Science.gov

Sample records for geomembrane steel sheet

  1. Use of a geomembrane steel sheet pile verticle barrier to curtail organic seepage

    SciTech Connect

    Guglielmetti, J.L.; Butler, P.B.

    1997-12-31

    At a Superfund site in Delaware, contaminated groundwater, seeping out of a riverbank, produced a visible sheen on the river. As part of an emergency response action, a geomembrane steel sheet pile vertical barrier system was installed to contain the sheen and contaminated soil and sediments. The response action presented an engineering challenge due to the close proximity manufacturing facilities, steep riverbank slopes, tidal fluctuations, high velocity river flow, and underground and overhead interferences. A unique vertical containment barrier was developed to stabilize the riverbank slope, curtail sheens on the river, and prevent groundwater mounding behind the vertical barrier. In addition, the cost-effective vertical barrier enables natural chemical and biological processes to contain the organic seepage without requiring a groundwater extraction system.

  2. FREEZE-THAW CYCLING AND COLD TEMPERATURE EFFECTS ON GEOMEMBRANE SHEETS AND SEAMS. Project summary

    EPA Science Inventory

    The effects of freeze-thaw cycling on the tensile strength of 19 geomembranes and 31 different seam types were investigated. The study was performed in three parts using different test conditions. Part I involved incubating unconfined specimens in freeze-thaw cycles and then per...

  3. Armored Geomembrane Cover Engineering

    PubMed Central

    Foye, Kevin

    2011-01-01

    Geomembranes are an important component of modern engineered barriers to prevent the infiltration of stormwater and runoff into contaminated soil and rock as well as waste containment facilities—a function generally described as a geomembrane cover. This paper presents a case history involving a novel implementation of a geomembrane cover system. Due to this novelty, the design engineers needed to assemble from disparate sources the design criteria for the engineering of the cover. This paper discusses the design methodologies assembled by the engineering team. This information will aid engineers designing similar cover systems as well as environmental and public health professionals selecting site improvements that involve infiltration barriers. PMID:21776229

  4. 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

  5. 10. KIDNER BRIDGE STRUCTURAL STEEL DETAIL SHEET (original plan sheet ...

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

    10. KIDNER BRIDGE STRUCTURAL STEEL DETAIL SHEET (original plan sheet is in possession of Ball State University, Drawings and Documents Archive, COllege of Architecture and Planing, Ball State University, Muncie, Indiana, 47306 - Kidner Bridge, Spanning Mississinewa River at County Road 700 South, Upland, Grant County, IN

  6. 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.

  7. Geomembrane special study. [UMTRA Project

    SciTech Connect

    Not Available

    1988-07-01

    The objective of the Geomembrane Special Study was to asses the suitability of geomembranes in Uranium Mill Tailings Remedial Action (UMTRA) Project pile designs. Geomembranes, also called flexible membrane liners, are made of polymer resins and are thermoplastic materials. Part of the special study was to evaluate regulatory compliance and acceptability issues. This study was proposed because of the extensive use of geomembranes in hazardous waste site remedial actions and their accepted use in Resource Conservation and Recovery Act (RCRA) cells as both covers and liners to limit infiltration, or as part of leachate collection systems. This study has reviewed the recent geomembrane literature focusing on: (1) longevity; (2) performance; (3) constructibility; and (4) quality control/quality assurance considerations. In addition to these technical considerations, regulatory compliance and acceptability concerns were also evaluated. This report describes the results of the literature review, including correspondence with manufacturers, resin producers, experts in the field, and long-term major users. 12 refs., 2 tabs.

  8. Formability of type 304 stainless steel sheet

    SciTech Connect

    Coubrough, G.J.; Matlock, D.K.; VanTyne, C.J.

    1992-09-01

    Punch-stretch tests to determine formability of type 304 stainless steel sheet were conducted using a hemispherical dome test. Sheets of 19.1 mm width and 177.8 mm width were stretched on a 101.6 mm diameter punch at punch rates between 0.042 to 2.12 mm/s with three lubricant systems: a mineral seal oil, thin polytetrafluoroethelyne sheet with mineral seal oil, and silicone rubber with mineral seal oil. The resulting strain distributions were measured and the amount of martensite was determined by magnetic means. Increasing lubricity resulted in more uniform strain distributions while increased punch rates tended to decrease both strain and transformation distributions. High forming limit values were related to the formation of high and uniformly distributed martensite volume fractions during deformation. The results of this study are interpreted with an analysis of the effects of strain and temperature on strain induced martensite formation in metastable austenitic stainless steels.

  9. Formability of type 304 stainless steel sheet

    SciTech Connect

    Coubrough, G.J. . Rocky Flats Plant); Matlock, D.K.; VanTyne, C.J. )

    1992-01-01

    Punch-stretch tests to determine formability of type 304 stainless steel sheet were conducted using a hemispherical dome test. Sheets of 19.1 mm width and 177.8 mm width were stretched on a 101.6 mm diameter punch at punch rates between 0.042 to 2.12 mm/s with three lubricant systems: a mineral seal oil, thin polytetrafluoroethelyne sheet with mineral seal oil, and silicone rubber with mineral seal oil. The resulting strain distributions were measured and the amount of martensite was determined by magnetic means. Increasing lubricity resulted in more uniform strain distributions while increased punch rates tended to decrease both strain and transformation distributions. High forming limit values were related to the formation of high and uniformly distributed martensite volume fractions during deformation. The results of this study are interpreted with an analysis of the effects of strain and temperature on strain induced martensite formation in metastable austenitic stainless steels.

  10. INSPECTION TECHNIQUES FOR THE FABRICATION OF GEOMEMBRANE FIELD SEAMS

    EPA Science Inventory

    Geomembranes employed to overlay the excavation for landfills must be seamed together at the site of the landfill. o ensure the integrity of the containment system of the landfill, these sheets or blankets must be carefully seamed. he methods in present, common use are extrusion ...

  11. TECHNIQUES FOR THE FABRICATION OF GEOMEMBRANE FILLED SEAMS

    EPA Science Inventory

    Geomembranes employed to overlay the excavation for landfills must be seamed together on-site at the landfill. To ensure the integrity of the containment system of the landfill, these sheets or blankets must be carefully seamed. Present methods in common use are: extrusion fil...

  12. Local Laser Heat Treatments of Steel Sheets

    NASA Astrophysics Data System (ADS)

    Järvenpää, A.; Jaskari, M.; Hietala, M.; Mäntyjärvi, K.

    In this work UHS structural and abrasion resistant (AR) steels were heat treated with a single 4 kW Yb: YAG-laser beam. Aim of the softening heat treatments was to enhance the formability locally with minimized strength lose. 1.8 mm thick B24CR boron steel was used for hardening tests. Study presents the possibilities and limitations in laser processing showing that a single laser beam is suitable for heat treating of sheets through the whole cross-section up to the thickness of 6 mm. In the case of the 6 mm thick sheets, the achieved maximum temperature in the cross-section varies as a function of the depth. Consequently, the microstructure and mechanical properties differ between the surfaces and the center of the cross-section (layered microstructure). For better understanding, all layers were tested in tensile tests. The 10 mm thick sheet was heat treated separately on the both surfaces by heating to a lower temperature range to produce a shallow tempered layer. The tensile and bendability tests as well as hardness measurements indicated that laser heat treatment can be used to highly improve the bendability locally without significant strength losses. Laser process has been optimized by transverse scanning movement and with a simple FE-model.

  13. 116. Photocopied August 1978. NEW INTERLOCKING STEEL SHEET PILING AT ...

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

    116. Photocopied August 1978. NEW INTERLOCKING STEEL SHEET PILING AT PENSTOCK 52 IN THE FALL OF 1926. THE PILES FOR SUPPORTING THE HORIZONTAL ELEMENTS OF THE NEW FOREBAY APRON ARE IN PLACE BETWEEN THE NEW SHEET PILING AND THE FOREBAY WALL. VISIBLE BEYOND THE NEW SHEET PILING IS THE TIMBER SHEET PILING DRIVEN IN 1903 BY VON SCHON TO PREVENT WASHOUTS. (1006) - Michigan Lake Superior Power Company, Portage Street, Sault Ste. Marie, Chippewa County, MI

  14. 6. INTERIOR VIEW, HIGH CARBON HOT ROLLED SHEET STEEL FOR ...

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

    6. INTERIOR VIEW, HIGH CARBON HOT ROLLED SHEET STEEL FOR NAIL PLATE BEING LOADED ON THE CRADLE USED DURING THE PICKLING PROCESS - LaBelle Iron Works, Thirtieth & Wood Streets, Wheeling, Ohio County, WV

  15. 5. INTERIOR VIEW, HIGH CARBON HOT ROLLED SHEET STEEL FOR ...

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

    5. INTERIOR VIEW, HIGH CARBON HOT ROLLED SHEET STEEL FOR NAIL PLATE BEING REMOVED FROM THE CRADLE USED DURING THE PICKLING PROCESS - LaBelle Iron Works, Thirtieth & Wood Streets, Wheeling, Ohio County, WV

  16. Zinc coated sheet steel for press hardening

    NASA Astrophysics Data System (ADS)

    Ghanbari, Zahra N.

    Galvanized steels are of interest to enhance corrosion resistance of press-hardened steels, but concerns related to liquid metal embrittlement have been raised. The objective of this study was to assess the soak time and temperature conditions relevant to the hot-stamping process during which Zn penetration did or did not occur in galvanized 22MnB5 press-hardening steel. A GleebleRTM 3500 was used to heat treat samples using hold times and temperatures similar to those used in industrial hot-stamping. Deformation at both elevated temperature and room temperature were conducted to assess the coating and substrate behavior related to forming (at high temperature) and service (at room temperature). The extent of alloying between the coating and substrate was assessed on undeformed samples heat treated under similar conditions to the deformed samples. The coating transitioned from an α + Gamma1 composition to an α (bcc Fe-Zn) phase with increased soak time. This transition likely corresponded to a decrease in availability of Zn-rich liquid in the coating during elevated temperature deformation. Penetration of Zn into the substrate sheet in the undeformed condition was not observed for any of the processing conditions examined. The number and depth of cracks in the coating and substrate steel was also measured in the hot-ductility samples. The number of cracks appeared to increase, while the depth of cracks appeared to decrease, with increasing soak time and increasing soak temperature. The crack depth appeared to be minimized in the sample soaked at the highest soak temperature (900 °C) for intermediate and extended soak times (300 s or 600 s). Zn penetration into the substrate steel was observed in the hot-ductility samples soaked at each hold temperature for the shortest soak time (10 s) before being deformed at elevated temperature. Reduction of area and elongation measurements showed that the coated sample soaked at the highest temperature and longest soak time

  17. Computational Strategies for Polymer Coated Steel Sheet Forming Simulations

    SciTech Connect

    Owen, D. R. J.; Andrade Pires, F. M.; Dutko, M.

    2007-05-17

    This contribution discusses current issues involved in the numerical simulation of large scale industrial forming processes that employ polymer coated steel sheet. The need for rigorous consideration of both theoretical and algorithmic issues is emphasized, particularly in relation to the computational treatment of finite strain deformation of polymer coated steel sheet in the presence of internal degradation. Other issues relevant to the effective treatment of the problem, including the modelling of frictional contact between the work piece and tools, low order element technology capable of dealing with plastic incompressibility and thermo mechanical coupling, are also addressed. The suitability of the overall approach is illustrated by the solution of an industrially relevant problem.

  18. Nd:YAG laser welding of coated sheet steel

    SciTech Connect

    Graham, M.P.; Kerr, H.W.; Weckman, D.C.

    1994-12-31

    Coated sheet steels are used extensively in the automotive industry for the fabrication of automobile body components; however, their reduced weldability by the traditional welding processes has led to numerous studies into the use of alternate process such as laser welding. In this paper, we present a modified joint geometry which allows high quality lap welds of coated sheet steels to be made by laser welding processes. Hot-dipped galvanized sheet (16 gauge), with a 60 g/m zinc coating was used in this study. A groove was created in the top sheet of a specimen pair by pressing piano wires of various diameters into the sheet. The specimens were clamped together in a lag-joint configuration such that they were in contacted only along the grove projection. A parametric study was conducted using the variables of welding speed, laser mean power (685 W, 1000 W and 1350 W), and grove size. Weld quality and weld pool dimensions were assessed using metallurgical cross-sections and image analysis techniques. Acceptable quality seam welds were produced in the galvanized sheet steel with both grove sizes when using 1000 W and 1350 W laser mean powers and a range of welding speeds. Results of the shear-tensile tests showed that high loads to failure, with failure occurring in the parent material, were predominately found in welds produced at speeds over 1.2 m/min and when using the high mean laser powers: 1000 W and 1350 W. A modified lap joint geometry, in which a groove is pre-placed in the top sheet of the lap-joint configuration, has been developed which permits laser welding of coated sheet steels. Good quality seam welds have been produced in 16 gauge galvanized sheet steels at speeds up to 2.7 m/min using a 2 kW CW Nd:YAG laser operating at 1350 W laser mean power. Weld quality was not affected by changes in groove size.

  19. Correlation Between Shear Punch and Tensile Strength for Low-Carbon Steel and Stainless Steel Sheets

    NASA Astrophysics Data System (ADS)

    Mahmudi, R.; Sadeghi, M.

    2013-02-01

    The deformation behavior of AISI 1015 low-carbon steel, and AISI 304 stainless steel sheets was investigated by uniaxial tension and the shear punch test (SPT). Both materials were cold rolled to an 80% thickness reduction and subsequently annealed in the temperature range 25-850 °C to produce a wide range of yield and ultimate strength levels. The correlations between shear punch and tensile yield and ultimate stresses were established empirically. Different linear relationships having different slopes and intercepts were found for the low-carbon and stainless steel sheets, and the possible parameters affecting the correlation were discussed. It was shown that, within limits, yield and tensile strength of thin steel sheets can be predicted from the shear data obtained by the easy-to-perform SPT.

  20. Nanoscale precipitation in hot rolled sheet steel

    NASA Astrophysics Data System (ADS)

    Sun, Jun

    Some newer hot rolled high strength low alloy (HSLA) steels with a single phase ferrite matrix have obtained substantial strengthening from nanoscale precipitation. These HSLA are reported to have a good combination of strength, ductility and hole-expansion ability. In the current work, Gleeble ® 3500 torsion testing was employed to simulate the hot rolling process with varying run-out table cooling rates and coiling temperatures on five microalloyed steels with additions of Ti, Nb, Mo, Cr and V, to investigate the effects of microalloy additions and processing conditions on microstructures as well as mechanical properties. Subsized tensile specimens obtained from as-twisted torsion samples were used to evaluate mechanical properties. The precipitation states of the five steels with different processing conditions were characterized using extraction replica TEM. Comparison of microstructures and mechanical properties was discussed. Characterization of the microstructure via light optical microscopy showed the matrix microstructure was mainly influenced by coiling temperature, which indicates that the transformation from austenite to ferrite occurred during the coiling period. A higher Ti content was shown to reduce the second constituent fractions. Investigation of carbon extraction replica specimens via TEM revealed the presence of nanoscale precipitation. Extensive nanoscale precipitation was observed in most of the specimens having a polygonal ferrite matrix, while in the granular bainite/ferrite microstructure at lower temperatures, fewer microalloy carbides were present. The specimens with polygonal ferrite had similar or higher yield strength than the specimens with granular bainite microstructure, which suggests the effectiveness of precipitation strengthening from extensive nanoscale precipitates. In the Nb-Mo steel, more significant strengthening due to grain refinement was evident. Yield strength values were less than reported for JFE's "NANOHITEN

  1. 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.

  2. Constitutive modelling of dual phase steel sheet and tube

    NASA Astrophysics Data System (ADS)

    Thompson, A. C.; Salisbury, C. P.; Worswick, M. J.; Mayer, R.

    2006-08-01

    Automobile manufacturers are currently striving to improve vehicle fuel efficiency through reduction of vehicle weight. Dual phase steels are good candidates for automotive bodies due to their high strength-to-weight ratio, and good formablity and weldability. As part of a project on the interaction between forming and crashworthiness, constitutive parameters of a dual phase steel were determined for both sheet and tube stock in order to support analysis of the tube response throughout forming processes and in crash simulations. Stress - strain data was collected at a quasi-static rate as well as rates from 0.1 to 1500 s - 1. The intermediate strain rate response was captured using an instrumented falling weight tensile tester (35 100 s - 1), while a tensile split Hopkinson bar (500 1500 s - 1) was used to capture the high-rate response. This range of strain rates is typical of the rates seen in a crash simulation. Tests were also performed at higher temperatures (150°C and 300°C) at rates of 500 and 1500 s - 1 to capture the thermal softening response. The dual phase steel sheet and tube show an appreciable amount of strain rate sensitivity throughout the complete range of strain rates. It also exhibited a large amount of thermal softening. The thermal sensitivity is identical for the sheet and tube. Fits to the Johnson-Cook constitutive model were obtained from the experimental results.

  3. Self-Pierce Riveting of Three Aluminium Alloy and Mild Steel Sheets

    SciTech Connect

    Mori, K.; Abe, Y.; Sakai, S.; Kato, T.

    2010-06-15

    Three aluminium alloy and steel sheets were joined with a self-piercing rivet. Self-pierce riveting has the function of joining steel and aluminium alloys having very different melting points due to plastic joining. The requisites for joining the three sheets are the driving of the rivet leg through the middle sheet, the flaring of the rivet leg in the lower sheet and the prevention of the fracture of the lower sheet. The joinability for various combinations of the three sheets was determined. When the rivet leg is small, no driving through the middle sheet occurs, the lower sheet ruptures for a large rivet leg. In addition, 980 MPa high strength steel, mild steel and aluminium alloy sheets were joined by the self-pierce riveting.

  4. STRESS CRACK TESTING OF POLYETHYLENE GEOMEMBRANES

    EPA Science Inventory

    The sensitivity of high density polyethylene (HDPE) geomembranes to stress cracking is evaluated under accelerated conditions at a constant stress. he test specimens are according to ASTM D-1822, and are of the dumbbell shape with a constant length in the central section. he acce...

  5. FIELD STUDIES OF GEOMEMBRANE INSTALLATION TECHNIQUES

    EPA Science Inventory

    Fourteen construction sites where geomembranes were being installed were visited to observe subgrade preparation and liner installation techniques. These sites were visited during a study conducted for the U.S. EPA, Solid and Hazardous Waste Research Division. The sites included ...

  6. Estimation Model for Magnetic Properties of Stamped Electrical Steel Sheet

    NASA Astrophysics Data System (ADS)

    Kashiwara, Yoshiyuki; Fujimura, Hiroshi; Okamura, Kazuo; Imanishi, Kenji; Yashiki, Hiroyoshi

    Less deterioration in magnetic properties of electrical steel sheets in the process of stamping out iron-core are necessary in order to maintain its performance. First, the influence of plastic strain and stress on magnetic properties was studied by test pieces, in which plastic strain was added uniformly and residual stress was not induced. Because the influence of plastic strain was expressed by equivalent plastic strain, at each equivalent plastic strain state the influence of load stress was investigated. Secondly, elastic limit was determined about 60% of macroscopic yield point (MYP), and it was found to agree with stress limit inducing irreversible deterioration in magnetic properties. Therefore simulation models, where beyond elastic limit plastic deformation begins and magnetic properties are deteriorated steeply, are proposed. Besides considered points in the deformation analysis are strain-rate sensitivity of flow stress, anisotropy under deformation, and influence of stress triaxiality on fracture. Finally, proposed models have been shown to be valid, because magnetic properties of 5mm width rectangular sheets stamped out from non-oriented electrical steel sheet (35A250 JIS grade) can be estimated with good accuracy. It is concluded that the elastic limit must be taken into account in both stamping process simulation and magnetic field calculation.

  7. License plate cosmetic corrosion test of automotive coated steel sheet

    SciTech Connect

    Townsend, H.E.; Simpson, M.W.; McCune, D.C.

    1999-04-01

    A new standard laboratory test (SAE J2334) for evaluation of the cosmetic corrosion resistance of autobody steel sheet has been developed through the joint efforts of the Society of Automotive Engineers Automotive Corrosion Prevention Committee (SAE/ACAP) and the Auto/Steel Partnership (A/SP) Corrosion Task Force. Results from this test gave an excellent correlation with those of on-vehicle tests conducted for 5 years in Canada at St. John`s, Newfoundland, and Montreal, Quebec. To determine how results of the Canadian tests related to environments in the United States, racks of identical materials were mounted on the front license plate brackets of cars driven in various locations in the US snowbelt, including Bethlehem, Pennsylvania; Detroit, Michigan, and Chardon, Ohio. After 4 years to 5 years, these tests showed the US environments produced less scribe creep and more red rust than those conducted in Canada. Similar rankings were obtained for the scribe creep resistance of the various coated steel sheet products when compared at equivalent amounts of corrosion. However, the ranking of materials changed at longer exposure times in Canada, and for that reason, it was concluded that the 5-year Canadian results used in the development of the SAE J2334 test provided a better real-world performance standard.

  8. Finite Element Simulation of Plastic Joining Processes of Steel and Aluminum Alloy Sheets

    SciTech Connect

    Mori, K.; Abe, Y.; Kato, T.

    2007-05-17

    Various high tensile strength steel sheets and an aluminum alloy sheet were joined with a self-piercing rivet. It is not easy to weld the aluminum alloy sheet and high tensile strength sheets by means of conventional resistance welding because of very different melting points. To obtain optimum joining conditions, joining defects were categorized into separation of the sheets and an inner fracture. The joining range of ultra high tensile strength steel and aluminum alloy sheets was extended by means of dies optimized by finite element simulation. The joint strength is greatly influenced by not only the strength of the sheets and rivets but also the ratio of the thickness of the lower sheet to the total thickness. In addition, mechanical clinching of high strength steel and aluminum alloy sheets was simulated.

