in the researches in offshore oil community. For example, significant increase in structure mass due to marine plant/animal growth and changes in modal properties by equipment noise are not the result of damage for riser structures. In an attempt to eliminate the need to determine modal parameters, a data-based method is developed. The implementation of the method requires that vibration data are first standardized to remove the influence of different loading conditions and the autoregressive moving average (ARMA) model is used to fit vibration response signals. In addition, a damage feature factor is introduced based on the autoregressive (AR) parameters. After that, the Euclidean distance between ARMA models is subtracted as a damage indicator for damage detection and localization and a top tensioned riser simulation model with different damage scenarios is analyzed using the proposed method with dynamic acceleration responses of a marine riser as sensor data. Finally, the influence of measured noise is analyzed. According to the damage localization results, the proposed method provides accurate damage locations of risers and is robust to overcome noise effect.

  18. Study and Test of a New Bundle-Structure Riser Stress Monitoring Sensor Based on FBG.

    PubMed

    Xu, Jian; Yang, Dexing; Qin, Chuan; Jiang, Yajun; Sheng, Leixiang; Jia, Xiangyun; Bai, Yang; Shen, Xiaohong; Wang, Haiyan; Deng, Xin; Xu, Liangbin; Jiang, Shiquan

    2015-01-01

    To meet the requirements of riser safety monitoring in offshore oil fields, a new Fiber Bragg Grating (FBG)-based bundle-structure riser stress monitoring sensor has been developed. In cooperation with many departments, a 49-day marine test in water depths of 1365 m and 1252 m was completed on the "HYSY-981" ocean oil drilling platform. No welding and pasting were used when the sensor was installed on risers. Therefore, the installation is convenient, reliable and harmless to risers. The continuous, reasonable, time-consistent data obtained indicates that the sensor worked normally under water. In all detailed working conditions, the test results show that the sensor can do well in reflecting stresses and bending moments both in and in magnitude. The measured maximum stress is 132.7 MPa, which is below the allowable stress. In drilling and testing conditions, the average riser stress was 86.6 MPa, which is within the range of the China National Offshore Oil Corporation (CNOOC) mechanical simulation results. PMID:26610517

  19. The effect of particle inlet conditions on FCC riser hydrodynamics and product yields.

    SciTech Connect

    Chang, S. L.; Golchert, B.; Lottes, S. A.; Zhou, C. Q.; Huntsinger, A.; Petrick, M.

    1999-10-11

    Essential to today's modern refineries and the gasoline production process are fluidized catalytic cracking units. By using a computational fluid dynamics (CFD) code developed at Argonne National Laboratory to simulate the riser, parametric and sensitivity studies were performed to determine the effect of catalyst inlet conditions on the riser hydrodynamics and on the product yields. Simulations were created on the basis of a general riser configuration and operating conditions. The results of this work are indications of riser operating conditions that will maximize specific product yields. The CFD code is a three-dimensional, multiphase, turbulent, reacting flow code with phenomenological models for particle-solid interactions, droplet evaporation, and chemical kinetics. The code has been validated against pressure, particle loading, and product yield measurements. After validation of the code, parametric studies were performed on various parameters such as the injection velocity of the catalyst, the angle of injection, and the particle size distribution. The results indicate that good mixing of the catalyst particles with the oil droplets produces a high degree of cracking in the riser.

  20. Dynamics of a vertical riser with weak structural nonlinearity excited by wakes

    NASA Astrophysics Data System (ADS)

    Keber, Marko; Wiercigroch, Marian

    2008-08-01

    In this paper we investigate the effect of a weak structural nonlinearity on the dynamical behaviour of a vertical offshore riser subjected to vortex-induced vibration (VIV). Coupling of the riser dynamics with the flow of the surrounding fluid is achieved by attaching a wake oscillator to a reduced model of the structure, which is obtained through the application of the invariant manifold technique for the derivation of nonlinear normal modes. By comparing the free responses of the linear and the nonlinear structure, it was found that the structural nonlinearity has a stiffening effect on the oscillation of the riser, which becomes more pronounced when the internal flow is incorporated into the model. Consequently, in the coupled system, the response is considerably modified for the structure as well as for the fluid variable.

  1. Eulerian-Lagrangian Simulations of Three-Dimensional Turbulent Riser Flows

    NASA Astrophysics Data System (ADS)

    Capecelatro, Jesse; Pepiot, Perrine; Desjardins, Olivier

    2010-11-01

    Particle suspended flows in vertical risers are used in many industries in the form of circulating fluidized beds. Applications include gasification/pyrolysis for biofuel conversion, coal combustion, and fluid catalytic cracking. Experimental studies have shown riser flows to be unsteady with large particle concentration fluctuations. Regions of densely packed particles, referred to as clusters form, which greatly affect the overall flow behavior and mixing properties. Because the solid phase is opaque, quantitative experimental results are limited, and therefore computational fluid dynamics (CFD) is used here to simulate 3D riser flows. The gas phase is solved with a high-order fully conservative finite difference code called NGA, tailored for turbulent flow computation. Lagrangian tracking is used to solve the particle phase. Statistics are computed for both the gas and particle phases, along with characteristic cluster sizes, shape, and velocities. Inter-particle collisions are considered and shown to affect the clustering behavior of the flow.

  2. Moving from Science to Service: Transposing and Sustaining the Early Risers Prevention Program in a Community Service System

    ERIC Educational Resources Information Center

    Bloomquist, Michael L.; August, Gerald J.; Horowitz, Jason L.; Lee, Susanne S.; Jensen, Cheryl

    2008-01-01

    This paper summarizes an effort to transpose and sustain the evidence-based Early Risers "Skills for Success" conduct problems prevention program in a real world community service system. The Early Risers program had previously been implemented by a local agency within the context of research-based operations. In the current initiative,…

  3. Pantograph-catenary monitoring by means of fibre Bragg grating sensors: Results from tests in an underground line

    NASA Astrophysics Data System (ADS)

    Bocciolone, Marco; Bucca, Giuseppe; Collina, Andrea; Comolli, Lorenzo

    2013-12-01

    One of the most common way to collect the traction current needed for the underground vehicle operation is by using the pantograph-overhead line system. The periodically check of pantographs and overhead lines is important to assure the correct interaction between the two systems in terms of good current collection quality. The main diagnostic tools are the monitoring of the vertical force between the overhead line and the pantograph head, and the vertical acceleration on the pantograph head. The pantograph system works under high voltage (1500 V, DC, in our tests) and high electromagnetic disturbances are present. For this reason, traditional electrical sensors can be used only with particular precautions that complicate the measurement set up; fibre optic sensors, and in particular fibre Bragg grating (FBG) sensors, are particularly suitable for this application. In this paper, the application of the FBG sensors on a pantograph for the monitoring of underground pantograph-catenary system is presented. FBG sensors are used to measure both the contact force and the vertical acceleration of the pantograph head. The same measurements are also gathered with a traditional electrical system, allowing a comparison. The result is a very good agreement between electrical and optical measurements, except in particular frequency ranges where the different positioning of the sensors influences the output, limiting the comparison. Moreover, some interesting results on the dynamic behaviour of the pantograph and its interaction with the overhead line are presented. Finally, a method to point out the main defects on the overhead line is shown.

  4. The design and installation of dynamic risers and umbilicals for the Atlantic Frontiers

    SciTech Connect

    Benstead, P.J.; Moore, F.; Holen, P.T.; Ekeberg, K.I.

    1996-12-31

    The Foinaven riser and umbilical system comprises 10 flexible pipes and 2 umbilicals and provides production, test, gas injection, water injection and control for two drilling centers. The design pressure for the system is 3,689 psi (254 bar g). The configuration of the risers is a ``pliant wave`` which is anchored to a gravity base structure by tethers and has buoyancy modules distributed along the lower end. The system is designed such that it can be released from the FPSO in extreme emergency conditions. The paper describes the design conditions, vessel interface, buoyancy modules, tether clamps and tether, flexible pipe design, umbilical design, schedules, subsea alliance, and installation.

  5. Marine riser protector for use on offshore oil drilling rigs in icy waters

    SciTech Connect

    Yashima, N.

    1985-03-19

    An apparatus for protecting a marine riser extending downwardly from a platform of an offshore station above a sea level toward a sea bottom. A tubular protector is removably mounted on the underside of the platform in surrounding relation to the marine riser in the vicinity of the sea level. According to another embodiment, a tubular protector has an upper portion in the shape of a truncated cone for contact with ice floes and a lower portion shaped as a grid-like truncated cone flaring downwardly for diverting ice floes away from the tubular protector.

  6. Yield Improvement in Steel Casting (Yield II)

    SciTech Connect

    Richard A. Hardin; Christoph Beckermann; Tim Hays

    2002-02-18

    This report presents work conducted on the following main projects tasks undertaken in the Yield Improvement in Steel Casting research program: Improvement of Conventional Feeding and Risering Methods, Use of Unconventional Yield Improvement Techniques, and Case Studies in Yield Improvement. Casting trials were conducted and then simulated using the precise casting conditions as recorded by the participating SFSA foundries. These results present a statistically meaningful set of experimental data on soundness versus feeding length. Comparisons between these casting trials and casting trials performed more than forty years ago by Pellini and the SFSA are quite good and appear reasonable. Comparisons between the current SFSA feeding rules and feeding rules based on the minimum Niyama criterion reveal that the Niyama-based rules are generally less conservative. The niyama-based rules also agree better with both the trials presented here, and the casting trails performed by Pellini an d the SFSA years ago. Furthermore, the use of the Niyama criterion to predict centerline shrinkage for horizontally fed plate sections has a theoretical basis according to the casting literature reviewed here. These results strongly support the use of improved feeding rules for horizontal plate sections based on the Niyama criterion, which can be tailored to the casting conditions for a given alloy and to a desired level of soundness. The reliability and repeatability of ASTM shrinkage x-ray ratings was investigated in a statistical study performed on 128 x-rays, each of which were rated seven different times. A manual ''Feeding and Risering Guidelines for Steel Castings' is given in this final report. Results of casting trials performed to test unconventional techniques for improving casting yield are presented. These use a stacked arrangement of castings and riser pressurization to increase the casting yield. Riser pressurization was demonstrated to feed a casting up to four time s the

  7. Acoustic and Perceptual Measures of SATB Choir Performances on Two Types of Portable Choral Riser Units in Three Singer-Spacing Conditions

    ERIC Educational Resources Information Center

    Daugherty, James F.; Manternach, Jeremy N.; Brunkan, Melissa C.

    2013-01-01

    Under controlled conditions, we assessed acoustically (long-term average spectra) and perceptually (singer survey, listener survey) six performances of an soprano, alto, tenor, and bass (SATB) choir ("N" = 27) as it sang the same musical excerpt on two portable riser units (standard riser step height, taller riser step height) with…

  8. Steel monoleg design tries for concrete advantages

    SciTech Connect

    Not Available

    1984-11-01

    The conceptual design of a fixed steel monoleg structure designed for North Sea water depths of 80-250 meters is described. The design was commissioned by the Dutch Ministry of Economic Affairs and funded in part by the European Economic Community. The design aims to give a steel structure some of the advantages of concrete condeeps. Maintenance should be minimized by enclosing the risers inside a monopod. The single-shell, variable geometry of the column structure should also serve to equalize stresses, unlike a conventional space frame where stresses tend to concentrate around the nodes. Construction and installation could be vertical, as in condeep style, or horizontal, as in steel jackets. Thus the fixed steel platform could be either barge-towed and upended with ballast tanks or floated out vertically as built and towed, like a condeep, to a mating with an integrated deck before final tow and installation by simple ballasting.

  9. The Early Risers Preventive Intervention: Testing for Six-year Outcomes and Mediational Processes

    ERIC Educational Resources Information Center

    Bernat, Debra H.; August, Gerald J.; Hektner, Joel M.; Bloomquist, Michael L.

    2007-01-01

    We examined effects of the Early Risers "Skills for Success" early-age-targeted prevention program on serious conduct problems following 5 years of continuous intervention and one year of follow-up. We also examined if intervention effects on proximally-targeted variables found after 3 years mediated intervention effects on conduct problems found…

  10. Tools for Inspecting and Sampling Waste in Underground Radioactive Storage Tanks with Small Access Riser Openings

    SciTech Connect

    Nance, T.A.

    1998-12-17

    Underground storage tanks with 2 inches to 3 inches diameter access ports at the Department of Energy's Savannah River Site have been used to store radioactive solvents and sludge. In order to close these tanks, the contents of the tanks need to first be quantified in terms of volume and chemical and radioactive characteristics. To provide information on the volume of waste contained within the tanks, a small remote inspection system was needed. This inspection system was designed to provide lighting and provide pan and tilt capabilities in an inexpensive package with zoom abilities and color video. This system also needed to be utilized inside of a plastic tent built over the access port to contain any contamination exiting from the port. This system had to be build to travel into the small port opening, through the riser pipe, into the tank evacuated space, and out of the riser pipe and access port with no possibility of being caught and blocking the access riser. Long thin plates were found in many access riser pipes that blocked the inspection system from penetrating into the tank interiors. Retrieval tools to clear the plates from the tanks using developed sampling devices while providing safe containment for the samples. This paper will discuss the inspection systems, tools for clearing access pipes, and solvent sampling tools developed to evaluate the tank contents of the underground solvent storage tanks.

  11. Enhanced multi-layer fatigue-analysis approach for unbonded flexible risers

    NASA Astrophysics Data System (ADS)

    Yang, He-zhen; Jiang, Hao; Yang, Qi

    2014-06-01

    This paper proposes an enhanced approach for evaluating the fatigue life of each metallic layer of unbonded flexible risers. Owing to the complex structure of unbonded flexible risers and the nonlinearity of the system, particularly in the critical touchdown zone, the traditional method is insufficient for accurately evaluating the fatigue life of these risers. The main challenge lies in the transposition from global to local analyses, which is a key stage for the fatigue analysis of flexible pipes owing to their complex structure. The new enhanced approach derives a multi-layer stress-decomposition method to meet this challenge. In this study, a numerical model validated experimentally is used to demonstrate the accuracy of the stress-decomposition method. And a numerical case is studied to validate the proposed approach. The results demonstrate that the multi-layer stress-decomposition method is accurate, and the fatigue lives of the metallic layers predicted by the enhanced multi-layer analysis approach are rational. The proposed fatigue-analysis approach provides a practical and reasonable method for predicting fatigue life in the design of unbonded flexible risers.

  12. Radioisotope inventory of T101AZ thermocouple tree from riser 13D

    SciTech Connect

    Kessler, S.F., Westinghouse Hanford

    1996-06-12

    The radionuclide inventory for the thermocouple tree removed from tank T101-AZ riser 13D was estimated using measured {sup 137}Cs activity. This activity was measured by detectors as the tree was removed from the tank. Other radionuclide activities were estimated using the results of tank samples.

  13. Riser Difference Evaluation from Ultrasonic Wall Thickness Inspection of Thirteen Double-Shell Tanks

    SciTech Connect

    Weier, Dennis R.; Pardini, Allan F.

    2010-03-15

    PNNL has performed an analysis of ultrasonic thickness measurements taken on Hanford's double-shell tanks (DSTs) approximately eight years apart. The analysis was performed to determine whether significant differences exist between ultrasonic thickness measurements made in two opposite risers in Hanford DSTs that have been examined twice.

  14. Deepwater completion/workover riser and control system: Operational experience and lessons learned

    SciTech Connect

    Parks, W.C.; Beebe, D.C.

    1996-12-31

    Sonsub International designed, built and is currently operating a deepwater Completion/Workover (C/WO) Riser and Control System which is being offered to the industry on a lease basis. In an industry partnering approach, Sonsub worked closely with both operating companies and Deepstar participants to develop a system that would meet both current and future requirements for completion/workover operations in deepwater subsea development applications. The C/WO Riser and Control System is designed for use in water depths up to 6,000 ft (but is capable of being extended to 10,000 ft) and is rated for 10,000 psi working pressure. The system includes all of the equipment required for use in well completion operations to run and install the tubing hanger and subsea tree and in workover operations to provide wireline and/or coiled tubing access into the well bore. The C/WO Riser and Control System was used initially by Shell Offshore, Inc. (SOI) to complete two wells in 2,040 ft of water in the Popeye Field in the US Gulf of Mexico (GOM) during the second half of 1995, and a single well in 2,960 ft of water in the Mars field in the GOM in early 1996. It is scheduled for use by SOI in 5,400 ft of water in the Mensa field in the GOM in late 1996/early 1997. This paper discusses the design of the C/WO Riser and Control System and the experience gained from operating this equipment in the Popeye and Mars fields and also discusses some of the lessons learned (both positive and negative). This information is currently being used to enhance the design and operating features of the C/WO Riser and Control System and to further refine the operating procedures to improve operating efficiency and reduce costs.

  15. Severe slugging in a flexible S-shaped riser system: Experimental studies and transient simulation

    NASA Astrophysics Data System (ADS)

    Li, Wensheng; Guo, Liejin; Li, Nailiang

    2013-07-01

    Severe slugging, which could induce large-amplitude pressure and flow rate fluctuations, is a major and expensive problem in multiphase transportation systems of offshore oil production system. To avoid such problem is a basic requirement for flow assurance management. This study is an experimental and numerical investigation of severe slugging in a relatively long pipeline-riser system. A series of experiments on two-phase, air-water flow in a flexible Sshaped riser were carried out. The experimental system has a 114m long horizontal pipeline connected to a 19m long pipe which is inclined to -2degree from horizontal, followed by a 15.3m high riser operating at atmospheric end pressure. Four types of flow patterns were found and characterized by the pressure fluctuations at the bottom of the riser. A flow patter map for the prediction of severe slugging was developed based on the experimental results. The detailed characteristics of severe slugging such as pressure fluctuations, liquid holdup, under different gas-liquid superficial velocities were provided. A transient model to predict the flow behavior in the pipeline-S-shaped riser system was developed based on an existing model (OLGA). The modified model, which was tested against new experimental results obtained in this study, showed that the four types of flow patterns observed in the experiment were predicted with acceptable discrepancies. The flow pattern map was obtained using present model, as well as the detailed characteristics of severe slugging. In addition, the reasons for the difference between experimental and numerical results were analysed in this article. The motive of the numerical studies was to identify the areas that could not be reproduced by the present model and to give some suggestions for future models.

  16. Bench and Riser Soil Water Content on Semiarid Hillslopes with Terracettes

    NASA Astrophysics Data System (ADS)

    Heinse, R.; Corrao, M.; Eitel, J.; Link, T. E.

    2015-12-01

    Microtopographic features known as terracettes are found throughout many semiarid rangelands. These path-like features roughly perpendicular to the slope are frequently traversed by grazing animals on steep hillslopes. The soil properties and hydrologic function, however, are virtually unknown. This research aimed to identify differences in soil properties between terracette bench and riser features, and their influence on soil water content for two terracetted sites and two non-terracetted control sites (grazed and ungrazed) in Eastern Washington State. Measurements of volumetric water content (θ_v), bulk density, soil texture, saturated hydraulic conductivity, pH, and ECa_a were collected along with compaction, vegetative cover and cattle density throughout the 2013 and 2014 field seasons. Results show small but significant volumetric water content differences between terracette benches and risers in the upper 10 cm with benches exhibiting higher mean θ_v than risers throughout the year. Soil bulk density on benches (1600 kg m-3^{-3}) was significantly higher than that of risers (1300 kg m-3^{-3}) with no differences in soil texture. The saturated hydraulic conductivity on benches was roughly half of that for risers. No significant soil differences were noted below 20 cm depth. Terracetted sites showed greater field-averaged θ_v compared to non-terracetted sites suggesting a positive trend with animal stocking rates. Higher water content on terracette benches is attributed to shifts in pore size distribution with compaction, and a reduction in root-water uptake due to plant-root impedance. This increased soil water does not however increase forage production as it is not accessible to plants.

  17. A fast rise-rate, adjustable-mass-bit gas puff valve for energetic pulsed plasma experiments

    SciTech Connect

    Loebner, Keith T. K. Underwood, Thomas C.; Cappelli, Mark A.

    2015-06-15

    A fast rise-rate, variable mass-bit gas puff valve based on the diamagnetic repulsion principle was designed, built, and experimentally characterized. The ability to hold the pressure rise-rate nearly constant while varying the total overall mass bit was achieved via a movable mechanical restrictor that is accessible while the valve is assembled and pressurized. The rise-rates and mass-bits were measured via piezoelectric pressure transducers for plenum pressures between 10 and 40 psig and restrictor positions of 0.02-1.33 cm from the bottom of the linear restrictor travel. The mass-bits were found to vary linearly with the restrictor position at a given plenum pressure, while rise-rates varied linearly with plenum pressure but exhibited low variation over the range of possible restrictor positions. The ability to change the operating regime of a pulsed coaxial plasma deflagration accelerator by means of altering the valve parameters is demonstrated.

  18. A fast rise-rate, adjustable-mass-bit gas puff valve for energetic pulsed plasma experiments

    NASA Astrophysics Data System (ADS)

    Loebner, Keith T. K.; Underwood, Thomas C.; Cappelli, Mark A.

    2015-06-01

    A fast rise-rate, variable mass-bit gas puff valve based on the diamagnetic repulsion principle was designed, built, and experimentally characterized. The ability to hold the pressure rise-rate nearly constant while varying the total overall mass bit was achieved via a movable mechanical restrictor that is accessible while the valve is assembled and pressurized. The rise-rates and mass-bits were measured via piezoelectric pressure transducers for plenum pressures between 10 and 40 psig and restrictor positions of 0.02-1.33 cm from the bottom of the linear restrictor travel. The mass-bits were found to vary linearly with the restrictor position at a given plenum pressure, while rise-rates varied linearly with plenum pressure but exhibited low variation over the range of possible restrictor positions. The ability to change the operating regime of a pulsed coaxial plasma deflagration accelerator by means of altering the valve parameters is demonstrated.

  19. Physical simulation of the response of the Enserch Garden Banks 388 FPF/free standing rigid riser to wind, waves, and current

    SciTech Connect

    Edwards, R.Y.; Johnson, T.L.; Johnson, R.P.

    1995-12-31

    This paper describes large scale hydrodynamic model tests of the Enserch Exploration Garden Banks 388 Floating Production Facility (FPF). This unique facility consists of a semi-submersible connected to a template on the sea floor 2,096 feet below the surface through a buoyant, free standing ``rigid`` riser. The top of the riser and its manifold are located well below the surface to minimize the forces exerted on the riser by waves. Numerous flexible conductors connect the semi-submersible to the manifold on the top of the riser. The emphasis of the model test program was to confirm the estimates of: The structural response of the buoyant, rigid production riser and an adjacent drilling riser; The relative displacements between the semisubmersible and the production riser; The relative displacements between the production riser and drilling riser; and The forces which must be endured by the tensioners and flexible hoses which join the semi-submersible to the production riser. The paper describes the planning and preparation of the model components, the unique aspects of the simulation of the environments and the structural properties of the models, the execution of the experiments and the handling of the large number of measurements necessary to characterize the response of the multi-component system. Finally, the data analysis tools which were employed to provide an understanding of the responses of the system are discussed. 22 figs., 1 tab.

  20. Statistical analysis on the signals monitoring multiphase flow patterns in pipeline-riser system

    NASA Astrophysics Data System (ADS)

    Ye, Jing; Guo, Liejin

    2013-07-01

    The signals monitoring petroleum transmission pipeline in offshore oil industry usually contain abundant information about the multiphase flow on flow assurance which includes the avoidance of most undesirable flow pattern. Therefore, extracting reliable features form these signals to analyze is an alternative way to examine the potential risks to oil platform. This paper is focused on characterizing multiphase flow patterns in pipeline-riser system that is often appeared in offshore oil industry and finding an objective criterion to describe the transition of flow patterns. Statistical analysis on pressure signal at the riser top is proposed, instead of normal prediction method based on inlet and outlet flow conditions which could not be easily determined during most situations. Besides, machine learning method (least square supported vector machine) is also performed to classify automatically the different flow patterns. The experiment results from a small-scale loop show that the proposed method is effective for analyzing the multiphase flow pattern.

  1. MP-Pic simulation of CFB riser with EMMS-based drag model

    SciTech Connect

    Li, F.; Song, F.; Benyahia, S.; Wang, W.; Li, J.

    2012-01-01

    MP-PIC (multi-phase particle in cell) method combined with the EMMS (energy minimization multi- scale) drag force model was implemented with the open source program MFIX to simulate the gas–solid flows in CFB (circulatingfluidizedbed) risers. Calculated solid flux by the EMMS drag agrees well with the experimental value; while the traditional homogeneous drag over-predicts this value. EMMS drag force model can also predict the macro-and meso-scale structures. Quantitative comparison of the results by the EMMS drag force model and the experimental measurements show high accuracy of the model. The effects of the number of particles per parcel and wall conditions on the simulation results have also been investigated in the paper. This work proved that MP-PIC combined with the EMMS drag model can successfully simulate the fluidized flows in CFB risers and it serves as a candidate to realize real-time simulation of industrial processes in the future.

  2. Developing flow of a gas-particle mixture in a vertical riser

    SciTech Connect

    Pita, J.A. ); Sundaresan, S. )

    1993-04-01

    The riser reactors used for the catalytic cracking of gas oil use a transported solid catalyst, and their performance can be predicted with confidence only if the physical mechanism that determines the cross-sectional distribution of the catalyst can be identified and modeled. A computational study of steady, developing flow of gas-particle suspensions in a vertical riser has been carried out, using a model based on kinetic theory of granular materials, to understand the role of inlet configuration on the pattern of flow development. Three inlet configurations - uniform inlet, core-annulus flow at the inlet and circumferential injection of secondary gas - were examined. It is found that the inlet configuration can have a profound impact on the rate of segregation of particles to the wall and the internal recirculation. Circumferential injection of gas has a favorable effect on the flow in the sense that it can decrease the extent of internal recirculation.

  3. Application of a catenary PBPK model to predict the disposition of "catch and release" anti-PCSK9 antibodies.

    PubMed

    Glassman, Patrick M; Balthasar, Joseph P

    2016-05-30

    The development of 'catch and release', or pH-sensitive, monoclonal antibodies (mAb) has become of interest to groups seeking to reduce the influence of target-mediated elimination on pharmacokinetics and pharmacodynamics. In this work, a catenary physiologically-based pharmacokinetic (PBPK) model is described to predict the pharmacokinetic benefit conferred by engineering mAbs for 'catch and release' binding. Our previously published PBPK model was adapted for consideration of the production and elimination of proprotein convertase subtilisin/kexin type 9 (PCSK9) in mice, and the model was then applied to predict the pharmacokinetics of anti-PCSK9 mAb with pH-stable (J10) and pH-sensitive binding (J17). The model was able to generate reasonable predictions of both J10 and J17 plasma pharmacokinetics. For J10, mean (±standard deviation) predicted vs. observed areas under the plasma concentration curve (AUCinf) were: 217 (77.1) vs. 103nMday (1mg/kg), 1.14×10(3) (858) vs. 769nMday (3mg/kg), and 6.60×10(3) (5.58×10(3)) vs. 2.86×10(3)nMday (10mg/kg), and for J17 the values were: 838 (161) vs. 818nMday (1mg/kg), 2.30×10(3) (441) vs. 2.57×10(3)nMday (3mg/kg), and 8.42×10(3) (1.50×10(3)) vs. 9.17×10(3)nMday (10mg/kg). Further simulations with the model predicted that target turnover and the magnitude of change in the complex dissociation rate constant between pH 7.4 and pH 6.0 are key determinants of the improvements in pharmacokinetics associated with 'catch and release' mAbs. The model described here may be useful for prediction of the pharmacokinetics of 'catch and release' mAbs directed against other targets. PMID:27041125

  4. Flow Regime Study in a Circulating Fluidized Bed Riser with an Abrupt Exit: [1] High Density Suspension

    SciTech Connect

    Mei, J.S.; Lee, G.T.; Seachman, S.M.; Ludlow, J.C.; Shadle, L.J.

    2008-05-13

    Flow regime study was conducted in a 0.3 m diameter, 15.5 m tall circulating fluidized bed (CFB) riser with an abrupt exit at the National Energy Technology Laboratory of the U. S. Department of Energy. A statistical designed test series was conducted including four (4) operating set points and a duplicated center point (therefore a total of 6 operating set points). Glass beads of mean diameter 200 μm and particle density of 2,430 kg/m3 were used as bed material. The CFB riser was operated at various superficial gas velocities ranging from 5.6 to 7.6 m/s and solid mass flux from a low of 86 to a high of 303 kg/m2-s. Results of the apparent solids fraction profile as well as the radial particle velocity profile were analyzed in order to identify the presence of Dense Suspension Upflow (DSU) conditions. DSU regime was found to exist at the bottom of the riser, while the middle section of the riser was still exhibiting core-annular flow structure. Due to the abrupt geometry of the exit, the DSU regime was also found at the top of the riser. In addition the effects of the azimuthal angle, riser gas velocity, and mass solids flux on the particle velocity were investigated and are discussed in this paper.

  5. A general kinetic-flow coupling model for FCC riser flow simulation.

    SciTech Connect

    Chang, S. L.

    1998-05-18

    A computational fluid dynamic (CFD) code has been developed for fluid catalytic cracking (FCC) riser flow simulation. Depending on the application of interest, a specific kinetic model is needed for the FCC flow simulation. This paper describes a method to determine a kinetic model based on limited pilot-scale test data. The kinetic model can then be used with the CFD code as a tool to investigate optimum operating condition ranges for a specific FCC unit.

  6. Analysis of the acceleration region in a circulating fluidized bed riser operating above fast fluidization velocities

    SciTech Connect

    Monazam, E.R.; Shadle, L.J.

    2008-11-05

    In commercial circulating fluidized bed (CFB) processes the acceleration zone greatly contributes to solids mixing, gas and solids dispersion, and particle residence times. A new analysis was developed to describe the relative gas-solids concentration in the acceleration region of a transport system with air as the fluidizing agent for Geldart-type B particles. A theoretical expression was derived from a drag relationship and momentum and continuity equations to describe the evolution of the gas-solids profile along the axial direction. The acceleration zone was characterized using nondimensional analysis of the continuum equations (balances of masses and momenta) that described multiphase flows. In addition to acceleration length, the boundary condition for the solids fraction at the bottom of the riser and the fully developed regions were measured using an industrial scale CFB of 0.3 m diameter and 15 m tall. The operating factors affecting the flow development in the acceleration region were determined for three materials of various sizes and densities in core annular and dilute regimes of the riser. Performance data were taken from statistically designed experiments over a wide range of Fr (0.5-39), Re (8-600), Ar (29-3600), load ratio (0.2-28), riser to particle diameter ratio (375-5000), and gas to solids density ratio (138-1381). In this one-dimensional system of equations, velocities and solid fractions were assumed to be constant over any cross section. The model and engineering correlations were compared with literature expressions to assess their validity and range of applicability. These expressions can be used as tools for simulation and design of a CFB riser and can also be easily coupled to a kinetics model for process simulation.

  7. Analysis of gas/particles flow in the riser of a circulating fluidized bed

    SciTech Connect

    Arastoopour, H.; Benyahia, S.

    1999-07-01

    Computational fluid dynamics (CFD) packages (CFX and Fluent) governing equations were modified using kinetic theory for cohesive and non-cohesive particles of different sizes, and used to simulate 2-dimensional and 3-dimensional transient gas/particle flow behavior using FCC particles in the riser section of a circulating fluidized bed. The calculated solid flux velocity and pressure drop agreed reasonably well with the experimental data obtained using laser doppler anemometer and large-scale experiments.

  8. Comparison of asymmetric with symmetric feed oil injection parameters in a riser reactor.

    SciTech Connect

    Bowman, B. J.; Chang, S. L.; Lottes, S. A.; Zhou, C. Q.

    1999-04-20

    A computational fluid dynamic (CFD) computer code was used to determine the effects of product yields of three feed injection parameters in a fluidized catalytic cracking (FCC) riser reactor. This study includes the effects of both symmetrical and non-symmetrical injection parameters. All these parameters have significant effects on the feed oil spray distribution, vaporization rates and the resulting product yields. This study also indicates that optimum parameter ranges exist for the investigated parameters.

  9. Riser-cable development for ocean-thermal-energy conversion plants. Progress report

    SciTech Connect

    Not Available

    1982-12-01

    Developmental testing and analysis of OTEC riser cables and component materials has been undertaken. Two full-size riser cables have been manufactured and tested, one using cross-linked polyethylene (XLPE) insulation, the other using self-contained, oil filled (SCOF) insulation. These cables and their components have been subjected to testing which simulates handling and insulation prior to OTEC service, as well as the electrical and mechanical loads predicted in service. Results of testing and analyses to date indicate that the XLPE cable has significant potential in the OTEC riser application. The cable has performed well in mechanical and electrical testing. The results for the SCOF cable are mixed. The SCOF cable collapses due to pressure at depths typical of OTEC service; slippage may occur within the insulation or between the conductor and insulation which could result in early cable failure. Particular attention must be paid to alleviating these problems in future cable design efforts. Implications of these findings for cable and system development are presented for use by OTEC platform designers. These findings are subject to change as additional test data are obtained.

  10. Upgrading naphtha in a multiple riser fluid catalytic cracking operation employing a catalyst mixture

    SciTech Connect

    Herbst, J.A.; Owen, H.; Schipper, P.H.

    1989-05-16

    A process is described for producing gasoline comprising contacting a hydrocarbon feed having an initial boiling-point of at least 400/sup 0/F., a 50% boiling of at least 500/sup 0/F. and an end boiling point of at least 600/sup 0/F., in a first riser, with a two component catalyst under fluid catalytic cracking conditions. At least one component of the catalyst is stripped in a stripping unit to remove entrained hydrocarbons, and regenerated wherein the two component catalyst comprises a first catalyst component selected from the group consisting of an amorphous cracking catalyst and a large pore cracking catalyst, whereby a product comprising olefins and naphtha is produced. Ethylene introduced together with the two component catalyst to a second riser, for contacting ethylene with a second catalyst component which is a shape selective medium pore crystalline silicate zeolite to produce products heavier than ethylene and to increase the temperature of the catalyst to an optimum temperature for upgrading naphtha; and naphtha is introduced to the second riser, down stream of the point of ethylene introduction, for contact with the catalyst at the optimum temperature and the naphtha is upgraded to gasoline product.

  11. Drilling Fluid Contamination during Riser Drilling Quantified by Chemical and Molecular Tracers

    NASA Astrophysics Data System (ADS)

    Inagaki, F.; Lever, M. A.; Morono, Y.; Hoshino, T.

    2012-12-01

    Stringent contamination controls are essential to any type of microbiological investigation, and are particularly challenging in ocean drilling, where samples are retrieved from hundreds of meters below the seafloor. In summer 2012, Integrated Ocean Drilling Expedition 337 aboard the Japanese vessel Chikyu pioneered the use of chemical tracers in riser drilling while exploring the microbial ecosystem of coalbeds 2 km below the seafloor off Shimokita, Japan. Contamination tests involving a perfluorocarbon tracer that had been successfully used during past riserless drilling expeditions were complemented by DNA-based contamination tests. In the latter, likely microbial contaminants were targeted via quantitative polymerase chain reaction assays using newly designed, group-specific primers. Target groups included potential indicators of (a) drilling mud viscosifiers (Xanthomonas, Halomonas), (b) anthropogenic wastewater (Bifidobacterium, Blautia, Methanobrevibacter), and (c) surface seawater (SAR 11, Marine Group I Archaea). These target groups were selected based on past evidence suggesting viscosifiers, wastewater, and seawater as the main sources of microbial contamination in cores retrieved by ocean drilling. Analyses of chemical and molecular tracers are in good agreement, and indicate microorganisms associated with mud viscosifiers as the main contaminants during riser drilling. These same molecular analyses are then extended to subseafloor samples obtained during riserless drilling operations. General strategies to further reduce the risk of microbial contamination during riser and riserless drilling operations are discussed.

  12. Heat loss model for flow assurance in a deep water riser

    NASA Astrophysics Data System (ADS)

    Soetikno, Darmadi; Rodiah, Isti; Islahuddin, Muhammad; Kania, Riska A. P.; Gunawan, Agus Y.; Sukarno, Pudjo; Permadi, Asep K.; Soewono, Edy

    2014-03-01

    The study is intended to investigate the heat loss phenomenon of oil flow in a riser. This heat loss happens due to the difference between the oil temperature in a riser and the surrounding sea water temperature. It causes the formation of wax that may disturb the flow. Heat loss can be reduced by setting up an insulator in a riser or by selecting appropriate pipeline specifications. It is necessary to determine the possible locations and specifications of insulator and pipeline. A mathematical model is formulated by considering the oil temperature and its flow velocity. Assuming that the density variation is small, the fluid behaves as an incompressible fluid. Furthermore, numerical solutions with finite difference methods are presented with some hypothetical data to give an overview of how the system works. Two surrounding conditions are taken into account, i.e. with and without sea current. From the simulation, the location of wax formation can be predicted. At a certain depth region of sea, where the sea current is present, a greater heat loss take place in which wax may be formed immediately. To overcome the formation of wax, we can control the parameters such as conductivity and wall thickness of pipe.

  13. Packaged FBG sensors for real-time stress monitoring on deep-water riser

    NASA Astrophysics Data System (ADS)

    Xu, Jian; Yang, Dexing; Jiang, Yajun; Wang, Meirong; Zhai, Huailun; Bai, Yang

    2014-11-01

    The safety of under-water risers in drilling platform is of great significance. A packaged fiber Bragg grating (FBG) sensor for real-time stress monitoring is designed for the applications on oil drilling risers under 3000 meters deep water. A copper tube which is the main component of the sensor has a small hole along its axes and a groove at its each end. The bare FBG is passed through the small hole and fixed to its ends by epoxy resin. Then the copper tube is packaged by filling the groove with structural adhesive. In order to avoid that the outer water-pressure is applied on the epoxy resin through the structural adhesive, a gap between the two types of glues is left. The relationships between the stress of the riser and the tension, pressure, temperature of the single sensor are discussed, respectively. The measured tension sensitivity is 136.75 pm/KN while the minimum R-square value is 0.99997. The experimental results also show that there is a good linear response between water-pressure and the Bragg wavelength from 0 to 30MPa, and the sensor can even survive under the pressure more than 30MPa. In addition, the Bragg wavelength shifts linearly with the increasing temperature from 0 to 40°C. So, the pressure and temperature can be easily compensated if another sensor without tension is used.

  14. Interactions of multiphase hydrodynamics, droplet evaporation, and chemical kinetics in FCC riser reactors.

    SciTech Connect

    Chang, S. L.

    1998-02-17

    A computational fluid dynamics (CFD) computer code, ICRKFLO, has been developed for flow simulation of fluid catalytic cracking (FCC) riser reactors, which convert crude oil into gasoline and other valuable products. The FCC flow, especially in the entry region, is a three-phase reacting flow including hot catalyst particles, inert lift gas, and feed oil droplets. The impact of the hydrodynamics processes of heat transfer, droplet evaporation, and mixing on the chemical kinetics or riser performance can be significant. ICRKFLO was used to evaluate the impact of these processes on the performance of an advanced FCC unit. The code solves for major flow properties of all three phases in an FCC riser, with models governing the transport of catalyst particles and feed oil droplet, the vaporization of the feed oil droplets, the cracking of the oil vapor, and the formation and deposition of coke on particles. First, the code was validated against available test data of a pilot-scale FCC unit. Then, flow calculations for the FCC unit were performed. Computational results indicate that the heat transfer and droplet vaporization processes have a significant impact on the performance of a pilot-scale FCC unit. The impact is expected to be even greater on commercial scale units.

  15. Time-frequency methods for structural health monitoring of deepwater risers subjected to vortex induced vibrations

    NASA Astrophysics Data System (ADS)

    Huang, Chaojun; Sun, Peng; Nagarajaiah, Satish; Gopalakrishnan, S.

    2013-04-01

    In this paper, an approach based on a new damage index-Distributed Force Change(WDFC), for monitoring the structural health of risers used for production in deep-water floating platforms, is presented. Experiments of a scaled pipe are carried out to validate the vibration based damage identification method. The influences of multiple cracks in the WDFC damage index are studied. Futhermore, this paper demonstrates the effectiveness of wave propagation based structural health monitoring (SHM) strategies within the pipe model. This is realized based on the results of numerical investigation obtained by the use of Finite Element Method(FEM) together with application of Time-of-Flight(FoT) damage identification method in which the damage severity is indicated by Root Mean Square(RMS) of the damage-reflected wave. The influence of crack(s) in the riser/pipe on the wave propagation are studied. The results from the experiments and numerical analysis indicate that both the two damage identification methods can provide information about the estimated crack location(s) and the possible extent of crack. Hence the two methods are suitable for globally and locally monitoring the structural health of deepwater risers respectively.