  9. Finite Element Simulation of Plastic Joining Processes of Steel and Aluminum Alloy Sheets

    NASA Astrophysics Data System (ADS)

    Mori, K.; Abe, Y.; Kato, T.

    2007-05-01

    Various high tensile strength steel sheets and an aluminum alloy sheet were joined with a self-piercing rivet. It is not easy to weld the aluminum alloy sheet and high tensile strength sheets by means of conventional resistance welding because of very different melting points. To obtain optimum joining conditions, joining defects were categorized into separation of the sheets and an inner fracture. The joining range of ultra high tensile strength steel and aluminum alloy sheets was extended by means of dies optimized by finite element simulation. The joint strength is greatly influenced by not only the strength of the sheets and rivets but also the ratio of the thickness of the lower sheet to the total thickness. In addition, mechanical clinching of high strength steel and aluminum alloy sheets was simulated.

  10. 75 FR 59744 - Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and Taiwan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-28

    ... group response to its notice of institution (75 FR 30437, June 1, 2010) was adequate and that the... COMMISSION Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and Taiwan AGENCY... Korea and the antidumping duty orders on stainless steel sheet and strip from Germany, Italy,...

  11. Fe-Zn Alloy Coating on Galvannealed (GA) Steel Sheet to Improve Product Qualities

    NASA Astrophysics Data System (ADS)

    Pradhan, Debabrata; Guin, Akshya Kumar; Raju, Pankaj; Manna, Manindra; Dutta, Monojit; Venugopalan, T.

    2014-09-01

    Galvannealed steel sheets (GA) have become the mainstream steel sheet for automobile applications because of their superior corrosion resistance, paintability, and weldability. To impart specific properties, different coatings on GA steel sheet were reported to improve properties further. In this context, we have developed an electroplating process (flash coating) for bright and adherent Fe-Zn alloy coating on GA steel sheet to enhance performances such as weldability, frictional behavior, phosphatability, and defect coverage. A comparative study with bare GA steel sheet was carried out for better elastration. The electroplating time was reduced below 10 s for practical applicability in an industrial coating line by modulating the bath composition. Electroplating was performed at current density of 200-500 A/m2 which yielded with higher cathode current efficiency of 85-95%. The performance results show that Fe-10 wt.% Zn-coated GA steel sheet (coating time 7 s) has better spot weldability, lower dynamic coefficient of friction (0.06-0.07 in lubrication), and better corrosion resistance compared to bare GA steel sheet. Uniform phosphate coating with globular crystal size of 2-5 µm was obtained on Fe-Zn flash-coated GA steel sheet. Hopeite was the main phosphate compound (77.9 wt.%) identified along with spencerite (13.6 wt.%) and phosphophyllite (8.5 wt.%).

  12. 76 FR 13357 - Stainless Steel Sheet and Strip in Coils From Mexico; Correction Notice to Amended Final Results...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-11

    ... International Trade Administration Stainless Steel Sheet and Strip in Coils From Mexico; Correction Notice to... administrative review for stainless steel sheet and strip in coils from Mexico. See Stainless Steel Sheet and..., 76 FR 9542 (February 18, 2011) (Amended Final Results). The Amended Final Results states...

  13. ELECTRICAL RESPONSE OF A LEAK IN A GEOMEMBRANE LINER

    EPA Science Inventory

    A leak in a geomembrane lined impoundment or landfill has a characteristic electrical response. imulate the waste material, the liner, and the soil under the liner by infinite horizontal layers and express the secondary potential for a leak in the geomembrane liner in terms of a ...

  14. Magnetic properties of 6.5% silicon steel sheets under PWM voltage excitation

    SciTech Connect

    Namikawa, M.; Ninomiya, H.; Tanaka, Y.; Takada, Y.

    1998-07-01

    Power losses of 6.5% silicon steel sheets under PWM (Pulse Width Modulation) voltage excitation were examined. The PWM wave was composed of a 50Hz fundamental wave, a 16kHz carrier frequency wave and some other higher harmonics. It was found that the power losses of the inductor cores were much larger than those of the transformer cores when the cores were driven by a PWM inverter, although such a great difference was not observed under sinusoidal voltage excitation. Power losses of the inductor made of 6.5% silicon steel sheets and conventional grain oriented 3% silicon steel sheets under PWM voltage excitation were also investigated. It was found that the power losses of the inductor made of 6.5% silicon steel sheets were reduced by more than 30% compared to those of the inductor made of grain oriented 3% silicon steel sheets. This was because the grain oriented 3% silicon steel sheets had higher losses at higher harmonics found in the PWM excitation. Therefore, it was clearly shown that 6.5% silicon steel sheet was a suitable material for the inductor under PWM voltage excitation.

  15. Cup-Drawing Behavior of High-Strength Steel Sheets Containing Different Volume Fractions of Martensite

    SciTech Connect

    Choi, Shi-Hoon; Kim, Dae-Wan; Yang, Hoe-Seok; Han, Seong-Ho; Yoon, Jeong Whan

    2010-06-15

    Planar anisotropy and cup-drawing behavior were investigated for high-strength steel sheets containing different volume fractions of martensite. Macrotexture analysis using XRD was conducted to capture the effect of crystallographic orientation on the planar anisotropy of high-strength steel sheets. A phenomenological yield function, Yld96, which accounts for the anisotropy of yield stress and r-values, was implemented into ABAQUS using the user subroutine UMAT. Cup drawing of high-strength steel sheets was simulated using the FEM code. The profiles of earing and thickness strain were compared with the experimentally measured results.

  16. Cup-Drawing Behavior of High-Strength Steel Sheets Containing Different Volume Fractions of Martensite

    NASA Astrophysics Data System (ADS)

    Choi, Shi-Hoon; Kim, Dae-Wan; Yang, Hoe-Seok; Han, Seong-Ho; Yoon, Jeong Whan

    2010-06-01

    Planar anisotropy and cup-drawing behavior were investigated for high-strength steel sheets containing different volume fractions of martensite. Macrotexture analysis using XRD was conducted to capture the effect of crystallographic orientation on the planar anisotropy of high-strength steel sheets. A phenomenological yield function, Yld96, which accounts for the anisotropy of yield stress and r-values, was implemented into ABAQUS using the user subroutine UMAT. Cup drawing of high-strength steel sheets was simulated using the FEM code. The profiles of earing and thickness strain were compared with the experimentally measured results.

  17. Improvement of formability of high strength steel sheets in shrink flanging

    NASA Astrophysics Data System (ADS)

    Hamedon, Z.; Abe, Y.; Mori, K.

    2016-02-01

    In the shrinkage flanging, the wrinkling tends to occur due to compressive stress. The wrinkling will cause a difficulty in assembling parts, and severe wrinkling may leads to rupture of parts. The shrinkage flange of the ultra-high strength steel sheets not only defects the product by the occurrence of the wrinkling but also causes seizure and wear of the dies and shortens the life of dies. In the present study, a shape of a punch having gradual contact was optimized in order to prevent the wrinkling in shrinkage flanging of ultra-high strength steel sheets. The sheet was gradually bent from the corner of the sheet to reduce the compressive stress. The wrinkling in the shrink flanging of the ultra-high strength steel sheets was prevented by the punch having gradual contact. It was found that the punch having gradual contact is effective in preventing the occurrence of wrinkling in the shrinkage flanging.

  18. Assessment of damage to geomembrane liners by shredded scrap tires

    SciTech Connect

    Reddy, K.R.; Saichek, R.E.

    1998-12-01

    This paper presents the results of a field and laboratory study performed to assess damage to the geomembrane liner caused by using shredded scrap tires as a leachate drainage layer material in landfills. The field testing was performed to assess the damage that occurred to the geomembrane liner during construction and included nine tests conducted with different combinations of tire chip size and thickness, both with a geotextile and without a geotextile overlying the geomembrane, and under different loading conditions. The laboratory testing was performed to characterize the shredded tires, particularly their size distribution, hydraulic conductivity, compressibility, and chemical resistance. The laboratory testing also included performing simulation testing to determine the extent of damage that occurs to the geomembrane liner by the shredded tires under long-term waste-loading conditions. the damage that occurred to the geomembrane liners in both field tests and simulated laboratory tests was determined by visual observations as well as by conducting multi-axial tension tests, wide strip tension tests, and water vapor transmission tests on the exhumed geomembrane samples. Based on these results, a 0.46-m thick layer of secondary shred tire chips, with an average size of 7.6 cm, placed over a 543-g/m{sup 2} geotextile installed over a geomembrane liner using low-ground-pressure (<58 kPa) equipment was determined to provide adequate protection in the geomembrane liner during construction. The degree of protection offered under long-term loading conditions depends on the normal stress and the random orientation of the shredded tire chips at the geomembrane interface.

  19. Transport of organic contaminants in geomembranes under stress

    SciTech Connect

    Xiao, S. ); Moresoli, C. . Dept. of Chemical Engineering); Burczyk, A. ); Pintauro, P.; De Kee, D. . Dept. of Chemical Engineering)

    1999-07-01

    The transport properties of aqueous solutions of benzene, dichloromethane, and trichloroethylene through extended polyvinyl chloride and high-density polyethylene geomembranes are investigated. It is found that extension enhances the permeation rates of the penetrants through polyvinyl chloride geomembranes, and the opposite effect is found in the case of high-density polyethylene. This difference in response is attributed to the type of structural change, which occurred as a result of the extension. The diffusivities of a mixture of the three organic solvents through the geomembranes are also determined.

  20. Bainitic stabilization of austenite in low alloy sheet steels

    NASA Astrophysics Data System (ADS)

    Brandt, Mitchell L.

    The stabilization of retained austenite in 'triple phase' ferrite/bainite/austenite sheet steels by isothermal bainite transformation after intercritical annealing has been studied in 0.27C-1.5Si steels with 0.8 to 2.4Mn. Dilatometric studies show that cooling rates comparable to CAPL processing result in approximately 30% conversion of austenite to epitaxial ferrite, but the reaction can be suppressed by the faster cooling rate of salt bath quenching. Measured isothermal transformation kinetics at 350 to 450sp°C shows a maximum overall rate near 400sp°C. X-ray diffraction shows that the amount of austenite retained from 400sp°C treatment peaks at 3 minutes but the carbon content increases monotonically to a saturation level. The stability of austenite in this type of steel has been quantified for the first time by direct measurement of the characteristic Msbsps{sigma} temperature. With variations in processing conditions and test temperatures, the tensile uniform ductility has been correlated with the amount and stability of retained austenite, while maintaining a constant 3% flow of 83 ksi. Consistent with previous transformations plasticity studies an optimal austenite stability is found at approximately 10 K above the Msbsps{sigma} temperature, demonstrating a maximum uniform ductility of 44% for an austenite content of 16%. Correlations indicate that desired uniform ductility levels of 20 to 25% could be achieved with only approximately 5% austenite if stability is optimized by placing Msbsps{sigma} 10 K below ambient temperature. Measured uniform ductility in plane strain tension shows similar trends with processing conditions, but models predict that stress state effects will shift the Msbsps{sigma} temperature approximately 5 K higher than that for uniaxial tension. The measured dependence of Msbsps{sigma} on austenite composition and particle size has been modeled via heterogeneous nucleation theory. The composition dependence is consistent with

  1. Investigation of Forming Performance of Laminated Steel Sheets Using Finite Element Analyses

    NASA Astrophysics Data System (ADS)

    Liu, Wenning; Sun, Xin; Ruokolainen, Robert; Gayden, Xiaohong

    2007-05-01

    Laminated steel sheets have been used in automotive structures for reducing in-cabin noise. However, due to the marked difference in material properties of the different laminated layers, integrating laminated steel parts into the manufacturing processes can be challenging. Especially, the behavior of laminated sheets during forming processes is very different from that of monolithic steel sheets. During the deep-draw forming process, large shear deformation and corresponding high interfacial stress may initiate and propagate interfacial cracks between the core polymer and the metal skin, hence degrading the performance of the laminated sheets. In this paper, the formability of the laminated steel sheets is investigated by means of numerical analysis. The goal of this work is to gain insight into the relationship between the individual properties of the laminated sheet layers and the corresponding formability of the laminated sheet as a whole, eventually leading to reliable design and successful forming process development of such materials. Finite element analyses of laminate sheet forming are presented. Effects of polymer core thickness and viscoelastic properties of the polymer core, as well as punching velocity, are also investigated.

  2. The Effect of Local Heating by Laser Irradiation for Aluminum, Deep Drawing Steel and Copper Sheets in Incremental Sheet Forming

    NASA Astrophysics Data System (ADS)

    Lehtinen, Pekka; Väisänen, Tapio; Salmi, Mika

    Incremental sheet forming is a technique where a metal sheet is formed into a product usually by a CNC-controlled (Computer Numerical Control) round tipped tool. The part is formed as the tool indents into the sheet and follows a contour of the desired product. In single point incremental forming (SPIF) there is no need for tailored tools and dies, since the process requires only a CNC machine, a clamping rig and a simple tool. The effect of applying local heating by laser irradiation from the bottom side of the metal sheet is investigated with a SPIF approach. Using a laser light source for local heating should increase the material ductility and decrease material strength, and thus, increase the formability. The research was performed using 0.50-0.75 mm thick, deep drawing steel, aluminum and copper sheets. The forming was done with a round tipped tool, whose tip diameter was 4 mm. In order to achieve selective heating, a 1 kW fiber laser was attached to a 3-axis stepper motor driven CNC milling machine. The results show that the applied heating increased the maximum achievable wall angle of aluminum and copper products. However, for the steel sheets the local heating reduced the maximum achievable wall angle and increased the surface roughness.

  3. Application technologies for effective utilization of advanced high strength steel sheets

    NASA Astrophysics Data System (ADS)

    Suehiro, Masayoshi

    2013-12-01

    Recently, application of high strength steel sheets for automobiles has increased in order to meet a demand of light weighting of automobiles to reduce a carbon footprint while satisfying collision safety. The formability of steel sheets generally decreases with the increase in strength. Fracture and wrinkles tend to occur easily during forming. The springback phenomenon is also one of the issues which we should cope with, because it makes it difficult to obtain the desired shape after forming. Advanced high strength steel sheets with high formability have been developed in order to overcome these issues, and at the same time application technologies have been developed for their effective utilization. These sheets are normally used for cold forming. As a different type of forming, hot forming technique has been developed in order to produce parts with ultra high strength. In this report, technologies developed at NSSMC in this field will be introduced.

  4. Application technologies for effective utilization of advanced high strength steel sheets

    SciTech Connect

    Suehiro, Masayoshi

    2013-12-16

    Recently, application of high strength steel sheets for automobiles has increased in order to meet a demand of light weighting of automobiles to reduce a carbon footprint while satisfying collision safety. The formability of steel sheets generally decreases with the increase in strength. Fracture and wrinkles tend to occur easily during forming. The springback phenomenon is also one of the issues which we should cope with, because it makes it difficult to obtain the desired shape after forming. Advanced high strength steel sheets with high formability have been developed in order to overcome these issues, and at the same time application technologies have been developed for their effective utilization. These sheets are normally used for cold forming. As a different type of forming, hot forming technique has been developed in order to produce parts with ultra high strength. In this report, technologies developed at NSSMC in this field will be introduced.

  5. Determination of the plasticity of N18K9M5T maraging steel thin sheet

    SciTech Connect

    Shishov, V.F.

    1985-08-01

    This paper investigates the value of the nominal elongation of N18K9M5T maraging steel in relation to sheet thickness, structure of steel, and the specimen type. The characteristics of strength and plasticity determined in testing of cylindrical and flat specimens of the investigated steel is presented. The authors conclude that the total elongation of N18K9M5T maraging steel is its abnormally high capacity for plastic deformation in the formation of the neck. To obtain closer values of elongation in testing N18K9M5T steel thin sheet of different thicknesses, it is desirable to use specimens in which the ratio b/sub 0//alpha/sub 0/ is less than or equal to 4:1.

  6. Dynamic Material Property Measurement of Steel Thin Sheets using Laser-Based Ultrasonics

    NASA Astrophysics Data System (ADS)

    Nagata, Y.; Yamada, H.; Hashiguchi, S.; Lim, C. S.; Park, H. C.; Huh, H. J.; Kang, M. K.; Oh, K. J.

    2014-06-01

    A material property measurement system for steel sheets using laser-based ultrasonics was developed. The system consists of a pulsed Nd:YAG laser for ultrasonic generation and multi-channel interferometer coupled with a CW single frequency laser for ultrasonic detection. The system can measure the frequency of the S1 Lamb wave mode of zero group velocity (S1f) as well as the longitudinal resonance frequencies without ablative damage to the steel surface. It was confirmed that Poisson's ratio could be directly obtained by combining the measured S1f value and the longitudinal resonance frequencies. To evaluate the applicability of this system in an actual steel production setting, the system was installed in hot rolling pilot plant that produces steel samples. As a result, it was demonstrated that the system can measure dynamic changes in Poisson's ratio values within steel sheets, even in the hot rolling pilot plant environment. Material property data, such as Poisson's ratio, during the thin sheet production process will be very useful for manufacturing high value-added steel, such as sheets with uniform quality.

  7. Failure Behavior of Three-Steel Sheets Resistance Spot Welds: Effect of Joint Design

    NASA Astrophysics Data System (ADS)

    Pouranvari, M.; Marashi, S. P. H.

    2012-08-01

    There is a lack of comprehensive understanding concerning failure characteristics of three-steel sheet resistance spot welds. In this article, macro/microstructural characteristics and failure behavior of 1.25/1.25/1.25 mm three-sheet low carbon steel resistance spot welds are investigated. To evaluate the mechanical properties of the joint, the tensile-shear test was performed in three different joint designs. Mechanical performance of the joint was described in terms of peak load, energy absorption, and failure mode. The critical weld nugget size required to insure pullout failure mode was obtained for each joint design. It was found that the joint design significantly affects the mechanical properties and the tendency to fail in the interfacial failure mode. It was also observed that stiffer joint types exhibit higher critical weld size. Fusion zone size along sheet/sheet interface proved to be the most important controlling factor of spot weld peak load and energy absorption.

  8. 78 FR 14270 - Stainless Steel Sheet and Strip in Coils From Mexico: Notice of Settlement of NAFTA Proceedings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-05

    ... FR 40560 (July 27, 1999) (notice of amended LTFV determination and antidumping duty order) (Order... sunset review. See Stainless Steel Sheet and Strip in Coils from Germany, Italy and Mexico, 76 FR 49450... 25, 2010. \\1\\ Stainless Steel Sheet and Strip in Coils from Mexico, 71 FR 76978 (December 22,...

  9. Development of aluminium-clad steel sheet by roll-bonding for the automotive industry

    SciTech Connect

    Buchner, M.; Buchmayr, B.; Bichler, Ch.; Riemelmoser, F.

    2007-04-07

    The objective of the present work is a basic study of production, modelling and validation of sheet composites of AA6xxx-automotive alloy and IF-steel. In this context the influence of surface preparation, pre-heating temperature of aluminium and steel plate, and thickness reduction on the bond strength of the composites as well as on the formation of intermetallic interface layers is analysed by shear tests and metallographic evaluations of the interface.

  10. Hole expansion in a variety of sheet steels

    NASA Astrophysics Data System (ADS)

    Comstock, R. J.; Scherrer, D. K.; Adamczyk, R. D.

    2006-12-01

    Expanding pierced holes is a common forming practice and problems during these operations are not unusual. A damczyk and Michal have previously developed an equation for maximum hole expansion of HSLA steels, for holes in the sheared then deburred condition. This paper expands the work of the above authors. Nineteen ferritic, ferritic stainless, and austenitic stainless steels were evaluated for hole expansion using various hole-edge conditions. It was found that the behavior of steels having finished holes is very different than those tested in the as-sheared condition. Relationships between hole expansion and tensile-mechanical properties were developed for both conditions.

  11. Standard specification for steel, sheet, carbon, for pressure vessels. ASTM standard

    SciTech Connect

    1998-09-01

    This specification is under the jurisdiction of ASTM Committee A-1 on Steel, Stainless Steel, and Related Alloys and is the direct responsibility of Subcommittee A01.19 on Sheet Steel and Strip. Current edition approved Jun. 10, 1998. Published September 1998. Originally published as A 414-71. Last previous edition A 414/A 414M-97. Copyright American Society for Testing and Materials (ASTM), 100 Barr Harbor Drive, West Conshohocken, PA, 19428, USA. This document is available from NTIS under license from ASTM.

  12. Perforation corrosion and its mechanism on galvanized steel sheets on vehicles

    SciTech Connect

    Fujita, Sakae

    1998-12-31

    Mechanism of perforation corrosion on vehicles in the area where deicing salts are dispersed on roads in winter was investigated, using the Gumbel probability plots of the maximum depth of corrosion inside the lapped portion and quantitative analyses of crystalline compositions of the iron rusts which formed on the steel panels of vehicles. It was estimated that perforation occurred in 7 years for zincrometal steel sheet and more than 14 years for galvanized steel sheet with zinc coating weight of 120g/m{sup 2} in the crevice of lapped panel. The composition of the rust in the lapped portion of galvanized steel panels was mainly amorphous at the initial stage of corrosion and moves towards the high content of ({gamma}-FeOOH+Fe{sub 3}O{sub 4}) regions of the non-galvanized parts. Zinc corrosion product prevented the redox reaction of the iron rust and performed as corrosion inhibitor of steel in laboratory simulation tests. Perforation mechanism on vehicles in real environments will be also discussed in the following stages; (1) corrosion of zinc layer, (2) galvanic corrosion of zinc, (3) corrosion of steel under zinc corrosion product, (4) corrosion of steel.