  16. Laboratory measurements of vortex-induced vibrations of a vertical tension riser in a stepped current

    NASA Astrophysics Data System (ADS)

    Chaplin, J. R.; Bearman, P. W.; Huera Huarte, F. J.; Pattenden, R. J.

    2005-11-01

    This paper describes measurements of the vortex-induced vibrations of a model vertical tension riser in a stepped current. The riser, 28 mm in diameter, 13.12 m long and with a mass ratio (mass/displaced mass) of 3.0, was tested in conditions in which the lower 45% was exposed to a uniform current at speeds up to 1 m/s, while the upper part was in still water. Its response in the in-line and cross-flow directions was inferred from measurements of bending strains at 32 equally spaced points along its length. Cross-flow vibrations were observed at modes up to the 8th, with standard deviations of individual modal weights greater than 50% of the riser's diameter. Except at the lowest reduced velocities, the response included significant contributions from several modes, all at a frequency controlled by lock-in of the dominant mode. In the presence of multi-mode responses, drag coefficients were up to 120% greater than those for a stationary cylinder at the same Reynolds numbers, and like overall measures of in-line and cross-flow displacements, revealed a strong dependence on the modal composition of the motion.

  17. Obseration of flow regime transition in CFB riser using an LDV

    SciTech Connect

    Yue, Paul C.; Mei, Joseph S.; Shadle, Lawrence J.

    2011-01-01

    The solids flow in a circulating fluidized bed (CFB) riser is often described to have a core-annular structure. For a given superficial gas velocity, at the initial introduction of solids into a riser a flow structure of dilute upflow regime exists. Continuing to increase the solids flow in the riser transitions the flow structure to the core-annular flow regime. However, with further increase of solids flow a condition is reached, depending on the superficial gas velocity, where all the solids across the riser cross section flow upwards, even those at the wall. When the solids flux, solids fraction and gas velocity are relatively high, such a condition is described as the dense phase suspense upflow (DSU) regime. In this paper we report our observations of these flow regime transitions by using a laser Doppler velocimeter (LDV) to monitor the upward and downward particle flow velocities at and near the riser wall of the National Energy Technology Laboratory’s 30.4 centimeters diameter CFB cold flow model. The particles were high density polyethylene (PPE) spheres with a Sauter mean diameter of 861 micron and a density of 800 kg/m3. Three superficial gas velocities of 6.55 m/s, 10.67 m/s and 13.72 m/s were used in this study. For the case of superficial gas velocity 6.55 m/s, the experimental data show that the transition from dilute upflow to core-annular flow occurred when the solids flux was about 7 kg/m{sup 2}-s and the transition from core-annular flow to dense suspension upflow was about 147 kg/m{sup 2}-s. As the superficial gas velocity was increased to 10.67 m/s the corresponding flow regime transitions were at 34 kg/m{sup 2}-s and 205 kg/m{sup 2}-s, respectively. For the case of superficial gas velocity of 13.72 m/s the data showed no distinct transition of flow regimes. The particles were all upflow for the range of solids fluxes from 10 kg/m{sup 2}-s to 286 kg/m{sup 2}-s.

  18. Dynamic assessment of existing soft catenary systems using modal analysis to explore higher train velocities: a case study of a Norwegian contact line system

    NASA Astrophysics Data System (ADS)

    Rønnquist, Anders; Nåvik, Petter

    2015-06-01

    Significant advances made on the rolling stock have considerably increased the possibility of higher speeds in existing railways. Thus, it is important to explore higher speeds and potential limiting factors of existing soft catenary systems. The present paper investigates procedures to assess the dynamic behaviour of these systems using response sampling and modal analysis. The assessment evaluates and quantifies dynamic response along the section. To verify the approach, a case study is conducted and the following assessment methods are used: lengthwise track correlation estimating dynamic predictability, power spectral density estimations before and after passage and short-time Fourier transforms and spectrograms. The combination provides detailed information on the dynamic behaviour. The first part introduces necessary considerations for suggested modal analysis. The second part describes an existing Norwegian section. The case study is conducted using a finite element model including a straight and a given section between Oslo-Trondheim, providing detailed evaluations and system limitation detections.

  19. CFD code development for performance evaluation of a pilot-scale FCC riser reactor

    SciTech Connect

    Chang, S.L.; Lottes, S.A.; Zhou, C.Q.; Golchert, B.; Petrick, M.

    1997-09-01

    Fluid Catalytic Cracking (FCC) is an important conversion process for the refining industry. The improvement of FCC technology could have a great impact on the public in general by lowering the cost of transportation fuel. A recent review of the FCC technology development by Bienstock et al. of Exxon indicated that the use of computational fluid dynamics (CFD) simulation can be very effective in the advancement of the technology. Theologos and Markatos used a commercial CFD code to model an FCC riser reactor. National Laboratories of the U.S. Department of Energy (DOE) have accumulated immense CFD expertise over the years for various engineering applications. A recent DOE survey showed that National Laboratories are using their CFD expertise to help the refinery industry improve the FCC technology under DOE`s Cooperative Research and Development Agreement (CRADA). Among them are Los Alamos National Laboratory with Exxon and Amoco and Argonne National Laboratory (ANL) with Chevron and UOP. This abstract briefly describes the current status of ANL`s work. The objectives of the ANL CRADA work are (1) to use a CFD code to simulate FCC riser reactor flow and (2) to evaluate the impacts of operating conditions and design parameters on the product yields. The CFD code used in this work was originally developed for spray combustion simulation in early 1980 at Argonne. It has been successfully applied to diagnosing a number of multi-phase reacting flow problems in a magneto-hydrodynamic power train. A new version of the CFD code developed for the simulation of the FCC riser flow is called Integral CRacKing FLOw (ICRKFLO). The CFD code solves conservation equations of general flow properties for three phases: gaseous species, liquid droplets, and solid particles. General conservation laws are used in conjunction with rate equations governing the mass, momentum, enthalpy, and species for a multi-phase flow with gas species, liquid droplets, and solid particles.

  20. Experimental Plan for Crystal Accumulation Studies in the WTP Melter Riser

    SciTech Connect

    Miller, D.; Fowley, M.

    2015-04-28

    This experimental plan defines crystal settling experiments to be in support of the U.S. Department of Energy – Office of River Protection crystal tolerant glass program. The road map for development of crystal-tolerant high level waste glasses recommends that fluid dynamic modeling be used to better understand the accumulation of crystals in the melter riser and mechanisms of removal. A full-scale version of the Hanford Waste Treatment and Immobilization Plant (WTP) melter riser constructed with transparent material will be used to provide data in support of model development. The system will also provide a platform to demonstrate mitigation or recovery strategies in off-normal events where crystal accumulation impedes melter operation. Test conditions and material properties will be chosen to provide results over a variety of parameters, which can be used to guide validation experiments with the Research Scale Melter at the Pacific Northwest National Laboratory, and that will ultimately lead to the development of a process control strategy for the full scale WTP melter. The experiments described in this plan are divided into two phases. Bench scale tests will be used in Phase 1 (using the appropriate solid and fluid simulants to represent molten glass and spinel crystals) to verify the detection methods and analytical measurements prior to their use in a larger scale system. In Phase 2, a full scale, room temperature mockup of the WTP melter riser will be fabricated. The mockup will provide dynamic measurements of flow conditions, including resistance to pouring, as well as allow visual observation of crystal accumulation behavior.

  1. Nonlinear Analysis of a Bolted Marine Riser Connector Using NASTRAN Substructuring

    NASA Technical Reports Server (NTRS)

    Fox, G. L.

    1984-01-01

    Results of an investigation of the behavior of a bolted, flange type marine riser connector is reported. The method used to account for the nonlinear effect of connector separation due to bolt preload and axial tension load is described. The automated multilevel substructing capability of COSMIC/NASTRAN was employed at considerable savings in computer run time. Simplified formulas for computer resources, i.e., computer run times for modules SDCOMP, FBS, and MPYAD, as well as disk storage space, are presented. Actual run time data on a VAX-11/780 is compared with the formulas presented.

  2. Bed inventory overturn in a circulating fluid bed riser with pant-leg structure

    SciTech Connect

    Jinjing Li; Wei Wang; Hairui Yang; Junfu Lv; Guangxi Yue

    2009-05-15

    The special phenomenon, nominated as bed inventory overturn, in circulating fluid bed (CFB) riser with pant-leg structure was studied with model calculation and experimental work. A compounded pressure drop mathematic model was developed and validated with the experimental data in a cold experimental test rig. The model calculation results agree well with the measured data. In addition, the intensity of bed inventory overturn is directly proportional to the fluidizing velocity and is inversely proportional to the branch point height. The results in the present study provide significant information for the design and operation of a CFB boiler with pant-leg structure. 15 refs., 10 figs., 1 tab.

  3. Strategy for understanding gas-solid riser hydrodynamics and other LANL status items

    SciTech Connect

    Kashiwa, B. A.

    2002-01-01

    The talk presents the status of work in progress in the area of momentum transport theory in turbulent gas-solid multiphase flow. Previous installments have reported details of the theory, and validation results. This talk provides a grand overview of how the details of dynamic simulations in 3D, 2D, 1D and 0D, all fit together to form a consistent strategy for understanding gas-solid riser hydrodynamics. The circulating fluidized bed is the canonical example for showing how the strategy works. Performance of the procedure is shown by comparison to data recently obtained by Sandia National Laboratory. Status of other LANL efforts is also mentioned.

  4. Offshore North Sea pipeline and riser loss of containment study (PARLOC) -- applications and limitations in the assessment of operating risks

    SciTech Connect

    Robertson, J.L.M.; Smart, D.; Al-Hassan, T.

    1996-05-01

    Since the Piper Alpha disaster in 1988, there has been an urgent requirement to prevent such tragedies occurring by the introduction of higher safety standards and by improving the confidence in the statistical information available for the assessment of the risks of loss of containment associated with operation of North Sea pipelines. In order to achieve the latter, two databases have been compiled: (1) a pipeline database containing details of pipelines and risers installed in the North Sea; (2) an incident database containing details of reported occurrences (covering the period from 1975 to end 1993), which directly resulted or threatened to result in loss of containment from a pipeline or riser, The data has been compiled from information obtained from: U.K., Norwegian, Dutch and Danish Regulatory Authorities; Operators in the U.K., Dutch and Danish Sectors; reports from previous studies made available to the study; published sources. The databases have been used to perform assessments of factors affecting the frequency of incidents, such as: incident cause; part of pipeline or riser affected; pipeline or riser diameter, length, contents, age, type; whether the line is trenched or buried, piggy-backed or not; hydrotest pressure; location of pipeline or riser in the North Sea. The PARLOC study identifies potential hazards and provides an indication of likely loss of containment frequency associated with the operation of North Sea pipelines and risers. Furthermore, PARLOC provides a continually updated key reference for comparative risk assessment and ultimately for the implementation of risk control as part of an overall risk management program.

  5. IMPACT OF PARTICLE AGGLOMERATION ON ACCUMULATION RATES IN THE GLASS DISCHARGE RISER OF HLW MELTER

    SciTech Connect

    Matyas, Josef; Jansik, Danielle P.; Owen, Antionette T.; Rodriguez, Carmen P.; Lang, Jesse B.; Kruger, Albert A.

    2013-08-05

    The major factor limiting waste loading in continuous high-level radioactive waste (HLW) melters is an accumulation of particles in the glass discharge riser during a frequent and periodic idling of more than 20 days. An excessive accumulation can produce robust layers a few centimeters thick, which may clog the riser, preventing molten glass from being poured into canisters. Since the accumulation rate is driven by the size of particles we investigated with X-ray microtomography, scanning electron microscopy, and image analysis the impact of spinel forming components, noble metals, and alumina on the size, concentration, and spatial distribution of particles, and on the accumulation rate. Increased concentrations of Fe and Ni in the baseline glass resulted in the formation of large agglomerates that grew over the time to an average size of ~185±155 µm, and produced >3 mm thick layer after 120 h at 850 °C. The noble metals decreased the particle size, and therefore significantly slowed down the accumulation rate. Addition of alumina resulted in the formation of a network of spinel dendrites which prevented accumulation of particles into compact layers.

  6. Effect of particle size distribution on the hydrodynamics of dense CFB risers

    NASA Astrophysics Data System (ADS)

    Bakshi, Akhilesh; Khanna, Samir; Venuturumilli, Raj; Altantzis, Christos; Ghoniem, Ahmed

    2015-11-01

    Circulating Fluidized Beds (CFB) are favorable in the energy and chemical industries, due to their high efficiency. While accurate hydrodynamic modeling is essential for optimizing performance, most CFB riser simulations are performed assuming equally-sized solid particles, owing to limited computational resources. Even though this approach yields reasonable predictions, it neglects commonly observed experimental findings suggesting the strong effect of particle size distribution (psd) on the hydrodynamics and chemical conversion. Thus, this study is focused on the inclusion of discrete particle sizes to represent the psd and its effect on fluidization via 2D numerical simulations. The particle sizes and corresponding mass fluxes are obtained using experimental data in dense CFB riser while the modeling framework is described in Bakshi et al 2015. Simulations are conducted at two scales: (a) fine grid to resolve heterogeneous structures and (b) coarse grid using EMMS sub-grid modifications. Using suitable metrics which capture bed dynamics, this study provides insights into segregation and mixing of particles as well as highlights need for improved sub-grid models.

  7. Impact Of Particle Agglomeration On Accumulation Rates In The Glass Discharge Riser Of HLW Melter

    SciTech Connect

    Kruger, A. A.; Rodriguez, C. A.; Matyas, J.; Owen, A. T.; Jansik, D. P.; Lang, J. B.

    2012-11-12

    The major factor limiting waste loading in continuous high-level radioactive waste (HLW) melters is an accumulation of particles in the glass discharge riser during a frequent and periodic idling of more than 20 days. An excessive accumulation can produce robust layers a few centimeters thick, which may clog the riser, preventing molten glass from being poured into canisters. Since the accumulation rate is driven by the size of particles we investigated with x-ray microtomography, scanning electron microscopy, and image analysis the impact of spinel forming components, noble metals, and alumina on the size, concentration, and spatial distribution of particles, and on the accumulation rate. Increased concentrations of Fe and Ni in the baseline glass resulted in the formation of large agglomerates that grew over the time to an average size of ~185+-155 {mu}m, and produced >3 mm thick layer after 120 h at 850 deg C. The noble metals decreased the particle size, and therefore significantly slowed down the accumulation rate. Addition of alumina resulted in the formation of a network of spinel dendrites which prevented accumulation of particles into compact layers.

  8. Experience with cable-operated ultrasonic pigs for pipeline and riser pipe inspection

    SciTech Connect

    Raad, J.A. de

    1995-10-01

    In order to establish the integrity of ageing pipelines, the use of self contained intelligent pigs has become of increasing interest. For several decades, pigs using magnetic flux leakage (MFL) were the only tools available on the market for this purpose. Over the past decade also ultrasonic pigs have been developed. (Off)loading lines and open risers often only provide single sided access and are not equipped with pig launch and receive traps. For this category of pipelines, RTD developed cable operated ultrasonic pigs. This paper provides an overview of the possibilities of such cable operated pigs. Tools for distances up to 17,000 m, propelled either by reversible wheel-driven crawlers or by differential pressure, are described. These systems are suitable for pipes with diameters between 150 and 1,500 mm. A novel approach for the inspection of gas risers is also mentioned, whereby full circumferential coverage is achieved by means of an oscillating probe ring. In this approach, the pipe has been flooded with a liquid. The first successful field application of such a system has been performed in the autumn of 1992.

  9. First Riser Logging in Scientific Ocean Drilling: Operational Planning and results/reality

    NASA Astrophysics Data System (ADS)

    Sanada, Yoshinori; Kyaw Thu, Moe; Kido, Yukari; Kawamura, Yoshihisa; Hino, Ryota; Eguchi, Nabuhisa; Toczko, Sean; Takahashi, Kyoma; 319 Science Party, Iodp

    2010-05-01

    The first wireline logging, downhole stress measurement, and two-ship walkaway VSP (Vertical Seismic Profiling) were conducted in the riser drilled hole during IODP Expedition 319 in 2009. The hole C0009 is first riser drilling hole in ODP/IODP history by JAMSTEC D/V Chikyu. The expedition 319 is one of series of NanTroSEIZE Project, which goal is to reveal earthquake mechanism in Nankai trough seismogenic zone in Japan. The hole C0009 is drilled at TD 1603.7mbsf under 2054m sea water. Sampling cores, cutting analysis, gas monitoring, wireline logging, downhole stress measurement, and two-ship walkaway VSP (Vertical Seismic Profiling) were conducted. This presentation report the operational planning, results and reality. IODP standard wireline logging items: natural gamma-ray, resistivity, density, porosity, sonic velocity, resistivity image were measured. The advantages of riser dilled hole against riserless drilled hole for wireline logging are 1) stable hole condition, 2) accurate environmental correction by controlled drilling mud, and 3) large variation of tool selection because of regular hole size instead of slimhole by conventional IODP riser drilling. A couple of new tools were used for new measurement and improvement of the data quality. The SonicScanner (trademark of Schulumberger) successfully measured compressional and share velocity in very low velocities at the soft sediment, where it has been difficult to measure them with conventional DSI tool. The stress and pore pressure in the borehole were measured with the wireline logging tool, (Schlumberger MDT). The single probe tool enable to measure temporal formation fluid pressure. The double packer tool enable to fracture test by sealing and pumping in the borehole. These in-situ measurement and stress experiment data are very important to understand physical properties and mechanism of fault zone. Super long offset walkaway VSP was conducted to reveal detail subsurface structure and velocity

  10. Early Risers

    ERIC Educational Resources Information Center

    Asquith, Chistina

    2002-01-01

    In this article, the author features Bard High School Early College, the first public school in the country to offer a free, full-time college curriculum--and all the credits that go with it--to high schoolers. In Bard's four-year program, students race through high school requirements in 9th and 10th grades, then take college courses in 11th and…

  11. Parent Participation within Community Center or In-Home Outreach Delivery Models of the Early Risers Conduct Problems Prevention Program

    ERIC Educational Resources Information Center

    Bloomquist, Michael L; August, Gerald J.; Lee, Susanne S.; Piehler, Timothy F.; Jensen, Marcia

    2012-01-01

    A variety of predictors of parent participation in prevention programming have been identified in past research, but few studies have investigated how those predictors may vary by implementation context. Patterns of parent participation were examined in the Early Risers Conduct Problems Prevention Program using two family-focused service delivery…

  12. Laboratory measurements of vortex- and wake-induced vibrations of a tandem arrangement of two flexible risers

    NASA Astrophysics Data System (ADS)

    Liu, Huai-zeng; Wang, Fei; Jiang, Guo-sheng; Guo, Hai-yan; Li, Xiao-min

    2016-03-01

    The dynamic response of two flexible model risers in tandem arrangement immersed in a stepped current was analyzed. The risers, with an external diameter of 20 mm and a total length of 6200 mm, had an aspect ratio of 310. They were hinged to the support structure at the center-to-center distances away 3-12 times the external diameter. The top 1200 mm was exposed to a uniform current at a speed which was up to 0.9 m/s (the Reynolds number was 18000) and the rest in still water. The dynamic responses, which were obtained through the Fiber Bragg Grating strain gauges mounted on the surface, were analyzed by studying the cross-flow amplitudes and modal weights. The cross-flow vibration were observed up to the third mode, and the modal transformation from the second mode to the third mode was clearly observed. The experiment confirmed that the typical vortex-induced vibration (VIV) had occurred on the up-stream riser. But for the down-stream riser, the main excitation mechanism was wake-induced vibration (WIV). The modal transformation of WIV was more complex than that of VIV, which might be helpful for other researchers to study the interference effect.

  13. 75 FR 26091 - Safety Zone; Riser for DEEPWATER HORIZON at Mississippi Canyon 252 Outer Continental Shelf MODU...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-11

    ... safety zone around the riser will significantly reduce the threat of collisions, oil spills, and releases...-54W. The regulation will reduce significantly the threat of collisions, allisions, oil spills, and... is needed to protect persons and vessels in the vicinity of the oil spill. Discussion of Rule...

  14. Secondary School Reform, Inclusion, and Authentic Assessment. Research Institute on Secondary Education Reform (RISER) for Youth with Disabilities Brief.

    ERIC Educational Resources Information Center

    Braden, Jeffery P.; Schroeder, Jennifer L.; Buckley, Jacquelyn A.

    The Research Institute on Secondary Education Reform for Youth with Disabilities (RISER) has identified Schools of Authentic and Inclusive Learning (SAIL) to explore whether and how secondary students with disabilities are included in secondary education reform. In this brief, the literature describing the intersection of reform, inclusion, and…

  15. Evaluating fluvial terrace riser degradation using LiDAR-derived topography: An example from the northern Tian Shan, China

    NASA Astrophysics Data System (ADS)

    Wei, Zhanyu; Arrowsmith, J. Ramon; He, Honglin

    2015-06-01

    The morphological degradation of fluvial terrace risers provides a constraint to terrace chronology. In this study, we morphologically date the terrace risers along the Kuitun River on the north flank of the Tian Shan, China and subsequently discuss possible relationships between terrace formation and the past regional climate changes and tectonic activity of the Dushanzi fault-related fold. To do this, 159 topographic profile swaths of terrace risers were extracted from LiDAR-derived DEM and were analysed to determine a range of best fitting morphological ages. Through Monte Carlo simulation, a locally applicable sediment transport coefficient (diffusivity) was calibrated as 5.5 ± 1.6 m2/ky given the morphological age of the T1/T2 riser and its independently known age. Taking this calibrated coefficient, we estimate age ranges of 11.6 ± 3.4 ka, 6.5 ± 1.4 ka, 5.3 ± 1.1 ka, and 4.2 ± 1.2 ka for terraces T3, T4, T5, and T6, respectively, under the assumption that the age of the riser is close to the abandonment age of the lower surface. These new terrace ages, combining climate proxy records from the oxygen isotope curve from the Guliya ice cap and paleoearthquake events in the Dushanzi fault related fold, suggest that tectonic activity may be an important factor in the formation of lower terraces within the growing anticlines, while in more extensive areas beyond anticlines, climate changes controlled the main deposition and incision events in the present study area, and thus terrace formation of T1-T3.

  16. Analytical and numerical models to predict the behavior of unbonded flexible risers under torsion

    NASA Astrophysics Data System (ADS)

    Ren, Shao-fei; Xue, Hong-xiang; Tang, Wen-yong

    2016-04-01

    This paper presents analytical and numerical models to predict the behavior of unbonded flexible risers under torsion. The analytical model takes local bending and torsion of tensile armor wires into consideration, and equilibrium equations of forces and displacements of layers are deduced. The numerical model includes lay angle, cross-sectional profiles of carcass, pressure armor layer and contact between layers. Abaqus/Explicit quasi-static simulation and mass scaling are adopted to avoid convergence problem and excessive computation time caused by geometric and contact nonlinearities. Results show that local bending and torsion of helical strips may have great influence on torsional stiffness, but stress related to bending and torsion is negligible; the presentation of anti-friction tapes may have great influence both on torsional stiffness and stress; hysteresis of torsion-twist relationship under cyclic loading is obtained by numerical model, which cannot be predicted by analytical model because of the ignorance of friction between layers.

  17. Impact of the Circulating Fluidized Bed Riser on the Performance of a Loopseal Nonmechanical Valve

    SciTech Connect

    Monazam, E.R.; Shadle, L.J.; Mei, J.S.

    2007-03-14

    Most advanced coal-fuel power systems require the transfer and control of solids between two or more vessels. In many instances, the key to a successful process operation is how well the solids transfer and control system has been designed. This is particularly true in a transport gasifier and circulating fluidized bed (CFB) combustors, which are dependent upon the rapid and reliable circulation of solids to maintain a constant solids concentration in the CFB. Proper design and operation of solids returning systems are essential to the performance and operation of CFB combustion systems. An experimental investigation was conducted at the National Energy Technology Laboratory (NETL) of the U.S. Department of Energy (DOE) to study the flow and control of a light material (cork), which has a particle density of 189 kg/m3 and a mean diameter of 812 ím, through a nonmechanical valve, or loopseal, in a 0.3 m diameter CFB cold model. Fluidizing this material in ambient air approximates the same gas:solids density ratio as coal and coal char in a pressurized gasifier. The loopseal is composed of the lower section of the standpipe, an upward-flowing fluidized-bed section, and a downwardly angled overflow tube which is connected to the desired return point at the bottom of the riser. In the nonmechanical valve, both the standpipe and the fluidized-bed up-flow section of the loopseal were aerated and fluidized with air, respectively. The objective of this study was to investigate the effects of standpipe aeration, loopseal aeration, solids inventory, and superficial gas velocity through the riser on the flow rate of circulating solids. A correlation that predicts the solids flow rate as a function of these variables was developed. Comparison of the correlation with the experimental data is discussed. Pressure drop across the fluidized-bed up-flow section of the loopseal was found to increase slightly with the solid flow rates.

  18. Static analysis of offshore risers with a geometrically-exact 3D beam model subjected to unilateral contact

    NASA Astrophysics Data System (ADS)

    Neto, Alfredo Gay; Martins, Clóvis A.; Pimenta, Paulo M.

    2014-01-01

    In offshore applications there are elements that can be modeled as long beams, such as umbilical cables, flexible and rigid pipes and hoses, immersed in the sea water, suspended from the floating unit to the seabed. The suspended part of these elements is named "riser" and is subjected to the ocean environment loads, such as waves and sea current. This work presents a structural geometrically-exact 3D beam model, discretized using the finite element method for riser modeling. An updated Lagrangian framework for the rotation parameterization has been used for the description of the exact kinematics. The goal is to perform a complete static analysis, considering the oceanic loads and the unilateral contact with the seabed, extending the current standard analysis for situations in which very large rotations occurs, in particular, large torsion. Details of the nonlinear 3D model and loads from oceanic environment are discussed, including the contact unilateral constraint.

  19. Evolution of terrace risers along the upper Rhine graben inferred from morphologic dating methods: evidence of climatic and tectonic forcing

    NASA Astrophysics Data System (ADS)

    Nivière, B.; Marquis, Guy

    2000-06-01

    We show that morphologic dating techniques that have been applied successfully in arid and semi-arid areas are also suitable for slowly evolving scarps that are usually found in temperate climate environments. We have attempted two morphologic approaches, based on diffusion, to relate the present-day shape of an abandoned terrace riser to its age. The first assumes a model of scarp degradation based on a diffusive process (the D method). The second evaluates the state of scarp degradation using the slope distribution (the SD method) along a topographic profile. By using a manmade scarp of known age, we have obtained a mass diffusivity close to 1.4m2ka-1 when the area experiences a temperate climate characterized by a continuous vegetation cover. However, this value decreases during glacial episodes, probably on account of the permafrost. Even though the SD method requires an age correction that can be easily computed, only this method reveals that at several profiles a later scarp reactivation event has occurred. Indeed, along several profiles, the slope distribution was best fitted by two offset Gaussian curves, suggesting that some scarps have undergone a complex evolution that cannot be modelled with a single diffusive process. This scarp reactivation may correspond to a new incisive episode and allows one to estimate the vertical incision rate along the terrace riser. Applied to a Wurmian terrace riser of the upper Rhine valley (NE France), this approach reveals that the vertical incision rate ranges from 0.2 to 0.85mmyr-1 between 35 and 15ka and that the terrace bevelling occurred during two episodes related to climatic forcing. Moreover, we can identify a component of tectonic forcing evidenced by an increase to the north of vertical incision rate and Rhine stream-power. Another major result is showing that this terrace riser is not isochronous along its strike and that younger portions result from lateral incision of a 30ka pre-existing scarp.

  20. Identification of a scaled-model riser dynamics through a combined computer vision and adaptive Kalman filter approach

    NASA Astrophysics Data System (ADS)

    Trigo, F. C.; Martins, F. P. R.; Fleury, A. T.; Silva, H. C.

    2014-02-01

    Aiming at overcoming the difficulties derived from the traditional camera calibration methods to record the underwater environment of a towing tank where experiments of scaled-model risers are carried on, a computer vision method, combining traditional image processing algorithms and a self-calibration technique was implemented. This method was used to identify the coordinates of control-points viewed on a scaled-model riser submitted to a periodic force applied to its fairlead attachment point. To study the observed motion, the riser was represented as a pseudo-rigid body model (PRBM) and the hypotheses of compliant mechanisms theory were assumed in order to cope with its elastic behavior. The derived Lagrangian equations of motion were linearized and expressed as a state-space model in which the state variables include the generalized coordinates and the unknown generalized forces. The state-vector thus assembled is estimated through a Kalman Filter. The estimation procedure allows the determination of both the generalized forces and the tension along the cable, with statistically proven convergence.

  1. High-Resolution Simulations of Gas-Solids Jet Penetration Into a High Density Riser Flow

    SciTech Connect

    Li, Tingwen

    2011-05-01

    High-resolution simulations of a gas-solids jet in a 0.3 m diameter and 15.9 m tall circulating fluidized bed (CFB) riser were conducted with the open source software-MFIX. In the numerical simulations, both gas and solids injected through a 1.6 cm diameter radial-directed tube 4.3 m above the bottom distributor were tracked as tracers, which enable the analysis of the characteristics of a two-phase jet. Two jetting gas velocities of 16.6 and 37.2 m/s were studied with the other operating conditions fixed. Reasonable flow hydrodynamics with respect to overall pressure drop, voidage, and solids velocity distributions were predicted. Due to the different dynamic responses of gas and particles to the crossflow, a significant separation of gas and solids within the jet region was predicted for both cases. In addition, the jet characteristics based on tracer concentration and tracer mass fraction profiles at different downstream levels are discussed. Overall, the numerical predictions compare favorably to the experimental measurements made at NETL.

  2. Yield improvement and defect reduction in steel casting

    SciTech Connect

    Kent Carlson

    2004-03-16

    This research project investigated yield improvement and defect reduction techniques in steel casting. Research and technology development was performed in the following three specific areas: (1) Feeding rules for high alloy steel castings; (2) Unconventional yield improvement and defect reduction techniques--(a) Riser pressurization; and (b) Filling with a tilting mold; and (3) Modeling of reoxidation inclusions during filling of steel castings. During the preparation of the proposal for this project, these areas were identified by the High Alloy Committee and Carbon and Low Alloy Committee of the Steel Founders' Society of America (SFSA) as having the highest research priority to the steel foundry industry. The research in each of the areas involved a combination of foundry experiments, modeling and simulation. Numerous SFSA member steel foundries participated in the project through casting trials and meetings. The technology resulting from this project will result in decreased scrap and rework, casting yield improvement, and higher quality steel castings produced with less iteration. This will result in considerable business benefits to steel foundries, primarily due to reduced energy and labor costs, increased capacity and productivity, reduced lead-time, and wider use and application of steel castings. As estimated using energy data provided by the DOE, the technology produced as a result of this project will result in an energy savings of 2.6 x 10{sup 12} BTU/year. This excludes the savings that were anticipated from the mold tilting research. In addition to the energy savings, and corresponding financial savings this implies, there are substantial environmental benefits as well. The results from each of the research areas listed above are summarized.

  3. An experimental study of the hydrodynamics and cluster formation in a circulating fluidized-bed riser. Semi-annual report, July 1, 1992--December 31, 1992

    SciTech Connect

    Gautam, M.; Jurewicz, J.T.; Johnson, E.K.; Heping, Y.

    1993-01-01

    A novel gas-solid flow measuring technique is being developed and tested for studying the hydrodynamics inside the riser of a Circulating Fluidized Bed (CFB). First of the two aims of the overall program, namely, design, development and testing of the technique to characterize the particle and gas velocities in two-phase flows was accomplished in the past year. The second objective, that of making detailed measurements of gas and solid phases in the rises of a cold CFB model to investigate the phenomena of clusters and streamers for different bed operating parameters is being accomplished in the current year. The differential pressure fluctuations were in order to study the solids cluster formation. Of the several factors which lead to differential pressure fluctuations, the solids cluster formation in CFB riser is by far the most important of all. Simultaneously, theoretical formulation of the two-phase flow in the CFB riser was initiated. The concept of entropy maximization is being applied to explain the hydrodynamics inside the riser. The results from this study will present a unique detailed description of the complex gas-solid behavior in the CFB riser.

  4. Numerical study of spray injection effects on the heat transfer and product yields of FCC riser reactors.

    SciTech Connect

    Chang, S. L.; Lottes, S. A.; Zhou, C. Q.; Bowman, B. J.; Petrick, M.; Energy Systems; Purdue Univ. at Calumet

    2001-06-01

    A three-phase reacting flow computational fluid dynamics (CFD) computer code was used to study the major effects of spray injection parameters on mixing, heat transfer, vaporization, and reaction product yields in fluidized catalytic cracking (FCC) riser reactors. The CFD code was validated using experimental or field data. A number of computations were performed with varied injection parameters, including injection velocity, injection angle, and droplet size. Local optimum operating windows for spray injection parameters were identified, and the sensitivity of local optima to variation in spray parameters was also investigated.

  5. IODP Expedition 338: Riser and Riserless Drilling Along the NanTroSEIZE Transect

    NASA Astrophysics Data System (ADS)

    Strasser, M.; Moore, G. F.; Dugan, B.; Kanagawa, K.; Toczko, S.

    2013-12-01

    Integrated Ocean Drilling Program (IODP) Expedition 338 provided new constraints on the Kumano Basin sediments, the accretionary prism inner wedge, the seaward extension of the megasplay fault, the architecture and mechanics of landslides, and the alteration of oceanic basement of the incoming Philippine Sea plate. This was accomplished through riser and riserless drilling, logging while drilling (LWD), and cuttings and core analysis. Cuttings and LWD analyses at Hole C0002F reveal two lithologic units in the prism inner wedge which are separated by a prominent fault zone at ~1640 mbsf. Mud-gases from the inner prism show high concentrations at the top of the wedge that decrease, but become more thermogenic, with depth. These data are from the previously unaccessed deeper part of the Nankai accretionary prism. Riserless coring at Site C0002 provided data across the gas hydrate zone of the Kumano Basin, across the Kumano Basin-accretionary prism unconformity, and in the uppermost accretionary prism. Within the Kumano basin section, gas and porewater geochemistry documents microbial methane gas in hydrates that are disseminated in sandy layers. Multiple penetrations of the Kumano Basin-accretionary prism boundary and 3D seismic data show that the boundary is erosive and complex. LWD (Site C0018) and coring and LWD (Site C0021) augment existing data to better understand submarine landslide dynamics and mass-transport deposit (MTD) emplacement processes. Previous coring at Site C0018 identified six MTDs, but only two MTD intervals were detected in resistivity images that show high angle, randomly oriented bedding. Site C0021, located more proximal to the MTD source, provides constraint on MTD variability. Correlation across the sites reveals a thick MTD with an erosional base characterized by a shear zone in muddy sediments vs. a translational basal surface within coarse volcaniclastic sand in the proximal and distal/lateral areas, respectively. LWD data and cores from

  6. Effect of catalyst additives on the production of biofuels from palm oil cracking in a transport riser reactor.

    PubMed

    Chew, Thiam Leng; Bhatia, Subhash

    2009-05-01

    Catalytic cracking of crude palm oil (CPO) and used palm oil (UPO) were studied in a transport riser reactor for the production of biofuels at a reaction temperature of 450 degrees C, with residence time of 20s and catalyst-to-oil ratio (CTO) of 5 gg(-1). The effect of HZSM-5 (different Si/Al ratios), beta zeolite, SBA-15 and AlSBA-15 were studied as physically mixed additives with cracking catalyst Rare earth-Y (REY). REY catalyst alone gave 75.8 wt% conversion with 34.5 wt% of gasoline fraction yield using CPO, whereas with UPO, the conversion was 70.9 wt% with gasoline fraction yield of 33.0 wt%. HZSM-5, beta zeolite, SBA-15 and AlSBA-15 as additives with REY increased the conversion and the yield of organic liquid product. The transport riser reactor can be used for the continuous production of biofuels from cracking of CPO and UPO over REY catalyst. PMID:19138514

  7. Effect of bidirectional internal flow on fluid-structure interaction dynamics of conveying marine riser model subject to shear current

    NASA Astrophysics Data System (ADS)

    Chen, Zheng-Shou; Kim, Wu-Joan

    2012-03-01

    This article presents a numerical investigation concerning the effect of two kinds of axially progressing internal flows (namely, upward and downward) on fluid-structure interaction (FSI) dynamics about a marine riser model which is subject to external shear current. The CAE technology behind the current research is a proposed FSI solution, which combines structural analysis software with CFD technology together. Efficiency validation for the CFD software was carried out first. It has been proved that the result from numerical simulations agrees well with the observation from relating model test cases in which the fluidity of internal flow is ignorable. After verifying the numerical code accuracy, simulations are conducted to study the vibration response that attributes to the internal progressive flow. It is found that the existence of internal flow does play an important role in determining the vibration mode (/dominant frequency) and the magnitude of instantaneous vibration amplitude. Since asymmetric curvature along the riser span emerges in the case of external shear current, the centrifugal and Coriolis accelerations owing to up- and downward internal progressive flows play different roles in determining the fluid-structure interaction response. The discrepancy between them becomes distinct, when the velocity ratio of internal flow against external shear current is relatively high.

  8. Maintenance Effects of an Evidence-Based Prevention Innovation for Aggressive Children Living in Culturally Diverse Urban Neighborhoods: The Early Risers Effectiveness Study

    ERIC Educational Resources Information Center

    August, Gerald J.; Lee, Susanne S.; Bloomquist, Michael L.; Realmuto, George M.; Hektner, Joel M.

    2004-01-01

    The present study assessed the ability of the Early Risers' Skills for Success Program to maintain program effects 1 year post intervention. Participants were 327 kindergarten and first-grade children who screened positive for aggressive behavior and who were randomized to program and control conditions. Program children participated in 2…

  9. Development of Millimeter-Wave Velocimetry and Acoustic Time-of-Flight Tomography for Measurements in Densely Loaded Gas-Solid Riser Flow

    SciTech Connect

    Fort, James A.; Pfund, David M.; Sheen, David M.; Pappas, Richard A.; Morgen, Gerald P.

    2007-04-01

    The MFDRC was formed in 1998 to advance the state-of-the-art in simulating multiphase turbulent flows by developing advanced computational models for gas-solid flows that are experimentally validated over a wide range of industrially relevant conditions. The goal was to transfer the resulting validated models to interested US commercial CFD software vendors, who would then propagate the models as part of new code versions to their customers in the US chemical industry. Since the lack of detailed data sets at industrially relevant conditions is the major roadblock to developing and validating multiphase turbulence models, a significant component of the work involved flow measurements on an industrial-scale riser contributed by Westinghouse, which was subsequently installed at SNL. Model comparisons were performed against these datasets by LANL. A parallel Office of Industrial Technology (OIT) project within the consortium made similar comparisons between riser measurements and models at NETL. Measured flow quantities of interest included volume fraction, velocity, and velocity-fluctuation profiles for both gas and solid phases at various locations in the riser. Some additional techniques were required for these measurements beyond what was currently available. PNNL’s role on the project was to work with the SNL experimental team to develop and test two new measurement techniques, acoustic tomography and millimeter-wave velocimetry. Acoustic tomography is a promising technique for gas-solid flow measurements in risers and PNNL has substantial related experience in this area. PNNL is also active in developing millimeter wave imaging techniques, and this technology presents an additional approach to make desired measurements. PNNL supported the advanced diagnostics development part of this project by evaluating these techniques and then by adapting and developing the selected technology to bulk gas-solids flows and by implementing them for testing in the SNL riser

  10. First time real-time mud gas monitoring during riser drilling in the Kumano Basin (IODP Exp 319)

    NASA Astrophysics Data System (ADS)

    Wiersberg, T.; Erzinger, J.; Horiguchi, K.; Saffer, D. M.; Byrne, T. B.; McNeill, L. C.; Araki, E.; Takahashi, K.; Eguchi, N. O.; Toczko, S.