  13. 76 FR 18518 - Stainless Steel Sheet and Strip in Coils From Mexico: Rescission of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    ... Investigation; Opportunity To Request Administrative Review, 75 FR 38074 (July 1, 2010). On July 30, 2010... Reviews and Deferral of Initiation of Administrative Review, 75 FR 53274 (August 31, 2010). Rescission of... International Trade Administration Stainless Steel Sheet and Strip in Coils From Mexico: Rescission...

  14. 76 FR 46323 - Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and Taiwan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-02

    ..., 2010 (75 FR 30437) and determined on September 7, 2010 that it would conduct a full review (75 FR 59744... 27, 2010 (75 FR 81308). The hearing was held in Washington, DC, on May 25, 2011, and all persons who... COMMISSION Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and...

  15. Description of anisotropy and the Bauschinger effect on various types of steel sheets

    NASA Astrophysics Data System (ADS)

    Yoshida, Fusahito; Hamasaki, Hiroshi; Uemori, Takeshi

    2013-05-01

    To describe the anisotropy of sheets a sixth-order polynomial type 3D yield function is proposed. The yield function is constructed as a sum of several components of the Cazacu-Barlat function (2001) which was derived as an extension of the J2-J3 Drucker yield criterion (1949) to orthotropy using the linear transformation of the stress deviator. In this framework of modeling, the convexity of the yield locus is perfectly guaranteed. The model was validated by comparing the numerical predictions of planar anisotropy of r-values and flow stress directionality, as well as the shape of yield loci, with the corresponding experimental data on several types of steel sheets (high r-valued IF steel and SPCE, and high strength steel sheets of 440-980MPa TS grades). For most of steel sheets, the model of the sum of two J2 components, which involve eight anisotropic coefficients, is sufficient for the description of their anisotropies. For the description of the Bauchinger effect and cyclic workhardening characteristic, Yoshida-Uemori kinematic hardening model (2002a, 2002b, 2003) was employed, which includes a new proposal to describe non-saturation type workhardening.

  16. 75 FR 30437 - Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and Taiwan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-01

    ... 207), as most recently amended at 74 FR 2847 (January 16, 2009). \\1\\ No response to this request for... Kingdom (64 FR 40555- 40570). On August 6, 1999, Commerce issued countervailing duty orders on imports of stainless steel sheet and strip in coils from France, Italy, and Korea (64 FR 42923-42925). Following...

  17. AISI/DOE Technology Roadmap Program: Improved Surface Quality of Exposed Automotive Sheet Steels

    SciTech Connect

    John G. Speer; David K. Matlock; Noel Meyers; Young-Min Choi

    2002-10-10

    Surface quality of sheet steels is an important economic and technical issue for applications such as critical automotive surfaces. This project was therefore initiated to develop a more quantitative methodology for measuring surface imperfections, and to assess their response to forming and painting, particularly with respect to their visibility or invisibility after painting. The objectives were met, and included evaluation of a variety of imperfections present on commercial sheet surfaces or simulated using methods developed in the laboratory. The results are expected to have significant implications with respect to the methodology for assessing surface imperfections, development of quantitative criteria for surface inspection, and understanding and improving key painting process characteristics that influence the perceived quality of sheet steel surfaces.

  18. Quantitative prediction of deformed austenite and transformed ferrite texture in hot-rolled steel sheet

    NASA Astrophysics Data System (ADS)

    Tanaka, Y.; Tomida, T.; Mohles, V.

    2015-04-01

    A model to quantitatively predict ferrite (α) textures in hot-rolled steel sheets has been developed. In this model, the crystal plasticity model, called “Grain Interaction model (GIA)”, and the transformation texture model, called “Double K-S relation (DKS)”, are linked together. The deformed austenite (γ) texture is predicted by GIA with taking not only the standard {111}<110> slip system but also non-octahedral slip systems into account. Then the transformed a texture is calculated by DKS, in which a nucleated α prefers to have orientation relationship near the Kurdjumov-Sachs relation with both of two neighboring γ grains. For validation, single pass hot-rolling tests on a C-Si-Mn steel were carried out. The comparison between the predicted and the experimental textures shows that the linked model (GIA & DKS) can lead to a remarkable reproduction of the texture of hot-rolled steel sheets.

  19. Tensile and pack compressive tests of some sheets of aluminum alloy, 1025 carbon steel, and chromium-nickel steel

    NASA Technical Reports Server (NTRS)

    Atchison, C S; Miller, James A

    1942-01-01

    Tensile and compressive stress-strain curves, stress-deviation curves, and secant modulus-stress curves are given for longitudinal and transverse specimens of 17S-T, 24S-T, and 24S-RT aluminum-alloy sheet in thicknesses from 0.032 to 0.081 inch, 1025 carbon steel sheet in thicknesses of 0.054 and 0.120 inch, and chromium-nickel steel sheet in thicknesses form 0.020 to 0.0275 inch. Significant differences were found between the tensile and the compressive stress-strain curves, and also the corresponding corollary curves; similarly, differences were found between the curves for the longitudinal and transverse directions. These differences are of particular importance in considering the compressive strength of aircraft structures made of thin sheet. They are explored further for the case of compression by giving tangent modulus-stress curves in longitudinal and transverse compression and dimensionless curves of the ratio of tangent modulus to Young's modulus and of the ratio of reduced modulus for a rectangular section to Young's modulus, both plotted against the ratio of stress to secant yield strength.

  20. Experimental optimisation of the gas-assisted laser cutting of thick steel sheets

    SciTech Connect

    Malikov, A G; Orishich, Anatolii M; Shulyat'ev, Viktor B

    2009-06-30

    We report on the experimental optimisation of the oxygen-assisted CO{sub 2} laser cutting of low-carbon sheet steel 5 to 25 mm in thickness. It is shown that the cut edge roughness is minimal when the energy input per unit volume of the material removed and the incident beam power per unit sheet thickness remain constant at {approx}20 J mm{sup -3} and {approx}200 W mm{sup -1}, respectively, over the entire range of sheet thicknesses examined. The corresponding Peclet number is Pe = 0.5. These results can be used to determine the optimal beam power and cutting speed for a particular sheet thickness. At sufficiently large thicknesses, the conditions that ensure the minimum roughness can be written in the form of relations between nondimensional parameters. (interaction of laser radiation with matter. laser plasma)

  1. STRESS CRACKING BEHAVIOR OF HDPE GEOMEMBRANES AND ITS PREVENTION

    EPA Science Inventory

    Geomembranes made from high density polyethylene (HOPE) have a high percent crystallinity and are therefore of concern with regard to stress cracking. A review of the literature plus our field exhuming of various sites-of-opportunity gave rise to twenty-five (25) situations wh...

  2. PROCEEDINGS OF THE WORKSHOP GEOMEMBRANE SEAMING: DATA ACQUISITION AND CONTROL

    EPA Science Inventory

    The U.S. Environmental Protection Agency's Risk Reduction Engineering Laboratory, in cooperation with the Geosynthetic Research Institute, sponsored a workshop on Geomembrane Wedge Welding Seaming: ata Acquisition and Control on April 22, 1993. he workshop was held at the Andrew ...

  3. EVALUATION OF GEOMEMBRANE SEAMS EXPOSED TO SELECTED ENVIRONMENTAL CONDITIONS

    EPA Science Inventory

    The integrity of a geomembrane installation is no better than its seaming system. In an attempt to learn more about the strength and durability of presently available seaming systems, the Municipal Environmental Research Laboratory of the United States Environmental Protection Ag...

  4. GEOMEMBRANE ANCHORAGE BEHAVIOR USING A LARGE SCALE PULLOUT APPARATUS

    EPA Science Inventory

    The terminus of most geomembrane lined facilities, e.g., landfills, surface impoundments and waste piles, is via a small horizontal runout distance and then into a shallow anchor trench. hile several analytic models are available for such a design, common practice is usually base...

  5. Reducing the Variability of HSLA Sheet Steels (TRP 9807)

    SciTech Connect

    Dr. Anthony J. DeArdo

    2004-03-12

    The sensitivity of the yield strength of a 70 ksi HSLA steel to changes in processing variables was investigated using a laboratory hot-rolling mill. Along with a detailed examination of the hot-rolled microstructures, auxiliary experiments were conducted to determine how the decomposition of the austenite phase and the occurrence of ultra-fine precipitate formation could account for the yield strength variability. A set of guidelines was recommended for the reduction of the yield strength variability.

  6. Analysis of hot forming of a sheet metal component made of advanced high strength steel

    NASA Astrophysics Data System (ADS)

    Demirkaya, Sinem; Darendeliler, Haluk; Gökler, Mustafa İlhan; Ayhaner, Murat

    2013-05-01

    To provide reduction in weight while maintaining crashworthiness and to decrease the fuel consumption of vehicles, thinner components made of Advanced High Strength Steels (AHSS) are being increasingly used in automotive industry. However, AHSS cannot be formed easily at the room temperature (i.e. cold forming). The alternative process involves heating, hot forming and subsequent quenching. A-pillar upper reinforcement of a vehicle is currently being produced by cold forming of DP600 steel sheet with a thickness of 1.8 mm. In this study, the possible decrease in the thickness of this particular part by using 22MnB5 as appropriate AHSS material and applying this alternative process has been studied. The proposed process involves deep drawing, trimming, heating, sizing, cooling and piercing operations. Both the current production process and the proposed process are analyzed by the finite element method. The die geometry, blank holding forces and the design of the cooling channels for the cooling process are determined numerically. It is shown that the particular part made of 22MnB5 steel sheet with a thickness of 1.2 mm can be successfully produced by applying the proposed process sequence and can be used without sacrificing the crashworthiness. With the use of the 22MnB5 steel with a thickness of 1.2 mm instead of DP600 sheet metal with a thickness of 1.8 mm, the weight is reduced by approximately 33%.

  7. Thirty year atmospheric corrosion performance of 55% aluminum-zinc alloy-coated sheet steel

    SciTech Connect

    Townsend, H.E.; Borzillo, A.R.

    1996-04-01

    In 1964, a series of aluminum-zinc (Al-Zn) alloy coatings were applied to steel sheet on a laboratory continuous hot-dip coating pilot line. The coated sheets were exposed in outdoor corrosion tests in severe marine, moderate marine, rural, and industrial atmospheres. Following eight years of testing, the 55% Al-Zn composition was selected as the optimum composition because it combined excellent long-term durability with the ability to provide cut-edge protection to the steel substrate. Now, after 30 years of continued outdoor testing, the results show conclusively that the 55% Al-Zn alloy coating has better than twice the life of an ordinary zinc coating of equal thickness, and that it provides enduring cut-edge protection. Following identification of the optimum composition in 1972, steel sheet with the 55% Al-Zn alloy coating was produced commercially by Bethlehem Steel. Large quantities of this material have been put in service as unpainted roofing on metal buildings. Inspections of these buildings show that the corrosion performance is excellent for roofs that have been in service for up to 22 years in a variety of US environments. These results confirm the conclusions of the earlier outdoor tests.

  8. Development of adapted GMR-probes for automated detection of hidden defects in thin steel sheets

    NASA Astrophysics Data System (ADS)

    Pelkner, Matthias; Pohl, Rainer; Kreutzbruck, Marc; Commandeur, Colin

    2016-02-01

    Thin steel sheets with a thickness of 0.3 mm and less are the base materials of many everyday life products (cans, batteries, etc.). Potential inhomogeneities such as non-metallic inclusions inside the steel can lead to a rupture of the sheets when it is formed into a product such as a beverage can. Therefore, there is a need to develop automated NDT techniques to detect hidden defects and inclusions in thin sheets during production. For this purpose Tata Steel Europe and BAM, the Federal Institute for Materials Research and Testing (Germany), collaborate in order to develop an automated NDT-system. Defect detection systems have to be robust against external influences, especially when used in an industrial environment. In addition, such a facility has to achieve a high sensitivity and a high spatial resolution in terms of detecting small inclusions in the μm-regime. In a first step, we carried out a feasibility study to determine which testing method is promising for detecting hidden defects and inclusions inside ferrous thin steel sheets. Therefore, two methods were investigated in more detail - magnetic flux leakage testing (MFL) using giant magneto resistance sensor arrays (GMR) as receivers [1,2] and eddy current testing (ET). The capabilities of both methods were tested with 0.2 mm-thick steel samples containing small defects with depths ranging from 5 µm up to 60 µm. Only in case of GMR-MFL-testing, we were able to detect parts of the hidden defects with a depth of 10 µm trustworthily with a SNR better than 10 dB. Here, the lift off between sensor and surface was 250 µm. On this basis, we investigated different testing scenarios including velocity tests and different lift offs. In this contribution we present the results of the feasibility study leading to first prototypes of GMR-probes which are now installed as part of a demonstrator inside a production line.

  9. PORTSMOUTH ON-SITE DISPOSAL CELL HIGH DENSITY POLYETHYLENE GEOMEMBRANE LONGEVITY

    SciTech Connect

    Phifer, M.

    2012-01-31

    It is anticipated that high density polyethylene (HDPE) geomembranes will be utilized within the liner and closure cap of the proposed On-Site Disposal Cell (OSDC) at the Portsmouth Gaseous Diffusion Plant. The likely longevity (i.e. service life) of HDPE geomembranes in OSDC service is evaluated within the following sections of this report: (1) Section 2.0 provides an overview of HDPE geomembranes, (2) Section 3.0 outlines potential HDPE geomembranes degradation mechanisms, (3) Section 4.0 evaluates the applicability of HDPE geomembrane degradation mechanisms to the Portsmouth OSDC, (4) Section 5.0 provides a discussion of the current state of knowledge relative to the longevity (service life) of HDPE geomembranes, including the relation of this knowledge to the Portsmouth OSDC, and (5) Section 6.0 provides summary and conclusions relative to the anticipated service life of HDPE geomembranes in OSDC service. Based upon this evaluation it is anticipated that the service life of HDPE geomembranes in OSDC service would be significantly greater than the 200 year service life assumed for the OSDC closure cap and liner HDPE geomembranes. That is, a 200 year OSDC HDPE geomembrane service life is considered a conservative assumption.

  10. Experimental Method for Characterizing Electrical Steel Sheets in the Normal Direction

    PubMed Central

    Hihat, Nabil; Lecointe, Jean Philippe; Duchesne, Stephane; Napieralska, Ewa; Belgrand, Thierry

    2010-01-01

    This paper proposes an experimental method to characterise magnetic laminations in the direction normal to the sheet plane. The principle, which is based on a static excitation to avoid planar eddy currents, is explained and specific test benches are proposed. Measurements of the flux density are made with a sensor moving in and out of an air-gap. A simple analytical model is derived in order to determine the permeability in the normal direction. The experimental results for grain oriented steel sheets are presented and a comparison is provided with values obtained from literature. PMID:22163394

  11. Fiber laser micro-cutting of stainless steel sheets

    NASA Astrophysics Data System (ADS)

    Baumeister, M.; Dickmann, K.; Hoult, T.

    2006-11-01

    The authors report on laser micro-cutting results for stainless steel foils with the aid of a 100 W fiber laser. This novel laser source combines a high output power in relation to conventional laser sources for micro-processing applications with an excellent beam quality (M2=1.1). Different material thicknesses were evaluated (100 μm to 300 μm). Processing was carried out with cw operation of the laser source, and with nitrogen and oxygen as assisting gases. Besides the high processing rate of oxygen assisted cutting, a better cutting performance in terms of a lower kerf width was obtained.

  12. Energy-saving regeneration of hydrochloric acid pickling liquor: NICE3 steel project fact sheet (NICE3 2000 award winners)

    SciTech Connect

    2000-06-19

    This is a fact sheet written for the NICE3 [National Industrial Competititveness through Energy, Environment, and Economics] Program on a new process for reusing hydrochloric acid from steel pickling operations.

  13. Effect of skin-pass rolling direction on magnetic properties of semiprocessed nonoriented electrical steel sheets

    SciTech Connect

    Kurosaki, Y.; Shimazu, T.; Shiozaki, M.

    1999-09-01

    Effect of skin-pass rolling direction on magnetic properties and directionality in semiprocessed nonoriented electrical steel sheets produced by skin-pass rolling process was studied. Skin-pass rolling direction greatly affects magnetic properties and directionality. By control of skin-pass rolling direction, the value of B{sub 50} in the required directions such as 0{degree}, 90{degree} and circumferential direction can be adjusted and the value of B{sub 50} is higher than that of the usual skin-pass rolling direction of 0{degree}. The textures of the steel sheets developed after batch annealing varied with the skin-pass rolling directions and this result indicates that the residual strain energy by skin-pass rolling varies with skin-pass rolling directions.

  14. The Relationship Between Hot and Cold Rolling Parameters and Secondary Recrystallization Behavior in Silicon Steel Sheets

    NASA Astrophysics Data System (ADS)

    Jahangiri, Mohammadreza

    2015-08-01

    The effect of different hot and cold rolling process variables was evaluated for the secondary recrystallization behavior of silicon steel sheets, and a simple model was developed. On the basis of the model, the following results can be drawn: (a) for complete secondary recrystallization of silicon steel sheets, rolling of cast ingots must precede MnS precipitation start; (b) if it is necessitated, intermediate annealing during hot rolling passes must be carried out in the temperature of about 1000 °C; (c) during hot rolling, the amount of initial strain before the intermediate annealing of rolled strips at 1000 °C must be >70% reduction in thickness; (d) in the two-stage cold rolling method, the thickness reduction in the second cold rolling stage must be <61%; and (e) secondary recrystallization is encouraged by using the non-conventional three-stage cold rolling method with two intermediate anneals.

  15. Progress in press forming computer aided analysis for high strength steel sheet applications

    NASA Astrophysics Data System (ADS)

    Hiramoto, Jiro; Urabe, Masaki; Ishiwatari, Akinobu; Urabe, Toshiaki

    2013-12-01

    The development of press-forming analysis technologies is important to expand the application of high strength steel sheets to automotive body structures. In general, there are various problems in the forming process of high strength steel sheets. In this study the improvements in the prediction accuracy of stretch-flange-fracture and springback were especially focused. In terms of the prediction accuracy of stretch-flange-fracture, a new stretch-flange-fracture prediction technology was developed based on a maximum principal strain gradient. It enables the accurate prediction of stretch- flange-fracture in press-forming of practical parts. On the other hand, springback prediction technologies were developed to solve springback problems. It is very important to clarify the root cause of springback in order to control. Therefore, a new method of springback factor analysis was developed, which can extract the areas and residual stresses which have major impacts on springback at press-forming.

  16. Orientation changes near the interface of explosively bonded (carbon steel)/Zr700 sheets

    NASA Astrophysics Data System (ADS)

    Paul, H.; Baudin, T.; Brisset, F.; Prazmowski, M.

    2015-04-01

    The microstructure and texture of explosively welded carbon steel (base) and Zr700 (flyer) plates were characterized by means of scanning electron microscopy equipped with a high resolution electron backscattered diffraction facility. The orientation maps demonstrate that the deformed zones near-the-interface are composed of several layers, the width of which depends on the applied bonding parameters. For both metals, the very thin layer of ultra-fine grains directly adheres to the interface. In the areas more distanced from the interface, the structure evolution depends on the plate material. In the case of a Zr 700 sheet the second layer is formed by highly dislocated (sub)grains, which progressively evolve, towards the structure composed of only lightly deformed grains. In the case of a carbon steel sheet, the second layer near the interface was composed of flattened grains.

  17. High-Strain-Rate Forming of Aluminum and Steel Sheets for Automotive Applications

    SciTech Connect

    Rohatgi, Aashish; Stephens, Elizabeth V; Soulami, Ayoub; Davies, Richard W; Smith, Mark T

    2010-06-01

    The formability of aluminum alloy AA5182-O and DP600 steel sheets at high-strain-rates was investigated using an electrohydraulic forming (EHF) setup. Test sheets, ~150 mm diameter x 1 mm thick, were clamped around their circumference and subjected to a pressure-pulse (several 100's duration) generated by a high-energy (up to ~34 kJ) under-water electrical discharge. The real-time strain and strain-rate of the deforming sheets were quantified by the digital image correlation (DIC) technique using a pair of high-speed cameras (~15's per frame). Strain-rate amplification was observed when the sheets were deformed into a conical die, with the maximum in-plane strain-rate and strain for aluminum measured as ~1200 /s and ~0.2, respectively. The deformation behavior of the sheets was modeled using ABAQUS/finite element explicit code and better correlation, between the predicted and the experimental sheet deformation behavior, was observed when an alternate pressure-profile was used instead of the one available from the literature.

  18. Detection of Steel Fatigue Cracks with Strain Sensing Sheets Based on Large Area Electronics

    PubMed Central

    Yao, Yao; Glisic, Branko

    2015-01-01

    Reliable early-stage damage detection requires continuous monitoring over large areas of structure, and with sensors of high spatial resolution. Technologies based on Large Area Electronics (LAE) can enable direct sensing and can be scaled to the level required for Structural Health Monitoring (SHM) of civil structures and infrastructure. Sensing sheets based on LAE contain dense arrangements of thin-film strain sensors, associated electronics and various control circuits deposited and integrated on a flexible polyimide substrate that can cover large areas of structures. This paper presents the development stage of a prototype strain sensing sheet based on LAE for crack detection and localization. Two types of sensing-sheet arrangements with size 6 × 6 inch (152 × 152 mm) were designed and manufactured, one with a very dense arrangement of sensors and the other with a less dense arrangement of sensors. The sensing sheets were bonded to steel plates, which had a notch on the boundary, so the fatigue cracks could be generated under cyclic loading. The sensors within the sensing sheet that were close to the notch tip successfully detected the initialization of fatigue crack and localized the damage on the plate. The sensors that were away from the crack successfully detected the propagation of fatigue cracks based on the time history of the measured strain. The results of the tests have validated the general principles of the proposed sensing sheets for crack detection and identified advantages and challenges of the two tested designs. PMID:25853407

  19. Effects of the Formation of Al x Cu y Gradient Interfaces on Mechanical Property of Steel/Al Laminated Sheets by Introducing Cu Binding-Sheets

    NASA Astrophysics Data System (ADS)

    Wei, Aili; Liu, Xinghai; Shi, Quanxin; Liang, Wei

    2015-07-01

    Steel/Cu/Al laminated sheets were fabricated by two-pass hot rolling to improve the mechanical properties of steel/Al sheets. The bonding properties and deformability of the steel/Cu/Al sheets were studied. Steel/Al and steel/Cu/Al samples were rolled at 350°C for 15 min with the first-pass reduction of 40%, and then heated at 600°C for 5 min with different reductions. It was found that the steel/Cu/Al samples rolled by the second-pass reduction of 85% could endure the maximum 90° bend cycle times of 45, exhibiting excellent fatigue resistance as well as deformability. The steel/Al samples could only reach the maximum 90° bend cycle times of 20. Furthermore, the scanning electron microscope, energy-dispersive spectrometer, and electron backscattered diffraction results showed that the preferred growth orientations of Cu, Al4Cu9, and Al2Cu on the steel/Cu/Al laminated sheets are {-1, 1, 2} <1, -1, 1>, {1, 0, 0} <0, 1, 0> and {-1, 1, 2} <1, -1, 1> {1, 1, 0} <0, 0, 1>. The orientation relationships between Cu and Al2Cu are {1, 1, 0}(fcc)//{1, 1, 0}(bct) and {1, 1, 1}(fcc)//{1, 1, 1}(bct). The improved bonding property and excellent fatigue resistance as well as deformability were mainly ascribed to the tight combination and consistent deformability across steel, Al, and the transition layers (Cu, Al4Cu9, and Al2Cu).

  20. Dynamic materials testing and constitutive modeling of structural sheet steel for automotive applications. Final progress report

    SciTech Connect

    Cady, C.M.; Chen, S.R.; Gray, G.T. III

    1996-08-23

    The objective of this study was to characterize the dynamic mechanical properties of four different structural sheet steels used in automobile manufacture. The analysis of a drawing quality, special killed (DQSK) mild steel; high strength, low alloy (HSLA) steel; interstitial free (IF); and a high strength steel (M-190) have been completed. In addition to the true stress-true strain data, coefficients for the Johnson-Cook, Zerilli-Armstrong, and Mechanical Threshold Stress constitutive models have been determined from the mechanical test results at various strain rates and temperatures and are summarized. Compression, tensile, and biaxial bulge tests and low (below 0.1/s) strain rate tests were completed for all four steels. From these test results it was determined to proceed with the material modeling optimization using the through thickness compression results. Compression tests at higher strain rates and temperatures were also conducted and analyzed for all the steels. Constitutive model fits were generated from the experimental data. This report provides a compilation of information generated from mechanical tests, the fitting parameters for each of the constitutive models, and an index and description of data files.

  1. In Search of the Attributes Responsible for Sliver Formation in Cold Rolled Steel Sheets

    NASA Astrophysics Data System (ADS)

    Mohanty, Itishree; Das, Prasun; Bhattacharjee, Debashish; Datta, Shubhabrata

    2016-06-01

    Surface quality is one of the most important characteristics of cold rolled (CR) steel sheets for its application in consumer goods industries. The actual cause of sliver formation is very difficult to determine, as it is revealed only after the final cold rolling of the steel. A thorough investigation on searching the root cause of sliver formation in CR steel is done here using several statistical tools towards mining the industrial data for extraction of knowledge. As the complex interactions between the variables make it difficult to identify the cause, it is seen that findings from different techniques differed to a certain extent. Still it is revealed that 21 variables could be short listed as major contributor for sliver formation, but those are found to be from all the areas of the processing. This leads to the conclusion that no particular process variable or particular processing could be held responsible for sliver formation.

  2. Flow rates through earthen, geomembrane & composite cut-off walls

    SciTech Connect

    Tachavises, C.; Benson, C.H.

    1997-12-31

    Flow rates through soil-bentonite (SIB), geomembrane (GM), and composite geomembrane-soil (CGS) cut-off walls were determined using a numerical model of ground water flow. Various geological and wall conditions were simulated. Results of the simulations show that flow rates past all wall types are affected by hydraulic conductivities of the aquifer and underlying confining layer. Flow rates past GM walls with perfect joints are very low, provided the confining layer has low hydraulic conductivity. However, if a small fraction of the joints are defective, GM walls can be ineffective in blocking flow. CGS walls with a low hydraulic conductivity shell are less sensitive to joint defects. CGS walls with good shells typically have lower flow rates than SB and GM walls, even if the CGS wall contains defective joints.

  3. Partitioning and diffusion of PBDEs through an HDPE geomembrane.

    PubMed

    Rowe, R Kerry; Saheli, Pooneh T; Rutter, Allison

    2016-09-01

    Polybrominated diphenyl ether (PBDE) has been measured in MSW landfill leachate and its migration through a modern landfill liner has not been investigated previously. To assure environmental protection, it is important to evaluate the efficacy of landfill liners for controlling the release of PBDE to the environment to a negligible level. The partitioning and diffusion of a commercial mixture of PBDEs (DE-71: predominantly containing six congeners) with respect to a high-density polyethylene (HDPE) geomembrane is examined. The results show that the partitioning coefficients of the six congeners in this mixture range from 700,000 to 7,500,000 and the diffusion coefficients range from 1.3 to 6.0×10(-15)m(2)/s depending on the congener. This combination of very high partitioning coefficients and very low diffusion coefficients suggest that a well constructed HDPE geomembrane liner will be an extremely effective barrier for PBDEs with respect to diffusion from a municipal solid waste landfill, as illustrated by an example. The results for pure diffusion scenario showed that the congeners investigated meet the guidelines by at least a factor of three for an effective geomembrane liner where diffusion is the controlling transport mechanism. PMID:27211313

  4. Dissimilar Arc Welding of Advanced High-Strength Car-Body Steel Sheets

    NASA Astrophysics Data System (ADS)

    Russo Spena, P.; D'Aiuto, F.; Matteis, P.; Scavino, G.

    2014-11-01

    A widespread usage of new advanced TWIP steel grades for the fabrication of car-body parts is conditional on the employment of appropriate welding methods, especially if dissimilar welding must be performed with other automotive steel grades. Therefore, the microstructural features and the mechanical response of dissimilar butt weld seams of TWIP and 22MnB5 steel sheets after metal-active-gas arc welding are examined. The microstructural and mechanical characterization of the welded joints was carried out by optical metallography, microhardness and tensile testing, and fractographic examination. The heat-affected zone on the TWIP side was fully austenitic and the only detectable effect was grain coarsening, while on the 22MnB5 side it exhibited newly formed martensite and tempered martensite. The welded tensile specimens exhibited a much larger deformation on the TWIP steel side than on the 22MnB5. The fracture generally occurred at the interface between the fusion zone and the heat-affected zones, with the fractures surfaces being predominantly ductile. The ultimate tensile strength of the butt joints was about 25% lower than that of the TWIP steel.

  5. Insoluble surface carbon on steel sheet annealed in hydrogen-nitrogen atmosphere

    NASA Astrophysics Data System (ADS)

    Biber, H. E.; Takacs, R. C.; Dickey, A. E.

    1983-09-01

    The way in which heating in hydrogen-nitrogen atmosphere affects the pyrolysis of the residual lubricant on cold-reduced steel sheet was studied to discover the factors responsible for the formation of carbonaceous films on the steel surface. These films, referred to as insoluble surface carbon, cannot be removed with the usual solvents or water-base cleaners and adversely affect the paintability of the steel. A surprising result was the observation that the full-hard steel surface has a significant amount of insoluble surface carbon; amounts in excess of 0.010 gm/m2 (1 mg/ft2) were observed. The origin of this “initial” insoluble carbon can be traced to the pickling operation after hot rolling. During annealing much of the residual rolling lubricant on the surface is driven off by evaporation, but concurrently insoluble pyrolysis products are formed. The amount of insoluble pyrolysis product formed is directly related to the amount of “initial” insoluble carbon on the surface before annealing. The results show that at some point during annealing the total amount of insoluble carbon on the surface is more than double the amount of “initial” insoluble carbon. These insoluble pyrolysis products can also be driven from the surface at higher temperatures than are required for evaporation of the oil. The results suggest that removal of the “initial” insoluble carbon prior to cold reduction might be very beneficial with respect to decreasing the amount of insoluble carbon on the surface of steel sheet after annealing.

  6. Behavior of painted steel and aluminum sheet in laboratory automotive corrosion tests

    SciTech Connect

    Townsend, H.E.

    1996-01-01

    Because of environmental concern and government pressure, automakers are exploring ways to increase the fuel economy of vehicles. Mass reduction can be achieved by substituting plastics, aluminum, or high-strength steel for ordinary grades of steel in the autobody. Estimates of fuel economy increases range from 3% to 7% for each 10% reduction in mass. The use of aluminum for mass reduction currently is receiving considerable attention. Cold-rolled steel, electrogalvanized steel (60 g/m{sup 2} coating), and three aluminum alloy sheet products (Al 2036, Al 5182, and Al 6111) were painted with a full automotive paint system. These materials were tested in two laboratory cyclic corrosion test environments, GM9540P(B) and CCT-IV. Resistance to cosmetic corrosion was measured in terms of underfilm paint delamination on scribed, flat panels. Crevice corrosion resistance was determined in terms of pitting on lapped panels of like materials, and galvanic corrosion resistance was determined in terms of pitting on lapped panels of unlike materials. Cosmetic corrosion of the aluminum alloys was found to be much better than that of cold-rolled steel and slightly better than that of electrogalvanized steel. The CCT-IV test was found to be more severe than GM9540P(B) for cosmetic corrosion, but GM9540P(B) was more severe for galvanic corrosion. Galvanic current measurements indicated the difference was related to the salt solutions used in each test. The aluminum alloys were prone to crevice corrosion and to galvanic corrosion when coupled to steel. Results indicated that comparative evaluations of the corrosion resistance of these materials must take into account the possibility of crevice and galvanic effects.

  7. Effect of material flow on joint strength in activation spot joining of Al alloy and steel sheets

    NASA Astrophysics Data System (ADS)

    Watanabe, Goro; Yogo, Yasuhiro; Takao, Hisaaki

    2014-08-01

    A new joining method for dissimilar metal sheets was developed where a rotated consumable rod of Al alloy is pressed onto an Al alloy sheet at the part overlapped with a mild steel sheet. The metal flow in the joining region is increased by the through-hole in the Al sheet and consumable Al rod. The rod creates the joint interface and pads out of the thinly joined parts through pressing. This produces a higher joint strength than that of conventional friction stir spot welding. Measurements of the joint interface showed the presence of a 5-10 nm thick amorphous layer consisting of Al and Mg oxides.

  8. Remote Laser Welding of Zinc Coated Steel Sheets in an Edge Lap Configuration with Zero Gap

    NASA Astrophysics Data System (ADS)

    Roos, Christian; Schmidt, Michael

    Remote Laser Welding (RLW) of zinc-coated steel sheets is a great challenge for the automotive industry but offers high potentials with respect to flexibility and costs. In state of the art applications, sheets are joined in overlap configuration with a preset gap for a stable zinc degassing. This paper investigates RLW of fillets without a preset gap and conditions for a stable process. The influence of process parameters on weld quality and process stability is shown. Experimental data give evidence, that the degassing of zinc through the capillary and the rear melt pool are the major degassing mechanisms. Furthermore the paper gives experimental validation of the zinc degassing in advance of the process zone to the open side of the fillet. Chemical analysis of the hot-dip galvanized zinc coating proof the iron-zinc-alloys to be the reason for a limited effectiveness of this mechanism in comparison to pure zinc as intermediate.

  9. Microstructure and crystallographic texture of strip-cast 4.3wt%Si steel sheet

    SciTech Connect

    Park, J.Y.; Oh, K.H.; Ra, H.Y.

    1999-03-19

    Since grain oriented silicon steel sheet was invented in 1935 by Goss, the material has been of considerable fundamental and technological interest to improve the sharpness of Goss orientation {l_brace}110{r_brace}{l_angle}100{r_angle} etc. In the present study, a Fe-4.3wt%Si strip was produced by the vertical type twin roll strip casting process and the microstructure and texture through the thickness direction were studied by optical metallography and quantitative X-ray texture analysis. The inhomogeneity of the texture and microstructure through the thickness direction were investigated.

  10. Importance of punching and workability in non-oriented electrical steel sheets

    NASA Astrophysics Data System (ADS)

    Kurosaki, Yousuke; Mogi, Hisashi; Fujii, Hiroyasu; Kubota, Takeshi; Shiozaki, Morio

    In order to reduce energy loss in motors, the use of high-efficiency non-oriented electrical steel sheets and an optimal motor core design are important. It is also crucial to minimize the deterioration of magnetic properties during the motor core manufacturing process. Accordingly, this report evaluates the effects of cutting and clamping methods on the deterioration factors of motor cores. Magnetic properties are largely influenced by both cutting and clamping methods. While it is difficult to avoid cutting and clamping altogether, it is necessary to adopt suitable production conditions and minimize the deterioration involved.

  11. Behavior of painted steel and aluminum sheet in laboratory corrosion tests

    SciTech Connect

    Townsend, H.E.

    1995-11-01

    Cold rolled steel, electrogalvanized steel (60 g/m{sup 2} coating), and three aluminum-alloy (2036, 5182, and 6111) sheet products were painted with a full automotive paint system. These materials were tested in two laboratory cyclic corrosion test environments, namely, GM9540Ps(B) and CCT-4. Resistance to cosmetic corrosion was measured in terms of underfilm paint delamination on scribed, flat panels. Crevice corrosion resistance was determined in terms of pitting on lapped panels of like materials, and galvanic corrosion resistance in terms of pitting on lapped panels of unlike materials. Cosmetic corrosion of the aluminum alloys was found to be much better than that of cold rolled, and slightly better than that of electrogalvanized steel. The CCT-IV test was found to be more severe than GM9540P(B) for cosmetic corrosion, but GM9540P(B) was more severe for galvanic corrosion. Galvanic current measurements indicate that the difference is related to the salt solutions used in each test. Aluminum alloys were found to be prone to crevice corrosion and to galvanic corrosion when coupled to steel. These results indicate that comparative evaluations of the corrosion resistance of these materials must take into account the possibility of crevice and galvanic effects.

  12. Nanoscale analysis of surface oxides on ZnMgAl hot-dip-coated steel sheets.

    PubMed

    Arndt, M; Duchoslav, J; Itani, H; Hesser, G; Riener, C K; Angeli, G; Preis, K; Stifter, D; Hingerl, K

    2012-05-01

    In this work, the first few nanometres of the surface of ZnMgAl hot-dip-galvanised steel sheets were analysed by scanning Auger electron spectroscopy, angle-resolved X-ray photoelectron spectroscopy and atomic force microscopy. Although the ZnMgAl coating itself is exhibiting a complex micro-structure composed of several different phases, it is shown that the topmost surface is covered by a smooth, homogeneous oxide layer consisting of a mixture of magnesium oxide and aluminium oxide, exhibiting a higher amount of magnesium than aluminium and a total film thickness of 4.5 to 5 nm. Especially by the combined analytical approach of surface-sensitive methods, it is directly demonstrated for the first time that within surface imprints--created by industrial skin rolling of the steel sheet which ensures a smooth surface appearance as well as reduced yield-point phenomenon--the original, smooth oxide layer is partly removed and that a layer of native oxides, exactly corresponding to the chemical structure of the underlying metal phases, is formed. PMID:22086398

  13. Equivalent orthotropic elastic moduli identification method for laminated electrical steel sheets

    NASA Astrophysics Data System (ADS)

    Saito, Akira; Nishikawa, Yasunari; Yamasaki, Shintaro; Fujita, Kikuo; Kawamoto, Atsushi; Kuroishi, Masakatsu; Nakai, Hideo

    2016-05-01

    In this paper, a combined numerical-experimental methodology for the identification of elastic moduli of orthotropic media is presented. Special attention is given to the laminated electrical steel sheets, which are modeled as orthotropic media with nine independent engineering elastic moduli. The elastic moduli are determined specifically for use with finite element vibration analyses. We propose a three-step methodology based on a conventional nonlinear least squares fit between measured and computed natural frequencies. The methodology consists of: (1) successive augmentations of the objective function by increasing the number of modes, (2) initial condition updates, and (3) appropriate selection of the natural frequencies based on their sensitivities on the elastic moduli. Using the results of numerical experiments, it is shown that the proposed method achieves more accurate converged solution than a conventional approach. Finally, the proposed method is applied to measured natural frequencies and mode shapes of the laminated electrical steel sheets. It is shown that the method can successfully identify the orthotropic elastic moduli that can reproduce the measured natural frequencies and frequency response functions by using finite element analyses with a reasonable accuracy.

  14. Springback analysis for the stamping of an automotive part with high strength steel sheet

    NASA Astrophysics Data System (ADS)

    Hung, Tzu-Hao; Tsai, Heng-Kuang; Chang, Chih-Kai; Hsu, Yu-Hung; Chen, Fuh-Kuo; Chung, Kuo-Hsin

    2013-05-01

    The study of springback analysis of 440MPa high strength steel is investigated in this paper. Because of the springback phenomenon is related to the material properties and the deformation mechanism during the forming process, the material properties of 440MPa high strength steel are studied at first. The material properties of 440MPa high strength steel are obtained by conducting cyclic uniaxial tension-compression tests with different strain ranges. In order to apply the material properties obtained from the experiments to the finite element analysis, the material constants required in the Yoshida-Uemori model (Y-U model) with the Bauschinger effect considered are established. For realizing the springback characteristics of 440MPa high strength steel, the U-hat draw-bending and V-shape bending are examined by the finite element analysis. From the simulation results, it finds that the side wall curl phenomenon occurs in the U-hat drawbending and the springback phenomenon appears in the V-shape bending. Moreover, it also shows that the side wall curl phenomenon and springback phenomenon are more obvious in the finite element simulations with the Bauschinger effect considered. Finally, the validation of springback prediction is performed by stamping an engine hood reinforcement with 440MPa high strength steel sheet. From the stamping results, it shows that the simulation results of springback prediction are in a well agreement to the production part data. It also finds that the springback predictions are more accurate by the finite element simulations with the use of the Y-U model. It is also found that for a stamping part which is subjected to a reversed tension-compression deformation in the forming process, the occurrence of the Bauschinger effect is obvious. It is also concluded that the accuracy of springback prediction can be much improved by the use of material model with the Bauschinger effect considered.

  15. 76 FR 31633 - Tin- and Chromium-Coated Steel Sheet from Japan; Institution of a Five-Year Review Concerning the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-01

    ... tin- and chromium-coated steel sheet from Japan (65 FR 52067). Following five-year reviews by Commerce... order on imports of tin- and chromium-coated steel sheet from Japan (71 FR 41422). The Commission is now..., subparts A, D, E, and F (19 CFR part 207), as most recently amended at 74 FR 2847 (January 16, 2009)....

  16. Corrosion of steel members strengthenened with carbon fiber reinforced polymer sheets

    NASA Astrophysics Data System (ADS)

    Bumadian, Ibrahim

    Due to many years of service at several cases of exposure at various environments there are many of steel bridges which are in need of rehabilitation. The infrastructure needs upgrading, repair or maintenance, and also strengthening, but by using an alternative as retrofits methods. The alternative retrofit method, which used fiber reinforced polymer (FRP) composite materials which their strength materials comes largely from the fiber such as carbon, glass, and aramid fiber. Of the most important materials used in the rehabilitation of infrastructure is a composite material newly developed in bonded externally carbon fiber and polymer (CFRP) sheets, which has achieved remarkable success in the rehabilitation and upgrading of structural members. This technique has many disadvantages one of them is galvanic corrosion. This study presents the effect of galvanic corrosion on the interfacial strength between carbon fiber reinforced polymer (CFRP) sheets and a steel substrate. A total of 35 double-lap joint specimens and 19 beams specimens are prepared and exposed to an aggressive service environment in conjunction with an electrical potential method accelerating corrosion damage. Six test categories are planned at a typical exposure interval of 12 hours, including five specimens per category for double-lap joint specimens. And six test categories are planned at a typical exposure interval of 12 hours, including three specimens per category for Beam section specimens. In addition one beam section specimen is control. The degree of corrosion is measured. Fourier transform infrared (FTIR) reflectance spectroscopy has been used to monitor and confirm the proposed corrosion mechanisms on the surface of CFRP. In this study we are using FTIR-spectroscopic measurement systems in the mid infrared (MIR) wavelength region (4000 - 400) cm-1 to monitor characteristic spectral features. Upon completion of corrosion processes, all specimens are monotonically loaded until failure

  17. The effect of surface morphology on the friction of electrogalvanized sheet steel in forming processes

    SciTech Connect

    Skarpelos, P. N.