    2009-12-01

    Chikyu Expedition 319 was the first cruise of the Integrated Ocean Drilling Program (IODP) where riser drilling was performed and real-time mud gas monitoring was conducted, because this technique requires drill-mud circulation. In contrast to conventional IODP drilling that uses drill water in combination with lost circulation, during riser drilling the drill mud returns back to the surface through a riser pipe which encases the drill pipe. The dissolved gas is extracted from returning drill mud, analyzed in real time and sampled for noble gas and stable isotopes studies. This technique has been applied in the past on scientific continental drilling projects of e.g. the International Continental Drilling Program. Expedition 319 is part of the NanTroSEIZE project, a multiexpedition, multistage IODP drilling program focused on understanding the mechanics of seismogenesis and ruptures propagation along the Nankai accretionary prism. Riser drilling was carried out on Hole C0009 that intersects the cover sediments of the Kumano Basin and probably penetrates into the accretionary prism below. Site NT2-11 is located approx. 60 km SE of the harbour of Shingu, Japan. Real-time mud gas monitoring was performed in Hole C0009 during drilling from 703 mbsf (meter below sea floor) down to 1594 mbsf and during hole enlargement from 703 mbsf to 1569 mbsf. Both datasets show similar gas distribution at depth. Gas was furthermore extracted, sampled and analyzed from drill cuttings. Drill mud gas is generally composed of air and gases that derive from the formation. The principal formation gas in drill mud from both drilling phases and in cuttings was methane. Up to 14 vol % CH4 was detected during drilling and up to 3 vol % during hole enlargement. Down to 800 mbsf and below 1280 mbsf, the methane concentration in drill mud is lower than in the surrounded interval, where methane peaks at several depths. At 1280 mbsf an unconformity is indicated from lihology, in seismic and

  11. Method and apparatus for production of subsea hydrocarbon formations

    DOEpatents

    Blandford, Joseph W.

    1992-01-01

    A well tender system for controlling, separating, storing and offloading well fluids produced from subsea hydrocarbon formations. The system comprises a vertically aligned series of tethered cylindrical tanks which are torsionally stabilized by flexible catenary production riser and expert riser bundles, and serviced by separate catenary pipe bundles. Piles are secured to the seabed, each pile assembly being pivotally connected to a lower rigid tendon, which is in turn connected to tendons arranged about the periphery of the interconnected cylindrical tanks.

  12. Method and apparatus for production of subsea hydrocarbon formations

    DOEpatents

    Blandford, Joseph W.

    1994-01-01

    A well tender system for controlling, separating, storing and offloading well fluids produced from subsea hydrocarbon formations. The system comprises a vertically aligned series of tethered cylindrical tanks which are torsionally stabilized by flexible catenary production riser and export riser bundles, and serviced by separate catenary pipe bundles. Piles are secured to the seabed, each pile assembly being pivotally connected to a lower rigid tendon, which is in turn connected to tendons arranged about the periphery of the interconnected cylindrical tanks.

  13. Two-year outcomes of the Early Risers prevention trial with formerly homeless families residing in supportive housing.

    PubMed

    Gewirtz, Abigail H; DeGarmo, David S; Lee, Susanne; Morrell, Nicole; August, Gerald

    2015-04-01

    This article reports 2-year outcomes from a cluster randomized, controlled trial of the Early Risers (ER) program implemented as a selective preventive intervention in supportive housing settings for homeless families. Based on the goals of this comprehensive prevention program, we predicted that intervention participants receiving ER services would show improvement in parenting and child outcomes relative to families in treatment-as-usual sites. The sample included 270 children in 161 families, residing in 15 supportive housing sites; multimethod, multi-informant assessments conducted at baseline and yearly thereafter included parent and teacher report of child adjustment, parent report of parenting self-efficacy, and parent-child observations that yielded scores of effective parenting practices. Data were modeled in HLM7 (4-level model accounting for nesting of children within families and families within housing sites). Two years' postbaseline, intent-to-treat (ITT) analyses indicated that parents in the ER group showed significantly improved parenting self-efficacy, and parent report indicated significant reductions in ER group children's depression. No main effects of ITT were shown for observed parenting effectiveness. However, over time, average levels of parenting self-efficacy predicted observed effective parenting practices, and observed effective parenting practices predicted improvements in both teacher- and parent-report of child adjustment. This is the first study to our knowledge to demonstrate prevention effects of a program for homeless families residing in family supportive housing. PMID:25844493

  14. Large deflection response of restrained steel beams under fire and explosion loads.

    PubMed

    Xi, Feng

    2016-01-01

    A numerical study on the response of steel beams to fire and explosion is presented in this paper. First, a unified computing model, which can be used to simulate the behaviour of beams under four loading scenarios that involve fire and explosion or impact, is constructed. The proposed technique allows complete transparency of the influence of the various parameters on the structural behaviour. Second, the effects of load level on critical temperature are analyzed for various static and explosion load ratios. Two cases of explosion and fire loading sequences are compared, it is shown that the critical temperature of the beam subjected to fire followed by an explosion is lower than that of the beam subjected to an explosion followed by fire. The influence of temperature on the p-i diagram is investigated, an iso-damage surface is introduced to distinguish safe and unsafe regions. Third, the limiting temperature criteria are further examined. That is, the first and second limiting temperatures can be determined when the dimensional catenary force is equal to zero or to one, which corresponds to the bending or stretching plastic hinge, respectively. PMID:27386235

  15. Supertough Stainless Bearing Steel

    NASA Technical Reports Server (NTRS)

    Olson, Gregory B.

    1995-01-01

    Composition and processing of supertough stainless bearing steel designed with help of computer-aided thermodynamic modeling. Fracture toughness and hardness of steel exceeds those of other bearing steels like 440C stainless bearing steel. Developed for service in fuel and oxidizer turbopumps on Space Shuttle main engine. Because of strength and toughness, also proves useful in other applications like gears and surgical knives.

  16. Measurement of Gas Velocities in the Presence of Solids in the Riser of a Cold Flow Circulating Fluidized Bed

    SciTech Connect

    Spenik, J.; Ludlow, J.C.; Compston, R.; Breault, R.W.

    2007-01-01

    The local gas velocity and the intensity of the gas turbulence in a gas/solid flow are a required measurement in validating the gas and solids flow structure predicted by computational fluid dynamic (CFD) models in fluid bed and transport reactors. The high concentration and velocities of solids, however, make the use of traditional gas velocity measurement devices such as pitot tubes, hot wire anemometers and other such devices difficult. A method of determining these velocities has been devised at the National Energy Technology Laboratory employing tracer gas. The technique developed measures the time average local axial velocity gas component of a gas/solid flow using an injected tracer gas which induces changes in the heat transfer characteristics of the gas mixture. A small amount of helium is injected upstream a known distance from a self-heated thermistor. The thermistor, protected from the solids by means of a filter, is exposed to gases that are continuously extracted from the flow. Changes in the convective heat transfer characteristics of the gas are indicated by voltage variations across a Wheatstone bridge. When pulsed injections of helium are introduced to the riser flow the change in convective heat transfer coefficient of the gas can be rapidly and accurately determined with this instrument. By knowing the separation distance between the helium injection point and the thermistor extraction location as well as the time delay between injection and detection, the gas velocity can easily be calculated. Variations in the measured gas velocities also allow the turbulence intensity of the gas to be estimated.

  17. Modeling of porosity formation and feeding flow during casting of steel and aluminum alloys

    NASA Astrophysics Data System (ADS)

    Lin, Zhiping

    Porosity is one of the most important defects in metal casting. To quantitatively predict the porosity formation during casting two numerical models are developed for steel and aluminum alloys respectively. For steel, a multi-phase model is developed that predicts melt pressure, feeding flow, porosity (both microscopic and macroscopic), and riser pipe formation during casting. The phases included in the model are solid, liquid, porosity, and air. An energy equation is solved to determine solid fraction. A multi-phase momentum equation, which is valid everywhere in the solution domain, is derived. A pressure equation is then derived from this momentum equation and a mixture continuity equation developed that accounts for all phases. The partial pressure of a gas species dissolved in the melt is determined using the species concentration, which is found by solving a species conservation equation that accounts for convection. Porosity forms once the gas pressure exceeds the sum of the melt pressure and the capillary pressure. The amount of porosity that forms is determined from the mixture continuity equation. The riser pipe is determined from an air continuity equation. A pore size model, which considers the effects of the solidifying steel microstructure on pore size, is incorporated into the multi-phase model. The multi-phase model is applied to one-dimensional, two-dimensional, and three-dimensional simulations. The results clearly illustrate the basic physical phenomena involved and predict microporosity and macroporosity distributions, as well as a riser pipe. For aluminum alloys a gas microsegregation model is developed to quantitatively predict porosity, coupled with the calculations of the pressure field, feeding flow, and distribution of dissolved gas species throughout the casting. The effects of dendritic and eutectic microstructure on the pore shape and size are considered in a pore size model. The model is applied to one-dimensional simulations of A319

  18. Safety Investigation of Liquid-Metal-Cooled Nuclear Systems with Heat Exchanger in the Risers of Simple Flow-Path Pool Design

    SciTech Connect

    Carlsson, Johan; Wider, Hartmut U.

    2005-12-15

    Safety investigations were performed on 600- and 1426-MW(thermal) liquid-metal-cooled reactors with the heat exchangers (HXs) located in the risers of simple flow-path pool designs. This includes both critical reactors and accelerator-driven systems (ADSs) using liquid-metal coolants. For the 600-MW(thermal) ADS, the safety implications were examined for vessel sizes of two heights (11 and 15 m) and two diameters (6 and 10 m). Then, the reference design of 11-m height and 6-m diameter was compared with a similar design, but with the HXs located in the downcomers. The transients investigated were total-loss-of-power (TLOP), unprotected-loss-of-flow (ULOF), protected-loss-of-flow, and unprotected loss-of-heat-sink accidents. The 600-MW(thermal) ADS of 11-m height and 6-m diameter peaks at 1041 K after 29 h during a TLOP accident. If the diameter is increased to 10 m, it will peak after 55 h at a 178 K lower temperature thanks to its larger thermal inertia. The difference between locating the HXs in the risers and the downcomers is insignificant for this accident type. With the HXs in the risers, the temperature peaks at 1045 K after 28 h. During a ULOF accident in an ADS at full power, the core outlet temperature stabilizes at 1010 K, which is 337 K above the nominal outlet temperature. When the vessel height is increased to 15 m, the natural convection is improved, and the core outlet temperature stabilizes at 911 K. A Pb-cooled 1426-MW(thermal) reactor of 11-m height and 12-m diameter is also shown to be sufficiently coolable during a TLOP accident; i.e., it peaks at 1093 K after 49 h. In a pool-type design with a simple flow path, the use of HXs in the risers and flaps at their inlets that prevent a flow reversal will have significant safety advantages in case of HX tube failures. Steam or gas bubbles exiting from the secondary circuit cannot be dragged into the core region by the liquid-metal coolant. Instead, they would rise with the coolant and exit through the

  19. Ultrahigh carbon steels, Damascus steels, and superplasticity

    SciTech Connect

    Sherby, O.D.; Wadsworth, J.

    1997-04-01

    The processing properties of ultrahigh carbon steels (UHCSs) have been studied at Stanford University over the past twenty years. These studies have shown that such steels (1 to 2.1% C) can be made superplastic at elevated temperature and can have remarkable mechanical properties at room temperature. It was the investigation of these UHCSs that eventually brought us to study the myths, magic, and metallurgy of ancient Damascus steels, which in fact, were also ultrahigh carbon steels. These steels were made in India as castings, known as wootz, possibly as far back as the time of Alexander the Great. The best swords are believed to have been forged in Persia from Indian wootz. This paper centers on recent work on superplastic UHCSs and on their relation to Damascus steels. 32 refs., 6 figs.

  20. Supporting steel

    SciTech Connect

    Badra, C.

    1995-10-01

    The US Department of Energy (DOE) and the American Iron and Steel Institute (AISI) have just completed a pilot program on the technical and economic viability of direct ironmaking by a process based on bath smelting. In this process, oxygen, prereduced iron ore pellets, coal, and flux are charged into a molten slag bath containing a high percentage of carbon. The carbon removes oxygen from the iron ore and generates carbon monoxide and liquid iron. Oxygen is then injected to burn some of the carbon monoxide gas before it leaves the smelting vessel. The partially combusted gas is sued to preheat and prereduced the ore before it is injected into the bath. There are several competing cokeless ironmaking processes in various stages of development around the world. A brief comparison of these processes provides a useful perspective with which to gauge the progress and objectives of the AISI-DOE research initiative. The principal competing foreign technologies include the Corex process, DIOS, HIsmelt, and Jupiter. The advantages of the direct ironmaking process examined by AISI-DOE were not sufficiently demonstrated to justify commercialization without further research. However, enough knowledge was gained from laboratory and pilot testing to teach researchers how to optimize the direct ironmaking process and to provide the foundation for future research. Researchers now better understand issues such as the dissolution of materials, reduction mechanisms and rates, slag foaming and control, the behavior of sulfur, dust generation, and the entire question of energy efficiency--including post combustion and the role of coal/volatile matter.

  1. Comminuting irradiated ferritic steel

    DOEpatents

    Bauer, Roger E.; Straalsund, Jerry L.; Chin, Bryan A.

    1985-01-01

    Disclosed is a method of comminuting irradiated ferritic steel by placing the steel in a solution of a compound selected from the group consisting of sulfamic acid, bisulfate, and mixtures thereof. The ferritic steel is used as cladding on nuclear fuel rods or other irradiated components.

  2. Welding Rustproof Steels

    NASA Technical Reports Server (NTRS)

    Hoffmann, W

    1929-01-01

    The following experimental results will perhaps increase the knowledge of the process of welding rustproof steels. The experiments were made with two chrome-steel sheets and with two chrome-steel-nickel sheets having the composition shown in Table I.

  3. The steel scrap age.

    PubMed

    Pauliuk, Stefan; Milford, Rachel L; Müller, Daniel B; Allwood, Julian M

    2013-04-01

    Steel production accounts for 25% of industrial carbon emissions. Long-term forecasts of steel demand and scrap supply are needed to develop strategies for how the steel industry could respond to industrialization and urbanization in the developing world while simultaneously reducing its environmental impact, and in particular, its carbon footprint. We developed a dynamic stock model to estimate future final demand for steel and the available scrap for 10 world regions. Based on evidence from developed countries, we assumed that per capita in-use stocks will saturate eventually. We determined the response of the entire steel cycle to stock saturation, in particular the future split between primary and secondary steel production. During the 21st century, steel demand may peak in the developed world, China, the Middle East, Latin America, and India. As China completes its industrialization, global primary steel production may peak between 2020 and 2030 and decline thereafter. We developed a capacity model to show how extensive trade of finished steel could prolong the lifetime of the Chinese steelmaking assets. Secondary steel production will more than double by 2050, and it may surpass primary production between 2050 and 2060: the late 21st century can become the steel scrap age. PMID:23442209

  4. Methods of forming steel

    DOEpatents

    Branagan, Daniel J.; Burch, Joseph V.

    2001-01-01

    In one aspect, the invention encompasses a method of forming a steel. A metallic glass is formed and at least a portion of the glass is converted to a crystalline steel material having a nanocrystalline scale grain size. In another aspect, the invention encompasses another method of forming a steel. A molten alloy is formed and cooled the alloy at a rate which forms a metallic glass. The metallic glass is devitrified to convert the glass to a crystalline steel material having a nanocrystalline scale grain size. In yet another aspect, the invention encompasses another method of forming a steel. A first metallic glass steel substrate is provided, and a molten alloy is formed over the first metallic glass steel substrate to heat and devitrify at least some of the underlying metallic glass of the substrate.

  5. Vertical Seismic Profiling at riser drilling site in the rupture area of the 1944 Tonankai Earthquake, Japan (Invited)

    NASA Astrophysics Data System (ADS)

    Hino, R.; Kinoshita, M.; Araki, E.; Byrne, T. B.; McNeill, L. C.; Saffer, D. M.; Eguchi, N. O.; Takahashi, K.; Toczko, S.

    2009-12-01

    A series of scientific drilling expeditions is in operation in the Nankai Trough to reveal the faulting mechanism of the magathrust earthquakes, through clarifying composition, fine structure, mechanical behavior, and environmental variables of the seismogenic faults. In the studied area, extensive seismic surveys for site characterization have been made to image detailed geometry of the fault complex in the accretionary prism as well as Vp distribution around the faults. Although these previous surveys provided invaluable information for understanding seismotectonic processes in this subduction zone, more complete knowledge is needed to be acquired to predict dynamic behavior of the faults, such as geometrical irregularities in short wavelength, Vs and seismic attenuation which are sensitive to fluid distribution in and around fault zones. It is expected that estimation of these parameters would be improved considerably by a seismic exploration using a vertical array of seismographs installed in a deep borehole (VSP: vertical seismic profiling). In July 2009, we made a VSP at one of the drilling sites located just above the rupture area of the 1994 Tonankai Earthquake (M 8.1), during the IODP Exp.319. The well site of our VSP was made by the riser drilling of D/V Chikyu. The seismic array, lowered from Chikyu into the hole, was composed of a three-component accelerometer and vertical separation of the array elements was 15.12 m. The VSP was composed of offset VSP and zero-offset VSP. In the offset VSP, a tuned airgun array towed by R/V Kairei was shot along one straight line (walk-away VSP) and another circular line (walk-around VSP) and seismic signals were recorded by an array consisting of 16 elements installed from 907 to 1,135 m in depth from seafloor. The object of the walk-away VSP is to obtain fine image of the faults using reflection arrivals with less attenuation. It is also expected to obtain spatial variation of Vs from arrival time tomography of

  6. Accretion process of sediments below Kumano basin by analyzing cuttings from IODP Exp.319, the first riser drilling

    NASA Astrophysics Data System (ADS)

    Kawabata, K.; Sakaguchi, A.; Kitamura, Y.; Saito, S.

    2012-12-01

    The structure, stress condition and rock properties of accreted sediments in the Nankai Trough have been studied by reflection seismology and deep sea drillings. Accretion processes have been suggested by onland geological studies that the sediments are circulated with undergoing lithification and deformation along thrusts in shallow subduction zone driven by the plate motion. However the process in the modern Nankai Trough has yet to be elucidated. We discuss the accretion process of the shallow Nankai Trough accretionary prism below Kumano basin by clarifying thermal structure and materials by vitrinite measurement and whole rock chemical analyses, respectively, using cuttings samples from IODP The Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) the first scientific riser drilling Expedition 319 at Site C0009. Cuttings were collected with an interval of every 5 m from 703.9 to 1604 m and cores were recovered from 1509.7 m to 1593.9 m below sea floor (mbsf). Due to poor consolidation of drilled sediments, cuttings samples typically consist of sand and silt floating in a matrix of mixed sedimentary and drilling muds, and solid rock chips were not retrieved above 802.7 mbsf. Visual description based on macro- and micro-scopic observation, XRD and XRF analysis, rocks properties and the age of washed cuttings (i.e. grains without mud) were made throughout the hole, which allowed to establish some indexes to estimate lithology. Four lithologic units (Unit I - IV) were defined at Site C0009 based on compositional and textural variations of cuttings samples, which are believed to closely reflect lithologic changes of drilled sequences, and show good consistency with logging data. Unit IV is believed to be accreted sediment by mainly age and the textural change of sediments. Dissoluble component ratios (TiO2/P2O5) and clay content ratios in the samples analyzed by XRF and XRD are different from that in basin sediment, which might support Unit IV are accreted

  7. Going-to-Scale with the Early Risers Conduct Problems Prevention Program: Use of a Comprehensive Implementation Support (CIS) System to Optimize Fidelity, Participation and Child Outcomes

    PubMed Central

    Bloomquist, Michael L.; August, Gerald J.; Lee, Susanne S.; Lee, Chih-Yuan S.; Realmuto, George M.; Klimes-Dougan, Bonnie

    2012-01-01

    The present study is a descriptive report of a comprehensive implementation support (CIS) service that was used to promote high levels of program fidelity in a going-to-scale intervention trial of the Early Risers conduct problems prevention program. The program was delivered across 27 geographically-dispersed, elementary school sites over a two-year period. In this study we examined the level of fidelity achieved by program implementers across intervention components, the rate of child and parent participation across intervention components, and proximal child outcomes targeted by the intervention across two years of programming. Results showed that over the two-year intervention period the program was implemented with high fidelity, participation rates were acceptable, and children made positive gains on target outcomes similar to those found in previous randomized controlled trials. The results suggest that implementation support services may be advantageous in the wide-scale implementation of prevention programs that aim to achieve high implementation fidelity. PMID:23266400

  8. Tool steels. 5. edition

    SciTech Connect

    Roberts, G.; Krauss, G.; Kennedy, R.

    1998-12-31

    The revision of this authoritative work contains a significant amount of new information from the past nearly two decades presented in an entirely new outline, making this a must have reference for engineers involved in tool-steel production, as well as in the selection and use of tool steels in metalworking and other materials manufacturing industries. The chapter on tool-steel manufacturing includes new production processes, such as electroslag refining, vacuum arc remelting, spray deposition processes (Osprey and centrifugal spray), and powder metal processing. The seven chapters covering tool-steel types in the 4th Edition have been expanded to 11 chapters covering nine main groups of tool steels as well as other types of ultrahigh strength steels sometimes used for tooling. Each chapter discusses in detail processing, composition, and applications specific to the particular group. In addition, two chapters have been added covering surface modification and trouble shooting production and performance problems.

  9. Experimental Study of the Vortex-Induced Vibration of Drilling Risers under the Shear Flow with the Same Shear Parameter at the Different Reynolds Numbers

    PubMed Central

    Liangjie, Mao; Qingyou, Liu; Shouwei, Zhou

    2014-01-01

    A considerable number of studies for VIV under the uniform flow have been performed. However, research on VIV under shear flow is scarce. An experiment for VIV under the shear flow with the same shear parameter at the two different Reynolds numbers was conducted in a deep-water offshore basin. Various measurements were obtained by the fiber bragg grating strain sensors. Experimental data were analyzed by modal analysis method. Results show several valuable features. First, the corresponding maximum order mode of the natural frequency for shedding frequency is the maximum dominant vibration mode and multi-modal phenomenon is appeared in VIV under the shear flow, and multi-modal phenomenon is more apparent at the same shear parameter with an increasing Reynolds number under the shear flow effect. Secondly, the riser vibrates at the natural frequency and the dominant vibration frequency increases for the effect of the real-time tension amplitude under the shear flow and the IL vibration frequency is the similar with the CF vibration frequency at the Reynolds number of 1105 in our experimental condition and the IL dominant frequency is twice the CF dominant frequency with an increasing Reynolds number. In addition, the displacement trajectories at the different locations of the riser appear the same shape and the shape is changed at the same shear parameter with an increasing Reynolds number under the shear flow. The diagonal displacement trajectories are observed at the low Reynolds number and the crescent-shaped displacement trajectories appear with an increasing Reynolds number under shear flow in the experiment. PMID:25118607

  10. Experimental study of the vortex-induced vibration of drilling risers under the shear flow with the same shear parameter at the different Reynolds numbers.

    PubMed

    Liangjie, Mao; Qingyou, Liu; Shouwei, Zhou

    2014-01-01

    A considerable number of studies for VIV under the uniform flow have been performed. However, research on VIV under shear flow is scarce. An experiment for VIV under the shear flow with the same shear parameter at the two different Reynolds numbers was conducted in a deep-water offshore basin. Various measurements were obtained by the fiber bragg grating strain sensors. Experimental data were analyzed by modal analysis method. Results show several valuable features. First, the corresponding maximum order mode of the natural frequency for shedding frequency is the maximum dominant vibration mode and multi-modal phenomenon is appeared in VIV under the shear flow, and multi-modal phenomenon is more apparent at the same shear parameter with an increasing Reynolds number under the shear flow effect. Secondly, the riser vibrates at the natural frequency and the dominant vibration frequency increases for the effect of the real-time tension amplitude under the shear flow and the IL vibration frequency is the similar with the CF vibration frequency at the Reynolds number of 1105 in our experimental condition and the IL dominant frequency is twice the CF dominant frequency with an increasing Reynolds number. In addition, the displacement trajectories at the different locations of the riser appear the same shape and the shape is changed at the same shear parameter with an increasing Reynolds number under the shear flow. The diagonal displacement trajectories are observed at the low Reynolds number and the crescent-shaped displacement trajectories appear with an increasing Reynolds number under shear flow in the experiment. PMID:25118607

  11. Catenary nanostructures as compact Bessel beam generators.

    PubMed

    Li, Xiong; Pu, Mingbo; Zhao, Zeyu; Ma, Xiaoliang; Jin, Jinjin; Wang, Yanqin; Gao, Ping; Luo, Xiangang

    2016-01-01

    Non-diffracting Bessel beams, including zero-order and high-order Bessel Beams which carry orbital angular momentum (OAM), enable a variety of important applications in optical micromanipulation, sub-diffraction imaging, high speed photonics/quantum communication, etc. The commonly used ways to create Bessel beams, including an axicon or a digital hologram written to a spatial light modulator (SLM), have great challenges to operate at the nanoscale. Here we theoretically design and experimentally demonstrate one kind of planar Bessel beam generators based on metasurfaces with analytical structures perforated in ultra-thin metallic screens. Continuous phase modulation between 0 to 2π is realized with a single element. In addition, due to the dispersionless phase shift stemming from spin-orbit interaction, the proposed device can work in a wide wavelength range. The results may find applications in future optical communication, nanofabrication and super-resolution imaging, etc. PMID:26843142

  12. Catenary nanostructures as compact Bessel beam generators

    NASA Astrophysics Data System (ADS)

    Li, Xiong; Pu, Mingbo; Zhao, Zeyu; Ma, Xiaoliang; Jin, Jinjin; Wang, Yanqin; Gao, Ping; Luo, Xiangang

    2016-02-01

    Non-diffracting Bessel beams, including zero-order and high-order Bessel Beams which carry orbital angular momentum (OAM), enable a variety of important applications in optical micromanipulation, sub-diffraction imaging, high speed photonics/quantum communication, etc. The commonly used ways to create Bessel beams, including an axicon or a digital hologram written to a spatial light modulator (SLM), have great challenges to operate at the nanoscale. Here we theoretically design and experimentally demonstrate one kind of planar Bessel beam generators based on metasurfaces with analytical structures perforated in ultra-thin metallic screens. Continuous phase modulation between 0 to 2π is realized with a single element. In addition, due to the dispersionless phase shift stemming from spin-orbit interaction, the proposed device can work in a wide wavelength range. The results may find applications in future optical communication, nanofabrication and super-resolution imaging, etc.

  13. Catenary nanostructures as compact Bessel beam generators

    PubMed Central

    Li, Xiong; Pu, Mingbo; Zhao, Zeyu; Ma, Xiaoliang; Jin, Jinjin; Wang, Yanqin; Gao, Ping; Luo, Xiangang

    2016-01-01

    Non-diffracting Bessel beams, including zero-order and high-order Bessel Beams which carry orbital angular momentum (OAM), enable a variety of important applications in optical micromanipulation, sub-diffraction imaging, high speed photonics/quantum communication, etc. The commonly used ways to create Bessel beams, including an axicon or a digital hologram written to a spatial light modulator (SLM), have great challenges to operate at the nanoscale. Here we theoretically design and experimentally demonstrate one kind of planar Bessel beam generators based on metasurfaces with analytical structures perforated in ultra-thin metallic screens. Continuous phase modulation between 0 to 2π is realized with a single element. In addition, due to the dispersionless phase shift stemming from spin-orbit interaction, the proposed device can work in a wide wavelength range. The results may find applications in future optical communication, nanofabrication and super-resolution imaging, etc. PMID:26843142

  14. Steel Industry Wastes.

    ERIC Educational Resources Information Center

    Schmidtke, N. W.; Averill, D. W.

    1978-01-01

    Presents a literature review of wastes from steel industry, covering publications of 1976-77. This review covers: (1) coke production; (2) iron and steel production; (3) rolling operations; and (4) surface treatment. A list of 133 references is also presented. (NM)

  15. Modern Steel Framed Schools.

    ERIC Educational Resources Information Center

    American Inst. of Steel Construction, Inc., New York, NY.

    In view of the cost of structural framing for school buildings, ten steel-framed schools are examined to review the economical advantages of steel for school construction. These schools do not resemble each other in size, shape, arrangement or unit cost; some are original in concept and architecture, and others are conservative. Cost and…

  16. The Steel Band.

    ERIC Educational Resources Information Center

    Weil, Bruce

    1996-01-01

    Describes studying the steel drum, an import from Trinidad, as an instrument of intellectual growth. Describes how developing a steel drum band provided Montessori middle school students the opportunity to experience some important feelings necessary to emotional growth during this difficult age: competence, usefulness, independence, and…

  17. EAST ELEVATION, LTV STEEL (FORMERLY REPUBLIC STEEL), 8" BAR MILL, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EAST ELEVATION, LTV STEEL (FORMERLY REPUBLIC STEEL), 8" BAR MILL, BUFFALO PLANT. VIEW LOOKING SOUTHWEST FROM ROLL SHOP. 8" BAR MILL DESIGNED AND BUILT BY DONNER STEEL CO. (PREDECESSOR OF REPUBLIC), 1919-1920. FOR DESCRIPTION OF ORIGINAL MILL SEE "IRON AGE", 116\\4 (23 JULY 1925): 201-204. - LTV Steel, 8-inch Bar Mill, Buffalo Plant, Buffalo, Erie County, NY

  18. Nuclear transmutation in steels

    NASA Astrophysics Data System (ADS)

    Belozerova, A. R.; Shimanskii, G. A.; Belozerov, S. V.

    2009-05-01

    The investigations of the effects of nuclear transmutation in steels that are widely used in nuclear power and research reactors and in steels that are planned for the application in thermonuclear fusion plants, which are employed under the conditions of a prolonged action of neutron irradiation with different spectra, made it possible to study the effects of changes in the isotopic and chemical composition on the tendency of changes in the structural stability of these steels. For the computations of nuclear transmutation in steels, we used a program complex we have previously developed on the basis of algorithms for constructing branched block-type diagrams of nuclide transformations and for locally and globally optimizing these diagrams with the purpose of minimizing systematic errors in the calculation of nuclear transmutation. The dependences obtained were applied onto a Schaeffler diagram for steels used for structural elements of reactors. For the irradiation in fission reactors, we observed only a weak influence of the effects of nuclear transmutation in steels on their structural stability. On the contrary, in the case of irradiation with fusion neutrons, a strong influence of the effects of nuclear transmutation in steels on their structural stability has been noted.

  19. Structural Amorphous Steels

    NASA Astrophysics Data System (ADS)

    Lu, Z. P.; Liu, C. T.; Thompson, J. R.; Porter, W. D.

    2004-06-01

    Recent advancement in bulk metallic glasses, whose properties are usually superior to their crystalline counterparts, has stimulated great interest in fabricating bulk amorphous steels. While a great deal of effort has been devoted to this field, the fabrication of structural amorphous steels with large cross sections has remained an alchemist’s dream because of the limited glass-forming ability (GFA) of these materials. Here we report the discovery of structural amorphous steels that can be cast into glasses with large cross-section sizes using conventional drop-casting methods. These new steels showed interesting physical, magnetic, and mechanical properties, along with high thermal stability. The underlying mechanisms for the superior GFA of these materials are discussed.

  20. Glass Stronger than Steel

    DOE R&D Accomplishments Database

    Yarris, Lynn

    2011-03-28

    A new type of damage-tolerant metallic glass, demonstrating a strength and toughness beyond that of steel or any other known material, has been developed and tested by a collaboration of researchers from Berkeley Lab and Caltech.

  1. Cobalt free maraging steel

    SciTech Connect

    Floreen, S.

    1984-04-17

    The subject invention is directed to ferrous-base alloys, particularly to a cobalt-free maraging steel of novel chemistry characterized by a desired combination of strength and toughness, notwithstanding that cobalt is non-essential.

  2. Fractographic Analysis of Weld Metal and HAZ Regions of API X-80 Steel Subjected to Simulation of the Reel-Lay Method

    NASA Astrophysics Data System (ADS)

    Beltrão, M. A. N.; Bastian, F. L.

    2014-10-01

    The reel-lay method is a process commonly used for rigid riser installation. During this process, riser materials are subjected to high strain levels and associated plastic damage which can affect their structural integrity. The aim of this work was to evaluate the fracture surfaces at weld metal and heat-affected zone regions of API X-80 steel three-point bend specimens, SE(B), subjected to reel-lay method simulations. The pre-existence of circumferential planar defects at 12 o'clock position was considered and the J-integral was used to simulate the reel-lay condition at the defects. Different strain levels considering conditions less and more severe than the real one were also studied. The results showed a great influence of J magnitude on fracture surface morphology. The increase of J magnitude led to a greater local surface damage on the specimens and stable crack growth during reel-lay simulation. High loading conditions should be avoided in the operation in order to prevent further structural damage of the materials.

  3. Life after Steel

    ERIC Educational Resources Information Center

    Mangan, Katherine

    2013-01-01

    Bobby Curran grew up in a working-class neighborhood in Baltimore, finished high school, and followed his grandfather's steel-toed bootprints straight to Sparrows Point, a 3,000-acre sprawl of industry on the Chesapeake Bay. College was not part of the plan. A gritty but well-paying job at the RG Steel plant was Mr. Curran's ticket to a secure…

  4. Full time-domain nonlinear coupled dynamic analysis of a truss spar and its mooring/riser system in irregular wave

    NASA Astrophysics Data System (ADS)

    Yang, MinDong; Teng, Bin; Xiao, LongFei; Ning, DeZhi; Shi, ZhongMin; Qu, Yan

    2014-01-01

    A new full time-domain nonlinear coupled method has been established and then applied to predict the responses of a Truss Spar in irregular wave. For the coupled analysis, a second-order time-domain approach is developed to calculate the wave forces, and a finite element model based on rod theory is established in three dimensions in a global coordinate system. In numerical implementation, the higher-order boundary element method (HOBEM) is employed to solve the velocity potential, and the 4th-order Adams-Bashforth-Moultn scheme is used to update the second-order wave surface. In deriving convergent solutions, the hull displacements and mooring tensions are kept consistent at the fairlead and the motion equations of platform and mooring-lines/risers are solved simultaneously using Newmark- β integration scheme including Newton-Raphson iteration. Both the coupled quasi-static analysis and the coupled dynamic analysis are performed. The numerical simulation results are also compared with the model test results, and they coincide very well as a whole. The slow-drift responses can be clearly observed in the time histories of displacements and mooring tensions. Some important characteristics of the coupled responses are concluded.

  5. Active tectonics in southern Xinjiang, China: Analysis of terrace riser and normal fault scarp degradation along the Hotan-Qira fault system

    NASA Technical Reports Server (NTRS)

    Avouac, Jean-Philippe; Peltzer, Gilles

    1993-01-01

    The northern piedmont of the western Kunlun mountains (Xinjiang, China) is marked at its easternmost extremity, south of the Hotan-Qira oases, by a set of normal faults trending N50E for nearly 70 km. Conspicuous on Landsat and SPOT images, these faults follow the southeastern border of a deep flexural basin and may be related to the subsidence of the Tarim platform loaded by the western Kunlun northward overthrust. The Hotan-Qira normal fault system vertically offsets the piedmont slope by 70 m. Highest fault scarps reach 20 m and often display evidence for recent reactivations about 2 m high. Successive stream entrenchments in uplifted footwallls have formed inset terraces. We have leveled topographic profiles across fault scarps and transverse abandoned terrace risers. The state of degradation of each terrace edge has been characterized by a degradation coefficient tau, derived by comparison with analytical erosion models. Edges of highest abandoned terraces yield a degradation coefficient of 33 +/- 4 sq.m. Profiles of cumulative fault scarps have been analyzed in a similar way using synthetic profiles generated with a simple incremental fault scarp model.

  6. Voidage and pressure profile characteristics of sand-iron ore-coal-FCC single-particle systems in the riser of a pilot plant circulating fluidized bed

    SciTech Connect

    Das, M.; Meikap, B.C.; Saha, R.K.

    2008-06-15

    Hydrodynamic behaviors of single system of particles were investigated in a circulating fluidized bed (CFB) unit. Particles belonging to Geldart groups A and B like sand of various sizes (90, 300, 417, 522, 599, and 622 mu m), FCC catalyst (120 mu m), iron ore (166 and 140 {mu} m), and coal (335 and 168 {mu} m) were used to study the hydrodynamic characteristics. Superficial air velocity used in the present study ranged between 2.01 and 4.681 m/s and corresponding mass fluxes were 12.5-50 kg/(m{sup 2} s). A CFB needs the creation of some special hydrodynamic conditions, namely a certain combination of superficial gas velocity, solids circulation rate, particle diameter, density of particle, etc. which can give rise to a state wherein the solid particles are subjected to an upward velocity greater than the terminal or free fall velocity of the majority of the individual particles. The hydrodynamics of the bed was investigated in depth and theoretical analysis is presented to support the findings. Based on gas-solid momentum balance in the riser, a distinction between apparent and real voidage has been made. The effects of acceleration and friction on the real voidage have been estimated. Results indicated a 0.995 voidage for higher superficial gas velocity of 4.681. m/s.

  7. Active tectonics in southern Xinjiang, China: Analysis of terrace riser and normal fault scarp degradation along the Hotan-Qira fault system

    SciTech Connect

    Avouac, J.P.; Peltzer, G. |

    1993-12-01

    The northern piedmont of the western Kunlun mountains (Xinjiang, China) is marked at its easternmost extremity, south of the Hotan-Qira oases, by a set of normal faults trending N50E for nearly 70 km. Conspicuous on Landsat and SPOT images, these faults follow the southeastern border of a deep flexural basin and may be related to the subsidence of the Tarim platform loaded by the western Kunlun northward overthrust. The Hotan-Qira normal fault system vertically offsets the piedmont slope by 70 m. Highest fault scarps reach 20 m and often display evidence for recent reactivations about 2 m high. Successive stream entrenchments in uplifted footwallls have formed inset terraces. We have leveled topographic profiles across fault scarps and transverse abandoned terrace risers. The state of degradation of each terrace edge has been characterized by a degradation coefficient tau, derived by comparison with analytical erosion models. Edges of highest abandoned terraces yield a degradation coefficient of 33 +/- 4 sq.m. Profiles of cumulative fault scarps have been analyzed in a similar way using synthetic profiles generated with a simple incremental fault scarp model.

  8. Articles comprising ferritic stainless steels

    DOEpatents

    Rakowski, James M.

    2016-06-28

    An article of manufacture comprises a ferritic stainless steel that includes a near-surface region depleted of silicon relative to a remainder of the ferritic stainless steel. The article has a reduced tendency to form an electrically resistive silica layer including silicon derived from the steel when the article is subjected to high temperature oxidizing conditions. The ferritic stainless steel is selected from the group comprising AISI Type 430 stainless steel, AISI Type 439 stainless steel, AISI Type 441 stainless steel, AISI Type 444 stainless steel, and E-BRITE.RTM. alloy, also known as UNS 44627 stainless steel. In certain embodiments, the article of manufacture is a fuel cell interconnect for a solid oxide fuel cell.

  9. Profiles in garbage: Steel cans

    SciTech Connect

    Miller, C.

    1998-02-01

    Steel mills are the largest market for steel cans. Integrated mills use the basic oxygen process to manufacture tinplate, appliances, car bodies, and steel framing. Electric arc furnaces use 100% scrap to produce steel shapes such as railroad ties and bridge spans. Electric arc furnaces are more geographically diverse and tend to have smaller capacities than basic oxygen furnaces. Detinners remove the tin from steel cans for resale to tin using industries. With less tin use in steel cans, the importance of the detinning market has declined substantially. Foundries use scrap as a raw material in making castings and molds for industrial users.

  10. View northwest, wharf A, sheet steel bulkhead, steel lift tower ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View northwest, wharf A, sheet steel bulkhead, steel lift tower - U.S. Coast Guard Sandy Hook Station, Western Docking Structure, West of intersection of Canfield Road & Hartshorne Drive, Highlands, Monmouth County, NJ

  11. Continuous steel production and apparatus

    DOEpatents

    Peaslee, Kent D.; Peter, Jorg J.; Robertson, David G. C.; Thomas, Brian G.; Zhang, Lifeng

    2009-11-17

    A process for continuous refining of steel via multiple distinct reaction vessels for melting, oxidation, reduction, and refining for delivery of steel continuously to, for example, a tundish of a continuous caster system, and associated apparatus.

  12. Brazing titanium to stainless steel

    NASA Technical Reports Server (NTRS)

    Batista, R. I.

    1980-01-01

    Titanium and stainless-steel members are usually joined mechanically for lack of any other effective method. New approach using different brazing alloy and plating steel member with nickel resolves problem. Process must be carried out in inert atmosphere.

  13. Alloyed steel wastes utilization

    SciTech Connect

    Sokol, I.V.

    1995-12-31

    Alloyed steel chips and swarf formed during metal processing are looked upon as additional raw materials in metallurgical production. This paper presents some new methods for steel waste chips and swarf cleaning. One of them is swarf and steel chips cleaning in tetrachloroethylene with ultrasonic assistance and solvent regeneration. Thermal cleaning of waste chips and swarf provides off gas products utilization. The catalyst influence of the metal surface on the thermal decomposition of liquid hydrocarbons during the cleaning process has been studied. It has been determined that the efficiency of this metal waste cleaning technique depends on the storage time of the swarf. The waste chips and swarf cleaning procedures have been proven to be economically advantageous and environmentally appropriate.

  14. A-3 steel work completed

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Stennis Space Center engineers celebrated a key milestone in construction of the A-3 Test Stand on April 9 - completion of structural steel work. Workers with Lafayette (La.) Steel Erector Inc. placed the last structural steel beam atop the stand during a noon ceremony attended by more than 100 workers and guests.

  15. Biodegradation of 2,4,6-trichlorophenol in a packed-bed biofilm reactor equipped with an internal net draft tube riser for aeration and liquid circulation.

    PubMed

    Jesús, A Gómez-De; Romano-Baez, F J; Leyva-Amezcua, L; Juárez-Ramírez, C; Ruiz-Ordaz, N; Galíndez-Mayer, J

    2009-01-30

    For the aerobic biodegradation of the fungicide and defoliant 2,4,6-trichlorophenol (2,4,6-TCP), a bench-scale packed-bed bioreactor equipped with a net draft tube riser for liquid circulation and oxygenation (PB-ALR) was constructed. To obtain a high packed-bed volume relative to the whole bioreactor volume, a high A(D)/A(R) ratio was used. Reactor's downcomer was packed with a porous support of volcanic stone fragments. PB-ALR hydrodynamics and oxygen mass transfer behavior was evaluated and compared to the observed behavior of the unpacked reactor operating as an internal airlift reactor (ALR). Overall gas holdup values epsilon(G), and zonal oxygen mass transfer coefficients determined at various airflow rates in the PB-ALR, were higher than those obtained with the ALR. When comparing mixing time values obtained in both cases, a slight increment in mixing time was observed when reactor was operated as a PB-ALR. By using a mixed microbial community, the biofilm reactor was used to evaluate the aerobic biodegradation of 2,4,6-TCP. Three bacterial strains identified as Burkholderia sp., Burkholderia kururiensis and Stenotrophomonas sp. constituted the microbial consortium able to cometabolically degrade the 2,4,6-TCP, using phenol as primary substrate. This consortium removed 100% of phenol and near 99% of 2,4,6-TCP. Mineralization and dehalogenation of 2,4,6-TCP was evidenced by high COD removal efficiencies ( approximately 95%), and by the stoichiometric release of chloride ions from the halogenated compound ( approximately 80%). Finally, it was observed that the microbial consortium was also capable to metabolize 2,4,6-TCP without phenol as primary substrate, with high removal efficiencies (near 100% for 2,4,6-TCP, 92% for COD and 88% for chloride ions). PMID:18539387

  16. Research and development of rapid hydrogenation for coal conversion to synthetic motor fuels (riser cracking of coal). Final report, April 1, 1976-September 30, 1980

    SciTech Connect

    Duncan, D. A.; Beeson, J. L.; Oberle, R. D.

    1981-02-01

    The objective of the program described was to develop a noncatalytic process for the hydropyrolysis of lignite and coal to produce high-octane blending gasoline constituents, methane, ethane, and carbon oxides. The process would operate in a balanced plant mode, using spent char to generate process hydrogen by steam-oxygen gasification. The technical program included the construction and operating of a bench-scale unit (5-10 lb/hr), the design, construction, and operation of a process development unit (PDU) (100 lb/hr), and a final technical and economic assessment of the process, called Riser Cracking of Coal. In the bench-scale unit program, 143 runs were made investigating the effects of pressure, temperature, heating rate, residence time, and particle size, processing North Dakota lignite in hydrogen. Some runs were made in which the hydrogen was preheated to pyrolysis temperatures prior to contact with the coal, and, also, in which steam was substituted for half of the hydrogen. Attempts to operate the bench-scale unit at 1200 psig and 1475/sup 0/F were not successful. Depth of carbon conversion was found to be influenced by hydrogen pressure, hydrogen-to-coal ratio, and the severity of the thermal treatment. The composition of hydrocarbon liquids produced was found to change with severity. At low severity, the liquids contained sizable fractions of phenols and cresols. At high severity, the fraction of phenols and cresols was much reduced, with an attendant increase in BTX. In operating the PDU, it was necessary to use more oxygen than was planned to achieve pyrolysis temperatures because of heat losses, and portions of hydrocarbon products were lost through combustion with a large increase in carbon oxide yields. Economic studies, however, showed that selling prices for gasoline blending stock, fuel oil, and fuel gas are competitive in current markets, so that the process is held to warrant further development.

  17. Microbial-Influenced Corrosion of Corten Steel Compared with Carbon Steel and Stainless Steel in Oily Wastewater by Pseudomonas aeruginosa

    NASA Astrophysics Data System (ADS)

    Mansouri, Hamidreza; Alavi, Seyed Abolhasan; Fotovat, Meysam

    2015-07-01

    The microbial corrosion behavior of three important steels (carbon steel, stainless steel, and Corten steel) was investigated in semi petroleum medium. This work was done in modified nutrient broth (2 g nutrient broth in 1 L oily wastewater) in the presence of Pseudomonas aeruginosa and mixed culture (as a biotic media) and an abiotic medium for 2 weeks. The behavior of corrosion was analyzed by spectrophotometric and electrochemical methods and at the end was confirmed by scanning electron microscopy. The results show that the degree of corrosion of Corten steel in mixed culture, unlike carbon steel and stainless steel, is less than P. aeruginosa inoculated medium because some bacteria affect Corten steel less than other steels. According to the experiments, carbon steel had less resistance than Corten steel and stainless steel. Furthermore, biofilm inhibits separated particles of those steels to spread to the medium; in other words, particles get trapped between biofilm and steel.

  18. Braze alloy spreading on steel

    NASA Technical Reports Server (NTRS)

    Siewert, T. A.; Heine, R. W.; Lagally, M. G.

    1978-01-01

    Scanning electron microscopy (SEM) and Auger electron microscopy (AEM) were employed to observe elemental surface decomposition resulting from the brazing of a copper-treated steel. Two types of steel were used for the study, stainless steel (treated with a eutectic silver-copper alloy), and low-carbon steel (treated with pure copper). Attention is given to oxygen partial pressure during the processes; a low enough pressure (8 x 10 to the -5th torr) was found to totally inhibit the spreading of the filler material at a fixed heating cycle. With both types of steel, copper treatment enhanced even spreading at a decreased temperature.

  19. Sensitization of stainless steel

    NASA Technical Reports Server (NTRS)

    Nagy, James P.

    1990-01-01

    The objective of this experiment is to determine the corrosion rates of 18-8 stainless steels that have been sensitized at various temperatures and to show the application of phase diagrams. The laboratory instructor will assign each student a temperature, ranging from 550 C to 1050 C, to which the sample will be heated. Further details of the experimental procedure are detailed.

  20. Special steel production on common carbon steel production line

    NASA Astrophysics Data System (ADS)

    Pi, Huachun; Han, Jingtao; Hu, Haiping; Bian, Ruisheng; Kang, Jianjun; Xu, Manlin

    2004-06-01

    The equipment and technology of small bar tandem rolling line of Shijiazhuang Iron & Steel Co. in China has reached the 90's international advanced level in the 20th century, but products on the line are mostly of common carbon steel. Currently there are few steel plants in China to produce 45 steel bars for cold drawing, which is a kind of shortage product. Development of 45 steel for cold drawing has a wide market outlook in China. In this paper, continuous cooling transformation (CCT) curve of 45 steel for cold drawing used for rolling was set out first. According to the CCT curve, we determined some key temperature points such as Ac3 temperature and Ac1 temperature during the cooling procedure and discussed the precipitation microstructure at different cooling rate. Then by studying thermal treatment process of 45 steel bars for cold drawing, the influence of cooling time on microstructure was analyzed and the optimum cooling speed has been found. All results concluded from the above studies are the basis of regulating controlled cooling process of 45 steel bars for cold drawing. Finally, the feasible production process of 45 steel bars for cold drawing on common carbon steel production line combined with the field condition was recommended.

  1. Ferritic steel melt and FLiBe/steel experiment : melting ferritic steel.

    SciTech Connect

    Troncosa, Kenneth P.; Smith, Brandon M.; Tanaka, Tina Joan

    2004-11-01

    In preparation for developing a Z-pinch IFE power plant, the interaction of ferritic steel with the coolant, FLiBe, must be explored. Sandia National Laboratories Fusion Technology Department was asked to drop molten ferritic steel and FLiBe in a vacuum system and determine the gas byproducts and ability to recycle the steel. We tried various methods of resistive heating of ferritic steel using available power supplies and easily obtained heaters. Although we could melt the steel, we could not cause a drop to fall. This report describes the various experiments that were performed and includes some suggestions and materials needed to be successful. Although the steel was easily melted, it was not possible to drip the molten steel into a FLiBe pool Levitation melting of the drop is likely to be more successful.

  2. 77 FR 30589 - SteelRiver Infrastructure Partners LP, SteelRiver Infrastructure Associates LLC, SteelRiver...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-23

    ... Surface Transportation Board SteelRiver Infrastructure Partners LP, SteelRiver Infrastructure Associates LLC, SteelRiver Infrastructure Fund North America LP, and Patriot Funding LLC--Control Exemption--Patriot Rail Corp., et al. SteelRiver Infrastructure Partners LP (SRIP LP), SteelRiver...

  3. History of ultrahigh carbon steels

    SciTech Connect

    Wadsworth, J.; Sherby, O.D.

    1997-06-20

    The history and development of ultrahigh carbon steels (i.e., steels containing between 1 and 2.l percent C and now known as UHCS) are described. The early use of steel compositions containing carbon contents above the eutectoid level is found in ancient weapons from around the world. For example, both Damascus and Japanese sword steels are hypereutectoid steels. Their manufacture and processing is of interest in understanding the role of carbon content in the development of modern steels. Although sporadic examples of UHCS compositions are found in steels examined in the early part of this century, it was not until the mid-1970s that the modern study began. This study had its origin in the development of superplastic behavior in steels and the recognition that increasing the carbon content was of importance in developing that property. The compositions that were optimal for superplasticity involved the development of steels that contained higher carbon contents than conventional modern steels. It was discovered, however, that the room temperature properties of these compositions were of interest in their own right. Following this discovery, a period of intense work began on understanding their manufacture, processing, and properties for both superplastic forming and room temperature applications. The development of superplastic cast irons and iron carbides, as well as those of laminated composites containing UHCS, was an important part of this history.

  4. The coupling VIV analysis of SCRs with rigid swing

    NASA Astrophysics Data System (ADS)

    Liu, Juan; Huang, Weiping

    2015-08-01

    With the development of deepwater oil and gas exploration, Steel Catenary Risers (SCRs) become preferred risers for resource production, import and export. Vortex induced vibration (VIV) is the key problem encountered in the design of SCRs. In this study, a new model, the rigid swing model, is proposed based on the consideration of large curvature of SCRs. The sag bend of SCRs is assumed as a rigid swing system around the axis from the hanging point to the touch down point (TDP) in the model. The torque, produced by the lift force and the swing vector, provides the driving torque for the swing system, and the weight of SCRs provides the restoring torque. The simulated response of rigid swing is coupled with bending vibration, and then the coupling VIV model of SCRs is studied in consideration of bending vibration and rigid motion. The calculated results indicate that the rigid swing has a magnitude equal to that of bending vibration, and the rigid motion affects the dynamic response of SCRs and can not be neglected in the VIV analysis.

  5. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Carbon-steel or alloy-steel castings. 59.20-1 Section 59... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  6. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Carbon-steel or alloy-steel castings. 59.20-1 Section 59... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  7. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Carbon-steel or alloy-steel castings. 59.20-1 Section 59... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  8. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Carbon-steel or alloy-steel castings. 59.20-1 Section 59... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  9. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Carbon-steel or alloy-steel castings. 59.20-1 Section 59... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  10. Nanoprecipitates in Steels

    SciTech Connect

    Schneibel, Joachim H; Lu, Zhao Ping; Shim, Sang Hoon

    2007-01-01

    The creep strength of ferritic steels can be substantially improved by the incorporation of a high number density of nano-scale dispersoids. Examples for such alloys are the oxide dispersion strengthened steels MA956, MA957, and PM2000. The dispersoids in these steels contain Y and Ti, or Y and Al. They can be as small as a few nanometers in size. Processing is traditionally carried out by mechanical alloying of elemental or pre-alloyed powders mixed with Y{sub 2}O{sub 3} powder. The goal of the present research is to identify alternative ways of producing ultrafine dispersoids. One possible way is internal oxidation, in which reactive elements dissolved in a metallic matrix are selectively oxidized. Internal oxidation experiments were carried out with Fe-Y, Fe-Ti-Y, and Fe-Al-Y precursors. Microstructural analysis showed that dispersoid dimensions as small as 10 nm could be achieved. Atomized Fe-0.25 at% Y powder was internally oxidized and consolidated by hot forging. An increase in the high-temperature creep strength by {approx} 20% was observed. Since it is likely that the composition of the precursor alloys is crucial for maximizing the number density and thermal stability of the oxides, experiments allowing the rapid screening of different compositions have been initiated.

  11. Nanoprecipitates in Steels

    SciTech Connect

    Schneibel, Joachim H; Kad, Bimal

    2008-01-01

    The creep strength of ferritic steels can be substantially improved by the incorporation of a high number density of nano-scale dispersoids. Examples for such alloys are the oxide dispersion strengthened steels MA956, MA957, and PM2000. The dispersoids in these steels contain Y and Ti, or Y and Al. They can be as small as a few nanometers in size. Processing is traditionally carried out by mechanical alloying of elemental or pre-alloyed powders mixed with Y{sub 2}O{sub 3} powder. The goal of the present research is to identify alternative ways of producing ultrafine dispersoids. One possible way is internal oxidation, in which reactive elements dissolved in a metallic matrix are selectively oxidized. Internal oxidation experiments were carried out with Fe-Y, Fe-Ti-Y, and Fe-Al-Y precursors. Microstructural analysis showed that dispersoid dimensions as small as 10 nm could be achieved. Atomized Fe-0.25 at% Y powder was internally oxidized and consolidated by hot forging. An increase in the high-temperature creep strength by {approx} 20% was observed. Since it is likely that the composition of the precursor alloys is crucial for maximizing the number density and thermal stability of the oxides, experiments allowing the rapid screening of different compositions have been initiated.

  12. Stainless Steel Permeability

    SciTech Connect

    Buchenauer, Dean A.; Karnesky, Richard A.

    2015-09-01

    An understanding of the behavior of hydrogen isotopes in materials is critical to predicting tritium transport in structural metals (at high pressure), estimating tritium losses during production (fission environment), and predicting in-vessel inventory for future fusion devices (plasma driven permeation). Current models often assume equilibrium diffusivity and solubility for a class of materials (e.g. stainless steels or aluminum alloys), neglecting trapping effects or, at best, considering a single population of trapping sites. Permeation and trapping studies of the particular castings and forgings enable greater confidence and reduced margins in the models. For FY15, we have continued our investigation of the role of ferrite in permeation for steels of interest to GTS, through measurements of the duplex steel 2507. We also initiated an investigation of the permeability in work hardened materials, to follow up on earlier observations of unusual permeability in a particular region of 304L forgings. Samples were prepared and characterized for ferrite content and coated with palladium to prevent oxidation. Issues with the poor reproducibility of measurements at low permeability were overcome, although the techniques in use are tedious. Funding through TPBAR and GTS were secured for a research grade quadrupole mass spectrometer (QMS) and replacement turbo pumps, which should improve the fidelity and throughput of measurements in FY16.

  13. Process for dezincing galvanized steel

    DOEpatents

    Morgan, William A.; Dudek, Frederick J.; Daniels, Edward J.

    1998-01-01

    A process for removing zinc from galvanized steel. The galvanized steel is immersed in an electrolyte containing at least about 15% by weight of sodium or potassium hydroxide and having a temperature of at least about 75.degree. C. and the zinc is galvanically corroded from the surface of the galvanized steel. The material serving as the cathode is principally a material having a standard electrode potential which is intermediate of the standard electrode potentials of zinc and cadmium in the electrochemical series. The corrosion rate may be accelerated by (i) increasing the number density of corrosion sites in the galvanized steel by mechanically abrading or deforming the galvanized steel, (ii) heating the galvanized steel to form an alloy of zinc on the surface of the galvanized steel, (iii) mixing the galvanized steel with a material having a standard electrode potential which is intermediate of the standard electrode potentials of zinc and cadmium in the electrochemical series, or (iv) moving the galvanized steel relative to itself and to the electrolyte while immersed in the electrolyte.

  14. High strength, tough alloy steel

    DOEpatents

    Thomas, Gareth; Rao, Bangaru V. N.

    1979-01-01

    A high strength, tough alloy steel is formed by heating the steel to a temperature in the austenite range (1000.degree.-1100.degree. C.) to form a homogeneous austenite phase and then cooling the steel to form a microstructure of uniformly dispersed dislocated martensite separated by continuous thin boundary films of stabilized retained austenite. The steel includes 0.2-0.35 weight % carbon, at least 1% and preferably 3-4.5% chromium, and at least one other substitutional alloying element, preferably manganese or nickel. The austenite film is stable to subsequent heat treatment as by tempering (below 300.degree. C.) and reforms to a stable film after austenite grain refinement.

  15. Process for dezincing galvanized steel

    DOEpatents

    Morgan, W.A.; Dudek, F.J.; Daniels, E.J.

    1998-07-14

    A process is described for removing zinc from galvanized steel. The galvanized steel is immersed in an electrolyte containing at least about 15% by weight of sodium or potassium hydroxide and having a temperature of at least about 75 C and the zinc is galvanically corroded from the surface of the galvanized steel. The material serving as the cathode is principally a material having a standard electrode potential which is intermediate of the standard electrode potentials of zinc and cadmium in the electrochemical series. The corrosion rate may be accelerated by (1) increasing the number density of corrosion sites in the galvanized steel by mechanically abrading or deforming the galvanized steel, (2) heating the galvanized steel to form an alloy of zinc on the surface of the galvanized steel, (3) mixing the galvanized steel with a material having a standard electrode potential which is intermediate of the standard electrode potentials of zinc and cadmium in the electrochemical series, or (4) moving the galvanized steel relative to itself and to the electrolyte while immersed in the electrolyte. 1 fig.

  16. Induction heat treatment of steel

    SciTech Connect

    Semiatin, S.L.; Stutz, D.E.

    1985-01-01

    This book discusses the induction heating. After reviewing heat treating operations for steel and the principles of the heat treatment of steel, an overview of induction heat treating is provided. Next, consideration is given to equipment and equipment selection, coil design, power requirements and temperature control. A discussion of surface and through hardening of steel is provided, including information on frequency and power selection and quenching apparatus. Tempering is considered, followed by information on control of residual stresses, cracking, temper brittleness and the important metallurgical and hardness differences between induction and furnace treated steel.

  17. Activation response of martensitic steels

    SciTech Connect

    Forty, C.B.A.

    1997-09-01

    A hypothetical martensitic steel has been compositionally designed in order to optimize both metallurgical and reduced activation properties. When compared with two other martensitic steels, its activation characteristics are shown to be superior for all activation indices examined. However, these excellent properties are found to be due to the assumed absence of deleterious tramp impurities. When limiting impurity concentrations are determined for the hypothetical steel, they are found to be extremely stringent, and wholly unachievable using industrial scale production methods. It is concluded that only slight improvements can be made to currently available low activation martensitic steels to reduce residual activity responses further. 26 refs., 1 fig., 2 tabs.

  18. Activation Response of Martensitic Steels

    NASA Astrophysics Data System (ADS)

    Forty, C. B. A.

    1997-09-01

    A hypothetical martensitic steel has been compositionally designed in order to optimize both metallurgical and reduced activation properties. When compared with two other martensitic steels, its activation characteristics are shown to be superior for all activation indices examined. However, these excellent properties are found to be due to the assumed absence of deleterious tramp impurities. When limiting impurity concentrations are determined for the hypothetical steel, they are found to be extremely stringent, and wholly unachievable using industrial scale production methods. It is concluded that only slight improvements can be made to currently available low activation martensitic steels to reduce residual activity responses further.

  19. Reduction in Energy Consumption & Variability in Steel Foundry Operations

    SciTech Connect

    Frank Peters

    2005-05-04

    This project worked to improve the efficiency of the steel casting industry by reducing the variability that occurs because of process and product variation. The project focused on the post shakeout operations since roughly half of the production costs are in this area. These improvements will reduce the amount of variability, making it easier to manage the operation and improve the competitiveness. The reduction in variability will also reduce the need for many rework operations, which will result in a direct reduction of energy usage, particularly by the reduction of repeated heat treatment operations. Further energy savings will be realized from the reduction of scrap and reduced handling. Field studies were conducted at ten steel foundries that represented the U.S. steel casting industry, for a total of over 100 weeks of production observation. These studies quantified the amount of variability, and looked toward determining the source. A focus of the data collected was the grinding operations since this is a major effort in the cleaning room, and it represents the overall casting quality. The grinding was divided into two categories, expected and unexpected. Expected grinding is that in which the location of the effort is known prior to making the casting, such as smoothing parting lines, gates, and riser contacts. Unexpected grinding, which was approximately 80% of the effort, was done to improve the surfaces at weld repair locations, to rectify burnt on sand, and other surface anomalies at random locations. Unexpected grinding represents about 80% of the grinding effort. By quantifying this effort, the project raised awareness within the industry and the industry is continuing to make improvements. The field studies showed that the amount of variation of grinding operations (normalized because of the diverse set of parts studied) was very consistent across the industry. The field studies identified several specific sources that individually contributed to

  20. Elevation, looking SE. Concrete and steel bridge with exposed steel ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Elevation, looking SE. Concrete and steel bridge with exposed steel frame is the central of three bridges crossing Brush Street between east Baltimore and Piquette. The bridge links Old Lake Shore and Michigan Central Main Line on the western side to a New York Central siding on the eastern side - Railroad Overpass, East Milwaukee & Hastings Avenues, Detroit, MI

  1. Photodesorption from stainless steels

    NASA Technical Reports Server (NTRS)

    Mesarwi, A.; Ignatiev, A.

    1988-01-01

    The photodesorption by low-energy photons from three types of stainless steels is examined. For all these systems both CO and CO2 were observed to photodesorb with high yields: about 0.001 molecules/photon for CO2 and about 0.0001 molecules/photon for CO at 250 nm. The observed threshold energies were found to be the same for all systems at E0 = 2.92 eV for CO2 and E0 = 2.92-3.10 eV for CO.

  2. Switch to duplex stainless steels

    SciTech Connect

    Quik, J.M.A.; Geudeke, M.

    1994-11-01

    Duplex stainless steels contain approximately equal proportions of ferrite and austenite. These stainless steels have become an established material of construction in the chemical process industries (CPI). Duplexes offer benefits over austenitic stainless steels and carbon steels because of their higher strength, and good toughness and ductility, in combination with equivalent resistance to general corrosion, as well as better resistance to localized corrosion and stress corrosion cracking. Additionally, duplex materials have thermal-conductivity and thermal-expansion coefficients similar to those of ferritic materials, are tough at low (sub-zero) temperatures, and have a high resistance to erosion and abrasion. In some of the highly corrosive environments encountered in the CPI, the super duplex stainless steels offer cost-effective options not possible with the standard austenitic stainless steels. The initial applications were almost exclusively as heat exchanger tubing in water-cooled service. In recent times, duplex stainless steels have been used in the oil, gas, and chemical industries. Examples include service in sweet and mildly sour corrosive environments, on offshore platforms where weight savings can be realized, and as a replacement for standard austenitic stainless steel in chemical-processing plants.

  3. The industrial ecology of steel

    SciTech Connect

    Considine, Timothy J.; Jablonowski, Christopher; Considine, Donita M.M.; Rao, Prasad G.

    2001-03-26

    This study performs an integrated assessment of new technology adoption in the steel industry. New coke, iron, and steel production technologies are discussed, and their economic and environmental characteristics are compared. Based upon detailed plant level data on cost and physical input-output relations by process, this study develops a simple mathematical optimization model of steel process choice. This model is then expanded to a life cycle context, accounting for environmental emissions generated during the production and transportation of energy and material inputs into steelmaking. This life-cycle optimization model provides a basis for evaluating the environmental impacts of existing and new iron and steel technologies. Five different plant configurations are examined, from conventional integrated steel production to completely scrap-based operations. Two cost criteria are used to evaluate technology choice: private and social cost, with the latter including the environmental damages associated with emissions. While scrap-based technologies clearly generate lower emissions in mass terms, their emissions of sulfur dioxide and nitrogen oxides are significantly higher. Using conventional damage cost estimates reported in the literature suggests that the social costs associated with scrap-based steel production are slightly higher than with integrated steel production. This suggests that adopting a life-cycle viewpoint can substantially affect environmental assessment of new technologies. Finally, this study also examines the impacts of carbon taxes on steel production costs and technology choice.

  4. Magnetoacoustic stress measurements in steel

    NASA Technical Reports Server (NTRS)

    Namkung, M.; Utrata, D.; Allison, S. G.; Heyman, J. S.

    1985-01-01

    Uniaxial stress effects on the low-field magnetoacoustic interaction have been studied using bulk compressional waves and Rayleigh surface waves in numerous steel samples having various impurity concentrations (Namkung et al., 1984). The results invariably showed that the initial slope of acoustic natural velocity variations, with respect to net induced magnetization parallel to the stress axis, is positive under tension and negative under compression. The results of current measurements in railroad rail steel having about 0.68 wt percent carbon content are typical for medium range carbon steels. The low-field natural velocity slope in this particular type of steel, which is almost zero when unstressed, becomes steeper with increased magnitude of stress in both directions. Hence, the nondestructive determination of the sign of residual stress in railroad wheels and rails is possible using this technique. This paper discusses the basic physical mechanism underlying the experimental observations and presents the results obtained in railroad rail steel.

  5. Why stainless steel corrodes.

    PubMed

    Ryan, Mary P; Williams, David E; Chater, Richard J; Hutton, Bernie M; McPhail, David S

    2002-02-14

    Stainless steels are used in countless diverse applications for their corrosion resistance. Although they have extremely good general resistance, they are nevertheless susceptible to pitting corrosion. This localized dissolution of an oxide-covered metal in specific aggressive environments is one of the most common and catastrophic causes of failure of metallic structures. The pitting process has been described as random, sporadic and stochastic and the prediction of the time and location of events remains extremely difficult. Many contested models of pitting corrosion exist, but one undisputed aspect is that manganese sulphide inclusions play a critical role. Indeed, the vast majority of pitting events are found to occur at, or adjacent to, such second-phase particles. Chemical changes in and around sulphide inclusions have been postulated as a mechanism for pit initiation but such variations have never been measured. Here we use nanometre-scale secondary ion mass spectroscopy to demonstrate a significant reduction in the Cr:Fe ratio of the steel matrix around MnS particles. These chromium-depleted zones are susceptible to high-rate dissolution that 'triggers' pitting. The implications of these results are that materials processing conditions control the likelihood of corrosion failures, and these data provide a basis for optimizing such conditions. PMID:11845203

  6. 2169 Steel Waveform Experiments

    NASA Astrophysics Data System (ADS)

    Furnish, M.; Alexander, C.; Reinhart, W.; Brown, J.

    2013-06-01

    In support of efforts to develop multiscale models of materials, we performed eight gas gun impact experiments on 2169 steel (21% Cr, 6% Ni, 9% Mn). These experiments provided shock, reshock and release velocimetry data, with initial shock stresses ranging from 10 to 50 GPa (particle velocities from 0.25 to 1.05 km/s). Both windowed and free-surface measurements were used, with samples 1 to 5 mm thick. The study focused on dynamic strength determination via the release/reshock paths. Reshock tests with explosively welded impactors produced clean results. The free-surface samples, which were steps on a single piece of steel, showed lower wavespeeds for thin (1 mm) samples than for thicker (2 or 4 mm) samples. A configuration used for the last three shots allowed release information to be determined from these free surface samples as well. The sample strength appears to increase with stress from ~1 GPa to ~3 GPa over this range, consistent with other recent work but about 40% above the Steinberg model. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  7. 49 CFR 192.55 - Steel pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Steel pipe. 192.55 Section 192.55 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.55 Steel pipe. (a) New steel pipe is... in accordance with paragraph (c) or (d) of this section. (b) Used steel pipe is qualified for...

  8. 49 CFR 192.55 - Steel pipe.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Steel pipe. 192.55 Section 192.55 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.55 Steel pipe. (a) New steel pipe is... in accordance with paragraph (c) or (d) of this section. (b) Used steel pipe is qualified for...

  9. 49 CFR 192.55 - Steel pipe.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Steel pipe. 192.55 Section 192.55 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.55 Steel pipe. (a) New steel pipe is... in accordance with paragraph (c) or (d) of this section. (b) Used steel pipe is qualified for...

  10. 49 CFR 192.55 - Steel pipe.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Steel pipe. 192.55 Section 192.55 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.55 Steel pipe. (a) New steel pipe is... in accordance with paragraph (c) or (d) of this section. (b) Used steel pipe is qualified for...

  11. 49 CFR 192.55 - Steel pipe.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Steel pipe. 192.55 Section 192.55 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.55 Steel pipe. (a) New steel pipe is... in accordance with paragraph (c) or (d) of this section. (b) Used steel pipe is qualified for...

  12. Occupational Profiles in the European Steel Industry.

    ERIC Educational Resources Information Center

    Franz, Hans-Werner; And Others

    The steel industry in Europe has faced great changes, with resulting layoffs and restructuring. Now that the most basic changes seem to be over, it has become evident that the remaining steel industry requires more highly trained workers than was the case previously. Although steel maintenance employees were always highly skilled, steel production…

  13. Improving the toughness of ultrahigh strength steel

    SciTech Connect

    Soto, Koji

    2002-08-15

    The ideal structural steel combines high strength with high fracture toughness. This dissertation discusses the toughening mechanism of the Fe/Co/Ni/Cr/Mo/C steel, AerMet 100, which has the highest toughness/strength combination among all commercial ultrahigh strength steels. The possibility of improving the toughness of this steel was examined by considering several relevant factors.

  14. Irradiation effects in ferritic steels

    NASA Astrophysics Data System (ADS)

    Lechtenberg, Thomas

    1985-08-01

    Since 1979 the Alloy Development for Irradiation Performance (ADIP) task funded by the US Department of Energy has been studying the 2-12Cr class of ferritic steels to establish the feasibility of using them in fusion reactor first wall/breeding blanket (FW/B) applications. The advantages of ferritic steels include superior swelling resistance, low thermal stresses compared to austenitic stainless steels, attractive mechanical properties up to 600°C. and service histories exceeding 100 000 h. These steels are commonly used in a range of microstructural conditions which include ferritic, martensitic. tempered martensitic, bainitic etc. Throughout this paper where the term "ferritic" is used it should be taken to mean any of these microstructures. The ADIP task is studying several candidate alloy systems including 12Cr-1MoWV (HT-9), modified 9Cr-1MoVNb, and dual-phased steels such as EM-12 and 2 {1}/{4}Cr-Mo. These materials are ferromagnetic (FM), body centered cubic (bcc), and contain chromium additions between 2 and 12 wt% and molybdenum additions usually below 2%. The perceived issues associated with the application of this class of steel to fusion reactors are the increase in the ductile-brittle transition temperature (DBTT) with neutron damage, the compatibility of these steels with liquid metals and solid breeding materials, and their weldability. The ferromagnetic character of these steels can also be important in reactor design. It is the purpose of this paper to review the current understanding of these bcc steels and the effects of irradiation. The major points of discussion will be irradiation-induced or -enhanced dimensional changes such as swelling and creep, mechanical properties such as tensile strength and various measurements of toughness, and activation by neutron interactions with structural materials.

  15. High-strength, low-alloy steels.

    PubMed

    Rashid, M S

    1980-05-23

    High-strength, low-alloy (HSLA) steels have nearly the same composition as plain carbon steels. However, they are up to twice as strong and their greater load-bearing capacity allows engineering use in lighter sections. Their high strength is derived from a combination of grain refinement; precipitation strengthening due to minor additions of vanadium, niobium, or titanium; and modifications of manufacturing processes, such as controlled rolling and controlled cooling of otherwise essentially plain carbon steel. HSLA steels are less formable than lower strength steels, but dualphase steels, which evolved from HSLA steels, have ferrite-martensite microstructures and better formability than HSLA steels of similar strength. This improved formability has substantially increased the utilization potential of high-strength steels in the manufacture of complex components. This article reviews the development of HSLA and dual-phase steels and discusses the effects of variations in microstructure and chemistry on their mechanical properties. PMID:17772810

  16. Welding tritium exposed stainless steel

    SciTech Connect

    Kanne, W.R. Jr.

    1994-11-01

    Stainless steels that are exposed to tritium become unweldable by conventional methods due to buildup of decay helium within the metal matrix. With longer service lives expected for tritium containment systems, methods for welding on tritium exposed material will become important for repair or modification of the systems. Solid-state resistance welding and low-penetration overlay welding have been shown to mitigate helium embrittlement cracking in tritium exposed 304 stainless steel. These processes can also be used on stainless steel containing helium from neutron irradiation, such as occurs in nuclear reactors.

  17. Stainless steel display evaluation

    NASA Astrophysics Data System (ADS)

    Hopper, Darrel G.; Meyer, Frederick M.; Longo, Sam J.; Trissell, Terry L.

    2007-04-01

    Active matrix organic light emitting diode (AMOLED) technology is one candidate to become a low power alternative in some applications to the currently dominant, active matrix liquid crystal display (AMLCD), technology. Furthermore, fabrication of the AMOLED on stainless steel (SS) foil rather than the traditional glass substrate, while presenting a set of severe technical challenges, opens up the potential for displays that are both lighter and less breakable. Also, transition to an SS foil substrate may enable rollable displays - large when used but small for stowage within gear already worn or carried or installed. Research has been initiated on AMOLED/SS technology and the first 320 x 240 color pixel 4-in. demonstration device has been evaluated in the AFRL Display Test and Evaluation Laboratory. Results of this evaluation are reported along with a research roadmap.

  18. 2169 steel waveform experiments.

    SciTech Connect

    Furnish, Michael David; Alexander, C. Scott; Reinhart, William Dodd; Brown, Justin L.

    2012-11-01

    In support of LLNL efforts to develop multiscale models of a variety of materials, we have performed a set of eight gas gun impact experiments on 2169 steel (21% Cr, 6% Ni, 9% Mn, balance predominantly Fe). These experiments provided carefully controlled shock, reshock and release velocimetry data, with initial shock stresses ranging from 10 to 50 GPa (particle velocities from 0.25 to 1.05 km/s). Both windowed and free-surface measurements were included in this experiment set to increase the utility of the data set, as were samples ranging in thickness from 1 to 5 mm. Target physical phenomena included the elastic/plastic transition (Hugoniot elastic limit), the Hugoniot, any phase transition phenomena, and the release path (windowed and free-surface). The Hugoniot was found to be nearly linear, with no indications of the Fe - phase transition. Releases were non-hysteretic, and relatively consistent between 3- and 5-mm-thick samples (the 3 mm samples giving slightly lower wavespeeds on release). Reshock tests with explosively welded impactors produced clean results; those with glue bonds showed transient releases prior to the arrival of the reshock, reducing their usefulness for deriving strength information. The free-surface samples, which were steps on a single piece of steel, showed lower wavespeeds for thin (1 mm) samples than for thicker (2 or 4 mm) samples. A configuration used for the last three shots allows release information to be determined from these free surface samples. The sample strength appears to increase with stress from ~1 GPa to ~ 3 GPa over this range, consistent with other recent work but about 40% above the Steinberg model.

  19. JPDR vessel steel examination

    SciTech Connect

    Corwin, W.R.; Broadhead, B.L.; Sokolov, M.A.

    1995-10-01

    There is a need to validate the results of irradiation effects research by the examination of material taken directly from the wall of a pressure vessel which has been irradiated during normal service. This task has been included with the HSSI Program to provide just such an evaluation of material from the wall of the pressure vessel from the JPDR. The JPDR was a small BWR that began operation in 1963. It operated until 1976, accumulating {approximately}17,000 h of operation, of which a little over 14,000 h were with the original 45-MWTh core, and the remaining fraction, late in life, with an upgraded 90-MWTh core. The pressure vessel of the JPDR, fabricated from A 302, grade B, modified steel with an internal weld overlay cladding of 304 stainless steel, is approximately 2 m ID and 73 mm thick. It was fabricated from two shell halves joined by longitudinal seam welds located 180{degrees} from each other. The rolling direction of the shell plates is parallel to the axis of the vessel. It operated at 273{degrees}C and reached a maximum fluence of about 2.3 x 10{sup 18} n/cm{sup 2} (> 1 MeV). The impurity contents in the base metal are 0.10 to 0.11% Cu and 0.010 to 0.017% P with a nickel content of 0.63 to 0.65%. Impurity contents of the weld metal are 0.11 to 0.14% Cu and 0.025 to 0.039% P with a nickel content of 0.59%.

  20. Fabrication of stainless steel foil utilizing chromized steel strip

    NASA Astrophysics Data System (ADS)

    Loria, Edward A.

    1980-10-01

    Stainless steel foil has properties which are, in many respects, unmatched by alternative thin films. The high strength to weight ratio and resistance to corrosion and oxidation at elevated temperatures are generally advantageous. The aerospace and automotive industries have used Type 430 and 304 foil in turbine engine applications. Foil around 2 mils (5.1 × 10-3 cm) thick has been appropriate for the recuperator or heat exchanger and this product has also been used in honeycomb and truss-core structures. Further, such foil has been employed as a wrap to protect tool steel parts from contamination during heat treating. A large part of the high cost of producing stainless steel foil by rolling is due to the complicated and expensive rolling mill and annealing equipment involved. A method will be described which produces (solid) stainless steel foil from chromized (coated) steel which can be cheaper than the conventional processing stainless steel, such as Type 430, from ingot to foil. Also, the material is more ductile and less work hardenable during processing to foil and consequently intermediate annealing treatments are eliminated and scrap losses minimized.

  1. Corrosion of Steels in Steel Reinforced Concrete in Cassava Juice

    NASA Astrophysics Data System (ADS)

    Oluwadare, G. O.; Agbaje, O.

    The corrosion of two types of construction steels, ST60Mn and RST37-2♦, in a low cyanide concentration environment (cassava juice) and embedded in concrete had been studied. The ST60 Mn was found to be more corrosion resistant in both ordinary water and the cassava juice environment. The cyanide in cassava juice does not attack the steel but it provides an environment of lower pH around the steel in the concrete which leads to breakdown of the passivating film provided by hydroxyl ions from cement. Other factors such as the curing time of the concrete also affect the corrosion rates of the steel in the concrete. The corrosion rate of the steel directly exposed to cassava juice i.e., steel not embedded in concrete is about twice that in concrete. Long exposure of concrete structure to cassava processing effluent might result in deterioration of such structures. Careful attention should therefore be paid to disposal of cassava processing effluents, especially in a country like Nigeria where such processing is now on the increase.

  2. Great Lakes Steel -- PCI facility

    SciTech Connect

    Eichinger, F.T.; Dake, S.H.; Wagner, E.D.; Brown, G.S.

    1997-12-31

    This paper discusses the planning, design, and start-up of the 90 tph PCI facility for National Steel`s Great Lakes Steel Division in River Rouge, MI. This project is owned and operated by Edison Energy Services, and was implemented on a fast-track basis by Raytheon Engineers and Constructors, Babcock Material Handling, and Babcock and Wilcox. This paper presents important process issues, basic design criteria, an the challenges of engineering and building a state-of-the-art PCI facility in two existing plants. Pulverized coal is prepared at the River Rouge Power Plant of Detroit Edison, is pneumatically conveyed 6,000 feet to a storage silo at Great Lakes Steel, and is injected into three blast furnaces.

  3. Corrosion resistance of stainless steels

    SciTech Connect

    Dillon, C.P.

    1995-12-31

    This book reviews the mechanisms and forms of corrosion and examines the corrosion of stainless steels and similar chromium-bearing nickel containing higher alloys, detailing various corrosive environments including atmospheric and fire-side corrosion, corrosion by water and soil, and corrosion caused by particular industrial processes. It provides information on specific groups and grades of stainless steels; summarizes typical applications for specific stainless alloys; describes common corrosion problems associated with stainless steels; presents the acceptable isocorrosion parameters of concentration and temperature for over 250 chemicals for which stainless steels are the preferred materials of construction; discusses product forms and their availability; elucidates fabrication, welding, and joining techniques; and covers the effects of pickling and passivation.

  4. Hydrogen embrittlement of structural steels.

    SciTech Connect

    Somerday, Brian P.