    1993-12-01

    The effect in the drawbead simulator test were evaluated for a set of commercially coated steels and a set of laboratory coated steels with underlying surfaces produced by laser textured, shot blast, and electro-discharge textured rolls. In general, surfaces with higher roughness (R{sub a} parameter) measured lower friction in the DBS tests. The requisite roughness amplitude necessary for low friction was moderated somewhat by having a more closely spaced roughness as described by the median wavelength, {lambda}m, of the power spectrum. This effect is due to interaction with the lubricant by the micro-roughness imparted by the galvanizing process. The lubricant tends to be retained better by the surfaces with the micro-roughness, thereby increasing the amount of elasto- and plasto-hydrodynamic support of the load. Other variables, such as large variations in thickness of the sheet can mask the effect of the surface by changing the actual distance of sliding contact during the DBS test. For tests where the amount of sliding is similar, the effect of roughness is significant. The friction measured for EG steels in the DBS test is dominated by deformation of the surface with plowing by the asperities of the tooling adding to that caused by the deformation. The size of the plow marks in the deformed surfaces corresponds to the roughness of the tooling and no significant evidence of wear particles was observed.

  18. Method and Apparatus for Monitoring the Integrity of a Geomembrane Liner using time Domain Reflectometry

    SciTech Connect

    Morris, John L.

    1998-11-09

    Leaks are detected in a multi-layered geomembrane liner by a two-dimensional time domain reflectometry (TDR) technique. The TDR geomembrane liner is constructed with an electrically conductive detection layer positioned between two electrically non-conductive dielectric layers, which are each positioned between the detection layer and an electrically conductive reference layer. The integrity of the TDR geomembrane liner is determined by generating electrical pulses within the detection layer and measuring the time delay for any reflected electrical energy caused by absorption of moisture by a dielectric layer.

  19. Method and apparatus for monitoring the integrity of a geomembrane liner using time domain reflectometry

    DOEpatents

    Morrison, John L.

    2001-04-24

    Leaks are detected in a multi-layered geomembrane liner by a two-dimensional time domain reflectometry (TDR) technique. The TDR geomembrane liner is constructed with an electrically conductive detection layer positioned between two electrically non-conductive dielectric layers, which are each positioned between the detection layer and an electrically conductive reference layer. The integrity of the TDR geomembrane liner is determined by generating electrical pulses within the detection layer and measuring the time delay for any reflected electrical energy caused by absorption of moisture by a dielectric layer.

  20. Laboratory testing of geomembrane for waste containment EPA Method 9090, March 1995. Final report

    SciTech Connect

    Whitlock, R.W.

    1995-05-15

    This report describes the work performed by TRI/Environmental, Inc. (TRI) to determine the chemical compatibility of one geomembrane and one seamed geomembrane with four synthetically generated leachates. The objective was to determine the resistance of the geomembrane to changes caused by exposure to the leachates. Changes in physical and mechanical properties were measured after exposure to the leachates at 23 C and 50 C for 30, 60, 90 and 120 days. Exposures were performed in accordance with the exposure regimen specified in US Environmental Protection Agency (EPA) Method 9090A. Methods, results and discussion are provided. Test results are also provided in the Tables of Results which accompany this report.

  1. The relationship between microstructure and damage evolution in hot-rolled complex-phase steel sheet

    NASA Astrophysics Data System (ADS)

    Bell, Grant A. S.

    Complex-phase (CP) steels are employed in applications that require high-strength and good edge formability. These steels derive their strength from a fine-grained bainite-ferrite microstructure, and alloying to provide solid-solution and precipitation strengthening. CP steels are produced industrially through a process of controlled rolling and cooling to produce desirable microstructures. Hole-expansion tests are typically used as a measure of edge formability for applications such as stretch-flanges. It has been shown that CP microstructures are susceptible to large fluctuations in hole-expansion performance with little change in processing or resulting tensile properties. The steel's characteristics of damage evolution are critical to the hole-expansion performance. This study investigates the role of microstructure in the development of damage in CP microstructural variants. Two variant pairs of different thicknesses were produced from the leading and trailing edge of industrially produced hot-rolled sheet. Each pair consisted of a variant with poor hole-expansion performance, and a variant with good hole-expansion performance. Each variant was tested via interrupted double-notched uniaxial tension testing to induce damage. Damage evolution in each variant was quantified by X-ray micro-computed tomography (XmicroCT), and supplementary optical micrography. The damage results were correlated with microstructural characteristics. It was shown that poor hole-expansion variants failed by intergranular fracture. In these variants, void damage induced by hard martensite and retained austenite was not critical in producing failure. Purely void-damaged microstructures failed by ductile fracture, whereas cracked microstructures failed in a mixed brittle-ductile failure initiated by planar cracks. Microstructural banding of large elongated ferrite grains correlated with the existence of intergranular planar fractures.

  2. 75 FR 57899 - Certain Stainless Steel Sheet and Strip in Coils from Italy and Mexico: Extension of Time Limits...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-23

    ... (``Sunset'') Review, 75 FR 30777 (June 2, 2010) (Notice of Initiation). The Department received a notice of... Act of 1930, As Amended, 70 FR 24533 (May 10, 2005). Accordingly, the deadline for the completion of... orders on certain stainless steel sheet and strip (SSSS) in coils from, inter alia, Italy and...

  3. 76 FR 49450 - Stainless Steel Sheet and Strip in Coils From Germany, Italy, and Mexico: Revocation of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-10

    ... (``Sunset'') Review, 75 FR 30777 (June 2, 2010). \\1\\ See Final Determination of Sales at Less Than Fair Value; Stainless Steel Sheet and Strip in Coils From Germany, 64 FR 30710 (June 8, 1999). \\2\\ See Notice... From Italy, 64 FR 30750 (June 8, 1999). \\3\\ See Notice of Final Determination of Sales at Less...

  4. 76 FR 9542 - Stainless Steel Sheet and Strip in Coils From Mexico; Notice of Amended Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-18

    ... Duty Administrative Review, 76 FR 2332 (January 13, 2011) (S4 from Mexico 2008-2009 Final Results). On... Proceedings: Assessment of Antidumping Duties, 68 FR 23954 (May 6, 2003). This clarification will apply to... International Trade Administration Stainless Steel Sheet and Strip in Coils From Mexico; Notice of Amended...

  5. 76 FR 58536 - Tin- and Chromium-Coated Steel Sheet From Japan; Notice of Commission Determination To Conduct a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-21

    ... FR 31633, June 1, 2011) were adequate. A record of the Commissioners' votes, the Commission's... COMMISSION Tin- and Chromium-Coated Steel Sheet From Japan; Notice of Commission Determination To Conduct a... From Japan AGENCY: United States International Trade Commission. ACTION: Notice. SUMMARY:...

  6. Standard specification for steel, sheet and strip, high-strength, low-alloy, columbium or vanadium, or both, hot-rolled and cold-rolled. ASTM standard

    SciTech Connect

    1998-09-01

    DoD adopted. This specification is under the jurisdiction of ASTM Committee A-1 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A05.19 on Steel Sheet and Strip. Current edition approved Jun. 10, 1998 and published September 1998. Originally published as A 607-70. Last previous edition was A 607-96.

  7. Resistance spot weldability of 11Cr-ferritic/martensitic steel sheets

    NASA Astrophysics Data System (ADS)

    Uwaba, Tomoyuki; Yano, Yasuhide; Ito, Masahiro

    2012-02-01

    Resistance spot welding of 11Cr-0.4Mo-2W, V, Nb ferritic/martensitic steel sheets with different thicknesses was examined to develop a manufacturing technology for a fast reactor fuel subassembly with an inner duct structure. In the spot welding, welding current, electrode force, welding time and holding time were varied as welding parameters to investigate the appropriate welding conditions. Welding conditions under which spot weld joints did not have either crack or void defects in the nugget could be found when the electrode force was increased to 9.8 kN. It was also found that the electrode cap with a longer tip end length was effective for preventing weld defect formations. Strength of the spot welded joint was characterized from micro hardness and shear tension tests. In addition, the ductile-to-brittle transition temperature of the spot welded joint was measured by Charpy impact tests with specimens that had notches in the welded zone.

  8. Sealable joint steel sheet piling for groundwater control and remediation: Case histories

    SciTech Connect

    Smyth, D.; Jowett, R.; Gamble, M.

    1997-12-31

    The Waterloo Barrier{trademark} steel sheet piling (patents pending) incorporates a cavity at each interlocking joint that is flushed clean and injected with sealant after the piles have been driven into the ground to form a vertical cutoff wall. The installation and sealing procedures allow for a high degree of quality assurance and control. Bulk wall hydraulic conductivities of 10{sup -8} to 10{sup -10} cm/sec have been demonstrated at field installations. Recent case histories are presented in which Waterloo Barrier{trademark} cutoff walls are used to prevent off-site migration of contaminated groundwater or soil gases to adjacent property and waterways. Full enclosures to isolate DNAPL source zones or portions of contaminated aquifers for pilot-scale remediation testing will also be described. Monitoring data will be used to demonstrate the effectiveness of the Waterloo Barrier{trademark} in these applications.

  9. Effect of Seam Welding on Forming Limits of IF-Steel Sheet

    NASA Astrophysics Data System (ADS)

    Sutariya, D.; Raval, H.; Kalaivani, K.; Hariharan, K.; Prabhu, A.; Narasimhan, K.

    2011-08-01

    Laser welding is the most commonly used process for producing Tailor Welded Blanks (TWB). Although laser welding is best suited for TWB applications, it is an expensive process. In this work an alternate cheap process, seam welding, is used to produce welded sheets of IF-steel of same grade and thickness. The effect of this welding on forming limit strains is explored in this work. Forming behavior is characterized by Forming Limit Diagram (FLD). The FLDs of welded blanks are compared with that of un-welded blanks. The effect of longitudinal, transverse and 450 weld orientation on formability is studied. Weld location includes both centered and offset weld location in the transverse weld orientation. Numerical simulations are carried out by considering weld as a zone. Experimental results are compared with the predictions carried out by FE method.

  10. Statistical modeling of laser welding of DP/TRIP steel sheets

    NASA Astrophysics Data System (ADS)

    Reisgen, U.; Schleser, M.; Mokrov, O.; Ahmed, E.

    2012-02-01

    In this research work, a statistical analysis of the CO 2 laser beam welding of dual phase (DP600)/transformation induced plasticity (TRIP700) steel sheets was done using response surface methodology. The analysis considered the effect of laser power (2-2.2 kW), welding speed (40-50 mm/s) and focus position (-1 to 0 mm) on the heat input, the weld bead geometry, uniaxial tensile strength, formability limited dome height and welding operation cost. The experimental design was based on Box-Behnken design using linear and quadratic polynomial equations for predicting the mathematical models. The results indicate that the proposed models predict the responses adequately within the limits of welding parameters being used and the welding speed is the most significant parameter during the welding process.

  11. Horizontal and vertical twin-belt casting of 1-inch-thin sections of sheet steel

    SciTech Connect

    Moore, M.R.; Daniel, S.S.; Ozgu, M.R.

    1988-01-01

    Innovative horizontal and vertical twin-belt casting systems were developed and tested in casting trials to provide alternative approaches to solving the crux technical problem of feeding liquid steel into the thin mold gap so as to achieve the excellent as-cast surface quality necessary to allow subsequent direct rolling of top-quality sheet. The horizontal approach involved an innovative feeding system to feed the 1-inch-thick caster entry, but the twin-belt Hazelett machine itself was largely conventional. In contrast, the opened-up entry of the vertical twin-belt machine allowed the use of conventional lathe tube and flux pouring systems, but the machine itself was complex and deformed the casting down to the 1-inch thickness. Extensive modeling work was done to support both approaches. 15 refs., 21 figs., 1 tab.

  12. Resistance spot welding of ultra-fine grained steel sheets produced by constrained groove pressing: Optimization and characterization

    SciTech Connect

    Khodabakhshi, F.; Kazeminezhad, M. Kokabi, A.H.

    2012-07-15

    Constrained groove pressing as a severe plastic deformation method is utilized to produce ultra-fine grained low carbon steel sheets. The ultra-fine grained sheets are joined via resistance spot welding process and the characteristics of spot welds are investigated. Resistance spot welding process is optimized for welding of the sheets with different severe deformations and their results are compared with those of as-received samples. The effects of failure mode and expulsion on the performance of ultra-fine grained sheet spot welds have been investigated in the present paper and the welding current and time of resistance spot welding process according to these subjects are optimized. Failure mode and failure load obtained in tensile-shear test, microhardness, X-ray diffraction, transmission electron microscope and scanning electron microscope images have been used to describe the performance of spot welds. The region between interfacial to pullout mode transition and expulsion limit is defined as the optimum welding condition. The results show that optimum welding parameters (welding current and welding time) for ultra-fine grained sheets are shifted to lower values with respect to those for as-received specimens. In ultra-fine grained sheets, one new region is formed named recrystallized zone in addition to fusion zone, heat affected zone and base metal. It is shown that microstructures of different zones in ultra-fine grained sheets are finer than those of as-received sheets. - Highlights: Black-Right-Pointing-Pointer Resistance spot welding process is optimized for joining of UFG steel sheets. Black-Right-Pointing-Pointer Optimum welding current and time are decreased with increasing the CGP pass number. Black-Right-Pointing-Pointer Microhardness at BM, HAZ, FZ and recrystallized zone is enhanced due to CGP.

  13. Nondestructive Evaluation of Friction Stir-Welded Aluminum Alloy to Coated Steel Sheet Lap Joint

    NASA Astrophysics Data System (ADS)

    Das, H.; Kumar, A.; Rajkumar, K. V.; Saravanan, T.; Jayakumar, T.; Pal, Tapan Kumar

    2015-11-01

    Dissimilar lap joints of aluminum sheet (AA 6061) of 2 mm thickness and zinc-coated steel sheet of 1 mm thickness were produced by friction stir welding with different combinations of rotational speed and travel speed. Ultrasonic C- and B-scanning, and radiography have been used in a complementary manner for detection of volumetric (cavity and flash) and planar (de bond) defects as the defects are in micron level. Advanced ultrasonic C-scanning did not provide any idea about the defects, whereas B-scanning cross-sectional image showed an exclusive overview of the micron-level defects. A digital x-ray radiography methodology is proposed for quality assessment of the dissimilar welds which provide three-fold increase in signal-to-noise ratio with improved defect detection sensitivity. The present study clearly shows that the weld tool rotational speed and travel speed have a decisive role on the quality of the joints obtained by the friction stir welding process. The suitability of the proposed NDE techniques to evaluate the joint integrity of dissimilar FSW joints is thus established.

  14. Texture development and hardening characteristics of steel sheets under plane-strain compression

    SciTech Connect

    Friedman, P.A.; Liao, K.C.; Pan, J.; Barlat, F.

    1999-04-01

    Crystallographic texture development and hardening characteristics of a hot-rolled, low-carbon steel sheet due to cold rolling were investigated by idealizing the cold rolling process as plane-strain compression. The starting anisotropy of the test material was characterized by examination of the grain structure by optical microscopy and the preferred crystal orientation distribution by x-ray diffraction. Various heat treatments were used in an effort to remove the initial deformation texture resulting from hot rolling. The plastic anisotropy of the starting material was investigated with tensile tests on samples with the tensile axis parallel, 45{degree}, and perpendicular to the rolling direction. The grain structure after plane-strain compression was studied by optical microscopy, and the new deformation texture was characterized by x-ray diffraction pole figures. These figures are compared with the theoretical pole figures produced from a Taylor-like polycrystal model based on a pencil-glide slip system. The uniaxial tensile stress-strain curve and the plane-strain, compressive stress-strain curve of the sheet were used to calibrate the material parameters in the model. The experimental pole figures were consistent with the findings in the theoretical study. The experimental and theoretical results suggest that the initial texture due to hot rolling was insignificant as compared with the texture induced by large strains under plane-strain compression.

  15. Effect of Imposing Temperature Gradient in Stretch Forming Process for Ferritic Stainless Steel Sheets

    NASA Astrophysics Data System (ADS)

    Iguchi, Takaaki; Ujiro, Takumi

    2010-06-01

    A new stamping method developed by the authors, in which a temperature gradient is imposed on the workpiece during stamping, is capable of improving stretch formability in stamping of ferritic stainless steel sheets. Unlike the conventional warm stamping method, the temperature gradient is utilized in order to diffuse the strain distribution induced in the material. Basically, the portions of the sheets which are in contact with the top of the punch and die face are heated, while simultaneously, the portions in contact with the punch corners and die corners are intensively cooled The authors developed a finite element simulation model of stamping which analyzes mechanical and thermal behaviors simultaneously utilizing LS-DYNA3D. The numerical analysis, combined with a numerical model which evaluates the ductile fracture limit of the material in the high temperature region, confirmed that the new stamping method improves stretch formability and the optimal temperature gradient is given. In order to verify the numerical analysis, an experimental apparatus was constructed, comprising a set of stamping tools containing heaters and cooling circuits. The experiments demonstrated the correctness of the numerical analysis and the effectiveness of the new stamping method.

  16. Mechanical Properties Involved in the Micro-forming of Ultra-thin Stainless Steel Sheets

    NASA Astrophysics Data System (ADS)

    Pham, Cong-Hanh; Thuillier, Sandrine; Manach, Pierre-Yves

    2015-08-01

    The objective of this paper is to characterize the mechanical behavior of an ultra-thin stainless steel, of 0.15-mm thickness, that is commonly used in the manufacturing of miniature connectors. The main focus is the relationship between some microstructural features, like grain size and surface roughness, and the macroscopic mechanical behavior investigated in uniaxial tension and simple shear. In tension, adaptations to the very small sheet thickness, in order to hold the specimen under the grips, are presented. Yield stress, initial elastic modulus, and evolution of the loading-unloading slope with plastic deformation were evaluated. Moreover, the kinematic contribution to the hardening was characterized by monotonic and cyclic simple shear test and reproduced by a mixed hardening law implemented in Abaqus finite element code. Then, the evolution of surface roughness with plastic strain, both in tension and simple shear, was analyzed. It was shown that in the case of an ultra-thin sheet, the stress levels, calculated either from an average thickness or when considering the effect of the surface roughness, exhibit a significant difference. Finally, the influence of surface roughness on the fracture of a tensile specimen was also investigated.

  17. Temperature Effects on the Magnetic Properties of Silicon-Steel Sheets Using Standardized Toroidal Frame

    PubMed Central

    Wu, Cheng-Ju; Lin, Shih-Yu; Chou, Shang-Chin; Tsai, Chia-Yun; Yen, Jia-Yush

    2014-01-01

    This study designed a detachable and standardized toroidal test frame to measure the electromagnetic characteristic of toroidal laminated silicon steel specimens. The purpose of the design was to provide the measurements with standardized and controlled environment. The device also can withstand high temperatures (25–300°C) for short time period to allow high temperature tests. The accompanying driving circuit facilitates testing for high frequency (50–5,000 Hz) and high magnetic flux (0.2–1.8 T) conditions and produces both sinusoidal and nonsinusoidal test waveforms. The thickness of the stacked laminated silicon-steel sheets must be 30~31 mm, with an internal diameter of 72 mm and an outer diameter of 90 mm. With the standardized setup, it is possible to carry out tests for toroidal specimen in high temperature and high flux operation. The test results show that there is a tendency of increased iron loss under high temperature operation. The test results with various driving waveforms also provide references to the required consideration in engineering designs. PMID:25525629

  18. Effect of deformation texture on the anisotropy of elasticity and damage of two-phase steel sheets

    NASA Astrophysics Data System (ADS)

    Bryukhanov, A. A.; Gerstein, G.; Dyachok, D. A.; Nürnberger, F.

    2016-07-01

    The effect of small tensile deformation (3, 6, and 10%) on the texture of preliminary annealed sheets of two-phase DP600 steel (0.10 C, 0.15 Si, 1.4 Mn, 0.007 P, 0.008 S, 0,009 N, 0.02-0,06 Al, 1 Cr-Mo-Ni (wt %)) is studied. Against the background of the annealing texture in the sheets, the {001} <110>, {111} <110>, {111} <112>, {111} <312> components of the slip texture and {115} <110>, {115} <552>, {221} <110>, {221} <114> orientations are developed, which can be associated with the twinning processes. The anisotropy pattern of the Young's modulus ( E) in the sheet plane remains the same after tensile deformation of the annealed sheets. After tension, the values of E decrease in all directions as a result of the onset and development of microdamages. The anisotropy of damage ( D) in the plane of the steel sheets after tension is characterized by a maximum in the transverse direction (TD) and a minimum in the rolling direction (RD).

  19. Modeling and FE Simulation of Quenchable High Strength Steels Sheet Metal Hot Forming Process

    NASA Astrophysics Data System (ADS)

    Liu, Hongsheng; Bao, Jun; Xing, Zhongwen; Zhang, Dejin; Song, Baoyu; Lei, Chengxi

    2011-08-01

    High strength steel (HSS) sheet metal hot forming process is investigated by means of numerical simulations. With regard to a reliable numerical process design, the knowledge of the thermal and thermo-mechanical properties is essential. In this article, tensile tests are performed to examine the flow stress of the material HSS 22MnB5 at different strains, strain rates, and temperatures. Constitutive model based on phenomenological approach is developed to describe the thermo-mechanical properties of the material 22MnB5 by fitting the experimental data. A 2D coupled thermo-mechanical finite element (FE) model is developed to simulate the HSS sheet metal hot forming process for U-channel part. The ABAQUS/explicit model is used conduct the hot forming stage simulations, and ABAQUS/implicit model is used for accurately predicting the springback which happens at the end of hot forming stage. Material modeling and FE numerical simulations are carried out to investigate the effect of the processing parameters on the hot forming process. The processing parameters have significant influence on the microstructure of U-channel part. The springback after hot forming stage is the main factor impairing the shape precision of hot-formed part. The mechanism of springback is advanced and verified through numerical simulations and tensile loading-unloading tests. Creep strain is found in the tensile loading-unloading test under isothermal condition and has a distinct effect on springback. According to the numerical and experimental results, it can be concluded that springback is mainly caused by different cooling rats and the nonhomogengeous shrink of material during hot forming process, the creep strain is the main factor influencing the amount of the springback.