    2010-06-01

    Carbon-manganese steels are candidates for the structural materials in hydrogen gas pipelines, however it is well known that these steels are susceptible to hydrogen embrittlement. Decades of research and industrial experience have established that hydrogen embrittlement compromises the structural integrity of steel components. This experience has also helped identify the failure modes that can operate in hydrogen containment structures. As a result, there are tangible ideas for managing hydrogen embrittement in steels and quantifying safety margins for steel hydrogen containment structures. For example, fatigue crack growth aided by hydrogen embrittlement is a key failure mode for steel hydrogen containment structures subjected to pressure cycling. Applying appropriate structural integrity models coupled with measurement of relevant material properties allows quantification of safety margins against fatigue crack growth in hydrogen containment structures. Furthermore, application of these structural integrity models is aided by the development of micromechanics models, which provide important insights such as the hydrogen distribution near defects in steel structures. The principal objective of this project is to enable application of structural integrity models to steel hydrogen pipelines. The new American Society of Mechanical Engineers (ASME) B31.12 design code for hydrogen pipelines includes a fracture mechanics-based design option, which requires material property inputs such as the threshold for rapid cracking and fatigue crack growth rate under cyclic loading. Thus, one focus of this project is to measure the rapid-cracking thresholds and fatigue crack growth rates of line pipe steels in high-pressure hydrogen gas. These properties must be measured for the base materials but more importantly for the welds, which are likely to be most vulnerable to hydrogen embrittlement. The measured properties can be evaluated by predicting the performance of the pipeline

  5. Process Hood Stand Support Steel

    SciTech Connect

    VAN KATWIJK, C.

    2000-04-03

    This package is written to comply with EN-6-035-00 for upgrade dedication of commercial grade items (CGI). The SNF-5953 CGI package provides the Technical evaluation to identify the critical characteristics and the acceptance criteria associated with the safety function of the Hood Stand Support Steel. Completion of the technical and quality requirements identified in the dedication package will provide enough data to be reasonably assured that CGI Hood Stand Support Steel will perform its SC function.

  6. Fatigue handbook: Offshore steel structures

    SciTech Connect

    Almarnaess, A.

    1985-01-01

    The contents of this book are: Overview of Offshore Steel Structures; Loads on Ocean Structures; Fracture Mechanics As a Tool in Fatigue Analysis; Basic Fatigue Properties of Welded Joints; Significance of Defects; Improving the Fatigue Strength of Welded Joints; Effects of Marine Environment and Cathodic Protection on Fatigue of Structural Steels Fatigue of Tubular Joints; Unstable Fracture; Fatigue Life Calculations; and Fatigue in Building Codes Background and Applications.

  7. Analysis of plasma nitrided steels

    NASA Technical Reports Server (NTRS)

    Salik, J.; Ferrante, J.; Honecy, F.; Hoffman, R., Jr.

    1987-01-01

    The analysis of plasma nitrided steels can be divided to two main categories - structural and chemical. Structural analysis can provide information not only on the hardening mechanisms but also on the fundamental processes involved. Chemical analysis can be used to study the kinetics for the nitriding process and its mechanisms. In this paper preliminary results obtained by several techniques of both categories are presented and the applicability of those techniques to the analysis of plasma-nitrided steels is discussed.

  8. Wear of steel by rubber

    NASA Technical Reports Server (NTRS)

    Gent, A. N.; Pulford, C. T. R.

    1978-01-01

    Wear of a steel blade used as a scraper to abrade rubber surfaces has been found to take place much more rapidly on a cis-polyisoprene (natural rubber) surface than on a cis-polybutadiene surface, and much more rapidly in an inert atmosphere than in air. These observations are attributed to the direct attack upon steel of free-radical species generated by mechanical rupture of elastomer molecules during abrasion.

  9. Development of New Stainless Steel

    SciTech Connect

    Robert F. Buck

    2005-08-30

    A new family of innovative martensitic stainless steels, 521-A, 521-B, and 521-C has been developed by Advanced Steel Technology, LLC (Trafford, PA) as high strength fastener (bolt) materials for use at moderate temperatures in turbine engines, including steam turbines, gas turbines, and aircraft engines. The primary objective of the development program was to create a martensitic stainless steel with high strength at moderate temperatures, and which could replace the expensive nickel-based superalloy IN 718 in some fasteners applications. A secondary objective was to replace conventional 12Cr steels such as AISI 422 used as blades, buckets and shafts that operate at intermediate temperatures in turbine engines with stronger steel. The composition of the new alloys was specifically designed to produce excellent mechanical properties while integrating heat treatment steps into production to reduce energy consumption during manufacturing. As a result, production costs and energy consumption during production of rolled bar products is significantly lower than conventional materials. Successful commercialization of the new alloys would permit the installed cost of certain turbine engines to be reduced without sacrificing high availability or operational flexibility, thereby enhancing the global competitiveness of U.S. turbine engine manufacturers. Moreover, the domestic specialty steel industry would also benefit through increased productivity and reduced operating costs, while increasing their share of the international market for turbine engine fasteners, blades, buckets and shafts.

  10. Hydrogen Permeation in Nanostructured Bainitic Steel

    NASA Astrophysics Data System (ADS)

    Kazum, Oluwole; Beladi, Hossein; Timokhina, Ilana B.; He, Yinghe; Bobby Kannan, M.

    2016-07-01

    Hydrogen permeation of nanostructured bainitic steel, produced at two different transformation temperatures, i.e., 473.15 K (200 °C) BS-200 and 623.15 K (350 °C) BS-350, was determined using Devanathan-Stachurski hydrogen permeation cell and compared with that of mild steel. Nanostructured bainitic steel showed lower effective diffusivity of hydrogen as compared to the mild steel. The BS-200 steel, which exhibited higher volume fraction of bainitic ferrite phase, showed lower effective diffusivity than BS-350 steel. The finer microstructural constituents (bainitic ferrite laths and retained austenite films) and higher dislocation density in the bainitic ferrite phase of BS-200 steel can be attributed to its lower effective diffusivity as compared to BS-350 steel and mild steel.

  11. A microstructure sensitive study of rolling contact fatigue in bearing steels: A numerical and experimental approach

    NASA Astrophysics Data System (ADS)

    Pandkar, Anup Surendra

    Bearings are an integral part of machine components that transmit rotary power such as cars, motors, engines etc. Safe bearing operation is essential to avoid serious failures and accidents, which necessitates their timely replacement. This calls for an accurate bearing life prediction methods. Based on the Lundberg-Palmgen (LP) model, current life models consistently under predict bearings lives. Improvement in life prediction requires understanding of the bearing failure mechanism i.e. Rolling Contact Fatigue (RCF). The goal of this research is to develop a mechanistic framework required for an improved bearing life prediction model. Such model should account for metal plasticity, influence of microstructural features and cyclically evolving stressstrain fields induced during RCF. To achieve this, elastic-plastic finite element (FE) study is undertaken to investigate the response of M50-NiL bearing steel during RCF. Specifically, a microstructure sensitive study of the influence of non-metallic inclusions on RCF response of bearings is presented. M50-NiL microstructure consists of carbides which are orders of magnitude smaller than bearing dimensions. To account for this size difference, a multi-scale FE modeling approach is employed. The FE results reveal that hard carbide particles act as local stress risers, alter surrounding stressstrain fields and cause micro-scale yielding of steel matrix. Moreover, they introduce a shear stress cycle with non-zero mean stress, which promotes micro-plastic strain accumulation via ratcheting mechanism. Localized ratcheting is primarily responsible for cyclic hardening within the RCF affected region. Such evolution of subsurface hardness can be used to quantify RCF induced damage. To investigate this further, cyclic hardening response of the RCF affected region is simulated. The results show good agreement with the experimental observations. The cyclic stress-strain fields obtained from these simulations and the knowledge of

  12. Review on Cold-Formed Steel Connections

    PubMed Central

    Tan, Cher Siang; Mohammad, Shahrin; Md Tahir, Mahmood; Shek, Poi Ngian

    2014-01-01

    The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed. PMID:24688448

  13. Microbial corrosion of stainless steel.

    PubMed

    Ibars, J R; Moreno, D A; Ranninger, C

    1992-11-01

    Stainless steel, developed because of their greater resistance to corrosion in different aggressive environments, have proved to be affected, however, by various processes and types of corrosion. Some of these types of corrosion, mainly pitting, is activated and developed in the presence of microorganisms, which acting in an isolated or symbiotic way, according to their adaptation to the environment, create a favorable situation for the corrosion of these steel. The microorganisms that are involved, mainly bacteria of both the aerobic and anaerobic type, modify the environment where the stainless steel is found, creating crevices, differential aeration zones or a more aggressive environment with the presence of metabolites. In these circumstances, a local break of the passive and passivating layer is produced, which is proper to these types of steel and impedes the repassivation that is more favorable to corrosion. In the study and research of these types of microbiologically influenced corrosion are found electrochemical techniques, since corrosion is fundamentally an electrochemical process, and microbiological techniques for the identification, culture, and evaluation of the microorganisms involved in the process, as well as in the laboratory or field study of microorganism-metal pairs. Microstructural characterization studies of stainless steel have also been considered important, since it is known that the microstructure of steel can substantially modify their behavior when faced with corrosion. As for surface analysis studies, it is known that corrosion is a process that is generated on and progresses from the surface. The ways of dealing with microbiologically influenced corrosion must necessarily include biocides, which are not always usable or successful, the design of industrial equipment or components that do not favor the adherence of microorganisms, using microstructures in steel less sensitive to corrosion, or protecting the materials. PMID:1492953

  14. 38. Photocopy of photograph. STEEL PLANT, BOILERS UNDER CONSTRUCTION IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. Photocopy of photograph. STEEL PLANT, BOILERS UNDER CONSTRUCTION IN BOILER PLANT LOCATED EAST OF MAIN STEEL PLANT, 1909. (From the Bethlehem Steel Corporation collection, Seattle, WA) - Irondale Iron & Steel Plant, Port Townsend, Jefferson County, WA

  15. Anodized Steel Electrodes for Supercapacitors.

    PubMed

    Sagu, Jagdeep S; Wijayantha, K G Upul; Bohm, Mallika; Bohm, Siva; Kumar Rout, Tapan

    2016-03-01

    Steel was anodized in 10 M NaOH to enhance its surface texture and internal surface area for application as an electrode in supercapacitors. A mechanism was proposed for the anodization process. Field-emission gun scanning electron microscopy (FEGSEM) studies of anodized steel revealed that it contains a highly porous sponge like structure ideal for supercapacitor electrodes. X-ray photoelectron spectroscopy (XPS) measurements showed that the surface of the anodized steel was Fe2O3, whereas X-ray diffraction (XRD) measurements indicated that the bulk remained as metallic Fe. The supercapacitor performance of the anodized steel was tested in 1 M NaOH and a capacitance of 18 mF cm(-2) was obtained. Cyclic voltammetry measurements showed that there was a large psueudocapacitive contribution which was due to oxidation of Fe to Fe(OH)2 and then further oxidation to FeOOH, and the respective reduction of these species back to metallic Fe. These redox processes were found to be remarkably reversible as the electrode showed no loss in capacitance after 10000 cycles. The results demonstrate that anodization of steel is a suitable method to produce high-surface-area electrodes for supercapacitors with excellent cycling lifetime. PMID:26891093

  16. Carbide transformations in constructional steels

    SciTech Connect

    Vinokur, B.B.

    1986-01-01

    In connection with the type of carbides formed in general purpose constructional steels or on the mechanisms of carbide transformations and the influence of carbide formation on the properties, this work presents an investigation that was made of medium-carbon chrome-nickel and chrome-manganese steels with 1, 2, and 3% Cr, 1% Ni, and 1% Mn additionally alloyed with 0.25-2% Mo or W (every 0.25%). All of the steels were hardened from temperatures providing the fullest solution of carbides in austenite and were tempered at 400-650/sup 0/C every 25-50/sup 0/C. The composition of the carbides and their type were established by chemical, x-ray diffraction, and microdiffraction methods and the mechanism of the carbide transformations was determined on the basis of the changes in distortions of the second and third order of the matrix electrical resistance, and coercive force of the steel. All of the carbideforming elements present in steel participate in saturation of the carbides, as a result of which the formation of a special carbide is eased and the degree of alloying of the matrix increases. In the carbide transformation with a certain share of carbide phase an increase or retarding of the reduction in strength with an increase in tempering temperature with constant plasticity and impact strength is possible.

  17. Steel erected at A-3 Test Stand

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Workers erect the first fabricated steel girders to arrive at the A-3 Test Stand at Stennis Space Center. Steel work began at the construction site Oct. 29 and is scheduled to continue into next spring.

  18. High-temperature brazing of stainless steel

    NASA Technical Reports Server (NTRS)

    Beuyukian, C. S.; Heisman, R. M.; Mitchell, M. J.

    1978-01-01

    Prevention of iron contamination of platens is eliminated by placing alumina/silica ceramic-fiber blankets between platens and carbon-steel plate. Carbon-steel plates provide rigidity and improve heat transfer.

  19. ESF GROUND SUPPORT - STRUCTURAL STEEL ANALYSIS

    SciTech Connect

    T. Misiak

    1996-06-26

    The purpose and objective of this analysis are to expand the level of detail and confirm member sizes for steel sets included in the Ground Support Design Analysis, Reference 5.20. This analysis also provides bounding values and details and defines critical design attributes for alternative configurations of the steel set. One possible configuration for the steel set is presented. This analysis covers the steel set design for the Exploratory Studies Facility (ESF) entire Main Loop 25-foot diameter tunnel.

  20. Metallography of maraging 350 steel

    SciTech Connect

    Hutson, S.M.; Merten, C.W.

    1987-01-01

    A technique for etching maraging 350 steel with Glyceregia is described. Surface activation procedures are integral to this technique. Microstructural features revealed by this technique are compared with those obtained with Kalling's reagent, Fry's reagent, and 5% Nital, three etchants commonly used to reveal microstructures of maraging steels. Features which may be simultaneously revealed using Glyceregia include prior austenite grain boundaries, martensitic structure, precipitates, titanium carbo-nitrides, and reverted austenite. The other etchants examined in this investigation typically reveal only a few of the microstructural features detailed above at any one time. 11 refs., 10 figs., 2 tabs.

  1. Steel industry wastes. [Wastewater treatment

    SciTech Connect

    Vachon, D.T.; Schmidt, J.W.; Schmidtke, N.W.

    1982-06-01

    A literature review dealing with waste processing of steel industry wastes is presented. The costs for the U.S. steel industry to comply with environmental standards are such that water reuse and recycling may be necessary. The review examines conventional coke plant wastewater treatments such as flotation, phenol extraction, ammonia stripping, and biological nitrification, and alternative treatment processes for blast furnace scrubber blowdown such as alkaline chlorination, ozonation, and reverse osmosis. A review of pickling operations and finishing processes is also included with their appropriate waste methods highlighted.

  2. Plating on stainless steel alloys

    SciTech Connect

    Dini, J.W.; Johnson, H.R.

    1981-09-11

    Quantitative adhesion data are presented for a variety of electroplated stainless steel type alloys. Results show that excellent adhesion can be obtained by using a Wood's nickel strike or a sulfamate nickel strike prior to final plating. Specimens plated after Wood's nickel striking failed in the deposit rather than at the interface between the substrate and the coating. Flyer plate quantitative tests showed that use of anodic treatment in sulfuric acid prior to Wood's nickel striking even further improved adhesion. In contrast activation of stainless steels by immersion or cathodic treatment in hydrochloric acid resulted in very reduced bond strengths with failure always occurring at the interface between the coating and substrate.

  3. Susceptibility of irradiated steels to hydrogen embrittlement

    NASA Technical Reports Server (NTRS)

    Rossin, A. D.

    1968-01-01

    Investigation determined whether irradiated pressure-vessel steels 4340 and 212-B are susceptible to hydrogen embrittlement and to catastrophic failure. Hydrogen-charging conditions which completely embrittled 4340 steel had negligible effect on 212-B steel in tensile and delayed-failure tests.

  4. Steel erected at A-3 Test Stand

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Fabricated steel began arriving by truck Oct. 24 for construction of the A-3 Test Stand that will be used to test the engine for the nation's next generation of moon rockets. Within days workers from Lafayette Steel Erector Inc. began assembling the 16 steel stages needed on the foundation and footings poured in the previous year.

  5. Steeling and Resilience in Art Education

    ERIC Educational Resources Information Center

    Heise, Donalyn

    2014-01-01

    Steel is an incredibly strong alloy of iron and carbon. Due to its incredible strength and durability, this resilient material is commonly used for constructing buildings. The transitive verb "steeling" is defined in Miriam-Webster dictionary as "to fill with resolution or determination, as in, she 'steeled herself to face the…

  6. Teaching Steel Connections Using an Interactive Virtual Steel Sculpture

    ERIC Educational Resources Information Center

    Moaveni, Saeed; Chou, Karen C.

    2015-01-01

    Steel connections play important roles in the integrity of a structure, and many structural failures are attributed to connection failures. Connections are the glue that holds a structure together. The failures of the Hartford Coliseum in 1977, the Hyatt Regency Hotel in Kansas City in 1980, and the I-35W Bridge in Minneapolis in 2007 are all…

  7. Superhard Nanocrystalline Homometallic Stainless Steel on Steel for Seamless Coatings

    NASA Technical Reports Server (NTRS)

    Tobin, Eric J.; Hafley, R. (Technical Monitor)

    2002-01-01

    The objective of this work is to deposit nanocrystalline stainless steel onto steel substrates (homometallic) for enhanced wear and corrosion resistance. Homometallic coatings provide superior adhesion, and it has been shown that ultrafine-grained materials exhibit the increased hardness and decreased permeability desired for protective coatings. Nanocrystals will be produced by controlling nucleation and growth and use of an ion beam during deposition by e-beam evaporation or sputtering. Phase I is depositing 31 6L nanocrystalline stainless steel onto 31 6L stainless steel substrates. These coatings exhibit hardnesses comparable to those normally obtained for ceramic coatings such ZrO2, and possess the superior adhesion of seamless, homometallic coatings. Hardening the surface with a similar material also enhances adhesion, by avoiding problems associated with thermal and lattice mismatch. So far we have deposited nanocrystalline homometallic 316L stainless steel coatings by varying the ions and the current density of the ion beams. For all deposition conditions we have produced smooth, uniform, superhard coatings. All coatings exhibit hardness of at least 200% harder than that of bulk materials. Our measurements indicate that there is a direct relationship between nanohardness and the current density of the ion beam. Stress measurements indicate that stress in the films is increasingly proportional to current density of the ion beam. TEM, XPS, and XRD results indicate that the coated layers consist of FCC structure nanocrystallites with a dimension of about 10 to 20 nm. The Ni and Mo concentration of these coating are lower than those of bulk 316L but the concentration of Cr is higher.

  8. GALVANIZED STEEL: NATIONAL DISTRIBUTION STUDY

    EPA Science Inventory

    This report describes a field survey done to observe the extent and application of bare galvanized steel in the United States. or purposes of the analysis, the conterminous 48 states were grouped into four regions. ndustrial and rural areas were considered In the study which exam...

  9. Precision machining of steel decahedrons

    NASA Technical Reports Server (NTRS)

    Abernathy, W. J.; Sealy, J. R.

    1972-01-01

    Production of highly accurate decahedron prisms from hardened stainless steel is discussed. Prism is used to check angular alignment of mounting pads of strapdown inertial guidance system. Accuracies obtainable using recommended process and details of operation are described. Photographic illustration of production device is included.

  10. 60 Years of duplex stainless steel applications

    SciTech Connect

    Olsson, J.; Liljas, M.

    1994-12-31

    In this paper the history of wrought duplex stainless steel development and applications is described. Ferritic-austenitic stainless steels were introduced only a few decades after stainless steels were developed. The paper gives details from the first duplex stainless steels in the 1930`s to the super duplex stainless steel development during the 1980`s. During the years much effort has been devoted to production and welding metallurgy as well as corrosion research of the duplex stainless steels. Therefore, duplex stainless steels are to-day established in a wide product range. Numerous important applications are exemplified. In most cases the selection of a duplex steel has been a result of the combination high strength excellent corrosion resistance. In the pulp and paper industry the most interesting use is as vessel material in digesters. For chemical process industry, the duplex steels are currently used in heat exchangers. The largest application of duplex steels exists in the oil and gas/offshore industry. Hundreds of kms of pipelines are installed and are still being installed. An increased use of duplex steels is foreseen in areas where the strength is of prime importance.

  11. Corrosion behavior of 2205 duplex stainless steel.

    PubMed

    Platt, J A; Guzman, A; Zuccari, A; Thornburg, D W; Rhodes, B F; Oshida, Y; Moore, B K

    1997-07-01

    The corrosion of 2205 duplex stainless steel was compared with that of AISI type 316L stainless steel. The 2205 stainless steel is a potential orthodontic bracket material with low nickel content (4 to 6 wt%), whereas the 316L stainless steel (nickel content: 10 to 14 wt%) is a currently used bracket material. Both stainless steels were subjected to electrochemical and immersion (crevice) corrosion tests in 37 degrees C, 0.9 wt% sodium chloride solution. Electrochemical testing indicates that 2205 has a longer passivation range than 316L. The corrosion rate of 2205 was 0.416 MPY (milli-inch per year), whereas 316L exhibited 0.647 MPY. When 2205 was coupled to 316L with equal surface area ratio, the corrosion rate of 2205 reduced to 0.260 MPY, indicating that 316L stainless steel behaved like a sacrificial anode. When 316L is coupled with NiTi, TMA, or stainless steel arch wire and was subjected to the immersion corrosion test, it was found that 316L suffered from crevice corrosion. On the other hand, 2205 stainless steel did not show any localized crevice corrosion, although the surface of 2205 was covered with corrosion products, formed when coupled to NiTi and stainless steel wires. This study indicates that considering corrosion resistance, 2205 duplex stainless steel is an improved alternative to 316L for orthodontic bracket fabrication when used in conjunction with titanium, its alloys, or stainless steel arch wires. PMID:9228844

  12. STEFINS: a steel freezing integral simulation program

    SciTech Connect

    Frank, M.V.

    1980-09-01

    STEFINS (STEel Freezing INtegral Simulation) is a computer program for the calculation of the rate of solidification of molten steel on solid steel. Such computations arize when investigating core melt accidents in fast reactors. In principle this problem involves a coupled two-dimensional thermal and hydraulic approach. However, by physically reasonable assumptions a decoupled approach has been developed. The transient solidification of molten steel on a cold wall is solved in the direction normal to the molten steel flow and independent from the solution for the molten steel temperature and Nusselt number along the direction of flow. The solutions to the applicable energy equations have been programmed in cylindrical and slab geometries. Internal gamma heating of steel is included.

  13. Dendritic inhomogeneity of stainless maraging steels

    SciTech Connect

    Krasnikova, S.I.; Drobot, A.V.; Shmelev, A.Y.; Vukelich, S.B.

    1986-03-01

    The authors investigated dendritic inhomogeneity in industrial ingots 630 mm (steel I) in diameter and 500 mm (steel II) in diameter. The variation in the degree of dendritic inhomogeneity was investigated over the height of the ingots and across the sections on an MS-46 microprobe. It was established that the elements can be placed in the following order in accordance with the degree of reduction in the liquation factor: titanium, molybdenum, nickel, chromium, and cobalt. Titanium and molybdenum exhibit forward liquation in both steels, and chromium in steel II. The distribution of nickel and chromium in the steel I ingots and cobalt in the steel II ingots is unconventional. Dendritic inhomogeneity, which must be considered in assigning the heat treatment for finished articles, develops during the crystallization of stainless maraging steels.

  14. Nickel release from stainless steels.

    PubMed

    Haudrechy, P; Mantout, B; Frappaz, A; Rousseau, D; Chabeau, G; Faure, M; Claudy, A

    1997-09-01

    In 1994, a study of nickel release and allergic contact dermatitis from nickel-plated metals and stainless steels was published in this journal. It was shown that low-sulfur stainless steel grades like AISI 304, 316L or 430 (S < or = 0.007%) release less than 0.03 microgram/cm2/week of nickel in acid artificial sweat and elicit no reactions in patients already sensitized to nickel. In contrast, nickel-plated samples release around 100 micrograms/cm2/week of Ni and high-sulfur stainless steel (AISI 303-S approximately 0.3%) releases about 1.5 micrograms/cm2/week in this acid artificial sweat. Applied on patients sensitized to nickel, these metals elicit positive reactions in 96% and 14%, respectively, of the patients. The main conclusion was that low-sulfur stainless steels like AISI 304, 316L or 430, even when containing Ni, should not elicit nickel contact dermatitis, while metals having a mean corrosion resistance like a high-sulfur stainless steel (AISI 303) or nickel-plated steel should be avoided. The determining characteristic was in fact the corrosion resistance in chloride media, which, for stainless steels, is connected, among other factors, to the sulfur content. Thus, a question remained concerning the grades with an intermediate sulfur content, around 0.03%, which were not studied. They are the object of the study presented in this paper. 3 tests were performed: leaching experiments, dimethylglyoxime and HNO3 spot tests, and clinical patch tests; however, only stainless steels were tested: a low-sulfur AISI 304 and AISI 303 as references and 3 grades with a sulfur content around 0.03%: AISI 304L, AISI 304L added with Ca, AISI 304L+Cu. Leaching experiments showed that the 4 non-resulfurised grades released less than 0.5 microgram/cm2/week in acid sweat while the reulfurized AISI 303 released around or more than 0.5 microgram/cm2/week. This is explained by the poorer corrosion resistance of the resulfurized grade. Yet all these grades had the same

  15. Steel project fact sheet: Steel reheating for further processing

    SciTech Connect

    1998-04-01

    Steel reheating is an energy-intensive process requiring uniform temperature distribution within reheating furnaces. Historically, recuperators have ben used to preheat combustion air, thereby conserving energy. More recent innovations include oxygen enrichment and the use of regenerative burners, which provide higher preheat air temperatures than recuperators. These processes have limitations such as equipment deterioration, decreasing energy efficiency over time, high maintenance costs, and increased NO{sub x} emissions with increased air preheat temperature, unless special equipment is used. Praxair, Inc., supplier of oxygen and other industrial gases to the steel industry, proposes to introduce an innovative oxy-fuel burner technology (using 100% oxygen) to the steel reheating industry. Oxy-fuel combustion reduces or eliminates nitrogen in combustion air and substantially reduces waste heat carried out with flue gas. Based on technology currently used in the glass, hazardous waste, and aluminum industries, Praxair has developed and patented low temperature, oxy-fuel burners that can be used in high temperature industrial furnaces where temperature uniformity is critical and extremely low NO{sub x} emissions are desired. The technical goal of the project is to demonstrate the use of oxy-fuel burners in a slab reheat furnace while reducing energy consumption by 45% and NO{sub x} emissions by 90% within the converted furnace zones. Successful implementation of this technology also will eliminate the need to periodically replace recuperators and install NO{sub x} removal equipment.

  16. A mortality study among mild steel and stainless steel welders.

    PubMed Central

    Moulin, J J; Wild, P; Haguenoer, J M; Faucon, D; De Gaudemaris, R; Mur, J M; Mereau, M; Gary, Y; Toamain, J P; Birembaut, Y

    1993-01-01

    A mortality study was carried out in conjunction with the European mortality study among welders coordinated by the International Agency for Research on Cancer (IARC). The study was aimed at assessing risks for lung cancer in relation to exposure to asbestos, welding fumes containing chromium and nickel, and tobacco smoke. The study included a cohort of 2721 welders and an internal comparison group of 6683 manual workers employed in 13 factories in France. The mortality of the two cohorts was studied from 1975 to 1988 by the historical prospective method. Job histories of welders were traced including welding processes used, metals welded, and proportion of worktime spent in welding. Data on smoking habits were collected from medical records. The observed number of deaths were compared with those expected (standardised mortality ratio (SMR)) based on national rates with adjustments for age, sex, and calendar time. The smoking habits of 87% of the whole study population were known. The distribution of welders and controls according to smoking was not statistically different. The overall mortality was slightly higher for welders (SMR = 1.02, 95% confidence interval (95% CI) 0.89-1.18) than for controls (SMR = 0.91, 95% CI 0.84-0.99). For lung cancer, the SMR was 1.24 (95% CI 0.75-1.94) for welders, whereas the corresponding value was lower for controls (SMR = 0.94, 95% CI 0.68-1.26). The SMR for lung cancer was 1.59 among non-shipyard mild steel welders (95% CI 0.73-3.02). This contrasted with the results for all stainless steel welders (SMR = 0.92, 95% CI 0.19-2.69), and for stainless steel welders predominantly exposed to chromium VI (SMR = 1.03, 95% CI 0.12-3.71). Moreover, SMRs for lung cancer for mild steel welders tended to increase with duration of exposure and time since first exposure, leading to significant excesses for duration > or = 20 years and latency > or = 20 years. Such a pattern was not found for stainless steel welders. PMID:8457490

  17. Steel Industry Energy Bandwidth Study

    SciTech Connect

    none,

    2004-10-01

    ITP conducted a study on energy use and potential savings, or "bandwidth" study, in major steelmaking processes. Intended to provide a realistic estimate of the potential amount of energy that can be saved in an industrial process, the "bandwidth" refers to the difference between the amount of energy that would be consumed in a process using commercially available technology versus the minimum amount of energy needed to achieve those same results based on the 2nd law of thermodynamics. The Steel Industry Energy Bandwidth Study (PDF 133 KB) also estimates steel industry energy use in the year 2010, and uses that value as a basis for comparison against the minimum requirements. This energy savings opportunity for 2010 will aid focus on longer term R&D.

  18. Underwater wet welding of steel

    SciTech Connect

    Ibarra, S.; Liu, S.; Olson, D.L.

    1995-05-01

    Underwater wet welding is conducted directly in water with the shielded metal arc (SMA) and flux cored arc (FCA) welding processes. Underwater wet welding has been demonstrated as an acceptable repair technique down to 100 meters (325 ft.) in depth, but wet welds have been attempted on carbon steel structures down to 200 meters (650 ft.). The primary purpose of this interpretive report is to document and evaluate current understanding of metallurgical behavior of underwater wet welds so that new welding consumables can be designed and new welding practices can be developed for fabrication and repair of high strength steel structures at greater depths. First the pyrometallurgical and physical metallurgy behaviors of underwater weldments are discussed. Second, modifications of the welding consumables and processes are suggested to enhance the ability to apply wet welding techniques.

  19. Longer Life for Steel Structures

    NASA Technical Reports Server (NTRS)

    1990-01-01

    IC 531 is a coating manufactured and marketed by Inorganic Coatings, Inc. The coating was developed by Goddard to protect structures at Kennedy Space Center. It is a high ratio potassium silicate formula. The coating is water based, nontoxic, and nonflammable. It generates no volatile organic compounds nor hazardous chemical waste, and bonds to steel in 30 minutes. At the present time, no one can say for sure how long IC 531's effective lifetime is. Some of the original Goddard test applications of 1976 are still going strong after lengthy exposure to the Sun, salt and moisture. Says IC in company literature: 'IC 531 offers virtually permanent protection for steel. We predict it will protect structures for well beyond 25 years. If necessary, it is infinitely maintainable; if damaged, it can easily be touched up with more IC 531.'

  20. Welding of high chromium steels

    NASA Technical Reports Server (NTRS)

    Miller, W B

    1928-01-01

    A brief description is given of different groups of high chromium steels (rustless iron and stainless steels) according to their composition and more generally accepted names. The welding procedure for a given group will be much the same regardless of the slight variations in chemical composition which may exist within a certain group. Information is given for the tensile properties (yield point and ultimate strength) of metal sheets and welds before and after annealing on coupons one and one-half inches wide. Since welds in rustless iron containing 16 to 18 percent chromium and 7 to 12 percent nickel show the best combination of strength and ductility in the 'as welded' or annealed condition, it is considered the best alloy to use for welded construction.

  1. Bond characteristics of steel fiber and deformed reinforcing steel bar embedded in steel fiber reinforced self-compacting concrete (SFRSCC)

    NASA Astrophysics Data System (ADS)

    Aslani, Farhad; Nejadi, Shami

    2012-09-01

    Steel fiber reinforced self-compacting concrete (SFRSCC) is a relatively new composite material which congregates the benefits of the self-compacting concrete (SCC) technology with the profits derived from the fiber addition to a brittle cementitious matrix. Steel fibers improve many of the properties of SCC elements including tensile strength, ductility, toughness, energy absorption capacity, fracture toughness and cracking. Although the available research regarding the influence of steel fibers on the properties of SFRSCC is limited, this paper investigates the bond characteristics between steel fiber and SCC firstly. Based on the available experimental results, the current analytical steel fiber pullout model (Dubey 1999) is modified by considering the different SCC properties and different fiber types (smooth, hooked) and inclination. In order to take into account the effect of fiber inclination in the pullout model, apparent shear strengths (τ (app)) and slip coefficient (β) are incorporated to express the variation of pullout peak load and the augmentation of peak slip as the inclined angle increases. These variables are expressed as functions of the inclined angle (ϕ). Furthurmore, steel-concrete composite floors, reinforced concrete floors supported by columns or walls and floors on an elastic foundations belong to the category of structural elements in which the conventional steel reinforcement can be partially replaced by the use of steel fibers. When discussing deformation capacity of structural elements or civil engineering structures manufactured using SFRSCC, one must be able to describe thoroughly both the behavior of the concrete matrix reinforced with steel fibers and the interaction between this composite matrix and discrete steel reinforcement of the conventional type. However, even though the knowledge on bond behavior is essential for evaluating the overall behavior of structural components containing reinforcement and steel fibers

  2. Bond characteristics of steel fiber and deformed reinforcing steel bar embedded in steel fiber reinforced self-compacting concrete (SFRSCC)

    NASA Astrophysics Data System (ADS)

    Aslani, Farhad; Nejadi, Shami

    2012-09-01

    Steel fiber reinforced self-compacting concrete (SFRSCC) is a relatively new composite material which congregates the benefits of the self-compacting concrete (SCC) technology with the profits derived from the fiber addition to a brittle cementitious matrix. Steel fibers improve many of the properties of SCC elements including tensile strength, ductility, toughness, energy absorption capacity, fracture toughness and cracking. Although the available research regarding the influence of steel fibers on the properties of SFRSCC is limited, this paper investigates the bond characteristics between steel fiber and SCC firstly. Based on the available experimental results, the current analytical steel fiber pullout model (Dubey 1999) is modified by considering the different SCC properties and different fiber types (smooth, hooked) and inclination. In order to take into account the effect of fiber inclination in the pullout model, apparent shear strengths ( τ ( app)) and slip coefficient ( β) are incorporated to express the variation of pullout peak load and the augmentation of peak slip as the inclined angle increases. These variables are expressed as functions of the inclined angle ( ϕ). Furthurmore, steel-concrete composite floors, reinforced concrete floors supported by columns or walls and floors on an elastic foundations belong to the category of structural elements in which the conventional steel reinforcement can be partially replaced by the use of steel fibers. When discussing deformation capacity of structural elements or civil engineering structures manufactured using SFRSCC, one must be able to describe thoroughly both the behavior of the concrete matrix reinforced with steel fibers and the interaction between this composite matrix and discrete steel reinforcement of the conventional type. However, even though the knowledge on bond behavior is essential for evaluating the overall behavior of structural components containing reinforcement and steel fibers

  3. A study of Damascus steel

    SciTech Connect

    Berge, P.

    1995-02-16

    The Damascus sword has been an article of fascination for many years to blade collectors and metallurgists alike. The blades were given their name by Europeans who encountered these blades which originated from Damascus, Syria. They are best known for the appearance of the blade face. Genuine Damascus blades show swirling patterns of alternating light and dark regions which are due to the microstructure of the steel. The microstructure consists of arrays of well rounded cementite patterns in a matrix of either pearlite, bainite, or martensite. When this structure is etched the matrix will turn dark leaving the cementite particles light. Although many blades were produced over the centuries, while some of the process is known the making of a genuine Damascus blade today is generally considered a lost art. Many scientists have studied the subject in an attempt to understand the complex process by which the clustered arrays of cementite particles develop in the steel blades. The most prominent theories to date are presented in the General Introduction to this thesis. The thesis is divided into four main parts. In the first part, four proposed mechanisms of cementite cluster sheet formation as they relate to the banding theory are introduced. Experiments to investigate these mechanisms are presented. In Part II, collaborative research focused on the methodology of the reconstructed process for making Damascus steel is presented. In the third part, a study into the graphitization of the reconstructed blades is presented. In Part IV, experimental attempts at producing Damascus steel ingots in the laboratory are presented.

  4. Steel Collet For Welding Electrodes

    NASA Technical Reports Server (NTRS)

    Gilbert, Jeffrey L.; Gutow, David A.; Burley, Richard K.; Fogul, Irving

    1992-01-01

    Improved steel collet holds electrode for tungsten inert-gas welding but allows quick and easy replacement. Also ensures reliable arc starting. Slip-on compression ring compresses tapered section of body of collet around inner end of welding electrode. Collet mounted in receptacle below stack of lenses and filters in coaxial-vision welding torch. Blind hole in collet protects outermost lens from damage by electrode.

  5. Determination of zirconium in steels.

    PubMed

    Iyer, C S; Asari, T P

    1989-03-01

    The determination of zirconium in the range 0.01-0.20% is required for some special alloy steels. A method has been developed, based on initial removal of iron as its chloro-complex by extraction with methyl isobutyl ketone, followed by further extraction after addition of potassium thiocyanate, and determination of the zirconium left in the aqueous phase, with Arsenazo III. The absorbance is measured at 665 nm. PMID:18964725

  6. Nano-composite stainless steel

    DOEpatents

    Dehoff, Ryan R.; Blue, Craig A.; Peter, William H.; Chen, Wei; Aprigliano, Louis F.

    2015-07-14

    A composite stainless steel composition is composed essentially of, in terms of wt. % ranges: 25 to 28 Cr; 11 to 13 Ni; 7 to 8 W; 3.5 to 4 Mo; 3 to 3.5 B; 2 to 2.5 Mn; 1 to 1.5 Si; 0.3 to 1.7 C; up to 2 O; balance Fe. The composition has an austenitic matrix phase and a particulate, crystalline dispersed phase.

  7. Steel Industry Marginal Opportunity Analysis

    SciTech Connect

    none,

    2005-09-01

    The Steel Industry Marginal Opportunity Analysis (PDF 347 KB) identifies opportunities for developing advanced technologies and estimates both the necessary funding and the potential payoff. This analysis determines what portion of the energy bandwidth can be captured through the adoption of state-of-the-art technology and practices. R&D opportunities for addressing the remainder of the bandwidth are characterized and plotted on a marginal opportunity curve.

  8. Nickel: makes stainless steel strong

    USGS Publications Warehouse

    Boland, Maeve A.

    2012-01-01

    Nickel is a silvery-white metal that is used mainly to make stainless steel and other alloys stronger and better able to withstand extreme temperatures and corrosive environments. Nickel was first identified as a unique element in 1751 by Baron Axel Fredrik Cronstedt, a Swedish mineralogist and chemist. He originally called the element kupfernickel because it was found in rock that looked like copper (kupfer) ore and because miners thought that "bad spirits" (nickel) in the rock were making it difficult for them to extract copper from it. Approximately 80 percent of the primary (not recycled) nickel consumed in the United States in 2011 was used in alloys, such as stainless steel and superalloys. Because nickel increases an alloy's resistance to corrosion and its ability to withstand extreme temperatures, equipment and parts made of nickel-bearing alloys are often used in harsh environments, such as those in chemical plants, petroleum refineries, jet engines, power generation facilities, and offshore installations. Medical equipment, cookware, and cutlery are often made of stainless steel because it is easy to clean and sterilize. All U.S. circulating coins except the penny are made of alloys that contain nickel. Nickel alloys are increasingly being used in making rechargeable batteries for portable computers, power tools, and hybrid and electric vehicles. Nickel is also plated onto such items as bathroom fixtures to reduce corrosion and provide an attractive finish.

  9. Microstructures in laser welded high strength steels

    NASA Astrophysics Data System (ADS)

    Rizzi, P.; Bellingeri, S.; Massimino, F.; Baldissin, D.; Battezzati, L.

    2009-01-01

    In this work, the effect of laser welding on the microstructure was studied for three Advanced High Strength Steels: transformation induced plasticity steel (TRIP), dual phase steel (DP) and martensitic steel. Two sheets of the same steel were laser welded and a microstructural study was performed by optical microscopy, scanning electron microscopy and X-ray diffraction. For all samples the welded zone was constituted by martensite and the heat affected zone shows a continuous change in microstructure depending on temperatures reached and on the different cooling rates. The change in mechanical properties in the welded area was followed by Vickers micro-hardness measurements. Quasi binary phase diagrams were calculated and, according to position of T0 lines, it was deduced that austenite is the primary phase forming during rapid solidification for all steels.

  10. A Method for Imaging Steel Bars Behind a Ferrous Steel Boundary

    SciTech Connect

    Fernandes, B.; Miller, G.; Zaid, M.; Gaydecki, P.