  20. Formability Analysis of Diode-Laser-Welded Tailored Blanks of Advanced High-Strength Steel Sheets

    NASA Astrophysics Data System (ADS)

    Panda, S. K.; Baltazar Hernandez, V. H.; Kuntz, M. L.; Zhou, Y.

    2009-08-01

    Currently, advances due to tailored blanking can be enhanced by the development of new grades of advanced high-strength steels (HSSs), for the further weight reduction and structural improvement of automotive components. In the present work, diode laser welds of three different grades of advanced high-strength dual-phase (DP) steel sheets (with tensile strengths of 980, 800, and 450 MPa) to high-strength low-alloy (HSLA) material were fabricated by applying the proper welding parameters. Formability in terms of Hecker’s limiting dome height (LDH), the strain distribution on the hemispherical dome surface, the weld line movement during deformation, and the load-bearing capacity during the stretch forming of these different laser-welded blanks were compared. Finite element (FE) analysis of the LDH tests of both the parent metals and laser-welded blanks was done using the commercially available software package LS-DYNA (Livermore Software Technology Corporation, Livermore, CA); the results compared well with the experimental data. It was also found that the LDH was not affected by the soft zone or weld zone properties; it decreased, however, with an increase in a nondimensional parameter, the “strength ratio” (SR). The weld line movement during stretch forming is an indication of nonuniform deformation resulting in a decrease in the LDH. In all the dissimilar weldments, fracture took place on the HSLA side, but the fracture location shifted to near the weld line (at the pole) in tailor-welded blanks (TWBs) of a higher strength ratio.

  1. Effect of electrode force condition on nugget diameter and residual stress in resistance spot welded high-strength steel sheets

    NASA Astrophysics Data System (ADS)

    Iyota, M.; Mikami, Y.; Hashimoto, T.; Taniguchi, K.; Ikeda, R.; Mochizuki, M.

    2012-08-01

    This study examines the effect of the electrode force condition on the nugget diameter and residual stress in spot welded high-strength steel sheets. Numerical simulations of spot welding were performed to examine the nugget diameter and residual stress. The results indicate that adjusting the force profile changes the current density and stress state at the spot welds. Therefore, choosing an appropriate force profile extends the nugget diameter and reduces the residual stress.

  2. Cosmetic corrosion of painted aluminum and steel automotive body sheet: Results from outdoor and accelerated laboratory test methods

    SciTech Connect

    Moran, J.P.; Ziman, P.R.; Egbert, M.W.

    1995-11-01

    In recent years, increasing attention has been given to the need to develop an accelerated laboratory test method(s) for cosmetic corrosion of painted panels that realistically simulate in-service exposure. Much of that work has focused on steel substrates. The purpose of this research is to compare the corrosion performance of painted aluminum and steel sheet as determined om various laboratory methods and in-service exposure, and to develop a realistic accelerated test method for evaluation of the cosmetic corrosion of painted aluminum. Several aluminum sheet products from the 2xxx, 5xxx, and 6xxx alloy series have been tested. The steel substrates are similar to those used in other programs. The test methods chosen represent a cross-section of methods common to the automotive and aluminum industries for evaluation of painted sheet metal products. The results indicate that there is considerable difference in the relative correlation of various test methods to in-service exposure. In addition, there is considerable difference in the relative magnitudes and morphologies of corrosion, and occasionally in the relative rankings, as a function of test method. The influence of alloy composition and zinc phosphate coating weight are also discussed.

  3. Investigation of galvanic corrosion in laser-welded stainless steel sheets

    NASA Astrophysics Data System (ADS)

    Kwok, Chi-Tat; Fong, Siu Lung; Cheng, Fai Tsun; Man, Hau-Chung

    2004-10-01

    In the present study, bead-on-plate specimens of 1-mm sheets of austenitic and duplex stainless steels were fabricated by laser penetration welding with a 2.5-kW CW Nd:YAG laser. The galvanic corrosion behavior of laser-weldment (LW) against as-received (AR) specimens with an area rato of 1:1 in 3.5% NaCL solution was studied by means of a zero-resistance ammeter. The free corrosion potentials of as-received specimens were found to be considerably higher than those of laser weldments, indicating that the weldments are more active and always act as anodes. The ranking of galvanic current densities (IG) of the couples in ascending order is: AR S31603-LW S31603 < AR S31803-LW S31803 < AR S32760-LW S32760 < AR S30400-LW S30400. For the galvanic couple between AR S30400 and LW S30400, the IG is the highest (78.6 nA/cm2) because large amount of δ-ferrite in the weld zone acts as active sites. On the other hand, the IG of the galvanic couple between AR S31603 and LW S31603 is the lowest (-26 nA/cm2) because no δ-ferrite is present after laser welding. The recorded IG of all couples revealed constantly low values (in the rnage of nA/cm2) and sometimes stayed negative, which indicated polarity reversal.

  4. Progress in Tridimensional (3d) Laser Forming of Stainless Steel Sheets

    NASA Astrophysics Data System (ADS)

    Gisario, Annamaria; Barletta, Massimiliano; Venettacci, Simone; Veniali, Francesco

    2015-09-01

    Achievement of complex shapes with high dimensional accuracy and precision by forming process is a demanding challenge for scientists and practitioners. Available technologies are numerous, with laser forming being progressively emerging because of limited springback, lack of molds and sophisticated auxiliary equipments. However, laser forming finds limited applications, especially when forming of tridimensional (3d) complex shapes is required. In this case, cost savings are often counterbalanced by the need for troublesome forming strategies. Therefore, traditional alternatives based on mechanical devices are usually preferred to laser systems. In the present work, 3d laser forming of stainless steel sheets by high power diode laser is investigated. In particular, the set of scanning patterns to form domes from flat blanks by simple and easy-to-manage radial paths alone was found. Numerous 3d items were also processed by diode laser to manufacture a number of complex shapes with high flexibility and limited efforts to modify the auxiliary forming equipment. Based on the experimental results and analytical data, the high power diode laser was found able to form arbitrary 3d shapes through the implementation of tailored laser scanning patterns and appropriate settings of the operational parameters.

  5. Deep drawing of 304 L Steel Sheet using Vegetable oils as Forming Lubricants

    NASA Astrophysics Data System (ADS)

    Shashidhara, Y. M.; Jayaram, S. R.

    2012-12-01

    The study involves the evaluation of deep drawing process using two non edible oils, Pongam (Pongammia pinnata) and Jatropha (Jatropha carcass) as metal forming lubricants. Experiments are conducted on 304L steel sheets under the raw and modified oils with suitable punch and die on a hydraulic press of 200 ton capacity. The punch load, draw-in-length and wall thickness distribution for deep drawn cups are observed. The drawn cups are scanned using laser scanning technique and 3D models are generated using modeling package. The wall thickness profiles of cups at different sections (or height) are measured using CAD package. Among the two raw oils, the drawn cups under Jatropha oil, have uniform wall thickness profile compared to Pongam oil. Uneven flow of material and cup rupturing is observed under methyl esters of Pongam and Jatropha oil lubricated conditions. However, the results are observed under epoxidised Jatropha oil with uniform metal flow and wall thicknesses compared to mineral and other versions of vegetable oils.

  6. Optimization of laser welding of DP/TRIP steel sheets using statistical approach

    NASA Astrophysics Data System (ADS)

    Reisgen, U.; Schleser, M.; Mokrov, O.; Ahmed, E.

    2012-02-01

    Generally, the quality of a weld joint is directly influenced by the welding input parameter settings. Selection of proper process parameters is important to obtain the desired weld bead profile and quality. In this research work, numerical and graphical optimization techniques of the CO 2 laser beam welding of dual phase (DP600)/transformation induced plasticity (TRIP700) steel sheets were carried out using response surface methodology (RSM) based on Box-Behnken design. The procedure was established to improve the weld quality, increase the productivity and minimize the total operation cost by considering the welding parameters range of laser power (2-2.2 kW), welding speed (40-50 mm/s) and focus position (-1 to 0 mm). It was found that, RSM can be considered as a powerful tool in experimental welding optimization, even when the experimenter does not have a model for the process. Strong, efficient and low cost weld joints could be achieved using the optimum welding conditions.

  7. Material Modeling and Springback Prediction of Ultra Thin Austenitic Stainless Steel Sheet

    NASA Astrophysics Data System (ADS)

    Verma, Rahul K.; Murakoso, Satoko; Chung, Kwansoo; Kuwabara, Toshihiko

    2010-06-01

    The constitutive model with combined isotropic-kinematic hardening along with hardening stagnation (or permanent softening) [Verma, Kuwabara, Chung, Haldar: Int. J. Plasticity (submitted)] was used here for modeling the tension-compression behaviors of a 0.1 mm thick austenitic stainless steel sheet (SUS304), which was observed in a recent work [Kuwabara and Murakoso: Proc. CIRP 2010 Conf. (submitted)]. Springback was also experimentally measured for a shallow drawn rectangular cup here and it was verified using the above model. It was found that this model can successfully predict the Bauschinger effect and hardening stagnation. As for springback, it was found that in this particular case it depends on, other than the material model, factors like boundary conditions, in the finite element analysis (FEA), during unloading. It was also observed that incorporation of the Bauschinger effect and permanent softening is a key for accurate springback prediction and, therefore, the present model performs better than the one which is based only on isotropic hardening without any hardening stagnation.

  8. Characterization of the Fracture Toughness of TRIP 800 Sheet Steels Using Microstructure-Based Finite Element Analysis

    SciTech Connect

    Soulami, Ayoub; Choi, Kyoo Sil; Liu, Wenning N.; Sun, Xin; Khaleel, Mohammad A.

    2009-04-01

    Recently, several studies conducted by automotive industry revealed the tremendous advantages of Advanced High Strength Steels (AHSS). TRansformation Induced Plasticity (TRIP) steel is one of the typical representative of AHSS. This kind of materials exhibits high strength as well as high formability. Analyzing the crack behaviour in TRIP steels is a challenging task due to the microstructure level inhomogeneities between the different phases (Ferrite, Bainite, Austenite, Martensite) that constitute these materials. This paper aims at investigating the fracture resistance of TRIP steels. For this purpose, a micromechanical finite element model is developed based on the actual microstructure of a TRIP 800 steel. Uniaxial tensile tests on TRIP 800 sheet notched specimens were also conducted and tensile properties and R-curves (Resistance curves) were determined. The comparison between simulation and experimental results leads us to the conclusion that the method using microstructure-based representative volume element (RVE) captures well enough the complex behavior of TRIP steels. The effect of phase transformation, which occurs during the deformation process, on the toughness is observed and discussed.

  9. Effect of Retained Austenite on the Fracture Toughness of Quenching and Partitioning (Q&P)-Treated Sheet Steels

    NASA Astrophysics Data System (ADS)

    Wu, Riming; Li, Wei; Zhou, Shu; Zhong, Yong; Wang, Li; Jin, Xuejun

    2014-04-01

    Fracture toughness K IC was measured by double edge-notched tension (DENT) specimens with fatigue precracks on quenching and partitioning (Q&P)-treated high-strength (ultimate tensile strength [UTS] superior to 1200 MPa) sheet steels consisting of 4 to 10 vol pct of retained austenite. Crack extension force, G IC, evaluated from the measured K IC, is used to analyze the role of retained austenite in different fracture behavior. Meanwhile, G IC is deduced by a constructed model based on energy absorption by martensite transformation (MT) behavior of retained austenite in Q&P-treated steels. The tendency of the change of two results is in good agreement. The Q&P-treated steel, quenched at 573 K (300 °C), then partitioned at 573 K (300 °C), holding for 60 seconds, has a fracture toughness of 74.1 MPa·m1/2, which is 32 pct higher than quenching and tempering steel (55.9 MPa·m1/2), and 16 pct higher than quenching and austempering (QAT) steel (63.8 MPa·m1/2). MT is found to occur preferentially at the tips of extension cracks on less stable retained austenite, which further improves the toughness of Q&P steels; on the contrary, the MT that occurs at more stable retained austenite has a detrimental effect on toughness.

  10. Influence of the geomembrane on time-lapse ERT measurements for leachate injection monitoring.

    PubMed

    Audebert, M; Clément, R; Grossin-Debattista, J; Günther, T; Touze-Foltz, N; Moreau, S

    2014-04-01

    Leachate recirculation is a key process in the operation of municipal waste landfills as bioreactors. To quantify the water content and to evaluate the leachate injection system, in situ methods are required to obtain spatially distributed information, usually electrical resistivity tomography (ERT). However, this method can present false variations in the observations due to several parameters. This study investigates the impact of the geomembrane on ERT measurements. Indeed, the geomembrane tends to be ignored in the inversion process in most previously conducted studies. The presence of the geomembrane can change the boundary conditions of the inversion models, which have classically infinite boundary conditions. Using a numerical modelling approach, the authors demonstrate that a minimum distance is required between the electrode line and the geomembrane to satisfy the good conditions of use of the classical inversion tools. This distance is a function of the electrode line length (i.e. of the unit electrode spacing) used, the array type and the orientation of the electrode line. Moreover, this study shows that if this criterion on the minimum distance is not satisfied, it is possible to significantly improve the inversion process by introducing the complex geometry and the geomembrane location into the inversion tools. These results are finally validated on a field data set gathered on a small municipal solid waste landfill cell where this minimum distance criterion cannot be satisfied. PMID:24529793

  11. Production of sheet rolled products made of a nitrogen-bearing high-strength corrosion-resistant steel using electroslag remelting

    NASA Astrophysics Data System (ADS)

    Gutman, E. R.; Durynin, V. A.; Kalinin, G. Yu.; Khar'kov, O. A.; Tsukanov, V. V.

    2009-12-01

    A commercial electroslag remelting process is designed for the production of nitrogen-bearing steel. This process is shown to make a high-quality sheet product with higher strength characteristics and impact toughness as compared to rolled products of the nitrogen-bearing steel melted in an open electric arc furnace.

  12. Geomembrane barriers using integral fiber optics to monitor barrier integrity

    DOEpatents

    Staller, G.E.; Wemple, R.P.

    1996-10-22

    This invention provides a geomembrane or geotextile with embedded optical sensors that are used to monitor the status of containment site barriers. Fiber optic strands are used to form the sensors that can detect and monitor conditions at the sites such as breaches, slope creep, subsidence, leachate levels, fires, and types of materials present or leaking from the site. The strands are integral to the membrane or textile materials. The geosynthetic membrane is deployed at the site in a fashion similar to carpet laying. Edges of the membrane or textile are joined to form a liner and the ends of the membrane or textile become the connection zones for obtaining signals from the sensors. A connection interface with a control system to generate Optical Time Delay Response or other light signals for transmission to the optic fiber strands or sensors and also to receive reflected signals from the sensors is included in the system. Software to interpret the sensor signals can be used in the geosynthetic monitoring system. 6 figs.

  13. Geomembrane barriers using integral fiber optics to monitor barrier integrity

    DOEpatents

    Staller, George E.; Wemple, Robert P.

    1996-01-01

    This invention provides a geomembrane or geotextile with embedded optical sensors that are used to monitor the status of containment site barriers. Fiber optic strands are used to form the sensors that can detect and monitor conditions at the sites such as breaches, slope creep, subsidence, leachate levels, fires, and types of materials present or leaking from the site. The strands are integral to the membrane or textile materials. The geosythetic membrane is deployed at the site in a fashion similar to carpet laying. Edges of the membrane or textile are joined to form a liner and the ends of the membrane or textile become the connection zones for obtaining signals from the sensors. A connection interface with a control system to generate Optical Time Delay Response or other light signals for transmission to the optic fiber strands or sensors and also to receive reflected signals from the sensors is included in the system. Software to interpret the sensor signals can be used in the geosythetic monitoring system.

  14. Biaxial Tensile Test of Cold Rolled IF Steel Sheet for Large Plastic Strain Range

    NASA Astrophysics Data System (ADS)

    Enatsu, Ryotaro; Kuwabara, Toshihiko

    2011-08-01

    Deformation behavior of cold rolled IF steel sheet (SPCE) under biaxial tension has been investigated for large plastic strain range over 15%. The test material was bent and TIG welded to form a tubular specimen with an outer diameter of 46.2 mm and wall thickness of 0.8 mm. The tubular specimens have been subjected to linear stress paths in the first quadrant of stress space with the use of a servo-controlled tension-internal pressure testing machine developed by one of the authors [T. Kuwabara, K. Yoshida, K. Narihara, S. Takahashi, Anisotropic plastic deformation of extruded aluminum alloy tube under axial forces and internal pressure, Int. J. Plasticity 21, 101-117 (2005)]. Moreover, biaxial tensile tests using a cruciform specimen have also been carried out to more precisely measure the deformation behavior for a small strain range following initial yielding. True stress-true plastic strain curves, contours of plastic work in stress space and the directions of plastic strain rates have been measured and compared with those calculated using selected yield functions: the von Mises, Hill's quadratic and Yld2000-2d [Barlat, F., Brem, J.C., Yoon, J.W., Chung, K., Dick, R.E., Lege, D.J., Pourboghrat, F., Choi, S.H., Chu, E., Plane stress yield function for aluminum alloy sheets—Part 1: Theory. Int. J. Plasticity 19, 1297-1319 (2003)]. The plastic deformation behavior up to a work equivalent plastic strain of ɛ0p = 0.19 has been successfully measured. It is found that the test material exhibits differential hardening and that the Yld2000-2d yield function with an exponent of six most closely predicts the contours of plastic work and the directions of plastic strain rates.

  15. Preparation of High Silicon Electrical Steel Sheets with Strong {100} Recrystallization Texture by the Texture Inheritance of Initial Columnar Grains

    NASA Astrophysics Data System (ADS)

    Pan, Hongjiang; Zhang, Zhihao; Xie, Jianxin

    2016-05-01

    Texture evolutions and recrystallization texture features in warm- and cold-rolled sheets of high silicon electrical steel with two different initial microstructures (columnar-grained and equiaxed-grained microstructures) were investigated. The relationships between the recrystallization textures and the initial textures (the textures before rolling) of the samples were analyzed. The results showed that after annealing at 1073 K (800 °C) for 1 hour, strong {100} recrystallization textures with volume fractions of more than 47 pct were obtained in the columnar-grained samples fabricated by warm and cold rolling along the growing direction of the columnar grains. While after rolling and annealing in the same processes, only 12.8 pct volume fractions of {100} recrystallization texture were revealed in the equiaxed-grained samples. The formation of strong {100} recrystallization texture in the annealed sheets of high silicon electrical steel with initial columnar grains was attributed to the favorable texture inheritance of the initial texture during rolling and annealing. The columnar grains of strong near {100}<001> ({100}<001> {310}<001>) orientation in the samples before rolling were transferred into deformed grains with orientations such as {100}<011> and {100}<012>. after rolling. Afterwards, these deformed grains were further transferred into {100} oriented recrystallized grains, which formed strong {100} recrystallization texture in the annealed sheets and exhibited preferable soft magnetic properties.

  16. Comparison of precipitate behaviors in ultra-low carbon, titanium-stabilized interstitial free steel sheets under different annealing processes

    SciTech Connect

    Shi, J.; Wang, X.

    1999-12-01

    Ultra-low carbon, titanium-stabilized interstitial free (ULC Ti-IF) steel sheets are widely used in the automobile industry because of excellent deep drawability. The annealing process is critical to their final property, and there are two different annealing processes used in industrial production of interstitial free (IF) steel sheets, namely batch annealing and continuous annealing. In this study, precipitation behaviors of titanium IF steels, that is, TiN, TiS, Ti{sub 4}(CS){sub 2}, and TiC, the size and dispersion of TiN, TiS, and Ti{sub 4}(CS){sub 2} remained almost unchanged after either annealing process. Conversely, the average size of a TiC particle increased substantially after both annealing processes, while TiC after continuous annealing was larger than that after batch annealing due to the higher heating temperature of continuous annealing. Two new particles, FeTiP and (Ti, Mn)S, were also observed in the batch annealing process but not in continuous annealing. The structure of FeTiP and (Ti, Mn)S were studied, and furthermore the evolution of FeTiP precipitation was found to be closely related to recrystallization in batch annealing. Finally, the interrelation among processing parameters, precipitation behaviors, and final property was studied.

  17. Investigation of Ductile Damage in DP980 Steel Sheets Using Mechanical Tests and X-ray Micro-Tomography

    NASA Astrophysics Data System (ADS)

    Mishra, A.; Leguen, C.; Thuillier, S.; Maire, E.

    2011-05-01

    This study is part of a broader research project on the prediction of formability limits in bending on radius of the order of the sheet thickness, based on ductile damage. As a first step, ductile damage in DP980 steel sheet was investigated by means of micro-tomography and mechanical testing, including tensile and simple shear tests. The local strain in tension was measured with a digital image correlation device up to rupture, on macroscopic samples of standard dimensions. Moreover, interrupted tensile tests on smaller specimen were also performed, in order to analyze the void distribution by X-ray micro-tomography. The final aim is to perform numerical simulation of the tests, with Gurson-Tvergaard-Needleman model, to take into account the influence of ductile damage on the mechanical behavior. A fair description of the void volume fraction was obtained as well as the stress level, in the case of small-size specimen.