    2006-03-06

    A system for detecting steel objects behind ferrous steel boundaries is described. It may be used to image steel reinforcing bars in concrete, where a steel sheet exists between the bars and the surface. The sensor comprises a transmitter, receiver and a dummy coil, which cancels cross-talk and enhances the signal from the bars. It is possible to penetrate a 2mm thick sheet at 125 Hz and image 16 mm diameter bars placed underneath.

  11. A Method for Imaging Steel Bars Behind a Ferrous Steel Boundary

    NASA Astrophysics Data System (ADS)

    Fernandes, B.; Miller, G.; Zaid, M.; Gaydecki, P.

    2006-03-01

    A system for detecting steel objects behind ferrous steel boundaries is described. It may be used to image steel reinforcing bars in concrete, where a steel sheet exists between the bars and the surface. The sensor comprises a transmitter, receiver and a dummy coil, which cancels cross-talk and enhances the signal from the bars. It is possible to penetrate a 2mm thick sheet at 125 Hz and image 16 mm diameter bars placed underneath.

  12. The Structure and Mechanical Properties of Bridge Steel Weldings With Glass-Steel Liners

    NASA Astrophysics Data System (ADS)

    Muzalev, V. N.; Semukhin, B. S.; Danilov, V. I.

    2016-04-01

    A new technology is developed for welding multi-span bridge constructions. The mechanical properties and structure of the low-carbon bridge steel welds have been studied. The welding parameters and application of steel-glass liners provide for long-term service of steel constructions in conformity with the welding industry specifications.

  13. Fracture Toughness of Functionally Graded Steels

    NASA Astrophysics Data System (ADS)

    Nazari, Ali; Mohandesi, Jamshid Aghazadeh; Riahi, Shadi

    2012-04-01

    In this study, fracture toughness of functionally graded steels in both crack divider and crack arrester configurations has been studied. Spot-welded plain carbon steel and austenitic stainless steel with different thicknesses and arrangements were used as electrodes of electroslag remelting to produce functionally graded steels. Fracture toughness of the specimens in crack divider configuration was found to depend on the arrangements of the primary electrodes' pieces together with the type of the containing phases. In crack arrester configuration, the fracture toughness was found to depend on the crack tip position and the distance of the crack tip with respect to the bainitic or martensitic intermediate layers.

  14. Corrosion of stainless steel, 2. edition

    SciTech Connect

    Sedriks, A.J.

    1996-10-01

    The book describes corrosion characteristics in all the major and minor groups of stainless steels, namely, in austenitic, ferritic, martensitic, duplex, and precipitation hardenable steels. Several chapters are spent on those special forms of corrosion that are investigated in the great detail in stainless steels, namely, pitting corrosion, crevice corrosion, and stress corrosion cracking. The influences of thermal treatment (heat affected zone cases), composition, and microstructure on corrosion are given good coverage. Corrosive environments include high temperature oxidation, sulfidation as well as acids, alkalis, various different petroleum plant environments, and even human body fluids (stainless steels are commonly used prosthetic materials).

  15. FINAL REPORT: Reduction in Energy Consumption and Variability in Steel Foundry Operations

    SciTech Connect

    F. Peters

    2005-05-24

    This project worked to improve the efficiency of the steel casting industry by reducing the variability that occurs because of process and product variation. The project focused on the post shakeout operations since roughly half of the production costs are in this area. These improvements will reduce the amount of variability, making it easier to manage the operation and improve the competitiveness. The reduction in variability will also reduce the need for many rework operations, which will result in a direct reduction of energy usage, particularly by the reduction of repeated heat treatment operations. Further energy savings will be realized from the reduction of scrap and reduced handling. Field studies were conducted at ten steel foundries that represented the U.S. steel casting industry, for a total of over 100 weeks of production observation. These studies quantified the amount of variability, and looked toward determining the source. A focus of the data collected was the grinding operations since this is a major effort in the cleaning room, and it represents the overall casting quality. The grinding was divided into two categories, expected and unexpected. Expected grinding is that in which the location of the effort is known prior to making the casting, such as smoothing parting lines, gates, and riser contacts. Unexpected grinding, which was approximately 80% of the effort, was done to improve the surfaces at weld repair locations, to rectify burnt on sand, and other surface anomalies at random locations. Unexpected grinding represents about 80% of the grinding effort. By quantifying this effort, the project raised awareness within the industry and the industry is continuing to make improvements. The field studies showed that the amount of variation of grinding operations (normalized because of the diverse set of parts studied) was very consistent across the industry. The field studies identified several specific sources that individually contributed to

  16. North and west facades of crucible steel building; looking southeast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    North and west facades of crucible steel building; looking southeast - Bethlehem Steel Corporation, South Bethlehem Works, Crucible Steel Plant, Along Lehigh River, North of Fourth Street, West of Minsi Trail Bridge, Bethlehem, Northampton County, PA

  17. 37. Photocopy of photograph. STEEL PLANT, OPEN HOUSE INSIDE PLANT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. Photocopy of photograph. STEEL PLANT, OPEN HOUSE INSIDE PLANT AT TIME OF ITS OPENING, 1910. (From the Bethlehem Steel Corporation Collection, Seattle, WA) - Irondale Iron & Steel Plant, Port Townsend, Jefferson County, WA

  18. 30. Photocopy of photograph. STEEL PLANT, OPEN HEARTH FURNACE CHARGING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. Photocopy of photograph. STEEL PLANT, OPEN HEARTH FURNACE CHARGING CREW, 1910. (From the Bethlehem Steel Corporation Colletion, Seattle, WA) - Irondale Iron & Steel Plant, Port Townsend, Jefferson County, WA

  19. Use of ferritic steels in breeder reactors worldwide

    SciTech Connect

    Patriarca, P.

    1983-01-01

    The performance of LMFBR reactor steam generator materials is reviewed. Tensile properties of stainless steel-304, stainless steel-316, chromium-molybdenum steels, and Incoloy 800H are presented for elevated temperatures.

  20. Steel shear walls, behavior, modeling and design

    SciTech Connect

    Astaneh-Asl, Abolhassan

    2008-07-08

    In recent years steel shear walls have become one of the more efficient lateral load resisting systems in tall buildings. The basic steel shear wall system consists of a steel plate welded to boundary steel columns and boundary steel beams. In some cases the boundary columns have been concrete-filled steel tubes. Seismic behavior of steel shear wall systems during actual earthquakes and based on laboratory cyclic tests indicates that the systems are quite ductile and can be designed in an economical way to have sufficient stiffness, strength, ductility and energy dissipation capacity to resist seismic effects of strong earthquakes. This paper, after summarizing the past research, presents the results of two tests of an innovative steel shear wall system where the boundary elements are concrete-filled tubes. Then, a review of currently available analytical models of steel shear walls is provided with a discussion of capabilities and limitations of each model. We have observed that the tension only 'strip model', forming the basis of the current AISC seismic design provisions for steel shear walls, is not capable of predicting the behavior of steel shear walls with length-to-thickness ratio less than about 600 which is the range most common in buildings. The main reasons for such shortcomings of the AISC seismic design provisions for steel shear walls is that it ignores the compression field in the shear walls, which can be significant in typical shear walls. The AISC method also is not capable of incorporating stresses in the shear wall due to overturning moments. A more rational seismic design procedure for design of shear walls proposed in 2000 by the author is summarized in the paper. The design method, based on procedures used for design of steel plate girders, takes into account both tension and compression stress fields and is applicable to all values of length-to-thickness ratios of steel shear walls. The method is also capable of including the effect of

  1. Evaluation of Steel Cleanliness in a Steel Deoxidized Using Al

    NASA Astrophysics Data System (ADS)

    Castro-Cedeño, Edgar-Ivan; Herrera-Trejo, Martín; Castro-Román, Manuel; Castro-Uresti, Fabián; López-Cornejo, Monserrat

    2016-06-01

    The effect of magnesium in the aluminum used as a deoxidizer on the cleanliness of steel was studied throughout a steelmaking route for the production of thin slabs. Two deoxidizers with different Mg contents were used. The Mg content of a "typical" deoxidizer was ~0.5 wt pct Mg, whereas that for an alternative deoxidizer was ~2 wt pct Mg. The inclusion population at different stages of the steelmaking process was characterized in terms of chemical composition, number, and size distribution. The inclusion modification path shows that the solid Al2O3 and Al2O3-MgO inclusions formed in the early stage of the steel ladle treatment are modified into Al2O3-MgO-CaO liquid and MgO-Al2O3-liquid inclusions. Although some slight differences were observed in the ladle furnace samples, the chemical composition of inclusions was similar in the samples taken at the mold of the continuous casting, regardless of the deoxidizer used. Gumbel, generalized extreme value (GEV), and generalized Pareto (GP) distributions were used for the description of the size distribution. The GEV and GP distributions resulted in proper distributions to describe the evolution of size distribution throughout the steelmaking process. Furthermore, no statistically significant differences between inclusion size distributions resulting from the use of either deoxidizer were found.

  2. Is stainless steel really "stainless"?

    PubMed

    Porteous, Joan

    2011-06-01

    Initial purchase and replacement costs for surgical instrumentation are significant components in today's operating room budgets. OR staff and medical device reprocessing personnel work together as a team to ensure effective management of this valuable commodity. The purpose of this article is to discuss the composition of stainless steel surgical instruments, to identify processes to minimize damage to instruments caused by staining, corrosion, and pitting, and to utilize that information to describe effective measures to manage instrumentation in both the OR and reprocessing areas. PMID:21823503

  3. Chromizing of 3Cr Steel

    SciTech Connect

    Ravi, Vilupanur; Harrison, Bradley; Koch, Jordan; Ly, Alexander; Schissler, Andrew; Pint, Bruce A; Haynes, James A

    2011-01-01

    Grade 315 steel (Fe-2.9 Cr-1.7 W-0.7 Mo-0.3 Mn-0.3 Si-0.2 V-0.1 Ni-0.13 C-0.01 N) was chromized by the halide-activated pack cementation (HAPC) process. Key process parameters, i.e., coating temperatures and pack compositions, were investigated. Ammonium chloride-activated packs in the 700-1000 C range produced coatings nominally in the 1-8 {micro}m range, as determined by optical and scanning electron microscopy (SEM). Coatings applied in the 900-1000 C temperature range resulted in Cr-rich coatings. The predominant phase in the coating was identified as Cr23C6 by X-ray diffraction. In addition, the presence of chromium nitride, Cr2N, was observed in the coating. The power generation industry is faced with an ever-increasing demand for energy while simultaneously having to reduce carbon emissions. These goals can be facilitated by increasing plant efficiency through the use of higher operating temperatures and pressures. Traditional construction materials, e.g., the ferritic Grade 22 high strength low alloy steel, are limited to operations below {approx} 550 C. Therefore, new materials are required for future plants designed to operate up to 650 C and possibly higher. These new materials need to have improved tensile strength, ductility, toughness, corrosion resistance, and creep properties at elevated temperatures. Oak Ridge National Laboratory (ORNL) is investigating the oxidation and creep behavior of various coatings on Grade 315 steel (Fe-2.9 Cr-1.7 W-0.7 Mo-0.3 Mn-0.3 Si-0.2 V-0.1 Ni-0.13 C-0.01 N), a super-bainitic steel developed for superior creep properties. Thin, chemical vapor-deposited (CVD) aluminide coatings were used to compensate for the reduced corrosion and oxidation resistance that resulted from the low chromium content of the alloy. However, the aluminized Grade 315 alloys performed less-than-favorably under conditions relevant to fossil boilers, leading to the conclusion that higher chromium contents are required for the formation of

  4. Help for the Steel Industry

    NASA Astrophysics Data System (ADS)

    1991-01-01

    A collaboration between NASA Lewis Research Center (LRC) and Gladwin Engineering resulted in the adaptation of aerospace high temperature metal technology to the continuous casting of steel. The continuous process is more efficient because it takes less time and labor. A high temperature material, once used on the X-15 research plane, was applied to metal rollers by a LRC developed spraying technique. Lewis Research Center also supplied mold prototype of metal composites, reducing erosion and promoting thermal conductivity. Rollers that previously cracked due to thermal fatigue, lasted longer. Gladwin's sales have increased, and additional NASA-developed innovations are anticipated.

  5. Corrosion behaviour of galvanized steel and electroplating steel in aqueous solution: AC impedance study and XPS

    NASA Astrophysics Data System (ADS)

    Lebrini, M.; Fontaine, G.; Gengembre, L.; Traisnel, M.; Lerasle, O.; Genet, N.

    2008-08-01

    The efficiency of a new triazole derivative, namely, 2-{(2-hydroxyethyl)[(4-methyl-1 H-1,2,3-benzotriazol-1-yl)methyl]amino}ethanol (TTA) has been studied for corrosion inhibition of galvanized steel and electroplating steel in aqueous solution. Corrosion inhibition was studied using electrochemical impedance spectroscopy (EIS). These studies have shown that TTA was a very good inhibitor. Data obtained from EIS show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPE) has been used. The corrosion behaviour of galvanized steel and electroplating steel in aqueous solution was also investigated in the presence of 4-methyl-1 H-benzotriazole (TTA unsubstituted) by EIS. These studies have shown that the ability of the molecule to adsorb on the steel surface was dependent on the group in triazole ring substituent. X-ray photoelectron spectroscopy surface analysis with TTA shows that it chemisorbed on surface of galvanized steel and electroplating steel.

  6. Clean steel technology -- Fundamental to the development of high performance steels

    SciTech Connect

    Wilson, A.D.

    1999-07-01

    The use of clean steel technology (low sulfur with calcium treatment for inclusion shape control) is a fundamental building block in the development of high performance plate steels. A brief review will be presented of the benefits of calcium treatment and its effect on non-metallic inclusions (sulfides and oxides) and reducing sulfur levels. During the past thirty years the requirements for low sulfur levels have been reduced from 0.010% maximum to 0.001% maximum. The effects of clean steel practices on specific properties will be reviewed including tensile ductility, Charpy V-notch and fracture toughness, fatigue crack propagation and hydrogen-induced-cracking resistance. Traditional low sulfur plate steel applications have included pressure vessels. offshore platforms, plastic injection molds and line-pipe skelp. More recent applications will be discussed including bridge steels, high strength structural steels to 130 ksi (897 MPa) minimum yield strength, 9% nickel steels for cryogenic applications, and military armor.

  7. A recycling process for dezincing steel scrap

    SciTech Connect

    Dudek, F.J.; Daniels, E.J. ); Morgan, W.A.; Kellner, A.W.; Harrison, J. )

    1992-01-01

    In response to the several-fold increase in consumption of galvanized steel in the last decade and the problems associated with refurnacing larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is electrowon as dendritic powder. The process is effective for zinc, lead, aluminum, and cadmium removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 1,000 tons of mostly baled scrap. A pilot plant to continuously treat loose scrap is under construction. Use of degalvanized steel scrap decreases raw materials and environmental compliance costs to steel- and iron-makers, may enable integrated steel producers to recycle furnace dusts to the sinter plant, and may enable EAF production of flat products without use of DRI or pig iron. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap.

  8. A recycling process for dezincing steel scrap

    SciTech Connect

    Dudek, F.J.; Daniels, E.J.; Morgan, W.A.; Kellner, A.W.; Harrison, J.

    1992-08-01

    In response to the several-fold increase in consumption of galvanized steel in the last decade and the problems associated with refurnacing larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is electrowon as dendritic powder. The process is effective for zinc, lead, aluminum, and cadmium removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 1,000 tons of mostly baled scrap. A pilot plant to continuously treat loose scrap is under construction. Use of degalvanized steel scrap decreases raw materials and environmental compliance costs to steel- and iron-makers, may enable integrated steel producers to recycle furnace dusts to the sinter plant, and may enable EAF production of flat products without use of DRI or pig iron. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap.

  9. Method for welding chromium molybdenum steels

    DOEpatents

    Sikka, Vinod K.

    1986-01-01

    Chromium-molybdenum steels exhibit a weakening after welding in an area adjacent to the weld. This invention is an improved method for welding to eliminate the weakness by subjecting normalized steel to a partial temper prior to welding and subsequently fully tempering the welded article for optimum strength and ductility.

  10. Ellie Mannette: Master of the Steel Drum.

    ERIC Educational Resources Information Center

    Svaline, J. Marc

    2001-01-01

    Presents an interview with Elliot ("Ellie") Mannette who has played a major role in the development and application of steel drums. States that he has spent most of his life designing and teaching the steel drums. Covers interview topics and background information on Mannette. (CMK)

  11. African Drum and Steel Pan Ensembles.

    ERIC Educational Resources Information Center

    Sunkett, Mark E.

    2000-01-01

    Discusses how to develop both African drum and steel pan ensembles providing information on teacher preparation, instrument choice, beginning the ensemble, and lesson planning. Includes additional information for the drum ensembles. Lists references and instructional materials, sources of drums and pans, and common note layout/range for steel pan…

  12. Low Mn alloy steel for cryogenic service

    DOEpatents

    Morris, J.W. Jr.; Niikura, M.

    A ferritic cryogenic steel which has a relatively low (about 4 to 6%) manganese content and which has been made suitable for use at cryogenic temperatures by a thermal cycling treatment followed by a final tempering. The steel includes 4 to 6% manganese, 0.02 to 0.06% carbon, 0.1 to 0.4% molybdenum and 0 to 3% nickel.

  13. Development of low activation Ferritic steels

    NASA Astrophysics Data System (ADS)

    Noda, T.; Abe, F.; Araki, H.; Okada, M.

    1986-11-01

    Fe-(2-15)%Cr-(0-4)%W-0.1%C and Fe-9%Cr-(0-l)%V-0.1%C steels were prepared on the basis of reduced activation of ferritic steels. Tempering characteristics of these alloys were studied as a preliminary evaluation of mechanical properties. Alloys except for 12-15%Cr, 9%Cr-4%W, and 9%Cr-1%V showed a single phase of martensite. Carbides which precipitated in as-tempered steels are M 23C 6, M 6C, and W 2C for Cr-W steels and M 23C 6 and V 4C 3 for Cr-V steels. The toughness of the alloys was examined with Charpy impact test. The minimum DBTT (ductile-brittle transition temperature) was observed at around 0.25 at% of W or V concentration for 9%Cr steels. 9%Cr-V steels were superior to commercial 9%Cr-2%Mo steel in the point of toughness. The order of alloying element with a low DBTT was V > Mo > W.

  14. Chem I Supplement: Chemistry of Steel Making.

    ERIC Educational Resources Information Center

    Sellers, Neal

    1980-01-01

    Provides information about the chemistry of steel making applicable to teaching secondary school science. Generalized chemical reactions describe the manufacture of steel from iron ore. Also discussed are raw materials, processing choices, and how various furnaces (blast, direct reduction, open hearth, basic oxygen, electric) work. (CS)

  15. VOLATILIZED LUBRICANT EMISSIONS FROM STEEL ROLLING OPERATIONS

    EPA Science Inventory

    The report gives results of a study of the volatilization of lubricants used in steel rolling. Data from nine steel mills were used to: define the volatilized portion of lubricants used in rolling; and prepare total oil, grease, and hydraulic material balances for actual and typi...

  16. Forming "dynamic" membranes on stainless steel

    NASA Technical Reports Server (NTRS)

    Brandon, C. A.; Gaddis, J. L.

    1979-01-01

    "Dynamic" zirconium polyacrylic membrane is formed directly on stainless steel substrate without excessive corrosion of steel. Membrane is potentially useful in removal of contaminated chemicals from solution through reversed osmosis. Application includes use in filtration and desalination equipment, and in textile industry for separation of dyes from aqueous solvents.

  17. METHOD FOR JOINING ALUMINUM TO STAINLESS STEEL

    DOEpatents

    Lemon, L.C.

    1960-05-24

    Aluminum may be joined to stainless steel without the use of flux by tinning the aluminum with a tin solder containing 1% silver and 1% lead, tinning the stainless steel with a 50% lead 50% tin solder, and then sweating the tinned surfaces together.

  18. Instabilities in stabilized austenitic stainless steels

    NASA Astrophysics Data System (ADS)

    Ayer, Raghavan; Klein, C. F.; Marzinsky, C. N.

    1992-09-01

    The effect of aging on the precipitation of grain boundary phases in three austenitic stainless steels (AISI 347, 347AP, and an experimental steel stabilized with hafnium) was investigated. Aging was performed both on bulk steels as well as on samples which were subjected to a thermal treatment to simulate the coarse grain region of the heat affected zone (HAZ) during welding. Aging of the bulk steels at 866 K for 8000 hours resulted in the precipitation of Cr23C6 carbides, σ, and Fe2Nb phases; the propensity for precipitation was least for the hafnium-stabilized steel. Weld simulation of the HAZ resulted in dissolution of the phases present in the as-received 347 and 347AP steels, leading to grain coarsening. Subsequent aging caused extensive grain boundary Cr23C6 carbides and inhomogeneous matrix precipitation. In addition, steel 347AP formed a precipitate free zone (PFZ) along the grain boundaries. The steel containing hafnium showed the best microstructural stability to aging and welding.

  19. Hydrogen transport in iron and steel

    NASA Technical Reports Server (NTRS)

    Louthan, M. R., Jr.; Derrick, R. G.; Donovan, J. A.; Caskey, G. R., Jr.

    1976-01-01

    The permeabilities of protium, deuterium, and tritium in foil specimens of Marz grade iron, 4130 steel, Armco iron, HP-9-4-20, and T-1 steels were studied at hydrogen pressures between 0.02 and 0.5 MPa over the temperature range 260-700 K. The permeability was measured by a pressure-rise method, deuterium counting with a detector, and radioactivity counting. Good agreement is found between the measurement techniques used. It is shown that the permeabilities of protium, deuterium, and tritium in iron and T-1 steel at temperatures as low as 260 K are in good agreement with the equation proposed by Gonzalez (1967). However, the permeabilities of HP-9-4-20 and 4130 steel to hydrogen are typically lower than predicted. The isotope effect on hydrogen permeability of HP-9-4-20, 4130 and T-1 steels, and high-purity iron can be estimated by an inverse square root of mass correction.

  20. Advances in crosswell electromagnetics steel cased boreholes

    SciTech Connect

    Harben, P E; Kirkendall, B A; Lewis, J P

    1999-03-01

    The Crosswell electromagnetic (EM) induction technique ideally measures the resistivity distribution between boreholes which may often be cased with carbon steel. Quantification of the effect of such steel casing on the induced field is the most significant limitation of the technique. Recent data acquired at a site in Richmond, California quantify the effect of steel casing on induction measurements and demonstrate this effect to be separable. This unique site contains adjacent steel and plastic wells in which frequency soundings demonstrate low spectrum (1.0 - 50 Hz) measurements an effective means of isolating the casing response from, the formation response. It is also shown that the steel casing effect on the induction coil is highly localized, and limited to less than 0.30 meters above and below the coil.

  1. Fatigue of stainless steel in hydrogen

    NASA Astrophysics Data System (ADS)

    Schuster, G.; Altstetter, C.

    1983-10-01

    The fatigue crack growth rates of two austenitic stainless steel alloys, AISI 301 and 302, were compared in air, argon, and hydrogen environments at atmospheric pressure and room temperature. Under the stresses at the crack tip the austenite in type 301 steel transformed martensitically to a’ to a greater extent than in type 302 steel. The steels were also tested in the cold worked condition under hydrogen or argon. Hydrogen was found to have a deleterious effect on both steels, but the effect was stronger in the unstable than in the stable alloy. Cold work decreased fatigue crack growth rates in argon and hydrogen, but the decrease was less marked in hydrogen than in argon. Metallographic, fractographic, and microhardness surveys in the vicinity of the fatigue crack were used to try to understand the reasons for the observed fatigue behavior.

  2. Aerosol filtration with steel fiber filters

    SciTech Connect

    Bergman, W.; Wilson, K.; Larsen, G.; Lopez, R.

    1993-04-01

    We have conducted an experimental study of aerosol penetration through a new high efficiency steel fiber filter and filter media that we developed in cooperation with Pall Corporation. Our previous studies have shown that sintered steel fiber media have significant improvements in higher filter efficiency and lower pressure drop than the previous steel filter technology based on sintered powder metal media. In the present study, we have measured the penetration of dioctyl sebacate (DOS) aerosols through flat sheet samples, pleated cartridge filters and a 1000 cfm filter having 64 cartridges housed in a 2 {times} 2 {times} 1 ft. frame. The steel fiber media used in our study consists of 2 {mu}m diameter stainless steel (316L) fibers sintered together into sheets.

  3. Aerosol filtration with steel fiber filters

    NASA Astrophysics Data System (ADS)

    Bergman, W.; Wilson, K.; Larsen, G.; Lopez, R.

    1993-04-01

    An experimental study has been conducted of aerosol penetration through a new high efficiency steel fiber filter and filter media that was developed in cooperation with Pall Corporation. Previous studies have shown that sintered steel fiber media have significant improvements in higher filter efficiency and lower pressure drop than the previous steel filter technology based on sintered powder metal media. In the present study, measurements were made of the penetration of dioctyl sebacate (DOS) aerosols through flat sheet samples, pleated cartridge filters, and a 1000 cfm filter having 64 cartridges housed in a 2 x 2 x 1 ft. frame. The steel fiber media used in our study consists of 2 micron diameter stainless steel (316 L) fibers sintered together into sheets.

  4. Interaction between stainless steel and plutonium metal

    SciTech Connect

    Dunwoody, John T; Mason, Richard E; Freibert, Franz J; Willson, Stephen P; Veirs, Douglas K; Worl, Laura A; Archuleta, Alonso; Conger, Donald J

    2010-01-01

    Long-term storage of excess plutonium is of great concern in the U.S. as well as abroad. The current accepted configuration involves intimate contact between the stored material and an iron-bearing container such as stainless steel. While many safety scenario studies have been conducted and used in the acceptance of stainless steel containers, little information is available on the physical interaction at elevated temperatures between certain forms of stored material and the container itself. The bulk of the safety studies has focused on the ability of a package to keep the primary stainless steel containment below the plutonium-iron eutectic temperature of approximately 410 C. However, the interactions of plutonium metal with stainless steel have been of continuing interest. This paper reports on a scoping study investigating the interaction between stainless steel and plutonium metal in a pseudo diffusion couple at temperatures above the eutectic melt-point.

  5. The comparison of frictional resistance in titanium, self-ligating stainless steel, and stainless steel brackets using stainless steel and TMA archwires: An in vitro study

    PubMed Central

    Khalid, Syed Altaf; Kumar, Vadivel; Jayaram, Prithviraj

    2012-01-01

    Aim: The aim of the study was to compare the frictional resistance of titanium, self-ligating stainless steel, and conventional stainless steel brackets, using stainless steel and titanium molybdenum alloy (TMA) archwires. Materials and Methods: We compared the frictional resistance in 0.018 slot and 0.022 slot of the three brackets – titanium, self-ligating stainless steel, and conventional stainless steel – using stainless steel archwires and TMA archwires. An in vitro study of simulated canine retraction was undertaken to evaluate the difference in frictional resistance between titanium, self-ligating stainless steel, and stainless steel brackets, using stainless steel and TMA archwires. Results and Conclusion: We compared the frictional resistance of titanium, self-ligating stainless steel, and conventional stainless steel brackets, using stainless steel and TMA archwires, with the help of Instron Universal Testing Machine. One-way analysis of variance (ANOVA), Student's “t” test, and post hoc multiple range test at level of <0.05 showed statistically significant difference in the mean values of all groups. Results demonstrated that the titanium, self-ligating stainless steel, and stainless steel brackets of 0.018-inch and 0.022-inch slot had no significant variations in frictional résistance. The self-ligating bracket with TMA archwires showed relatively less frictional resistance compared with the other groups. The titanium bracket with TMA archwires showed relatively less frictional resistance compared with the stainless steel brackets. PMID:23066253

  6. An understanding of HSLA-65 plate steels

    NASA Astrophysics Data System (ADS)

    Sampath, K.

    2006-02-01

    HSLA-65 plate steels can be produced using one of five plate manufacturing techniques: normalizing, controlled rolling (CR), controlled rolling followed by accelerated cooling (CR-AC), direct quenching and tempering (DQT), or conventional quenching and tempering (Q&T). The HSLA-65 steels are characterized by low carbon content and low alloy content, and they exhibit a low carbon equivalent that allows improved plate weldability. These characteristics in turn (a) provide the steel plate with a refined microstructure that ensures high strength and toughness; (b) eliminate or substantially reduce the need for preheating during welding; (c) resist susceptibility to hydrogen-assisted cracking (HAC) in the weld heat affected zone (HAZ) when fusion (arc) welded using low heat-input conditions; and (d) depending on section thickness, facilitate high heat-input welding (about 2 kJ/mm) without significant loss of strength or toughness in the HAZ. However, application of this plate manufacturing process and of these controls produces significant differences in the metallurgical structure and range of mechanical properties of the HSLA-65 plate steels both among themselves and versus conventional higher strength steel (HSS) plates. For example, among the HSLA-65 plate steels, those produced by Q&T exhibit minimal variability in mechanical properties, especially in thicker plates. Besides variability in mechanical properties depending on plate thickness, the CR and CR-AC plate steels exhibit a relatively higher yield strength to ultimate tensile strength (YS/UTS) ratio than do DQT and Q&T steels. Such differences in processing and properties of HSLA-65 plate steels could potentially affect the selection and control of various secondary fabrication practices, including arc welding. Consequently, fabricators must exercise extreme caution when transferring allowable limits of certified secondary fabrication practices from one type of HSLA-65 plate steel to another, even for the

  7. Recycling steel from grinding swarf

    SciTech Connect

    Fu, H.; Matthews, M.A.; Warner, L.S.

    1998-12-31

    Two cleaning processes have been investigated for removing contaminants (cutting oil with phosphorus ester) from high speed steel (HSS) griding swarf. One process uses an aqueous surfactant washing technique, and the second process uses supercritical carbon dioxide (SCCO{sub 2}) extraction. Both technical and preliminary financial analysis are performed to have a better evaluation of these two competing cleaning technologies. Bench scale aqueous washings have shown that the required phosphorus removal is easily obtained, but a sufficient oil removal is more difficult. The experimental results also indicate a strong dependence of the aqueous washing efficiency on the choice of a suitable surfactant. SCCO{sub 2} extraction at 80 C and 340 atm shows that approximately 80% of the oil can be removed from swarf during a 60-minute process to produce a batch of recyclable steel, and that the phosphorus removal also reaches the required level. The cost of processing swarf using either aqueous surfactant washing or SCCO{sub 2} extraction in a 3,000,000 lbs per year plant is analyzed and the market forces impacting the feasibility of recycling on a commercial basis are reviewed. Commercial scale recycling is, in part, dependent upon resolution of regulatory uncertainty on the definition of swarf. States regulating swarf as hazardous provide a significant financial incentive to recycle. In states that regulate swarf as a solid waste, low disposal costs provide a disincentive that must be balanced with the possible hidden, future liabilities of landfill disposal.

  8. Automated Steel Cleanliness Analysis Tool (ASCAT)

    SciTech Connect

    Gary Casuccio; Michael Potter; Fred Schwerer; Dr. Richard J. Fruehan; Dr. Scott Story

    2005-12-30

    The objective of this study was to develop the Automated Steel Cleanliness Analysis Tool (ASCATTM) to permit steelmakers to evaluate the quality of the steel through the analysis of individual inclusions. By characterizing individual inclusions, determinations can be made as to the cleanliness of the steel. Understanding the complicating effects of inclusions in the steelmaking process and on the resulting properties of steel allows the steel producer to increase throughput, better control the process, reduce remelts, and improve the quality of the product. The ASCAT (Figure 1) is a steel-smart inclusion analysis tool developed around a customized next-generation computer controlled scanning electron microscopy (NG-CCSEM) hardware platform that permits acquisition of inclusion size and composition data at a rate never before possible in SEM-based instruments. With built-in customized ''intelligent'' software, the inclusion data is automatically sorted into clusters representing different inclusion types to define the characteristics of a particular heat (Figure 2). The ASCAT represents an innovative new tool for the collection of statistically meaningful data on inclusions, and provides a means of understanding the complicated effects of inclusions in the steel making process and on the resulting properties of steel. Research conducted by RJLG with AISI (American Iron and Steel Institute) and SMA (Steel Manufactures of America) members indicates that the ASCAT has application in high-grade bar, sheet, plate, tin products, pipes, SBQ, tire cord, welding rod, and specialty steels and alloys where control of inclusions, whether natural or engineered, are crucial to their specification for a given end-use. Example applications include castability of calcium treated steel; interstitial free (IF) degasser grade slag conditioning practice; tundish clogging and erosion minimization; degasser circulation and optimization; quality assessment/steel cleanliness; slab, billet

  9. 46 CFR 154.172 - Contiguous steel hull structure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Contiguous steel hull structure. 154.172 Section 154.172... Structure § 154.172 Contiguous steel hull structure. (a) Except as allowed in paragraphs (b) and (c) of this... construction of the contiguous steel hull structure must meet the thickness and steel grade in Table 1 for...

  10. 49 CFR 192.105 - Design formula for steel pipe.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Design formula for steel pipe. 192.105 Section 192... for steel pipe. (a) The design pressure for steel pipe is determined in accordance with the following... § 192.113. T=Temperature derating factor determined in accordance with § 192.115. (b) If steel pipe...

  11. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....

  12. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....

  13. 46 CFR 154.172 - Contiguous steel hull structure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Contiguous steel hull structure. 154.172 Section 154.172... Structure § 154.172 Contiguous steel hull structure. (a) Except as allowed in paragraphs (b) and (c) of this... construction of the contiguous steel hull structure must meet the thickness and steel grade in Table 1 for...

  14. 49 CFR 178.504 - Standards for steel drums.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Standards for steel drums. 178.504 Section 178.504...-Oriented Packaging Standards § 178.504 Standards for steel drums. (a) The following are identification codes for steel drums: (1) 1A1 for a non-removable head steel drum; and (2) 1A2 for a removable...

  15. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....

  16. 49 CFR 192.105 - Design formula for steel pipe.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Design formula for steel pipe. 192.105 Section 192... for steel pipe. (a) The design pressure for steel pipe is determined in accordance with the following... § 192.113. T=Temperature derating factor determined in accordance with § 192.115. (b) If steel pipe...

  17. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....

  18. 46 CFR 154.172 - Contiguous steel hull structure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Contiguous steel hull structure. 154.172 Section 154.172... Structure § 154.172 Contiguous steel hull structure. (a) Except as allowed in paragraphs (b) and (c) of this... construction of the contiguous steel hull structure must meet the thickness and steel grade in Table 1 for...

  19. 49 CFR 192.105 - Design formula for steel pipe.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Design formula for steel pipe. 192.105 Section 192... for steel pipe. (a) The design pressure for steel pipe is determined in accordance with the following... § 192.113. T=Temperature derating factor determined in accordance with § 192.115. (b) If steel pipe...

  20. 49 CFR 178.504 - Standards for steel drums.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Standards for steel drums. 178.504 Section 178.504...-Oriented Packaging Standards § 178.504 Standards for steel drums. (a) The following are identification codes for steel drums: (1) 1A1 for a non-removable head steel drum; and (2) 1A2 for a removable...

  1. 49 CFR 178.504 - Standards for steel drums.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Standards for steel drums. 178.504 Section 178.504...-Oriented Packaging Standards § 178.504 Standards for steel drums. (a) The following are identification codes for steel drums: (1) 1A1 for a non-removable head steel drum; and (2) 1A2 for a removable...

  2. 29 CFR 1926.757 - Open web steel joists.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Open web steel joists. 1926.757 Section 1926.757 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.757 Open web steel joists. (a) General. (1) Except as provided in paragraph (a)(2) of this section, where steel joists are...

  3. 46 CFR 154.172 - Contiguous steel hull structure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Contiguous steel hull structure. 154.172 Section 154.172... Structure § 154.172 Contiguous steel hull structure. (a) Except as allowed in paragraphs (b) and (c) of this... construction of the contiguous steel hull structure must meet the thickness and steel grade in Table 1 for...

  4. 46 CFR 154.172 - Contiguous steel hull structure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Contiguous steel hull structure. 154.172 Section 154.172... Structure § 154.172 Contiguous steel hull structure. (a) Except as allowed in paragraphs (b) and (c) of this... construction of the contiguous steel hull structure must meet the thickness and steel grade in Table 1 for...

  5. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....

  6. 49 CFR 192.105 - Design formula for steel pipe.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Design formula for steel pipe. 192.105 Section 192... for steel pipe. (a) The design pressure for steel pipe is determined in accordance with the following... § 192.113. T=Temperature derating factor determined in accordance with § 192.115. (b) If steel pipe...

  7. 29 CFR 1926.757 - Open web steel joists.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 8 2012-07-01 2012-07-01 false Open web steel joists. 1926.757 Section 1926.757 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.757 Open web steel joists. (a) General. (1) Except as provided in paragraph (a)(2) of this section, where steel joists are...

  8. 29 CFR 1926.757 - Open web steel joists.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Open web steel joists. 1926.757 Section 1926.757 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.757 Open web steel joists. (a) General. (1) Except as provided in paragraph (a)(2) of this section, where steel joists are...

  9. 49 CFR 192.105 - Design formula for steel pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Design formula for steel pipe. 192.105 Section 192... for steel pipe. (a) The design pressure for steel pipe is determined in accordance with the following... § 192.113. T=Temperature derating factor determined in accordance with § 192.115. (b) If steel pipe...

  10. Cryogenic treatment of steels. (Latest citations from Metadex). Published Search

    SciTech Connect

    1997-01-01

    The bibliography contains citations concerning the use of cryogenic temperatures to improve the properties of steels. Stainless steels, tool steels, electrical steels, and metal matrix composites are discussed. Citations cover fatigue life, wear resistance, tool life, and increased high temperature ductility. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  11. Cryogenic treatment of steels. (Latest citations from Metadex). Published Search

    SciTech Connect

    1998-03-01

    The bibliography contains citations concerning the use of cryogenic temperatures to improve the properties of steels. Stainless steels, tool steels, electrical steels, and metal matrix composites are discussed. Citations cover fatigue life, wear resistance, tool life, and increased high temperature ductility. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  12. Duplex stainless steels for osteosynthesis devices.

    PubMed

    Cigada, A; Rondelli, G; Vicentini, B; Giacomazzi, M; Roos, A

    1989-09-01

    The austenitic stainless steels used today for the manufacture of osteosynthesis devices are sensitive to crevice corrosion. In this study the corrosion properties of some duplex stainless steels were evaluated and compared to traditional austenitic stainless steels. According to our results the following ranking was established: 23Cr-4Ni less than AISI 316L less than ASTM F138 less than 22Cr-5Ni-3Mo less than 27Cr-31Ni-3.5Mo less than 25Cr-7Ni-4Mo-N. In particular the results showed that the high-performance 25Cr-7Ni-4Mo-N duplex stainless steel, with high molybdenum and nitrogen contents, can be considered not susceptible to crevice corrosion in the human body. The duplex stainless steels have also better mechanical properties at the same degree of cold working compared with austenitic stainless steels. Hence the 25Cr-7Ni-4Mo-N duplex stainless steel can be considered a convenient substitute of ASTM F138 for orthopedic and osteosynthesis devices. PMID:2777835

  13. Magnetic sheet steel lamination detection, phase 1

    NASA Astrophysics Data System (ADS)

    Carignan, F. J.; Syniuta, W. D.

    1980-08-01

    Research to assess the feasibility of a nondestructive magnetic inspection technique for detecting defective sheet steel is reported. A major problem in the deep drawing and stamping industry is the failure of sheet steel due to laminations which occur when the steel is formed into various shapes or processed further. A continuous nondestructive testing method was developed based upon differences in magnetic properties of acceptable steel and defective steel. The technique assumes an increase in the magnetic hardness of the defect compared to the base material. Experimental results obtained with the artificial flaw demonstrate that it is possible to sense magnetic differences in sheet steel if the differences are large enough. However, as the differences in magnetic hardness diminish, or where thin surface defects or internal laminations occur, detection becomes increasingly difficult. Moreoever, it has not been established that all sheet steel defects are magnetically harder than unflawed material. It was concluded that the technique, which can detect only some flaws and is incapable of detecting many important defects, would be only marginally useful.

  14. Recycling galvanized steel: Operating experience and benefits

    SciTech Connect

    Dudek, F.J.; Daniels, E.J.; Morgan, W.A.

    1993-08-01

    In response to the increase in consumption of galvanized steel for automobiles in the last decade and the problems associated with remelting larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is recovered electrolytically as dendritic powder. The dezinced ferrous scrap is rinsed and used directly. The process is effective for zinc, lead, and aluminum removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 900 tonnes of mostly baled scrap. A pilot plant to continuously treat loose scrap, with a design capacity of 48,000 tonnes annually, has been in operation in East Chicago, Indiana since early in 1993. The first 450 t of scrap degalvanized in the pilot plant have residual zinc below 0.01% and sodium dragout below 0.01%. Use of degalvanized steel scrap decreases raw materials, environmental compliance, and opportunity costs to steel- and iron-makers. Availability of clean degalvanized scrap may enable integrated steel producers to recycle furnace dusts to the sinter plant and EAF shops to produce flat products without use of high quality scrap alternatives such as DRI, pig iron, or iron carbide. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap. The quantities of zinc available by the year 2000 from prompt and obsolete automotive scrap win approach 25% of zinc consumed in the major automotive production centers of the world. Zinc recycling from galvanized steel scrap, either before or after scrap melting, will have to be implemented.

  15. Steel Creek wildlife: L-Lake/Steel Creek Biological Monitoring Program, January 1986--December 1987

    SciTech Connect

    Giffin, M.A.; Patterson, K.K.

    1988-03-01

    Reptile and amphibian populations in Steel Creek below L-Lake were assessed in monthly or quarterly sampling programs. Thirty-eight species of reptiles or amphibians were collected during 1987 in the Steel Creek corridor below the L-Lake impoundment, and in the delta and channel. Juvenile turtles and alligators, and larval amphibians were observed or collected during the study, indicating continued reproduction in Steel Creek. The reptile and amphibian populations in Steel Creek show no indication of any effect due to the impoundment of the lake or the operation of L-Reactor. Waterfowl and associated birds in Steel Creek below L-Lake were observed, in conjunction with other sampling programs, during winter--spring and fall--winter migrations. Nine species of waterfowl and five species of associated birds were observed in 1987 in the Steel Creek corridor below the L-Lake impoundment and in the delta and channel.

  16. Tritiated Water Interaction with Stainless Steel

    SciTech Connect

    Glen R. Longhurst

    2007-05-01

    Experiments conducted to study tritium permeation of stainless steel at ambient and elevated temperatures revealed that HT converts relatively quickly to HTO. Further, the HTO partial pressure contributes essentially equally with elemental tritium gas in driving permeation through the stainless steel. Such permeation appears to be due to dissociation of the water molecule on the hot stainless steel surface. There is an equilibrium concentration of HTO vapor above adsorbed gas on the walls of the experimental apparatus evident from freezing transients. The uptake process of tritium from the carrier gas involves both surface adsorption and isotopic exchange with surface bound water.

  17. Reducing corrosion in aluminum-steel joints

    SciTech Connect

    Not Available

    1994-01-01

    This article examines how galvanic corrosion in aluminum-intensive steel structures can be controlled, without losing performance, by using transition materials. The topics of the article include the transition material concept, corrosion resistance, experimental conditions, and the results of the experiment including mass loss of lap joints, strength retention, joining methods. The results show how use of steel-clad aluminum transition material in joining aluminum and steel deals successfully addresses the problems of joining and durability associated with increasing use of aluminum on automobiles.

  18. Hydrogen Susceptibility of Nanostructured Bainitic Steels

    NASA Astrophysics Data System (ADS)

    Peet, Mathew James; Hojo, Tomohiko

    2016-02-01

    Nanostructured steels with an ultimate tensile strength of 1.6 GPa were produced with austenite content varying from 0 to 35 vol pct. The effect on the mechanical properties was assessed after saturating the steel with hydrogen. Elongation was reduced to 2 to 5 pct and UTS to 65 to 70 pct of prior value. Thermal desorption measurements confirmed the higher solubility of hydrogen in the steel with higher austenite content. The level of hydrogen saturation was found to correlate to the total area of grain boundaries rather than to the volume fraction of retained austenite.

  19. Steel Foil Improves Performance Of Blasting Caps

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Perry, Ronnie; Schimmel, Morry L.

    1990-01-01

    Blasting caps, which commonly include deep-drawn aluminum cups, give significantly higher initiation performance by application of steel foils on output faces. Steel closures 0.005 in. (0.13 mm) thick more effective than aluminum. Caps with directly bonded steel foil produce fragment velocities of 9,300 ft/s (2.8 km/s) with large craters and unpredictable patterns to such degree that no attempts made to initiate explosions. Useful in military and aerospace applications and in specialized industries as mining and exploration for oil.

  20. Strain hardening of steel EP836

    SciTech Connect

    Lyadskaya, A.A.; Lappa, R.M.; Spuskanyuk, V.Z.

    1986-03-01

    The authors investigate the effect of different combinations of cold hydraulic pressing and heat treatment on the physical and mechanical properties of steel EP836 (03N17K10V10MT), containing 0.03% C, 16-17% Ni, 10-11.5% Co, 9.5-11.5% W, 1% Ti, 1% Mo, and 0.15% A1. Deformation of the unaged steel resulted in insignificant hardening without a decrease in plasticity; this agrees with the results of investigations of other steels of this class.

  1. Bouncing steel balls on water

    NASA Astrophysics Data System (ADS)

    de Podesta, Michael

    2007-09-01

    The 'skimming' of stones on water is a subject of perennial fascination for children and adults alike. In this article I describe the construction of an apparatus for safely and reproducibly demonstrating a similar phenomenon: the bouncing of 25 mm diameter steel balls from a water surface. The 'bouncing' is technically known as a ricochet and the article recounts the use of the effect in the Second World War in the 'Dam Busting' air raids of 1943. A number of calculations are made which allow an estimate of the projectile speed and energy, and the use of simple experimental techniques for validating these estimates is suggested. The role of spin is discussed, and a literature review collates the available empirical and theoretical results concerning the incident angle and speed for successful ricochet of spinning and non-spinning projectiles.

  2. Ultrasonic attenuation in pearlitic steel.

    PubMed

    Du, Hualong; Turner, Joseph A

    2014-03-01

    Expressions for the attenuation coefficients of longitudinal and transverse ultrasonic waves are developed for steel with pearlitic microstructure. This type of lamellar duplex microstructure influences attenuation because of the lamellar spacing. In addition, longitudinal attenuation measurements were conducted using an unfocused transducer with 10 MHz central frequency on the cross section of a quenched railroad wheel sample. The dependence of longitudinal attenuation on the pearlite microstructure is observed from the changes of longitudinal attenuation from the quenched tread surface to deeper locations. The results show that the attenuation value is lowest and relatively constant within the quench depth, then increases linearly. The experimental results demonstrate a reasonable agreement with results from the theoretical model. Ultrasonic attenuation provides an important non-destructive method to evaluate duplex microstructure within grains which can be implemented for quality control in conjunction with other manufacturing processes. PMID:24268679

  3. Modernization of Controls Improves Productivity and Reduces Energy Costs at a Large Steel Plant (Weirton Steel Plant)

    SciTech Connect

    2000-04-01

    In 1996 and 1997, Weirton Steel upgraded the utilities control systems at its main steel manufacturing plant in Weirton, WV. In response to increasing energy costs and the need to remain competitive in the steel industry, Weirton Steel commissioned a comprehensive energy management study of the facility, which provided the basis for an energy management control strategy.

  4. Early Risers Benefit from Scholars Program.

    ERIC Educational Resources Information Center

    Jackson, Maria L.; Russell, Ernest L.

    1987-01-01

    The 7 O'Clock Scholars Program for gifted and talented students at Pontiac (Michigan) Central Senior High School brings speakers from a nearby university to speak to interested high school students during 50-minute sessions before regular classes begin. (PGD)

  5. Keep Laptop Cool with Simple Custom Riser

    ERIC Educational Resources Information Center

    Rynone, William

    2012-01-01

    Although the author's netbook computer--a diminished capacity laptop computer--uses less power than its big brother, when working with it on his lap, his thighs are roasted, even in the winter. When using the unit on a flat surface, such as a table top, the bottom surface of the computer and table top become quite warm--and it is generally…

  6. Protective riser-conductor for offshore structures

    SciTech Connect

    Rutherford, D. A.; Albers, G. P.

    1985-07-09

    A protective sleeve for fitting about the periphery of the leg of an offshore structure. The sleeve comprises means for carrying and enclosing a plurality of conductors. It further includes one or more inner rings; an outer jacket is fixedly spaced from the rings to define longitudinal passages within which the respective conductors are fixedly positioned. The sleeve is capable of deflecting packed ice and floating objects which represent possible sources of damage to the structure or to conductors.

  7. Microstructural characterization in dissimilar friction stir welding between 304 stainless steel and st37 steel

    SciTech Connect

    Jafarzadegan, M.; Feng, A.H.; Abdollah-zadeh, A.; Saeid, T.; Shen, J.; Assadi, H.

    2012-12-15

    In the present study, 3 mm-thick plates of 304 stainless steel and st37 steel were welded together by friction stir welding at a welding speed of 50 mm/min and tool rotational speed of 400 and 800 rpm. X-ray diffraction test was carried out to study the phases which might be formed in the welds. Metallographic examinations, and tensile and microhardness tests were used to analyze the microstructure and mechanical properties of the joint. Four different zones were found in the weld area except the base metals. In the stir zone of the 304 stainless steel, a refined grain structure with some features of dynamic recrystallization was evidenced. A thermomechanically-affected zone was characterized on the 304 steel side with features of dynamic recovery. In the other side of the stir zone, the hot deformation of the st37 steel in the austenite region produced small austenite grains and these grains transformed to fine ferrite and pearlite and some products of displacive transformations such as Widmanstatten ferrite and martensite by cooling the material after friction stir welding. The heat-affected zone in the st37 steel side showed partially and fully refined microstructures like fusion welding processes. The recrystallization in the 304 steel and the transformations in the st37 steel enhanced the hardness of the weld area and therefore, improved the tensile properties of the joint. - Highlights: Black-Right-Pointing-Pointer FSW produced sound welds between st37 low carbon steel and 304 stainless steel. Black-Right-Pointing-Pointer The SZ of the st37 steel contained some products of allotropic transformation. Black-Right-Pointing-Pointer The material in the SZ of the 304 steel showed features of dynamic recrystallization. Black-Right-Pointing-Pointer The finer microstructure in the SZ increased the hardness and tensile strength.

  8. Project B: Improved Liquid Steel Feed For Slab Casters

    SciTech Connect

    Brent S. Isaacson; Mike Slepian; Thomas Richter

    1998-10-01

    This report describes the completion of the development of an electromagnetic valve to control liquid steel flow for improved liquid steel feeding for slab casters. Achievements result from a joint research effort between Westinghouse Science and Technology Center, North American Refractories and U.S. Steel. This effort is part of the American Iron and Steel Institute's (AISI) Advanced Process Control Program, a collaboration between the U.S. Department of Energy (DOE) and fifteen North American steel makers.

  9. Clean Cast Steel Technology, Phase IV

    SciTech Connect

    Charles E. Bates

    2003-02-24

    The objective of the Clean Cast Steel Technology Program was to improve casting product quality by removing or minimizing oxide defects and to allow the production of higher integrity castings for high speed machining lines. Previous research has concentrated on macro-inclusions that break, chip, or crack machine tool cutters and drills and cause immediate shutdown of the machining lines. The overall goal of the project is to reduce the amount of surface macro-inclusions and improve the machinability of steel castings. Macro-inclusions and improve the machinability of steel castings. Macro-inclusions have been identified by industrial sponsors as a major barrier to improving the quality and marketability of steel castings.

  10. Precise carbon control of fabricated stainless steel

    DOEpatents

    Nilsen, R.J.

    1975-12-01

    A process is described for controlling the carbon content of fabricated stainless steel components including the steps of heat treating the component in hydrogen atmospheres of varying dewpoints and carbon potentials.

  11. Lightweight Steel Solutions for Automotive Industry

    SciTech Connect

    Lee, Hong Woo; Kim, Gyosung; Park, Sung Ho

    2010-06-15

    Recently, improvement in fuel efficiency and safety has become the biggest issue in worldwide automotive industry. Although the regulation of environment and safety has been tightened up more and more, the majority of vehicle bodies are still manufactured from stamped steel components. This means that the optimized steel solutions enable to demonstrate its ability to reduce body weight with high crashworthiness performance instead of expensive light weight materials such as Al, Mg and composites. To provide the innovative steel solutions for automotive industry, POSCO has developed AHSS and its application technologies, which is directly connected to EVI activities. EVI is a technical cooperation program with customer covering all stages of new car project from design to mass production. Integrated light weight solutions through new forming technologies such as TWB, hydroforming and HPF are continuously developed and provided for EVI activities. This paper will discuss the detailed status of these technologies especially light weight steel solutions based on innovative technologies.

  12. Hydrogen compatibility handbook for stainless steels

    SciTech Connect

    Caskey, G.R. Jr.

    1983-06-01

    This handbook compiles data on the effects of hydrogen on the mechanical properties of stainless steels and discusses this data within the context of current understanding of hydrogen compatibility of metals. All of the tabulated data derives from continuing studies of hydrogen effects on materials that have been conducted at the Savannah River Laboratory over the past fifteen years. Supplementary data from other sources are included in the discussion. Austenitic, ferritic, martensitic, and precipitation hardenable stainless steels have been studied. Damage caused by helium generated from decay of tritium is a distinctive effect that occurs in addition to the hydrogen isotopes protium and deuterium. The handbook defines the scope of our current knowledge of hydrogen effects in stainless steels and serves as a guide to selection of stainless steels for service in hydrogen.

  13. Development of a carburizing stainless steel alloy

    SciTech Connect

    Wert, D.E. )

    1994-06-01

    A new carburizing stainless steel alloy that resists corrosion, heat, and fatigue has been developed for bearing and gear applications. Pyrowear 675 Stainless alloy is vacuum induction melted and vacuum arc remelted (VIM/VAR) for aircraft-quality cleanliness. Test results show that it has corrosion resistance similar to that of AISI Type 440-C stainless, and its rolling fatigue resistance is superior to that of AISI M50 (UNS K88165). In contrast to alloy gear steels and Type 440C, Pyrowear 675 maintains case hardness of HRC 60 at operating temperatures up to 200 C (400 F). Impact and fracture toughness are superior to that of other stainless bearing steels, which typically are relatively brittle and can break under severe service. Toughness is also comparable or superior to conventional noncorrosion-resistant carburizing bearing steels, such as SAE Types 8620 and 9310.

  14. Corrosion behavior of sensitized duplex stainless steel.

    PubMed

    Torres, F J; Panyayong, W; Rogers, W; Velasquez-Plata, D; Oshida, Y; Moore, B K

    1998-01-01

    The present work investigates the corrosion behavior of 2205 duplex stainless steel in 0.9% NaCl solution after various heat-treatments, and compares it to that of 316L austenitic stainless steel. Both stainless steels were heat-treated at 500, 650, and 800 degrees C in air for 1 h, followed by furnace cooling. Each heat-treated sample was examined for their microstructures and Vickers micro-hardness, and subjected to the X-ray diffraction for the phase identification. Using potentiostatic polarization method, each heat-treated sample was corrosion-tested in 37 degrees C 0.9% NaCl solution to estimate its corrosion rate. It was found that simulated sensitization showed an adverse influence on both steels, indicating that corrosion rates increased by increasing the sensitization temperatures. PMID:9713683

  15. The interphase precipitation reaction in HSLA steels

    NASA Astrophysics Data System (ADS)

    Todd, Judith A.

    1991-01-01

    An in-depth study of the interphase precipitation reaction in model vanadium steels has shown that the reaction may not just be confined to HSLA steels, but may be part of a general class of banded microstructures which are common to both eutectoid and eutectic systems. A new mass transport theory has been developed in which the interphase precipitation reaction in Fe-C-V steels is treated as a generalized type of cooperative growth. In addition to predicting the spacings of sheets of interphase precipitates and the precipitate sizes in steels, this theory is providing new insights into the origin of banded structures occurring in eutectic systems at solid-liquid interface boundary velocities faster than those required for coupled growth, but slower than those required to produce the extended metastable solid solution.

  16. Adhesive bonding between polyamide and steel

    NASA Astrophysics Data System (ADS)

    Vettegren', V. I.; Bashkarev, A. Ya.; Savitskii, A. V.; Shcherbakov, I. P.; Sytov, V. V.; Mamalimov, R. I.

    2015-08-01

    Fluorescence and IR absorption spectra are taken of coatings obtained by applying polyamide 6 powder on a steel substrate heated above the polymer melting point and subsequently cooling to room temperature. It follows from the coating spectra that the energy of a π* → n transition in the C—O bonds of polyamide decreases. Simultaneously, the maximum of a band assigned to the deformation vibrations of N—H bonds shifts toward longer wavelengths. These effects are explained by the formation of coordination bonds between Fe2+ ions having diffused from the steel into the polymer and nitrogen atoms entering into polyamide 6 molecules. As a result, a coordination-compound-saturated diffusion layer up to 100 µm thick arises near the steel surface. Coordination compounds squeeze the framework of the polyamide 6 molecule roughly by 0.06%. Eventually, a polyamide layer that is stronger than the surroundings appears at the polyamide 6—steel interface.

  17. TiC reinforced cast Cr steels

    SciTech Connect

    Dogan, O.N.; Hawk, J.A.; Schrems, K.K.

    2006-06-01

    A new class of materials, namely TiC-reinforced cast chromium (Cr) steels, was developed for applications requiring high abrasion resistance and good fracture toughness. The research approach was to modify the carbide structure of commercial AISI 440C steel for better fracture resistance while maintaining the already high abrasion resistance. The new alloys contained 12Cr, 2.5–4.5Ti, and 1–1.5C (wt.%) and were melted in a vacuum induction furnace. Their microstructure was composed primarily of a martensitic matrix with a dispersion of TiC precipitates. Modification of TiC morphology was accomplished through changing the cooling rate during solidification. Wear rates of the TiC-reinforced Cr steels were comparable to that of AISI 440C steel, but the impact resistance was much improved.

  18. Lightweight Steel Solutions for Automotive Industry

    NASA Astrophysics Data System (ADS)

    Lee, Hong Woo; Kim, Gyosung; Park, Sung Ho

    2010-06-01

    Recently, improvement in fuel efficiency and safety has become the biggest issue in worldwide automotive industry. Although the regulation of environment and safety has been tightened up more and more, the majority of vehicle bodies are still manufactured from stamped steel components. This means that the optimized steel solutions enable to demonstrate its ability to reduce body weight with high crashworthiness performance instead of expensive light weight materials such as Al, Mg and composites. To provide the innovative steel solutions for automotive industry, POSCO has developed AHSS and its application technologies, which is directly connected to EVI activities. EVI is a technical cooperation program with customer covering all stages of new car project from design to mass production. Integrated light weight solutions through new forming technologies such as TWB, hydroforming and HPF are continuously developed and provided for EVI activities. This paper will discuss the detailed status of these technologies especially light weight steel solutions based on innovative technologies.

  19. Stainless steel to titanium bimetallic transitions

    NASA Astrophysics Data System (ADS)

    Kaluzny, J. A.; Grimm, C.; Passarelli, D.

    2015-12-01

    In order to use stainless steel piping in an LCLS-II (Linac Coherent Light Source Upgrade) cryomodule, stainless steel to titanium bimetallic transitions are needed to connect the stainless steel piping to the titanium cavity helium vessel. Explosion bonded stainless steel to titanium transition pieces and bimetallic transition material samples have been tested. A sample transition tube was subjected to tests and x-ray examinations between tests. Samples of the bonded joint material were impact and tensile tested at room temperature as well as liquid helium temperature. The joint has been used successfully in horizontal tests of LCLS-II cavity helium vessels and is planned to be used in LCLS-II cryomodules. Results of material sample and transition tube tests will be presented. Operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy.

  20. Dissolution and redistribution of hydrogen in steel

    SciTech Connect

    Astaf`ev, A.A.

    1995-11-01

    The danger of flakes initiated by hydrogen dissolved in steel may arise in the production of forgings from alloyed steels. Hydrogen penetrates steel in melting, heat treatment, welding, galvanizing, and pickling and during operation in aggressive media, which reduces the ductility and increases the probability of brittle failure. It is of interest from the standpoint of practice and theory to investigate the possibility of evaluating the amount of hydrogen dissolved in steel and capable of diffusion and to analyze the redistribution and penetration of hydrogen into pores and collectors. In this case atomic hydrogen recombines and transforms into molecular hydrogen, which does not cause flakes or hydrogen embrittlement. This problem is considered in the present work.

  1. Factors Affecting Scale Adhesion on Steel Forgings

    NASA Astrophysics Data System (ADS)

    Zitterman, J. A.; Bacco, R. P.; Boggs, W. E.

    1982-04-01

    Occasionally, undesirable "sticky" adherent scale forms on low-carbon steel during reheating for hot forging. The mechanical abrading or chemical pickling required to remove this scale adds appreciably to the fabrication cost. Characterization of the steel-scale system by metallographic examination, x-ray diffraction, and electron-probe microanalysis revealed that nickel, silicon, and/or sulfur might be involved in the mechanism of sticky-scale formation. Laboratory reheating tests were conducted on steels with varied concentrations of nickel and silicon in atmospheres simulating those resulting from burning natural gas or sulfur-bearing fuels. Subsequent characterization of the scale formed during the tests tends to confirm that the composition of the steel, especially increased nickel and silicon contents, and the presence of the sulfur in the furnace atmosphere cause the formation of this undesirable scale.

  2. Stainless Steel to Titanium Bimetallic Transitions

    SciTech Connect

    Kaluzny, J. A.; Grimm, C.; Passarelli, D.

    2015-01-01

    In order to use stainless steel piping in an LCLS-II (Linac Coherent Light Source Upgrade) cryomodule, stainless steel to titanium bimetallic transitions are needed to connect the stainless steel piping to the titanium cavity helium vessel. Explosion bonded stainless steel to titanium transition pieces and bimetallic transition material samples have been tested. A sample transition tube was subjected to tests and x-ray examinations between tests. Samples of the bonded joint material were impact and tensile tested at room temperature as well as liquid helium temperature. The joint has been used successfully in horizontal tests of LCLS-II cavity helium vessels and is planned to be used in LCLS-II cryomodules. Results of material sample and transition tube tests will be presented.

  3. Bearing steels: Into the 21. century

    SciTech Connect

    Hoo, J.J.C.; Green, W.B. Jr.

    1998-12-31

    The symposium was organized in 9 separate categories, some sessions updating information previously presented, and some presenting brand new materials and processing to advance bearing technology. Subjects covered include steel cleanliness and measuring methods, bearing fatigue life, and advanced steel processing. Also covered are advances in both thru-hardening and carburizing heat treatments, progress in aerospace and corrosion resistant materials, and surface modifying processes, such as induction hardening and coating methods. Papers have been processed separately for inclusion on the data base.

  4. High strength and high toughness steel

    DOEpatents

    Parker, Earl R.; Zackay, Victor F.

    1979-01-01

    A structural steel which possess both high strength and high toughness and has particular application of cryogenic uses. The steel is produced by the utilization of thermally induced phase transformation following heating in a three-phase field in iron-rich alloys of the Fe-Ni-Ti system, with a preferred composition of 12% nickel, 0.5% titanium, the remainder being iron.

  5. High strength, high ductility low carbon steel

    DOEpatents

    Koo, Jayoung; Thomas, Gareth

    1978-01-01

    A high strength, high ductility low carbon steel consisting essentially of iron, 0.05-0.15 wt% carbon, and 1-3 wt% silicon. Minor amounts of other constituents may be present. The steel is characterized by a duplex ferrite-martensite microstructure in a fibrous morphology. The microstructure is developed by heat treatment consisting of initial austenitizing treatment followed by annealing in the (.alpha. + .gamma.) range with intermediate quenching.

  6. Neutron irradiation creep in stainless steel alloys

    NASA Astrophysics Data System (ADS)

    Schüle, Wolfgang; Hausen, Hermann

    1994-09-01

    Irradiation creep elongations were measured in the HFR at Petten on AMCR steels, on 316 CE-reference steels, and on US-316 and US-PCA steels varying the irradiation temperature between 300°C and 500°C and the stress between 25 and 300 MPa. At the beginning of an irradiation a type of "primary" creep stage is observed for doses up to 3-5 dpa after which dose the "secondary" creep stage begins. The "primary" creep strain decreases in cold-worked steel materials with decreasing stress and decreasing irradiation temperature achieving also negative creep strains depending also on the pre-treatment of the materials. These "primary" creep strains are mainly attributed to volume changes due to the formation of radiation-induced phases, e.g. to the formation of α-ferrite below about 400°C and of carbides below about 700°C, and not to irradiation creep. The "secondary" creep stage is found for doses larger than 3 to 5 dpa and is attributed mainly to irradiation creep. The irradiation creep rate is almost independent of the irradiation temperature ( Qirr = 0.132 eV) and linearly dependent on the stress. The total creep elongations normalized to about 8 dpa are equal for almost every type of steel irradiated in the HFR at Petten or in ORR or in EBR II. The negative creep elongations are more pronounced in PCA- and in AMCR-steels and for this reason the total creep elongation is slightly smaller at 8 dpa for these two steels than for the other steels.

  7. A Duplex Stainless Steel for Chloride Environments

    NASA Astrophysics Data System (ADS)

    Sridhar, N.; Kolts, J.; Flasche, L. H.

    1985-03-01

    This paper examines the effects of microstructural changes on the corrosion, stress corrosion cracking and corrosion fatigue resistance of a duplex stainless steel to chloride environments. The microstructural changes can be precipitation of phases such as sigma and carbides, or changes in the distribution of austenite and ferrite. The former can be important in hot forming operations while the latter is important in welding. The methods of minimizing these deleterious effects can sometimes be different from those used for austenitic stainless steel.

  8. Analysis of plasma-nitrided steels

    NASA Technical Reports Server (NTRS)

    Salik, J.; Ferrante, J.; Honecy, F.; Hoffman, R., Jr.

    1986-01-01

    The analysis of plasma nitrided steels can be divided to two main categories - structural and chemical. Structural analysis can provide information not only on the hardening mechanisms but also on the fundamental processes involved. Chemical analysis can be used to study the kinetics for the nitriding process and its mechanisms. In this paper preliminary results obtained by several techniques of both categories are presented and the applicability of those techniques to the analysis of plasma-nitrided steels is discussed.

  9. Ion-beam nitriding of steels

    NASA Technical Reports Server (NTRS)

    Salik, J.

    1985-01-01

    The application of the ion beam technique to the nitriding of steels is described. It is indicated that the technique can be successfully applied to nitriding. Some of the structural changes obtained by this technique are similar to those obtained by ion nitriding. The main difference is the absence of the iron nitride diffraction lines. It is found that the dependence of the resultant microhardness on beam voltage for super nitralloy is different from that of 304 stainless steel.

  10. Hybrid Laser-Arc Welding Tanks Steels

    NASA Astrophysics Data System (ADS)

    Turichin, G.; Tsibulskiy, I.; Kuznetsov, M.; Akhmetov, A.; Klimova-Korsmik, O.

    2016-04-01

    The results investigate hybrid laser-arc welding of high strength steels using design responsible metallic construction and the highest strength body of vehicles. Welds from modern high strength steels grade Hardox 400, Hardox 450, Armox 600T and AB were created. High power fiber laser LS-15 with output 15 kW and arc rectifier VDU - 1500 DC were used in the experiment. Results of the metallographic research and mechanical tests are presented.

  11. Ion-beam nitriding of steels

    NASA Technical Reports Server (NTRS)

    Salik, J.

    1984-01-01

    The application of the ion beam technique to the nitriding of steels is described. It is indicated that the technique can be successfully applied to nitriding. Some of the structural changes obtained by this technique are similar to those obtained by ion nitriding. The main difference is the absence of the iron nitride diffraction lines. It is found that the dependence of the resultant microhardness on beam voltage for super nitralloy is different from that of 304 stainless steel.

  12. Thermal treatment of dissimilar steels' welded joints

    NASA Astrophysics Data System (ADS)

    Nikulina, A. A.; Denisova, A. S.; Gradusov, I. N.; Ryabinkina, P. A.; Rushkovets, M. V.

    2016-04-01

    In this paper combinations of chrome-nickel steel and high-carbon steel, produced by flash butt welding after heat treatment, are investigated. Light and electron microscopic studies show that the welded joints after heat treatment have a complex structure consisting of several phases as initial welded joints. A martensite structure in welded joints after thermal treatment at 300... 800 °C has been found.

  13. Microstructural design in low alloy steels

    NASA Technical Reports Server (NTRS)

    Honeycombe, R. W. K.

    1982-01-01

    The evolution of microalloyed steels from plain carbon steels is examined with emphasis on grain size control by use of Nb, Ti and V additions and by the application of controlled rolling. The structural changes during controlled rolling are described as well as the influence of alloying elements on these changes, and on the final microstructure. The achievement of high strength and toughness is discussed including the role of inclusions.

  14. Irradiation Assisted Grain Boundary Segregation in Steels

    SciTech Connect

    Lu, Zheng; Faulkner, Roy G.

    2008-07-01

    The understanding of radiation-induced grain boundary segregation (RIS) has considerably improved over the past decade. New models have been introduced and much effort has been devoted to obtaining comprehensive information on segregation from the literature. Analytical techniques have also improved so that chemical analysis of layers 1 nm thick is almost routine. This invited paper will review the major methods used currently for RIS prediction: namely, Rate Theory, Inverse Kirkendall, and Solute Drag approaches. A summary is made of the available data on phosphorus RIS in reactor pressure vessel (RPV) steels. This will be discussed in the light of the predictions of the various models in an effort to show which models are the most reliable and easy to use for forecasting P segregation behaviour in steels. A consequence of RIS in RPV steels is a radiation induced shift in the ductile to brittle transition temperature (DBTT). It will be shown how it is possible to relate radiation-induced P segregation levels to DBTT shift. Examples of this exercise will be given for RPV steels and for ferritic steels being considered for first wall fusion applications. Cr RIS in high alloy stainless steels and associated irradiation-assisted stress corrosion cracking (IASCC) will be briefly discussed. (authors)

  15. Microstructural studies of advanced austenitic steels

    SciTech Connect

    Todd, J. A.; Ren, Jyh-Ching

    1989-11-15

    This report presents the first complete microstructural and analytical electron microscopy study of Alloy AX5, one of a series of advanced austenitic steels developed by Maziasz and co-workers at Oak Ridge National Laboratory, for their potential application as reheater and superheater materials in power plants that will reach the end of their design lives in the 1990's. The advanced steels are modified with carbide forming elements such as titanium, niobium and vanadium. When combined with optimized thermo-mechanical treatments, the advanced steels exhibit significantly improved creep rupture properties compared to commercially available 316 stainless steels, 17--14 Cu--Mo and 800 H steels. The importance of microstructure in controlling these improvements has been demonstrated for selected alloys, using stress relaxation testing as an accelerated test method. The microstructural features responsible for the improved creep strengths have been identified by studying the thermal aging kinetics of one of the 16Ni--14Cr advanced steels, Alloy AX5, in both the solution annealed and the solution annealed plus cold worked conditions. Time-temperature-precipitation diagrams have been developed for the temperature range 600 C to 900 C and for times from 1 h to 3000 h. 226 refs., 88 figs., 10 tabs.

  16. Development of Steel Foam Materials and Structures

    SciTech Connect

    Kenneth Kremer; Anthony Liszkiewicz; James Adkins

    2004-10-20

    In the past few years there has been a growing interest in lightweight metal foams. Demands for weight reduction, improved fuel efficiency, and increased passenger safety in automobiles now has manufacturers seriously considering the use of metal foams, in contrast to a few years ago, when the same materials would have been ruled out for technical or economical reasons. The objective of this program was to advance the development and use of steel foam materials, by demonstrating the advantages of these novel lightweight materials in selected generic applications. Progress was made in defining materials and process parameters; characterization of physical and mechanical properties; and fabrication and testing of generic steel foam-filled shapes with compositions from 2.5 wt.% to 0.7 wt.% carbon. A means of producing steel foam shapes with uniform long range porosity levels of 50 to 60 percent was demonstrated and verified with NDE methods. Steel foam integrated beams, cylinders and plates were mechanically tested and demonstrated advantages in bend stiffness, bend resistance, and crush energy absorption. Methods of joining by welding, adhesive bonding, and mechanical fastening were investigated. It is important to keep in mind that steel foam is a conventional material in an unconventional form. A substantial amount of physical and mechanical properties are presented throughout the report and in a properties database at the end of the report to support designer's in applying steel foam in unconventional ways.

  17. Ultrahigh Ductility, High-Carbon Martensitic Steel

    NASA Astrophysics Data System (ADS)

    Qin, Shengwei; Liu, Yu; Hao, Qingguo; Zuo, Xunwei; Rong, Yonghua; Chen, Nailu

    2016-07-01

    Based on the proposed design idea of the anti-transformation-induced plasticity effect, both the additions of the Nb element and pretreatment of the normalization process as a novel quenching-partitioning-tempering (Q-P-T) were designed for Fe-0.63C-1.52Mn-1.49Si-0.62Cr-0.036Nb hot-rolled steel. This high-carbon Q-P-T martensitic steel exhibits a tensile strength of 1890 MPa and elongation of 29 pct accompanied by the excellent product of tensile and elongation of 55 GPa pct. The origin of ultrahigh ductility for high-carbon Q-P-T martensitic steel is revealed from two aspects: one is the softening of martensitic matrix due to both the depletion of carbon in the matensitic matrix during the Q-P-T process by partitioning of carbon from supersaturated martensite to retained austenite and the reduction of the dislocation density in a martensitic matrix by dislocation absorption by retained austenite effect during deformation, which significantly enhances the deformation ability of martensitic matrix; another is the high mechanical stability of considerable carbon-enriched retained austenite, which effectively reduces the formation of brittle twin-type martensite. This work verifies the correctness of the design idea of the anti-TRIP effect and makes the third-generation advanced high-strength steels extend to the field of high-carbon steels from low- and medium-carbon steels.

  18. Stainless steel recycle FY94 progress report

    SciTech Connect

    Imrich, K.J.

    1994-10-28

    The Materials Technology Section (MTS) of the Savannah River Technology Center (SRTC) was asked to demonstrate the practicality of recycling previously contaminated stainless steel components such as reactor heat exchanger heads, process water piping and slug buckets into 208 liters (55 gallon) drums and 2.8 cubic meter (100 ft{sup 3}) storage boxes. Radioactively contaminated stainless steel scrap will be sent to several industrial partners where it will be melted, decontaminated/cast into ingots, and rolled into plate and sheet and fabricated into the drums and boxes. As part of this recycle initiative, MTS was requested to demonstrate that radioactively contaminated Type 304L stainless steel could be remelted and cast to meet the applicable ASTM specification for fabrication of drums and boxes. In addition, MTS was requested to develop the technical basis of melt decontamination and establish practicality of using this approach for value added products. The findings presented in this investigation lead to the following conclusions: recycle of 18 wt% Cr-8 wt% Ni alloy can be achieved by melting Type 304 stainless steel in a air vacuum induction furnace; limited melt decontamination of the contaminated stainless steel was achieved, surface contamination was removed by standard decontamination techniques; carbon uptake in the as-cast ingots resulted from the graphite susceptor used in this experiment and is unavoidable with this furnace configuration. A new furnace optimized for melting stainless steel has been installed and is currently being tested for use in this program.

  19. The abrasion-wear resistance of arc sprayed stainless steel and composite stainless steel coatings

    SciTech Connect

    Dallaire, S.; Legoux, J.G.; Levert, H.

    1994-12-31

    Stainless steels are often used to palliate wear problems in various industries. Though they are not wear resistant, they have been used to a limited extent in applications involving both corrosive and abrasive/erosive environments. The protection of industrial components by arc sprayed stainless steel composite coatings could be considered very attractive provided these coatings offer a better wear protection than bulk stainless steel. The wear resistance of stainless steel and composite stainless steel-titanium boride coatings arc sprayed with air and argon was evaluated following the ASTM G-65 Abrasion Wear Test procedures. Wear volume loss measurements show that stainless steel coatings arc sprayed with air were slightly more resistant than bulk stainless steel while those sprayed with argon were slightly less resistant. The abrasion wear resistance of composite stainless steel-titanium diboride coatings is by two or four times beyond the wear resistance of bulk stainless steel depending upon the core wire constitution and the type of gas used for spraying. Microstructural analysis of coatings, microhardness measurements of sprayed lamellae and optical profilometry were used to characterize coatings and wear damages. Spraying with air instead of argon produced much more small particles. These particles, being removed from the metal sheath surface, are individually sprayed without diluting the concentration hard phases within cores. It results in coatings that contain large lamellae with hardnesses sufficient to withstand abrasion. By considering both the wire constitution and the spraying conditions, it was found possible to fabricate composite stainless steel coatings that show a 400% increase in wear resistance over bulk stainless steel.

  20. Tensile-property characterization of thermally aged cast stainless steels.

    SciTech Connect

    Michaud, W. F.; Toben, P. T.; Soppet, W. K.; Chopra, O. K.; Energy Technology

    1994-03-03

    The effect of thermal aging on tensile properties of cast stainless steels during service in light water reactors has been evaluated. Tensile data for several experimental and commercial heats of cast stainless steels are presented. Thermal aging increases the tensile strength of these steels. The high-C Mo-bearing CF-8M steels are more susceptible to thermal aging than the Mo-free CF-3 or CF-8 steels. A procedure and correlations are presented for predicting the change in tensile flow and yield stresses and engineering stress-vs.-strain curve of cast stainless steel as a function of time and temperature of service. The tensile properties of aged cast stainless steel are estimated from known material information, i.e., chemical composition and the initial tensile strength of the steel. The correlations described in this report may be used for assessing thermal embrittlement of cast stainless steel components.

  1. Tensile-property characterization of thermally aged cast stainless steels

    SciTech Connect

    Michaud, W.F.; Toben, P.T.; Soppet, W.K.; Chopra, O.K.

    1994-02-01

    The effect of thermal aging on tensile properties of cast stainless steels during service in light water reactors has been evaluated. Tensile data for several experimental and commercial heats of cast stainless steels are presented. Thermal aging increases the tensile strength of these steels. The high-C Mo-bearing CF-8M steels are more susceptible to thermal aging than the Mo-free CF-3 or CF-8 steels. A procedure and correlations are presented for predicting the change in tensile flow and yield stresses and engineering stress-vs.-strain curve of cast stainless steel as a function of time and temperature of service. The tensile properties of aged cast stainless steel are estimated from known material information, i.e., chemical composition and the initial tensile strength of the steel. The correlations described in this report may be used for assessing thermal embrittlement of cast stainless steel components.

  2. Mesa corrosion attack in carbon steel and 0.5% chromium steel

    SciTech Connect

    Nyborg, R.; Dugstad, A.

    1998-12-31

    Local breakdown of protective corrosion films may result in rapid local attack or mesa corrosion attack during CO{sub 2} corrosion of carbon steel. The factors affecting formation and local breakdown of protective corrosion films were studied in a series of flow loop experiments performed at 40--80 C with pH 5.8, 1.8 bar CO{sub 2} partial pressure, high iron content in the water and flow rates 0.1--7 m/s. Carbon steels with or without chromium and nickel additions up to 1% were tested. Addition of 0.5% chromium in the steel was found to reduce the tendency for severe mesa attack in carbon steels during CO{sub 2} corrosion significantly. Deep mesa attack did not occur in steels with 0.5--1% Cr in experiments at 80 C and pH 5.8. Protective corrosion films reform more easily in the chromium containing steels, making localized attack less dangerous in chromium containing steels than in unalloyed carbon steels.

  3. High Mn austenitic stainless steel

    DOEpatents

    Yamamoto, Yukinori [Oak Ridge, TN; Santella, Michael L [Knoxville, TN; Brady, Michael P [Oak Ridge, TN; Maziasz, Philip J [Oak Ridge, TN; Liu, Chain-tsuan [Knoxville, TN

    2010-07-13

    An austenitic stainless steel alloy includes, in weight percent: >4 to 15 Mn; 8 to 15 Ni; 14 to 16 Cr; 2.4 to 3 Al; 0.4 to 1 total of at least one of Nb and Ta; 0.05 to 0.2 C; 0.01 to 0.02 B; no more than 0.3 of combined Ti+V; up to 3 Mo; up to 3 Co; up to 1W; up to 3 Cu; up to 1 Si; up to 0.05 P; up to 1 total of at least one of Y, La, Ce, Hf, and Zr; less than 0.05 N; and base Fe, wherein the weight percent Fe is greater than the weight percent Ni, and wherein the alloy forms an external continuous scale including alumina, nanometer scale sized particles distributed throughout the microstructure, the particles including at least one of NbC and TaC, and a stable essentially single phase FCC austenitic matrix microstructure that is essentially delta-ferrite-free and essentially BCC-phase-free.

  4. Nanoindentation on ion irradiated steels

    NASA Astrophysics Data System (ADS)

    Hosemann, P.; Vieh, C.; Greco, R. R.; Kabra, S.; Valdez, J. A.; Cappiello, M. J.; Maloy, S. A.