  18. Two-beam Laser Brazing of Thin Sheet Steel for Automotive Industry Using Cu-base Filler Material

    NASA Astrophysics Data System (ADS)

    Mittelstädt, C.; Seefeld, T.; Reitemeyer, D.; Vollertsen, F.

    This work shows the potential of two-beam laser brazing for joining both Zn-coated steel and 22MnB5. Brazing of Zn-coated steel sheets using Cu-Si filler wire is already state of the art in car manufacturing. New press-hardened steels like 22MnB5 are more and more used in automotive industry, offering high potential to save costs and improve structural properties (reduced weight / higher stiffness). However, for joining of these ultra-high strength steels investigations are mandatory. In this paper, a novel approach using a two-beam laser brazing process and Cu-base filler material is presented. The use of Cu-base filler material leads to a reduced heat input, compared to currently applied welding processes, which may result in benefits concerning distortion, post processing and tensile strength of the joint. Reliable processing at desired high speeds is attained by means of laser-preheating. High feed rates prevent significant diffusion of copper into the base material.

  19. Springback evaluation for TRIP 800 steel sheets by simple bending tests

    NASA Astrophysics Data System (ADS)

    Avellaneda, F. J.; Miguel, V.; Coello, J.; Martínez, A.; Calatayud, A.

    2012-04-01

    TRIP steels, or Transformed Induced Plasticity steels, have excellent mechanical properties if compared with conventional steels. Strain hardening is also greater, thus they offer a good combination of strength and formability properties that may be justified by the multiphase structure of these steels. The highlighted characteristic of these steels is that they modify the microstructure with the deformation process as part of the austenite transforms to martensite, with the consequent change of the material properties. One of the main problems of TRIP steels is strong elastic recovery, or springback, after forming. In this work, the springback phenomenon is evaluated by bending tests and the influence of the variables involved in it is determined. The factor found to affect material recovery the most was the bending angle. Experimental bending forces do not agree with theoretical predictions.

  20. Fracture prediction in hydraulic bulging of AISI 304 austenitic steel sheets based on a modified ductile fracture criterion

    NASA Astrophysics Data System (ADS)

    Xu, Y.; Song, H. W.; Zhang, S. H.; Cheng, M.

    2011-08-01

    The demand for weight reduction in modern vehicle construction has resulted in an increase in the application of hydroforming processes for the manufacture of automotive lightweight components. This trend led to the research of evaluation on formability of the sheet or tube hydroforming to be noted, particularly the prediction of fracture. In this study, a new proposed approach based on damage theory for fracture prediction considering the deformation history was introduced. And the modified ductile fracture criterion was applied to predict the failure for hydraulic bulging of AISI 304 austenitic steel sheets. The material parameters in terms of the function of strain rate in the failure criterion were determined from the equivalent fracture strains corresponding tensile tests under different stress conditions. Then, in the finite element simulation the effect of strain rates and their distribution as well during practical sheet metal forming process was considered. The hydraulic bulging tests were carried out to identify the fracture behavior predicted from FE analysis. A comparison between the prediction and experimental results showed that the proposed approach with a modified ductile fracture criteria can give better fracture predictions than traditional ways.

  1. Steel--Project Fact Sheet: Recycling Acid and Metal Salts from Pickling Liquors

    SciTech Connect

    Poole, L.; Recca, L.

    1999-01-14

    Regenerating hydrochloric acids from metal finishing pickling baths reduces costs, wastes, and produces a valuable by-product--ferrous sulfate. Order your copy of this OIT project fact sheet and learn more about how your company can benefit.

  2. Textured substrate method for the direct continuous casting of steel sheet; Final report

    SciTech Connect

    Gaspar, T.; Hackman, L.E.; Hsiao, Yu-Hsian; Daehn, G.

    1990-03-30

    The three goals of this research project were to demonstrate the feasibility of casting steel strip up to 2 mm (0.079 in) thick on a textured chill roll, to develop the thermal-mechanical processing to optimize the properties of the steel strip and to measure the properties of the steel strip as a function of casting and metalworking variables. Each of these goals have been realized. Type 304 stainless strip measuring up to 329 mm (12.9 in) wide and up to 1.98 mm (0.078 in) thick was cast on a 600 mm (24 in) copper chill roll with a 14 pitch, 60 degree diamond knurl pattern machined on it`s circumference. The casting speed was 0.15 m/s and the depth of liquid steel in contact with the chill roll was approximately 127 m (5 in). The most important process variables are the texture on the chill roll, the chemistry and temperature of the liquid steel, the depth of liquid in contact with the chill roll and the casting speed. It has been shown that thermal mechanical treatment can significantly improve both the surface finish and mechanical properties of Type 304 stainless steel. Cold rolling in excess of 30% reduction serves to completely eliminate the textured pattern from direct cast Type 304 stainless steel strips. Furthermore, cold rolling followed by annealing can produce commercial ingot metallurgy steels. Specifically, for Type 304 stainless steel, 30% cold rolling followed by a 40 minute anneal at 1100 {degree}C (2012 {degree}F) produced equiaxed austenite grains with an average diameter of approximately 20 {mu}m (0.0008 in), and this material gives approximately 45% elongation to failure with and ultimate tensile strength of 660 MPa (96 ksi). 27 refs., 40 figs., 7 tabs.

  3. Textured substrate method for the direct continuous casting of steel sheet: Technical progress report No. 1

    SciTech Connect

    Gaspar, T.

    1988-10-21

    The overall objective of this research project will be to demonstrate the feasibility of casting rapidly solidified steel strip 2 mm (0.080 in.) thick or greater using a textured chill block as described in US Patent No. 4,705,095, issued on November 10, 1987, to Ribbon Technology Corporation. The effect of melt overflow process variables on strip dimensions and uniformity will be investigated. Process variables include, but are not limited to, the following: super heat of the melt; wetting of substrate material; tundish design; and casting speed. Type 304 stainless steel and AISI 1020 standard carbon steel will be investigated.

  4. Effect of gadolinium addition on the corrosion, wear, and neutron absorbing behaviors of duplex stainless steel sheet

    NASA Astrophysics Data System (ADS)

    Baik, Youl; Choi, Yong; Moon, Byung M.; Sohn, Dong S.; Bogdanov, S. G.; Pirogov, A. N.

    2015-11-01

    In order to develop the neutron absorbing and shield materials, a hot-rolled 0.02%-Gd duplex stainless steel was prepared with 55 vol. % of ferrite and 45 vol. % of austenite. The σ phase with an average grain size of 9-11 μm in austenitic (γ) grains tended to be elongated parallel to the rolling direction, with (100) poles concentrated towards the normal direction, and (110) poles located between the normal and radial directions (ND and RD, respectively). Most of the gadolinium existed as sub-micro-meter-sized Gd2O3 and GdCrO3 precipitates. The yield strength, ultimate tensile strength, elongation, and microhardness of the 0.02%-Gd duplex stainless steel were 522.8 MPa, 700.2 MPa, 38.1%, and 258.5-314.7 HV, respectively. The friction coefficient and wear resistance were 3.11 and 0.004 mg/kg/cycle, respectively. The corrosion potential and corrosion rate of the 0.02%-Gd duplex stainless steel were-0.448 V SHE and 1.263 × 10-3 A/cm2 for 1M-HCl,-0.544 V SHE and 2.619 × 10-3 A/cm2 for 1M-NaCl,-0.299 V SHE and 1.469 × 10-3 A/cm2 for 1M-H2SO4, and-0.607 V SHE and 2.295 × 10-3 A/cm2 for synthetic water, respectively. The coefficient of neutron transmission for the 0.02%-Gd duplex stainless steel sheet of 2 mm thickness at neutron beam wavelength of 0.48 nm was 0.6.

  5. 76 FR 77013 - Tin- and Chromium-Coated Steel Sheet From Japan; Scheduling of a Full Five-Year Review Concerning...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-09

    ...-year review were such that a full review pursuant to section 751(c)(5) of the Act should proceed (76 FR... COMMISSION Tin- and Chromium-Coated Steel Sheet From Japan; Scheduling of a Full Five-Year Review Concerning.... SUMMARY: The Commission hereby gives notice of the scheduling of a full review pursuant to section...

  6. Laser-Assisted Sheet Metal Working of High Strength Steels in Serial Production

    NASA Astrophysics Data System (ADS)

    Brecher, Christian; Emonts, Michael; Eckert, Markus

    Within the sheet metal working industry the demand for thinner sheet materials with very high strength is growing due to the increasing need to save energy and a responsible use of natural resources. The high strength and the low ductility restricts using state of art technology to sheer, bend, emboss or deep draw parts with the needed complexity and quality. The Fraunhofer IPT developed a combination of laser-assisted preheating and conventional punching to a new hybrid technology which allows to shear, bend, emboss and draw high strength materials with a high quality and complexity in a serial production.

  7. Springback Analysis of Draw-Bending of 980 MPa Cold Rolled Steel Sheet and Its Experimental Validation

    NASA Astrophysics Data System (ADS)

    Noma, Nobuyasu; Kuwabara, Toshihiko

    2011-01-01

    Draw-bending experiment is carried out using a 1.2 mm-thick high strength steel sheet with a tensile strength of 980 MPa and the residual curvature of the draw-bent specimens are precisely measured. The die profile of the draw-bending testing machine rotates, so that the effect of friction force on the curvature data after springback can be neglected. Moreover, in order to quantitatively evaluate the Bauschinger effect of the test material, stress reversal tests are performed using an in-plane stress reversal testing machine. Furthermore, the finite element analyses (FEA) of the draw-bending experiment are carried out. The effect of the work hardening models (isotropic or combined), element types (shell or solid), and the number of integration points in the through-thickness direction on the amount of springback (residual curvature) are investigated in detail.

  8. Controlled rolling process for dual phase steels and application to rod, wire, sheet and other shapes

    DOEpatents

    Thomas, G.; Ahn, J.H.; Kim, N.J.

    1986-10-28

    An improved, energy efficient, hot rolling method for direct production of cold formable dual-phase steel is provided. The steel is heated to completely austenitize it and then continuously hot rolled and cooled down into the ferrite-austenite two phase region to a temperature which is just below the effective Ar[sub 3] temperature. The hot rolled steel is then rapidly quenched to provide an alloy containing strong, tough lath martensite (fibers) in a ductile soft ferrite matrix. The method is particularly useful for providing rods in which form the alloy is capable of being drawn into high strength wire or the like in a cold drawing operation without any intermediate annealing or patenting, and has excellent strength, ductility and fatigue characteristics. 3 figs.

  9. Controlled rolling process for dual phase steels and application to rod, wire, sheet and other shapes

    DOEpatents

    Thomas, Gareth; Ahn, Jae-Hwan; Kim, Nack-Joon

    1986-01-01

    An improved, energy efficient, hot rolling method for direct production of cold formable dual-phase steel is provided. The steel is heated to completely austenitize it and then continuously hot rolled and cooled down into the ferrite-austenite two phase region to a temperature which is just below the effective Ar.sub.3 temperature. The hot rolled steel is then rapidly quenched to provide an alloy containing strong, tough lath martensite (fibers) in a ductile soft ferrite matrix. The method is particularly useful for providing rods in which form the alloy is capable of being drawn into high strength wire or the like in a cold drawing operation without any intermediate annealing or patenting, and has excellent strength, ductility and fatigue characteristics.

  10. Effect of strain rate on formability in warm deep drawing of high tensile strength steel sheet

    NASA Astrophysics Data System (ADS)

    Yoshihara, Shoichiro; Iwamatsu, Go

    2014-10-01

    In tensile test of the high tensile strength steel, tensile strength isdrastically decreased as the temperature is raised. Then, the strain rate sensitivity exponent of high tensile strength steel (SUS631) in this study is high at 800 degrees especially. Also, elongation is increased as the temperature is raised. In deep drawing, the maximum punch load of the high tensile strength steel is examined on difference punch speed at 600 and 800 degrees. On the other hand, finite element (FE) simulation was used for the possibility to evaluate the forming load on difference punch speed in warm deep drawing. In FE simulation, we have considered both the strain hardening exponent and the strain rate sensitivity exponent (m-value) because we cannot neglect m-value 0.184 at 800 degrees. The tendency of the forming load in the experiments agrees the results in FE simulation.

  11. 78 FR 79667 - Stainless Steel Sheet and Strip in Coils From Japan: Initiation of Expedited Changed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-31

    ... Sheet and Strip in Coils from Japan: Final Results of Antidumping Duty Administrative Review, 75 FR 6631... Circumstances Review, 75 FR 8925 (Feb. 26, 2010), unchanged in Pressure Sensitive Plastic Tape From Italy: Final Results of Antidumping Duty Changed Circumstances Review, 75 FR 27706 (May 18, 2010); Brake Rotors...

  12. Deformation and damage mechanisms of zinc coatings on hot-dip galvanized steel sheets: Part I. Deformation modes

    NASA Astrophysics Data System (ADS)

    Parisot, Rodolphe; Forest, Samuel; Pineau, André; Grillon, François; Demonet, Xavier; Mataigne, Jean-Michel

    2004-03-01

    Zinc-based coatings are widely used for protection against corrosion of steel-sheet products in the automotive industry. The objective of the present article is to investigate the deformation modes at work in three different microstructures of a thin (8 µm) zinc coating on an interstitial-free steel substrate under tension, plane-strain tension, and expansion loading. Damage mechanisms are addressed in a companion article. The plastic slip and twinning activity in the zinc grains of an untempered cold-rolled coating (labeled NSK), a tempered cold-rolled coating (labeled SK), and a recrystallized coating are compared with the response of the corresponding bulk low-alloyed zinc material. The in-plane grain size in the NSK and SK coatings ranges from 300 to 600 µm, vs about 30 µm in the recrystallized coating and bulk material. The coatings exhibit a strong crystallographic texture, with the c-axis generally normal to the sheet plane. Basal slip is shown to be the main deformation mechanism in bulk zinc and the recrystallized coating, whereas pyramidal π2 slip and mechanical twinning are found to be major modes in the NSK and SK coatings. These results, obtained from an extensive, quantitative slip-line analysis combined with electron backscattered diffraction (EBSD) measurements, are explained by the constraining effect of the substrate. This effect is successfully modeled using a simple Taylor-like polycrystalline approach. The recrystallized coating behaves much like the bulk material. The interpretation of this grain-size effect between the NSK and SK coating, on the one hand, and the recrystallized coating, on the other hand, requires a full three-dimensional finite-element analysis of the multicrystalline coating provided in this work. The simulations show that strong strain gradients can develop in the recrystallized coating from the interface to the surface, which is not the case in the NSK and SK coatings.

  13. Study and numerical analysis on formability of quenching and partitioning steel sheets of auto-body

    NASA Astrophysics Data System (ADS)

    Hu, Xing; Liu, Yifan; Zhu, Lin

    2013-05-01

    Advanced high strength steel is the basic structure material for lightweight design and safety enhancement for automobile industry. Quenching and partitioning steel is a recently developed kind of low carbon and low alloy material with retained Austenite for the requirements of both high strength and high ductility. This paper focuses on the formability of a hinge pillar for some car under numerical modelling analysis. The results show that QP980 has an equal elongation comparing with DP590. Moreover, the numerical modelling results of QP980 are more sensitive to the selection of yielding equation comparing with DP590.

  14. Textured substrate method for the direct continuous casting of steel sheet: Technical progress report No. 4

    SciTech Connect

    Gaspar, T.

    1989-07-14

    The overall objective of this research project will be to demonstrate the feasibility of casting rapidly solidified steel strip 2 mm (0.080 in.) thick or greater using a textured chill block as described in US Patent No. 4,705,095, issues on November 10, 1987, to Ribbon Technology Corporation. The effect of melt overflow process variables on strip dimensions and uniformity will be investigated. Process variables include, but are not limited to, the following: super heat of the melt; wetting of substrate material; tundish design; and casting speed. Type 304 stainless and AISI 1020 standard carbon steel will be investigated.

  15. Effect of formation and state of interface on joint strength in friction stir spot welding for advanced high strength steel sheets

    NASA Astrophysics Data System (ADS)

    Taniguchi, Koichi; Matsushita, Muneo; Ikeda, Rinsei; Oi, Kenji

    2014-08-01

    The tensile shear strength and cross tension strength of friction stir spot welded joints were evaluated in the cases of lap joints of 270 N/mm2 grade and 980 N/mm2 grade cold rolled steel sheets with respect to the stir zone area, hardness distribution, and interface condition between the sheets. The results suggested that both the tensile shear strength and cross tension strength were based on the stir zone area and its hardness in both grades of steel. The "hook" shape of the interface also affected the joint strength. However, the joining that occurred across the interfaces had a significant influence on the value of the joint strength in the case of the 270 N/mm2 grade steel.

  16. Metal release from stainless steel powders and massive sheets--comparison and implication for risk assessment of alloys.

    PubMed

    Hedberg, Yolanda; Mazinanian, Neda; Odnevall Wallinder, Inger

    2013-02-01

    Industries that place metal and alloy products on the market are required to demonstrate that they are safe for all intended uses, and that any risks to humans, animals or the environment are adequately controlled. This requires reliable and robust in vitro test procedures. The aim of this study is to compare the release of alloy constituents from stainless steel powders of different grades (focus on AISI 316L) and production routes into synthetic body fluids with the release of the same metals from massive sheets in relation to material and surface characteristics. The comparison is justified by the fact that the difference between massive surfaces and powders from a metal release/dissolution and surface perspective is not clearly elucidated within current legislations. Powders and abraded and aged (24 h) massive sheets were exposed to synthetic solutions of relevance for biological settings and human exposure routes, for periods of up to one week. Concentrations of released iron, chromium, nickel, and manganese in solution were measured, and the effect of solution pH, acidity, complexation capacity, and proteins elucidated in relation to surface oxide composition and its properties. Implications for risk assessments based on in vitro metal release data from alloys are elucidated. PMID:25208703

  17. Analytical study of the performance of a geomembrane leak detection system.

    PubMed

    Lugli, Francesco; Mahler, Claudio Fernando

    2016-05-01

    The electrical detection of leaks in geomembranes is a method that allows identifying leakage of contaminants in lined facilities (e.g. sanitary landfills, pollutant ponds, etc.). The procedure in the field involves placing electrodes above and below the geomembrane, to generate an electrical current, which in turn engenders an electric potential distribution in the protective layer (generally a clayey soil). The electric potential will be greater in areas with higher current density, i.e. near leaks. In this study, we combined models from the literature to carry out a parametric analysis to identify the variables that most influence the amplitude of the electrical signals produced by leaks. The basic hypothesis is that the electrical conduction phenomena in a liner system could be depicted by a direct current circuit. After determining the value of the current at the leak, we calculated the electric potential distribution according to the model of Darilek and Laine. This enabled analysing the sensitivity of the parameters, which can be useful in the design of landfills and facilitate the location of leaks. This study showed that geomembranes with low electrical resistance (owing to low thickness, low resistivity, or extensive area) can hinder the leak detection process. In contrast, low thickness and high resistivity of the protection layer magnify the leak signal. PMID:27094694

  18. Effect of laser incidence angle on cut quality of 4 mm thick stainless steel sheet using fiber laser

    NASA Astrophysics Data System (ADS)

    Mullick, Suvradip; Agrawal, Arpit Kumar; Nath, Ashish Kumar

    2016-07-01

    Fiber laser has potential to outperform the more traditionally used CO2 lasers in sheet metal cutting applications due to its higher efficiency, better beam quality, reliability and ease of beam delivery through optical fiber. It has been however, reported that the higher focusability and shorter wavelength are advantageous for cutting thin metal sheets up to about 2 mm only. Better focasability results in narrower kerf-width, which leads to an earlier flow separation in the flow of assist gas within the kerf, resulting in uncontrolled material removal and poor cut quality. However, the advarse effect of tight focusability can be taken care by shifting the focal point position towards the bottom surface of work-piece, which results in a wider kerf size. This results in a more stable flow within the kerf for a longer depth, which improves the cut quality. It has also been reported that fiber laser has an unfavourable angle of incidence during cutting of thick sections, resulting in poor absorption at the metal surface. Therefore, the effect of laser incidence angle, along with other process parameters, viz. cutting speed and assist gas pressure on the cut quality of 4 mm thick steel sheet has been investigated. The change in laser incidence angle has been incorporated by inclining the beam towards and away from the cut front, and the quality factors are taken as the ratio of kerf width and the striation depth. Besides the absorption of laser radiation, beam inclination is also expected to influence the gas flow characteristics inside the kerf, shear force phenomena on the molten pool, laser beam coupling and laser power distribution at the inclined cut surface. Design of experiment has been used by implementing response surface methodology (RSM) to study the parametric dependence of cut quality, as well as to find out the optimum cut quality. An improvement in quality has been observed for both the inclination due to the combined effect of multiple phenomena.

  19. Two-surface plasticity Model and Its Application to Spring-back Simulation of Automotive Advanced High Strength Steel Sheets

    NASA Astrophysics Data System (ADS)

    Park, Taejoon; Seok, Dong-Yoon; Lee, Chul-Hwan; Noma, Nobuyasu; Kuwabara, Toshihiko; Stoughton, Thomas B.; Chung, Kwansoo

    2011-08-01

    A two-surface isotropic-kinematic hardening law was developed based on a two-surface plasticity model previously proposed by Lee et al., (2007, Int. J. Plast. 23, 1189-1212). In order to properly represent the Bauschinger and transient behaviors as well as permanent softening during reverse loading with various pre-strains, both the inner yield surface and the outer bounding surface expand (isotropic hardening) and translate (kinematic hardening) in this two-surface model. As for the permanent softening, both the isotropic hardening and the kinematic hardening evolution of the outer bounding surface were modified by introducing softening parameters. The numerical formulation was also developed based on the incremental plasticity theory and the developed constitutive law was implemented into the commercial finite element program, ABAQUS/Explicit and ABAQUS/Standard using the user-defined material subroutines. In this work, a dual phase (DP) steel was considered as an advanced high strength steel sheet and uni-axial tension tests and uni-axial tension-compression-tension tests were performed for the characterization of the material property. For a validation purpose, the developed two-surface plasticity model was applied to the 2-D draw bending test proposed as a benchmark problem of the NUMISHEET 2011 conference and successfully validated with experiments.