    2009-06-01

    Radiation induced mechanical property changes can cause major difficulties in designing systems operating in a radiation environment. Investigating these mechanical property changes in an irradiation environment is a costly and time consuming activity. Ion beam accelerator experiments have the advantage of allowing relatively fast and inexpensive materials irradiations without activating the sample but do in general not allow large beam penetration depth into the sample. In this study, the ferritic/martensitic steel HT-9 was processed and heat treated to produce one specimen with a large grained ferritic microstructure and further heat treated to form a second specimen with a fine tempered martensitic lath structure and exposed to an ion beam and tested after irradiation using nanoindentation to investigate the irradiation induced changes in mechanical properties. It is shown that the HT-9 in the ferritic heat treatment is more susceptible to irradiation hardening than HT-9 after the tempered martensitic heat treatment. Also at an irradiation temperature above 550 °C no detectable hardness increase due to irradiation was detected. The results are also compared to data from the literature gained from the fast flux test facility.

  5. EMPLACEMENT DRIFT INVERT-LOW STEEL EVALUATION

    SciTech Connect

    M. E. Taylor and D. H. Tang

    2000-09-29

    This technical report evaluates and develops options for reducing the amount of steel in the emplacement drift invert. Concepts developed in the ''Invert Configuration and Drip Shield Interface'' were evaluated to determine material properties required for the proposed invert concepts. Project requirements documents prescribe the use of a carbon steel frame for the invert with a granular material of crushed tuff as ballast. The ''Invert Configuration and Drip Shield Interface'' developed three concepts: (1) All-Ballast Invert; (2) Modified Steel Invert with Ballast; and (3) Steel Tie with Ballast Invert. Analysis of the steel frame members, runway beams, and guide beams, for the modified steel invert with ballast, decreased the quantity of steel in the emplacement drift invert, however a substantial steel support frame for the gantry and waste package/pallet assembly is still required. Use of one of the other two concepts appears to be an alternative to the steel frame and each of the concepts uses considerably less steel materials. Analysis of the steel tie with ballast invert shows that the bearing pressure on the ballast under the single steel tie, C 9 x 20, loaded with the waste package/pallet assembly, drip shield, and backfill exceeds the upper bound of the allowable bearing capacity for tuff used in this study. The single tie, C 10 x 20, will also fail for the same loading condition except for the tie length of 4.2 meters and longer. Analysis also shows that with two ties, C 9 or 10 x 20's, the average ballast pressure is less than the allowable bearing capacity. Distributing the waste package/pallet, drip shield, and backfill loads to two steel ties reduces the contact bearing pressure. Modifying the emplacement pallet end beams to a greater width, reducing the tie spacing, and increasing the width of the ties would ensure that the pallet beams are always supported by two steel ties. Further analysis is required to determine compatible tie size and spacing

  6. Corrosion of alloy steels in oil field fluids

    SciTech Connect

    Martin, R.L.

    1987-01-01

    Laboratory and field tests have been conducted on two low alloy and two higher alloy steels at a range of brine salinities and sulfide contents typical of oil well production fluids. AISI types 4130 and 4340 show the same behavior in these fluids as mild steel. AISI type 410 stainless steel and 9% chromium - 1% molybdenum steel corrode at rates as great as that of mild steel at higher chloride or sulfide concentrations. Special corrosion inhibitors are required for higher alloy steels when they are exposed to these conditions.

  7. Peculiarity of the process of quenching carburized steel parts

    SciTech Connect

    Kobasko, N.I.

    1995-12-31

    The intensive steel quenching methods are widely used for the thermohardening of alloy and high alloy steels. In the present work an opportunity for the application of intensive steel quenching methods with reference to carburized steel parts is justified. Advantages and disadvantages are discussed. The advantages consist of an opportunity to reduce the duration of the carburizing process, increase the quality and durability of carburized steel parts, achieve additional strengthening of material and optimize the distribution of residual stresses after quenching carburized steel parts. Disadvantages consist of a necessity to modify continuous gas carburizing furnaces.

  8. Liquid Metal Corrosion of 316L Stainless Steel, 410 Stainless Steel, and 1015 Carbon Steel in a Molten Zinc Bath

    NASA Astrophysics Data System (ADS)

    Xu, Jing; Bright, Mark A.; Liu, Xingbo; Barbero, Ever

    2007-11-01

    Corrosion tests of 1015 low-carbon steel and two stainless steels (410 and 316L) were conducted in a pure zinc bath (99.98 wt pct Zn) in order to better understand the reaction mechanisms that occur during the degradation of submerged hardware at industrial general (batch) galvanizing operations. Through this testing, it was found that, in general, 316L stainless steel showed the best dissolution resistance among these three alloys, while 1015 carbon steel provided a lower solubility than 410 stainless steel. Investigating the failure mechanisms, both metallurgical composition and lattice structure played important roles in the molten metal corrosion behaviors of these alloys. High contents of nickel combined with the influence of chromium improved the resistance to molten zinc corrosion. Moreover, a face-centered-cubic (fcc) structure was more corrosion resistant than body-centered-cubic (bcc) possibly due to the compactness of the atomic structure. Analogously, the body-centered-tetragonal (bct) martensite lattice structure possessed enhanced susceptibility to zinc corrosion as a result of the greater atomic spacing and high strain energy. Finally, an increased bath temperature played an important role in molten metal corrosion by accelerating the dissolution process and changing the nature of intermetallic layers.

  9. Mechanical properties of irradiated 9Cr-2WVTa steel

    SciTech Connect

    Klueh, R.L.; Alexander, D.J.; Rieth, M.

    1998-09-01

    An Fe-9Cr-2W-0.25V-0.07Ta-0.1C (9Cr-2WVTa) steel has excellent strength and impact toughness before and after irradiation in the Fast Flux Test Facility and the High Flux Reactor (HFR). The ductile-brittle transition temperature (DBTT) increased only 32 C after 28 dpa at 365 C in FFTF, compared to a shift of {approx}60 C for a 9Cr-2WV steel--the same as the 9Cr-2WVTa steel but without tantalum. This difference occurred despite the two steels having similar tensile but without tantalum. This difference occurred despite the two steels having similar tensile properties before and after irradiation. The 9Cr-2WVTa steel has a smaller prior-austenite grain size, but otherwise microstructures are similar before irradiation and show similar changes during irradiation. The irradiation behavior of the 9Cr-2WVTa steel differs from the 9Cr-2WV steel and other similar steels in two ways: (1) the shift in DBTT of the 9Cr-2WVTa steel irradiated in FFTF does not saturate with fluence by {approx}28 dpa, whereas for the 9Cr-2WV steel and most similar steels, saturation occurs at <10 dpa, and (2) the shift in DBTT for 9Cr-2WVTa steel irradiated in FFTF and HFR increased with irradiation temperature, whereas it decreased for the 9Cr-2WV steel, as it does for most similar steels. The improved properties of the 9Cr-2WVTa steel and the differences with other steels were attributed to tantalum in solution.

  10. A Comparative Study on Nd:YAG Laser Cutting of Steel and Stainless Steel Using Continuous, Square, and Sine Waveforms

    NASA Astrophysics Data System (ADS)

    Lo, K. H.

    2012-06-01

    Laser cutting with the sine waveform is seldom reported. This article is a comparative study on Nd:YAG laser cutting using the continuous (CW), square, and sine waveforms. The materials used in this study were steel and stainless steel. It has been found that the cutting capability, in descending order, is: CW > sine > square. The cutting of steel (C ~0.3 wt.%) and AISI304 austenitic stainless steel may be satisfactorily described by the Steen model, irrespective of waveform. Steel is slightly easier to cut than stainless steel. Limitations of the present study are discussed and suggestions for future work are made.

  11. Superplastic forming of stainless steel automotive components

    SciTech Connect

    Bridges, B.; Elmer, J.; Carol, L.

    1997-02-06

    Exhaust emission standards are governmentally controlled standards, which are increasingly stringent, forcing alternate strategies to meet these standards. One approach to improve the efficiency of the exhaust emission equipment is to decrease the time required to get the catalytic converter to optimum operating temperature. To accomplish this, automotive manufacturers are using double wall stainless steel exhaust manifolds to reduce heat loss of the exhaust gases to the converter. The current method to manufacture double wall stainless steel exhaust components is to use a low-cost alloy with good forming properties and extensively form, cut, assemble, and weld the pieces. Superplastic forming (SPF) technology along with alloy improvements has potential at making this process more cost effective. Lockheed Martin Energy Systems (LMES), Lawrence Livermore National Laboratory (LLNL) and USCAR Low Emission Partnership (LEP) worked under a Cooperative Research And Development Agreement (CRADA) to evaluate material properties, SPF behavior, and welding behavior of duplex stainless steel alloy for automotive component manufacturing. Battelle Pacific Northwest National Laboratory (PNNL) has a separate CRADA with the LEP to use SPF technology to manufacture a double wall stainless steel exhaust component. As a team these CRADAs developed and demonstrated a technical plan to accomplish making double wall stainless steel exhaust manifolds.

  12. Bearing and gear steels for aerospace applications

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.

    1990-01-01

    Research in metallurgy and processing for bearing and gear steels has resulted in improvements in rolling-element bearing and gear life for aerospace application by a factor of approximately 200 over that obtained in the early 1940's. The selection and specification of a bearing or gear steel is dependent on the integration of multiple metallurgical and physical variables. For most aerospace bearings, through-hardened VIM-VAR AISI M-50 steel is the material of preference. For gears, the preferential material is case-carburized VAR AISI 9310. However, the VAR processing for this material is being replaced by VIM-VAR processing. Since case-carburized VIM-VAR M-50NiL incorporates the desirable qualities of both the AISI M-50 and AISI 9310 materials, optimal life and reliability can be achieved in both bearings and gears with a single steel. Hence, this material offers the promise of a common steel for both bearings and gears for future aerospace applications.

  13. Equilibrium Model of Precipitation in Microalloyed Steels

    NASA Astrophysics Data System (ADS)

    Xu, Kun; Thomas, Brian G.; O'Malley, Ron

    2011-02-01

    The formation of precipitates during thermal processing of microalloyed steels greatly influences their mechanical properties. Precipitation behavior varies with steel composition and temperature history and can lead to beneficial grain refinement or detrimental transverse surface cracks. This work presents an efficient computational model of equilibrium precipitation of oxides, sulfides, nitrides, and carbides in steels, based on satisfying solubility limits including Wagner interaction between elements, mutual solubility between precipitates, and mass conservation of alloying elements. The model predicts the compositions and amounts of stable precipitates for multicomponent microalloyed steels in liquid, ferrite, and austenite phases at any temperature. The model is first validated by comparing with analytical solutions of simple cases, predictions using the commercial package JMat-PRO, and previous experimental observations. Then it is applied to track the evolution of precipitate amounts during continuous casting of two commercial steels (1004 LCAK and 1006Nb HSLA) at two different casting speeds. This model is easy to modify to incorporate other precipitates, or new thermodynamic data, and is a useful tool for equilibrium precipitation analysis.

  14. Nanostructuring steel for injection molding tools

    NASA Astrophysics Data System (ADS)

    Al-Azawi, A.; Smistrup, K.; Kristensen, A.

    2014-05-01

    The production of nanostructured plastic items by injection molding with ridges down to 400 nm in width, which is the smallest line width replicated from nanostructured steel shims, is presented. Here we detail a micro-fabrication method where electron beam lithography, nano-imprint lithography and ion beam etching are combined to nanostructure the planar surface of a steel wafer. Injection molded plastic parts with enhanced surface properties, like anti-reflective, superhydrophobic and structural colors can be achieved by micro- and nanostructuring the surface of the steel molds. We investigate the minimum line width that can be realized by our fabrication method and the influence of etching angle on the structure profile during the ion beam etching process. Trenches down to 400 nm in width have been successfully fabricated into a 316 type electro-polished steel wafer. Afterward a plastic replica has been produced by injection molding with good structure transfer fidelity. Thus we have demonstrated that by utilizing well-established fabrication techniques, nanostructured steel shims that are used in injection molding, a technique that allows low cost mass fabrication of plastic items, are produced.

  15. Process development of thin strip steel casting

    SciTech Connect

    Sussman, R.C.; Williams, R.S.

    1990-12-01

    An important new frontier is being opened in steel processing with the emergence of thin strip casting. Casting steel directly to thin strip has enormous benefits in energy savings by potentially eliminating the need for hot reduction in a hot strip mill. This has been the driving force for numerous current research efforts into the direct strip casting of steel. The US Department of Energy initiated a program to evaluate the development of thin strip casting in the steel industry. In earlier phases of this program, planar flow casting on an experimental caster was studied by a team of engineers from Westinghouse Electric corporation and Armco Inc. A subsequent research program was designed as a fundamental and developmental study of both planar and melt overflow casting processes. This study was arranged as several separate and distinct tasks which were often completed by different teams of researchers. An early task was to design and build a water model to study fluid flow through different designs of planar flow casting nozzles. Another important task was mathematically modeling of melt overflow casting process. A mathematical solidification model for the formation of the strip in the melt overflow process was written. A study of the material and conditioning of casting substrates was made on the small wheel caster using the melt overflow casting process. This report discusses work on the development of thin steel casting.

  16. Hydrogen trapping in high-strength steels

    SciTech Connect

    Pound, B.G.

    1998-10-09

    Hydrogen trapping in three high-strength steels -- AerMet 100 and AISI 4340 and H11 -- was studied using a potentiostatic pulse technique. Irreversible trapping constants (k) and hydrogen entry fluxes were determined for these alloys in 1 mol/1 acetic acid/1 mol/1 sodium acetate. The order of the k values for the three steels and two 18Ni maraging steels previously studies inversely parallels their threshold stress intensities for stress corrosion cracking (K{sub 1SCC}). Irreversible trapping in AerMet 100 varies with aging temperature and appears to depend on the type of carbide (Fe{sub 3}C or M{sub 2}C) present. For 4340 steel, k can be correlated with K{sub 1SCC} over a range of yield strengths. The change in k is consistent with a change in the principal type of irreversible trap from matrix boundaries to incoherent Fe{sub 3}C. The principal irreversible traps in H11 at high yield strengths are thought to be similar to those in 4340 steel.

  17. Recycling zinc by dezincing steel scrap

    SciTech Connect

    Dudek, F.J.; Daniels, E.J.; Morgan, W.A.

    1995-06-01

    In response to the worldwide increase in consumption of galvanized steel for automobiles in the last fifteen years, and the increased cost of environmental compliance associated with remelting larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is recovered electrolytically as dendritic powder. The designed ferrous scrap is rinsed and used directly. The process is effective for zinc, lead, and aluminum removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested in Hamilton, Ontario for batch treatment of 900 tonnes of mostly baled scrap. A pilot plant in East Chicago, Indiana has designed in a continuous process mode 900 tonnes of loose stamping plant scrap; this scrap typically has residual zinc below 0.1% and sodium dragout below 0.001%. This paper reviews pilot plant performance and the economics of recycling galvanized steel and recovering zinc using a caustic process.

  18. View of steel warehouses (from left: building 807, 808, 809, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of steel warehouses (from left: building 807, 808, 809, 810, 811); camera facing east. - Naval Supply Annex Stockton, Steel Warehouse Type, Between James & Humphreys Drives south of Embarcadero, Stockton, San Joaquin County, CA

  19. View of steel warehouses (building 710 second in on left); ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of steel warehouses (building 710 second in on left); camera facing west. - Naval Supply Annex Stockton, Steel Warehouse Type, Between James & Humphreys Drives south of Embarcadero, Stockton, San Joaquin County, CA

  20. View of steel warehouses, building 710 north sidewalk; camera facing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of steel warehouses, building 710 north sidewalk; camera facing east. - Naval Supply Annex Stockton, Steel Warehouse Type, Between James & Humphreys Drives south of Embarcadero, Stockton, San Joaquin County, CA

  1. First Structural Steel Erected at NSLS-II

    SciTech Connect

    2009-09-14

    Ten steel columns were incorporated into the ever-growing framework for the National Synchrotron Light Source II last week, the first structural steel erected for the future 400,000-square-foot facility.

  2. View of steel warehouses at Gilmore Avenue (building 710 second ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of steel warehouses at Gilmore Avenue (building 710 second in on left); camera facing east. - Naval Supply Annex Stockton, Steel Warehouse Type, Between James & Humphreys Drives south of Embarcadero, Stockton, San Joaquin County, CA

  3. View of steel warehouses on Ellsberg Drive, building 710 full ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of steel warehouses on Ellsberg Drive, building 710 full building at center; camera facing southeast. - Naval Supply Annex Stockton, Steel Warehouse Type, Between James & Humphreys Drives south of Embarcadero, Stockton, San Joaquin County, CA

  4. First Structural Steel Erected at NSLS-II

    ScienceCinema

    None

    2010-01-08

    Ten steel columns were incorporated into the ever-growing framework for the National Synchrotron Light Source II last week, the first structural steel erected for the future 400,000-square-foot facility.

  5. View of steel warehouses (building 710 second in on right); ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of steel warehouses (building 710 second in on right); camera facing south. - Naval Supply Annex Stockton, Steel Warehouse Type, Between James & Humphreys Drives south of Embarcadero, Stockton, San Joaquin County, CA

  6. Interior of shop, detail of charging machine Bethlehem Steel ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior of shop, detail of charging machine - Bethlehem Steel Corporation, South Bethlehem Works, Tool Steel-Electric Furnace Shop, Along Lehigh River, North of Fourth Street, West of Minsi Trail Bridge, Bethlehem, Northampton County, PA

  7. 3. INTERIOR VIEW OF SMOKEHOUSE UNIT; NOTE STAINLESS STEEL NOZZLES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. INTERIOR VIEW OF SMOKEHOUSE UNIT; NOTE STAINLESS STEEL NOZZLES THAT INTRODUCED SMOKE INTO UNIT; FLOOR IS UNPAINTED STEEL - Rath Packing Company, Smokehouse-Hog Chilling Building, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

  8. Casting Stainless-Steel Models Around Pressure Tubes

    NASA Technical Reports Server (NTRS)

    Vasquez, Peter; Micol, John R.

    1992-01-01

    Survivability of thin-wall stainless-steel tubing increased to nearly 100 percent. Improves state of art in pressure-model castings and reduces cost associated with machining complete model from stainless-steel blank.

  9. 3. View of Julia Steele House, north side face and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. View of Julia Steele House, north side face and rear (west) looking south. - Julia Steele House, 5875 Paris Road (US Highway 27/68); 1 1/5 miles north of Bourbon County line, Paris, Bourbon County, KY

  10. 2. View of Julia Steele House, front (east), and northeast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. View of Julia Steele House, front (east), and northeast corner, looking southwest. - Julia Steele House, 5875 Paris Road (US Highway 27/68); 1 1/5 miles north of Bourbon County line, Paris, Bourbon County, KY

  11. Symbiosis of Steel, Energy, and CO2 Evolution in Korea

    NASA Astrophysics Data System (ADS)

    Lee, Hyunjoung; Matsuura, Hiroyuki; Sohn, Il

    2016-05-01

    This study looks at the energy intensity of the steel industry and the greenhouse gas intensity involved with the production of steel. Using several sources of steel production data and the corresponding energy sources used provides a time-series analysis of the greenhouse gas (GHG) and energy intensity from 1990 to 2014. The impact of the steel economy with the gross domestic product (GDP) provides indirect importance of the general manufacturing sector within Korea and in particular the steel industry. Beyond 2008, the shift in excess materials production and significant increase in total imports have led to an imbalance in the Korean steel market and continue to inhibit the growth of the domestic steel market. The forecast of the GHG and energy intensity along with the steel production up to 2030 is provided using the auto regressive integrated moving average analysis.

  12. 20. DETAILED OBLIQUE VIEW SOUTHWEST FURNACE 2, SHOWING STEEL FRAME ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. DETAILED OBLIQUE VIEW SOUTHWEST FURNACE 2, SHOWING STEEL FRAME BOXES FOR COUNTERWEIGHTS, AND FURNACE HEATING PIPES AT RIGHT. - Vulcan Crucible Steel Company, Building No. 3, 100 First Street, Aliquippa, Beaver County, PA

  13. 12. Detail: pier wall and undersides of encased steel beams: ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Detail: pier wall and undersides of encased steel beams: easternmost steel beam span, facing west. - Puente del Caño Perdomo, Route PR-2 spanning Cano Perdomo Channel, Arecibo, Arecibo Municipio, PR

  14. Detail section of guardrail configuration, showing notched steel post (typical) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail section of guardrail configuration, showing notched steel post (typical) with stock steel tubing and chain link; view is to east - Mather Point Overlook, South Entrance Road, Grand Canyon Village, Coconino County, AZ

  15. 4. VIEW EASTSOUTH ELEVATION OF THE BETHLEHEM STEEL COMPANY SHIPYARD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW EAST-SOUTH ELEVATION OF THE BETHLEHEM STEEL COMPANY SHIPYARD BLACKSMITH SHOP/BOILER SHOP. - Bethlehem Steel Company Shipyard, Blacksmith Shop-Boiler Shop, 1201-1321 Hudson Street, Hoboken, Hudson County, NJ

  16. 1. VIEW WESTEAST ELEVATION OF THE BETHLEHEM STEEL COMPANY SHIPYARD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW WEST-EAST ELEVATION OF THE BETHLEHEM STEEL COMPANY SHIPYARD BLACKSMITH SHOP/BOILER SHOP. - Bethlehem Steel Company Shipyard, Blacksmith Shop-Boiler Shop, 1201-1321 Hudson Street, Hoboken, Hudson County, NJ

  17. DETAIL VIEW OF STEEL PLATES IN WALKWAY CONNECTING NO. 3 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF STEEL PLATES IN WALKWAY CONNECTING NO. 3 TREATMENT SHOP (HIGH HOUSE) WITH NO. 2 TREATMENT SHOP - Bethlehem Steel Corporation, Along Lehigh River, North of Fourth Street, Bethlehem, Northampton County, PA

  18. Microstructure and cleavage in lath martensitic steels

    NASA Astrophysics Data System (ADS)

    Morris, John W., Jr.; Kinney, Chris; Pytlewski, Ken; Adachi, Y.

    2013-02-01

    In this paper we discuss the microstructure of lath martensitic steels and the mechanisms by which it controls cleavage fracture. The specific experimental example is a 9Ni (9 wt% Ni) steel annealed to have a large prior austenite grain size, then examined and tested in the as-quenched condition to produce a relatively coarse lath martensite. The microstructure is shown to approximate the recently identified ‘classic’ lath martensite structure: prior austenite grains are divided into packets, packets are subdivided into blocks, and blocks contain interleaved laths whose variants are the two Kurjumov-Sachs relations that share the same Bain axis of the transformation. When the steel is fractured in brittle cleavage, the laths in the block share {100} cleavage planes and cleave as a unit. However, cleavage cracks deflect or blunt at the boundaries between blocks with different Bain axes. It follows that, as predicted, the block size governs the effective grain size for cleavage.

  19. Fatigue of 1018 steel in hydrogen

    NASA Technical Reports Server (NTRS)

    Lo, S. H.; Johnson, H. H.

    1986-01-01

    Tests are performed at different hydrogen pressures and mechanical load parameter values (applied load, stress concentration factor, applied load frequency) to study enhanced fatigue crack growth in SAE 1018 steel. Oxygen was introduced as a hydrogen-oxygen gas mixture environment in order to compare the role of oxygen in crack inhibition with that previously reported for both static and cyclic loading of higher strength steels. In a number of experiments, a thin film of palladium was applied to the specimen surface to facilitate the study of steel-hydrogen interaction in the absence of any surface impedance to hydrogen entry. The kinetics of the diffusing atoms are found to be influenced by the stress field around the notch tip and the applied frequency. An increment in environmental effect occurred when applied load or stress concentration factor was increased.

  20. Ultrasonic Spectroscopy of Stainless Steel Sandwich Panels

    NASA Technical Reports Server (NTRS)

    Cosgriff, Laura M.; Lerch, Bradley A.; Hebsur, Mohan G.; Baaklini, George Y.; Ghosn, Louis J.

    2003-01-01

    Enhanced, lightweight material systems, such as 17-4PH stainless steel sandwich panels are being developed for use as fan blades and fan containment material systems for next generation engines. In order to improve the production for these systems, nondestructive evaluation (NDE) techniques, such as ultrasonic spectroscopy, are being utilized to evaluate the brazing quality between the 17-4PH stainless steel face plates and the 17-4PH stainless steel foam core. Based on NDE data, shear tests are performed on sections representing various levels of brazing quality from an initial batch of these sandwich structures. Metallographic characterization of brazing is done to corroborate NDE findings and the observed shear failure mechanisms.

  1. Explosive Surface Hardening of Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Kovacs-Coskun, T.

    2016-04-01

    In this study, the effects of explosion hardening on the microstructure and the hardness of austenitic stainless steel have been studied. The optimum explosion hardening technology of austenitic stainless steel was researched. In case of the explosive hardening used new idea mean indirect hardening setup. Austenitic stainless steels have high plasticity and can be easily cold formed. However, during cold processing the hardening phenomena always occurs. Upon the explosion impact, the deformation mechanism indicates a plastic deformation and this deformation induces a phase transformation (martensite). The explosion hardening enhances the mechanical properties of the material, includes the wear resistance and hardness. In case of indirect hardening as function of the setup parameters specifically the flayer plate position the hardening increased differently. It was find a relationship between the explosion hardening setup and the hardening level.

  2. Residual stress patterns in steel welds

    SciTech Connect

    Spooner, S.; Hubbard, C.R.; Wang, X.L.; David, S.A.; Holden, T.M.; Root, J.H.; Swainson, I.

    1994-12-31

    Neutron strain scanning of residual stress is a valuable nondestructive tool for evaluation of residual stress in welds. The penetrating characteristic of neutrons permits mapping of strain patterns with a spatial resolution approaching 1mm at depths of 20mm in steels. While the overall patterns of the residual stress tensor in a weld are understood, the detailed patterns depend on welding process parameters and the effects of solid state transformation. The residual strain profiles in two multi-pass austenitic welds and a ferritic steel weld are presented. The stress-free lattice parameters within the fusion zone and the adjacent heat affected zone in the two austenitic welds show that the interpretation of residual stress from strains are affected by welding parameters. An interpretation of the residual strain pattern in the ferritic steel plate can be made using the strain measurements of a Gleeble test bar which has undergone the solid state austenite decomposition.

  3. Solidification Sequence of Spray-Formed Steels

    NASA Astrophysics Data System (ADS)

    Zepon, Guilherme; Ellendt, Nils; Uhlenwinkel, Volker; Bolfarini, Claudemiro

    2016-02-01

    Solidification in spray-forming is still an open discussion in the atomization and deposition area. This paper proposes a solidification model based on the equilibrium solidification path of alloys. The main assumptions of the model are that the deposition zone temperature must be above the alloy's solidus temperature and that the equilibrium liquid fraction at this temperature is reached, which involves partial remelting and/or redissolution of completely solidified droplets. When the deposition zone is cooled, solidification of the remaining liquid takes place under near equilibrium conditions. Scanning electron microscopy (SEM) and optical microscopy (OM) were used to analyze the microstructures of two different spray-formed steel grades: (1) boron modified supermartensitic stainless steel (SMSS) and (2) D2 tool steel. The microstructures were analyzed to determine the sequence of phase formation during solidification. In both cases, the solidification model proposed was validated.

  4. Application of RST in the steel industry

    NASA Astrophysics Data System (ADS)

    Raman, R. V.; Maringer, R. E.

    1982-05-01

    The rapid solidification technology (RST) involves quenching molten metals at rates of perhaps 102 to 1010 degrees C per second. First reported in 1960, RST has experienced rapid growth during the last decade and is now established on the commercial market-place. This has resulted from the simple facts that unusual properties result from RST, that relatively easy techniques are available to produce large quantities of material, and that applications for these materials have been recognized. Ferrous-base materials produced by RST methods include staple fibers of mild and stainless steel for incorporation into concrete and castable refractories, powder metallurgy tool steels, and amorphous strip for power transformers. Research results suggest that RST will have a strong continuing influence on ferrous powder metallurgy, on the direct casting of strip and foil of carbon and stainless steel, and on core materials for motor and transformers.

  5. Hydrogen-Trapping Mechanisms in Nanostructured Steels

    NASA Astrophysics Data System (ADS)

    Szost, B. A.; Vegter, R. H.; Rivera-Díaz-del-Castillo, Pedro E. J.

    2013-10-01

    Nanoprecipitation-hardened martensitic bearing steels (100Cr6) and carbide-free nanobainitic steels (superbainite) are examined. The nature of the hydrogen traps present in both is determined via the melt extraction and thermal desorption analysis techniques. It is demonstrated that 100Cr6 can admit large amounts of hydrogen, which is loosely bound to dislocations around room temperature; however, with the precipitation of fine coherent vanadium carbide traps, hydrogen can be immobilized. In the case of carbide-free nanostructured bainite, retained austenite/bainite interfaces act as hydrogen traps, while concomitantly retained austenite limits hydrogen absorption. In nanostructured steels where active hydrogen traps are present, it is shown that the total hydrogen absorbed is proportional to the trapped hydrogen, indicating that melt extraction may be employed to quantify trapping capacity.

  6. Residual stress measurements in carbon steel

    NASA Technical Reports Server (NTRS)

    Heyman, J. S.; Min, N.

    1986-01-01

    External dc magnetic field-induced changes in natural velocity of Rayleigh surface waves were measured in steel specimens under various stress conditions. The low field slopes of curves representing the fractional changes of natural velocity were proved to provide correct stress information in steels with different metallurgical properties. The slopes of curves under uniaxial compression, exceeding about one third of the yield stress, fell below zero in all the specimens when magnetized along the stress axis. The slopes under tension varied among different steels but remained positive in any circumstances. The stress effect was observed for both applied and residual stress. A physical interpretation of these results is given based on the stress-induced domain structure changes and the delta epsilon effect. Most importantly, it is found that the influence of detailed metallurgical properties cause only secondary effects on the obtained stress information.

  7. Enhanced Inclusion Removal from Steel in the Tundish

    SciTech Connect

    R. C. Bradt; M.A.R. Sharif

    2009-09-25

    The objective of this project was to develop an effective chemical filtering system for significantly reducing the content of inclusion particles in the steel melts exiting the tundish for continuous casting. This project combined a multi-process approach that aimed to make significant progress towards an "inclusion free" steel by incorporating several interdependent concepts to reduce the content of inclusions in the molten steel exiting the tundish for the caster. The goal is to produce "cleaner" steel.

  8. Enhanced Incluison Removal from Steel in the Tundish

    SciTech Connect

    R.C. Bradt; M.A.R. Sharif

    2009-09-25

    The objective of this project was to develop an effective chemical filtering system for significantly reducing the content of inclusion particles in the steel melts exiting the tundish for continuous casting. This project combined a multi-process approach that aimed to make significant progress towards an "inclusion free" steel by incorporating several interdependent concepts to reduce the content of inclusions in the molten steel exiting the tundish for the caster. The goal is to produce "cleaner" steel.

  9. Effect of rust on the wettability of steel by water

    SciTech Connect

    Lu, W.; Chung, D.D.L.

    1998-04-01

    Rust, as formed on steel by immersion of low-carbon steel in water, was found to improve the wettability of steel by water. The advancing contact angle decreased from 87{degree} to 32{degree}, and the receding contact angle decreased from 81{degree} to 29{degree}. Cleansing of steel by acetone also helped improve the wettability, but the advancing angle only decreased from 87{degree} to 73{degree}, and the receding angle only decreased from 81{degree} to 41{degree}.

  10. Investigation of the plastic fracture of high strength steels

    NASA Technical Reports Server (NTRS)

    Cox, T. B.; Low, J. R., Jr.

    1972-01-01

    This investigation deals in detail with the three recognized stages of plastic fracture in high strength steels, namely, void initiation, void growth, and void coalescence. The particular steels under investigation include plates from both commercial purity and high purity heats of AISI 4340 and 18 Ni, 200 grade maraging steels. A scanning electron microscope equipped with an X-ray energy dispersive analyzer, together with observations made using light microscopy, revealed methods of improving the resistance of high strength steels to plastic fracture.

  11. Iron and steel industry process model

    SciTech Connect

    Sparrow, F.T.; Pilati, D.; Dougherty, T.; McBreen, E.; Juang, L.L.

    1980-01-01

    The iron and steel industry process model depicts expected energy-consumption characteristics of the iron and steel industry and ancillary industries for the next 25 years by means of a process model of the major steps in steelmaking, from ore mining and scrap recycling to the final finishing of carbon, alloy, and stainless steel into steel products such as structural steel, slabs, plates, tubes, and bars. Two plant types are modeled: fully integrated mills and mini-mills. User-determined inputs into the model are as follows: projected energy and materials prices; projected costs of capacity expansion and replacement; energy-conserving options, both operating modes and investments; the internal rate of return required on investment; and projected demand for finished steel. Nominal input choices in the model for the inputs listed above are as follows: National Academy of Sciences Committee on Nuclear and Alternative Energy Systems Demand Panel nominal energy-price projections for oil, gas, distillates, residuals, and electricity and 1975 actual prices for materials; actual 1975 costs; new technologies added; 15% after taxes; and 1975 actual demand with 1.5%/y growth. The model reproduces the base-year (1975) actual performance of the industry; then, given the above nominal input choices, it projects modes of operation and capacity expansion that minimize the cost of meeting the given final demands for each of 5 years, each year being the midpoint of a 5-year interval. The output of the model includes the following: total energy use and intensity (Btu/ton) by type, by process, and by time period; energy conservation options chosen; utilization rates for existing capacity; capital-investment decisions for capacity expansion.

  12. Neutron Irradiation Resistance of RAFM Steels

    SciTech Connect

    Gaganidze, Ermile; Dafferner, Bernhard; Aktaa, Jarir

    2008-07-01

    The neutron irradiation resistance of the reduced-activation ferritic/martensitic (RAFM) steel EUROFER97 and international reference steels (F82H-mod, OPTIFER-Ia, GA3X and MANET-I) have been investigated after irradiation in the Petten High Flux Reactor up to 16.3 dpa at different irradiation temperatures (250-450 deg. C). The embrittlement behavior and hardening are investigated by instrumented Charpy-V tests with sub-size specimens. Neutron irradiation-induced embrittlement and hardening of EUROFER97 was studied under different heat treatment conditions. Embrittlement and hardening of as-delivered EUROFER97 steel are comparable to those of reference steels. Heat treatment of EUROFER97 at a higher austenitizing temperature substantially improves the embrittlement behaviour at low irradiation temperatures. Analysis of embrittlement vs. hardening behavior of RAFM steels within a proper model in terms of the parameter C={delta}DBTT/{delta}{sigma} indicates hardening-dominated embrittlement at irradiation temperatures below 350 deg. C with 0.17 {<=} C {<=} 0.53 deg. C/MPa. Scattering of C at irradiation temperatures above 400 deg. C indicates non hardening embrittlement. A role of He in a process of embrittlement is investigated in EUROFER97 based steels, that are doped with different contents of natural B and the separated {sup 10}B-isotope (0.008-0.112 wt.%). Testing on small scale fracture mechanical specimens for determination of quasi-static fracture toughness will be also presented in a view of future irradiation campaigns. (authors)

  13. Stainless Steel Microstructure and Mechanical Properties Evaluation

    SciTech Connect

    Switzner, Nathan T

    2010-06-01

    A nitrogen strengthened 21-6-9 stainless steel plate was spinformed into hemispherical test shapes. A battery of laboratory tests was used to characterize the hemispheres. The laboratory tests show that near the pole (axis) of a spinformed hemisphere the yield strength is the lowest because this area endures the least “cold-work” strengthening, i.e., the least deformation. The characterization indicated that stress-relief annealing spinformed stainless steel hemispheres does not degrade mechanical properties. Stress-relief annealing reduces residual stresses while maintaining relatively high mechanical properties. Full annealing completely eliminates residual stresses, but reduces yield strength by about 30%.

  14. Superhydrophobic conductive carbon nanotube coatings for steel.

    PubMed

    Sethi, Sunny; Dhinojwala, Ali

    2009-04-21

    We report the synthesis of superhydrophobic coatings for steel using carbon nanotube (CNT)-mesh structures. The CNT coating maintains its structural integrity and superhydrophobicity even after exposure to extreme thermal stresses and has excellent thermal and electrical properties. The coating can also be reinforced by optimally impregnating the CNT-mesh structure with cross-linked polymers without significantly compromising on superhydrophobicity and electrical conductivity. These superhydrophobic conductive coatings on steel, which is an important structural material, open up possibilities for many new applications in the areas of heat transfer, solar panels, transport of fluids, nonwetting and nonfouling surfaces, temperature resilient coatings, composites, water-walking robots, and naval applications. PMID:19281157

  15. Exploratory study on H13 steel dies

    SciTech Connect

    Sunwoo, A.J.

    1994-04-01

    Ultrahigh-strength H13 steel is a recommended die material for aluminum die casting; dies made from H13 steel can be safely water- cooled during hot working operations without cracking. However, after time the dies exhibited surface cracking and excessive wear. Erosive wear also occurs owing to high pressure injection of molten Al. An exploratory study was made of the causes for surface cracking of H13 dies. Results suggest that surface cracking is caused by interrelated factors, internal to the die material as well as externally induced conditions.

  16. Nondestructive Technique To Assess Embrittlement In Steels

    NASA Technical Reports Server (NTRS)

    Allison, Sidney G.; Yost, William T.; Cantrell, John H.

    1990-01-01

    Recent research at NASA Langley Research Center led to identification of nondestructive technique for detection of temper embrittlement in HY80 steel. Measures magnetoacoustic emission associated with reversible motion of domain walls at low magnetic fields. Of interest to engineers responsible for reliability and safety of various dynamically loaded and/or thermally cycled steel parts. Applications include testing of landing gears, naval vessels, and parts subjected to heat, such as those found in steam-pipe fittings, boilers, turbine rotors, and nuclear pressure vessels.

  17. Hydrogen induced plastic deformation of stainless steel

    SciTech Connect

    Gadgil, V.J.; Keim, E.G.; Geijselaers, H.J.M.

    1998-12-31

    Hydrogen can influence the behavior of materials significantly. The effects of hydrogen are specially pronounced in high fugacities of hydrogen which can occur at the surface of steels in contact with certain aqueous environments. In this investigation the effect of high fugacity hydrogen on the surface of stainless steel was investigated using electrochemical cathodic charging. Microhardness was measured on the cross section. Transmission electron microscopy was used to investigate the dislocation substructure just below the surface. Computer simulation using finite element method was carried out to estimate the extent and severity of the deformation. The significance of the results are discussed in relation to the loss of ductility due to hydrogen.

  18. Measuring secondary phases in duplex stainless steels

    NASA Astrophysics Data System (ADS)

    Calliari, I.; Brunelli, K.; Dabalà, M.; Ramous, E.

    2009-01-01

    The use of duplex stainless steels is limited by their susceptibility to the formation of dangerous intermetallic phases resulting in detrimental effects on impact toughness and corrosion resistance. This precipitation and the quantitative determinations of the phases have received considerable attention and different precipitation sequences (σ phase, χ phase, and carbides) have been suggested. This study investigates the phase transformation during continuous cooling and isothermal treatments in commercial duplex stainless steel grades and the effects on alloy properties, and compares the most common techniques of analysis.

  19. Direct Coating of Nanocrystalline Diamond on Steel

    NASA Astrophysics Data System (ADS)

    Tsugawa, Kazuo; Kawaki, Shyunsuke; Ishihara, Masatou; Hasegawa, Masataka

    2012-09-01

    Nanocrystalline diamond films have been successfully deposited on stainless steel substrates without any substrate pretreatments to promote diamond nucleation, including the formation of interlayers. A low-temperature growth technique, 400 °C or lower, in microwave plasma chemical vapor deposition using a surface-wave plasma has cleared up problems in diamond growth on ferrous materials, such as the surface graphitization, long incubation time, substrate softening, and poor adhesion. The deposited nanocrystalline diamond films on stainless steel exhibit good adhesion and tribological properties, such as a high wear resistance, a low friction coefficient, and a low aggression strength, at room temperature in air without lubrication.

  20. Modern steels at atomic and nanometre scales

    DOE PAGESBeta

    Caballero, F. G.; Garcia-Mateo, C.; Miller, M. K.

    2014-10-10

    Processing bulk nanocrystalline materials for structural applications still poses a difficult challenge, particularly in achieving an industrially viable process. Recent work in ferritic steels has proved that it is possible to move from ultrafine to nanoscale by exploiting the bainite reaction without the use of severe deformation, rapid heat treatment or mechanical processing. This new generation of steels has been designed in which transformation at low temperature leads to a nanoscale structure consisting of extremely fine, 20–40 nm thick plates of bainitic ferrite and films of retained austenite. Finally, a description of the characteristics and significance of this remarkable microstructuremore » is provided here.« less