  20. Numerical investigation and experimental validation of a plasticity model for sheet steel forming

    NASA Astrophysics Data System (ADS)

    Carvalho-Resende, Tales; Balan, Tudor; Bouvier, Salima; Abed-Meraim, Farid; Sablin, Simon-Serge

    2013-01-01

    This paper investigates a recently developed elasto-plastic constitutive model. For this purpose, the model was implemented in a commercial finite element code and was used to simulate the cross-die deep drawing test. Deep drawing experiments and numerical simulations were conducted for five interstitial-free steels and seven dual-phase (DP) steels, each of them having a different thickness and strength. The main interest of the adopted model is a very efficient parameter identification procedure, due to the physical background of the model and the physical significance of some of its parameters and state variables. Indeed, the dislocation density, grain size and martensite volume fraction explicitly enter the model's formulation, although the overall approach is macroscopic. For the DP steels, only the chemical composition and the average grain sizes were measured for the martensite and ferrite grains, as well as the martensite volume fraction. The mild steels required three additional tensile tests along three directions, in order to describe the plastic anisotropy. Information concerning the transient mechanical behavior after strain-path changes (reverse and orthogonal) was not collected for each material, but for only one material of each family of steels (IF, DP), based on previous works available in the literature. This minimalistic experimental base was used to feed the numerical simulations for the twelve materials that were confronted to deep drawing experiments in terms of thickness distributions. The results suggested that the accuracy of the numerical simulations is very satisfactory in spite of the scarce experimental input data. Additional investigations indicated that the modeling of the transient behavior due to strain-path changes may have a significant impact on the simulation results, and that the adopted approach provides a simple and efficient alternative in this regard.

  1. Deformation and damage mechanisms of zinc coatings on hot-dip galvanized steel sheets: Part II. Damage modes

    NASA Astrophysics Data System (ADS)

    Parisot, Rodolphe; Forest, Samuel; Pineau, André; Grillon, François; Demonet, Xavier; Mataigne, Jean-Michel

    2004-03-01

    Zinc-based coatings are widely used for protection against corrosion of steel-sheet products in the automotive industry. The objective of the present article is to investigate the damage modes at work in three different microstructures of a zinc coating on an interstitial-free steel substrate under tension, planestrain tension, and expansion loading. Plastic-deformation mechanisms are addressed in the companion article. Two main fracture mechanisms, namely, intergranular cracking and transgranular cleavage fracture, were identified in an untempered cold-rolled coating, a tempered cold-rolled coating, and a recrystallized coating. No fracture at the interface between the steel and zinc coating was observed that could lead to spalling, in the studied zinc alloy. A complex network of cleavage cracks and their interaction with deformation twinning is shown to develop in the material. An extensive quantitative analysis based on systematic image analysis provides the number and cumulative length of cleavage cracks at different strain levels for the three investigated microstructures and three loading conditions. Grain refinement by recrystallization is shown to lead to an improved cracking resistance of the coating. A model for crystallographic cleavage combining the stress component normal to the basal plane and the amount of plastic slip on the basal slip systems is proposed and identified from equibiaxial tension tests and electron backscattered diffraction (EBSD) analysis of the cracked grains. This analysis requires the computation of the nonlinear stress-strain response of each grain using a crystal-plasticity constitutive model. The model is then applied successfully to other loading conditions and is shown to account for the preferred orientations of damaged grains observed in the case of plane-strain tension.

  2. An Investigation of The Reticulated Foam - Perforated Steel Sheet Sandwich Structure As A Blast Mitigation Media

    NASA Astrophysics Data System (ADS)

    Nguyen, Thuy-Tien Ngoc; Proud, William; Institute of Shock Physics, Imperial College London Collaboration; Royal British Legion CentreBlast Injury Studies at Imperial College London Collaboration

    2015-06-01

    Explosions have always been the main cause of injuries during battles and conflicts, with improvised explosive devices (IEDs) becoming more and more common nowadays. In this paper, the interaction between blast waves and sandwich structures of reticulated foam and perforated sheets, with varying thickness and configuration, is studied using an air-driven shock tube apparatus. The mitigation effects for primary blast injuries of these structures are discussed in terms of pulse shape, pressure magnitude as well as shock impulse. Schlieren photography together with other high-speed imaging was also used to visually investigate the matter. The results show that lower open area of perforated sheet and increased thickness of foam offer best protection. However, below a threshold thickness, no mitigation is seen. The Institute of Shock Physics acknowledges the support of AWE, Aldermaston, UK and Imperial College London. The Centre for Blast Injury Studies acknowledges the support of the Royal British Legion and Imperial College London.

  3. Springback Simulation of High Strength Steel Sheet using Local Interpolation for Tool Surfaces

    SciTech Connect

    Hama, Takayuki; Fujimoto, Hitoshi; Takuda, Hirohiko; Teodosiu, Cristian; Makinouchi, Akitake

    2007-05-17

    This paper presents the effect of tool modelling accuracy on the simulation accuracy of springback in high strength steels. Simulations of a two-dimensional draw-bending process are carried out by using a polyhedral tool model whose surface is approximated by a polyhedron, and a model whose surface is smoothed by quadratic parametric surfaces proposed by Nagata [Nagata, Comput. Aided Geom. D, 22(2005), 55-59] (Nagata patch model). It is found that not only the shape accuracy but also the normal vector accuracy of tool models are of importance for accurate springback predictions. The use of the Nagata patch model is an efficient approach not only to improve the simulation accuracy but also to make the simulation be hardly influenced by the tool mesh, even for simulations of a high strength steel in which large amount of springback is involved.

  4. Local Laser Strengthening of Steel Sheets for Load Adapted Component Design in Car Body Structures

    NASA Astrophysics Data System (ADS)

    Jahn, Axel; Heitmanek, Marco; Standfuss, Jens; Brenner, Berndt; Wunderlich, Gerd; Donat, Bernd

    The current trend in car body construction concerning light weight design and car safety improvement increasingly requires an adaption of the local material properties on the component load. Martensitic hardenable steels, which are typically used in car body components, show a significant hardening effect, for instance in laser welded seams. This effect can be purposefully used as a local strengthening method. For several steel grades the local strengthening, resulting from a laser remelting process was investigated. The strength in the treated zone was determined at crash relevant strain rates. A load adapted design of complex reinforcement structures was developed for compression and bending loaded tube samples, using numerical simulation of the deformation behavior. Especially for bending loaded parts, the crash energy absorption can be increased significantly by local laser strengthening.

  5. Impact of using high-density polyethylene geomembrane layer as landfill intermediate cover on landfill gas extraction.

    PubMed

    Chen, Zezhi; Gong, Huijuan; Zhang, Mengqun; Wu, Weili; Liu, Yu; Feng, Jin

    2011-05-01

    Clay is widely used as a traditional cover material for landfills. As clay becomes increasingly costly and scarce, and it also reduces the storage capacity of landfills, alternative materials with low hydraulic conductivity are employed. In developing countries such as China, landfill gas (LFG) is usually extracted for utilization during filling stage, therefore, the intermediate covering system is an important part in a landfill. In this study, a field test of LFG extraction was implemented under the condition of using high-density polyethylene (HDPE) geomembrane layer as the only intermediate cover on the landfill. Results showed that after welding the HDPE geomembranes together to form a whole airtight layer upon a larger area of landfill, the gas flow in the general pipe increased 25% comparing with the design that the HDPE geomembranes were not welded together, which means that the gas extraction ability improved. However as the heat isolation capacity of the HDPE geomembrane layer is low, the gas generation ability of a shallow landfill is likely to be weakened in cold weather. Although using HDPE geomembrane layer as intermediate cover is acceptable in practice, the management and maintenance of it needs to be investigated in order to guarantee its effective operation for a long term. PMID:21232931

  6. Microstructure and Crystallographic Texture of Strip-Cast FE-3.2%SI Steel Sheet

    NASA Astrophysics Data System (ADS)

    Xu, Y. B.; Yu, Y. M.; Cao, G. M.; Li, C. S.; Wang, G. D.; Jiang, Z. Y.

    Fe-3.2%Si steel strips were produced using vertical type twin casting process, and the changes of microstructure and texture trough thickness direction were analyzed. The equiaxed grains of approximately 44.6µm were observed in the center layer, the great mass of columnar dendrite was formed near the surface, and the dendrite truck mainly developed in the transverse direction with respect to the casting direction of about 45° or less. From the subsurface to the center, the volume fraction of the Goss texture (110)[001] gradually decreases. The Goss {110} <001> components at the surface are two times those at the center layer, the {001} <100> components are three times those at the center layer, and the overall texture components are similar to that of the hot-rolled oriented silicon steel strip. The minor α texture could be found from the φ2=45° sections of ODF, and there is no remarkable composition segregation of Si element in the thickness direction of thin strip.

  7. Effect of second phase morphology on warm stretch-flangeability in high strength TRIP-aided dual-phase steel sheets

    SciTech Connect

    Nagasaka, A.; Sugimoto, K.; Kobayashi, M.

    1996-12-31

    The effects of second phase morphology on warm stretch-flangeability in 0.2C-(1.0-2.5)Si-(1.0-2.0)Mn (mass%) high strength transformation-induced plasticity TRIP-aided dual-phase (TDP) steel sheets were investigated. Good warm stretch-flangeability in terms of warm hole-punching and the successive warm hole-expanding was achieved in a TDP steel with an isolated fine and acicular second phase. In the acicular type of TDP steel, volume fraction and carbon concentration (stability) of retained austenite increased considerably over a conventional type of TDP steel with a network second phase along ferrite grain boundary. Warm hole-punching suppressed void formation in a surface layer of punched hole, and developed severe flow band which disturbs crack propagation on expanding. On the successive warm hole-expanding it increased local elongation due to TRIP effect of a large amount of untransformed retained austenite. Optimum forming temperatures for punching and for expanding were between 150-200{degrees}C and between 50-200{degrees}C, respectively. These temperatures were related with retained austenite stability. The acicular type of TDP steel also had the best balance of stretch-formability and stretch-flangeability of conventional high strength steels, such as a bainitic steel and a ferrite-bainite steel which have an excellent stretch-flangeability. Also, it was found that the newest TRIP-aided bainitic steel attained the same good balance as the acicular type of TDP steel.

  8. Quenching and partitioning response of carbon-manganese-silicon sheet steels containing nickel, molybdenum, aluminum and copper additions

    NASA Astrophysics Data System (ADS)

    Kahkonen, Joonas

    In order to produce passenger vehicles with improved fuel economy and increased passenger safety, car manufacturers are in need of steels with enhanced strength levels and good formability. Recently, promising combinations of strength and ductility have been reported for several, so-called third generation advanced high-strength steels (AHSS) and quenching and partitioning (Q&P) steels are increasingly being recognized as a promising third generation AHSS candidate. Early Q research used conventional TRIP steel chemistries and richer alloying strategies have been explored in more recent studies. However, systematic investigations of the effects of alloying elements on tensile properties and retained austenite fractions of Q&P steels are sparse. The objective of the present research was to investigate the alloying effects of carbon, manganese, molybdenum, aluminum, copper and nickel on tensile properties and microstructural evolution of Q&P heat treated sheet steels. Seven alloys were investigated with 0.3C-1.5Mn-1.5Si (wt pct) and 0.4C-1.5Mn-1.5Si alloys used to study carbon effects, a 0.3C-5Mn-1.6Si alloy to study manganese effects, 0.3C-3Mn-1.5Si-0.25Mo and 0.3C-3Mn-1.5Si-0.25Mo-0.85Al alloys to study molybdenum and aluminum effects and 0.2C-1.5Mn-1.3Si-1.5Cu and 0.2C-1.5Mn-1.3Si-1.5Cu-1.5Ni alloys to study copper and nickel effects. Increasing alloy carbon content was observed to mainly increase the ultimate tensile strength (UTS) up to 1865 MPa without significantly affecting total elongation (TE) levels. Increasing alloy carbon content also increased the resulting retained austenite (RA) fractions up to 22 vol pct. Measured maximum RA fractions were significantly lower than the predicted maximum RA levels in the 0.3C-1.5Mn-1.5Si and 0.4C-1.5Mn-1.5Si alloys, likely resulting from transition carbide formation. Increasing alloy manganese content increased UTS, TE and RA levels, and decreased yield strength (YS) and austenite carbon content (Cgamma) levels

  9. Numerical analysis of high strain rate failure of electro-magnetically loaded steel sheets

    NASA Astrophysics Data System (ADS)

    Erice, Borja; Mohr, Dirk

    2015-09-01

    Electro-magnetic forces provide a potentially power full means in designing dynamic experiments with active control of the loading conditions. This article deals with the development of computational models to simulate the thermo-mechanical response of electro-magnetically loaded metallic structures. The model assumes linear electromagnetic constitutive equations and time-independent electric induction to estimate the Joule heating and the Lorentz forces. The latter are then taken into account when evaluating stress equilibrium. A thermo-visco-plastic model with Johnson-Cook type of temperature and strain rate dependence and combined Swift-Voce hardening is used to evaluate the material's thermo-mechanical response. As a first application, the model is used to analyse the effect of electro-magnetic loading on the ductility of advanced high strength steels.

  10. Tribology and Tool Wear of Hot Dip Galvanized Zinc Magnesium Alloys on Cold Rolled Steel Sheets

    NASA Astrophysics Data System (ADS)

    Raab, A. E.; Berger, E.; Freudenthaler, J.; Leomann, F.; Walch, C.

    2011-05-01

    Recently zinc based coatings on cold rolled steel with improved functionality in terms of forming and/or corrosion behaviour have been intensively investigated in the steel industry1,2,3. One of the most promising products are zinc magnesium alloys produced in hot dip galvanizing process. These coatings were already introduced in construction industry a few years ago1. With some modifications the improved properties of the coating are also interesting for automotive industry. In the present work the tribological potential of hot dip galvanized zinc magnesium coatings (HDG/ZM) produced at an industrial line under regular production, was studied in terms of sliding properties, adhesive and abrasive tool wear. First a short introduction into surface morphology of HDG/ZM will be given. For the tribological characterization of the material, which is the main topic of the contribution, different tests were performed on hot dip galvanised zinc magnesium material and results were compared with classic hot dip galvanized zinc coating (HDG/Z). The investigations are mainly based on the strip draw test which allows the determination of the friction coefficient directly by using a constant contact pressure. Deep drawing property was tested by forming model cups. The abrasive tool wear was tested using a standard test for material used in automotive industry. The adhesive tool wear was investigated by characterizing the coating material transferred to the tool in the strip draw test. All performed tests show an improved drawability of HDG/ZM compared to classical HDG/Z reference material. However the most promising difference between HDG/ZM and HDG/Z is that galling was found to be less for HDG/ZM than for HDG/Z. Therefore HDG/ZM is an interesting system not only with respect to corrosion protection but also in terms of tribology and provides clear advantages in formability.

  11. Tribology and Tool Wear of Hot Dip Galvanized Zinc Magnesium Alloys on Cold Rolled Steel Sheets

    SciTech Connect

    Raab, A. E.; Berger, E.; Freudenthaler, J.; Leomann, F.; Walch, C.

    2011-05-04

    Recently zinc based coatings on cold rolled steel with improved functionality in terms of forming and/or corrosion behaviour have been intensively investigated in the steel industry. One of the most promising products are zinc magnesium alloys produced in hot dip galvanizing process. These coatings were already introduced in construction industry a few years ago. With some modifications the improved properties of the coating are also interesting for automotive industry. In the present work the tribological potential of hot dip galvanized zinc magnesium coatings (HDG/ZM) produced at an industrial line under regular production, was studied in terms of sliding properties, adhesive and abrasive tool wear.First a short introduction into surface morphology of HDG/ZM will be given. For the tribological characterization of the material, which is the main topic of the contribution, different tests were performed on hot dip galvanised zinc magnesium material and results were compared with classic hot dip galvanized zinc coating (HDG/Z). The investigations are mainly based on the strip draw test which allows the determination of the friction coefficient directly by using a constant contact pressure. Deep drawing property was tested by forming model cups. The abrasive tool wear was tested using a standard test for material used in automotive industry. The adhesive tool wear was investigated by characterizing the coating material transferred to the tool in the strip draw test.All performed tests show an improved drawability of HDG/ZM compared to classical HDG/Z reference material. However the most promising difference between HDG/ZM and HDG/Z is that galling was found to be less for HDG/ZM than for HDG/Z. Therefore HDG/ZM is an interesting system not only with respect to corrosion protection but also in terms of tribology and provides clear advantages in formability.

  12. Laser-Assisted Bending of Sharp Angles With Small Fillet Radius on Stainless Steel Sheets: Analysis of Experimental Set-Up and Processing Parameters

    NASA Astrophysics Data System (ADS)

    Gisario, Annamaria; Barletta, Massimiliano; Venettacci, Simone; Veniali, Francesco

    2015-06-01

    Achievement of sharp bending angles with small fillet radius on stainless steel sheets by mechanical bending requires sophisticated bending device and troublesome operational procedures, which can involve expensive molds, huge presses and large loads. In addition, springback is always difficult to control, thus often leading to final parts with limited precision and accuracy. In contrast, laser-assisted bending of metals is an emerging technology, as it often allows to perform difficult and multifaceted manufacturing tasks with relatively small efforts. In the present work, laser-assisted bending of stainless steel sheets to achieve sharp angles is thus investigated. First, bending trials were performed by combining laser irradiation with an auxiliary bending device triggered by a pneumatic actuator and based on kinematic of deformable quadrilaterals. Second, laser operational parameters, that is, scanning speed, power and number of passes, were varied to identify the most suitable processing settings. Bending angles and fillet radii were measured by coordinate measurement machine. Experimental data were elaborated by combined ANalysis Of Mean (ANOM) and ANalysis Of VAriance (ANOVA). Based on experimental findings, the best strategy to achieve an aircraft prototype from a stainless steel sheet was designed and implemented.

  13. Systematic study of polycrystalline flow during tension test of sheet 304 austenitic stainless steel at room temperature

    NASA Astrophysics Data System (ADS)

    Muñoz-Andrade, Juan D.

    2013-12-01

    By systematic study the mapping of polycrystalline flow of sheet 304 austenitic stainless steel (ASS) during tension test at constant crosshead velocity at room temperature was obtained. The main results establish that the trajectory of crystals in the polycrystalline spatially extended system (PCSES), during irreversible deformation process obey a hyperbolic motion. Where, the ratio between the expansion velocity of the field and the velocity of the field source is not constant and the field lines of such trajectory of crystals become curved, this accelerated motion is called a hyperbolic motion. Such behavior is assisted by dislocations dynamics and self-accommodation process between crystals in the PCSES. Furthermore, by applying the quantum mechanics and relativistic model proposed by Muñoz-Andrade, the activation energy for polycrystalline flow during the tension test of 304 ASS was calculated for each instant in a global form. In conclusion was established that the mapping of the polycrystalline flow is fundamental to describe in an integral way the phenomenology and mechanics of irreversible deformation processes.

  14. Systematic study of polycrystalline flow during tension test of sheet 304 austenitic stainless steel at room temperature

    SciTech Connect

    Muñoz-Andrade, Juan D.

    2013-12-16

    By systematic study the mapping of polycrystalline flow of sheet 304 austenitic stainless steel (ASS) during tension test at constant crosshead velocity at room temperature was obtained. The main results establish that the trajectory of crystals in the polycrystalline spatially extended system (PCSES), during irreversible deformation process obey a hyperbolic motion. Where, the ratio between the expansion velocity of the field and the velocity of the field source is not constant and the field lines of such trajectory of crystals become curved, this accelerated motion is called a hyperbolic motion. Such behavior is assisted by dislocations dynamics and self-accommodation process between crystals in the PCSES. Furthermore, by applying the quantum mechanics and relativistic model proposed by Muñoz-Andrade, the activation energy for polycrystalline flow during the tension test of 304 ASS was calculated for each instant in a global form. In conclusion was established that the mapping of the polycrystalline flow is fundamental to describe in an integral way the phenomenology and mechanics of irreversible deformation processes.

  15. Fiber laser welding of dual-phase galvanized sheet steel (DP590): traditional analysis and new quality assessment techniques

    NASA Astrophysics Data System (ADS)

    Miller, Stephanie; Pfeif, Erik; Kazakov, Andrei; Baumann, Esther; Dowell, Marla

    2016-03-01

    Laser welding has many advantages over traditional joining methods, yet remains underutilized. NIST has undertaken an ambitious initiative to improve predictions of weldability, reliability, and performance of laser welds. This study investigates butt welding of galvanized and ungalvanized dual-phase automotive sheet steels (DP 590) using a 10 kW commercial fiber laser system. Parameter development work, hardness profiles, microstructural characterization, and optical profilometry results are presented. Sound welding was accomplished in a laser power range of 2.0 kW to 4.5 kW and travel speed of 2000 mm/min to 5000 mm/min. Vickers hardness ranged from approximately 2 GPa to 4 GPa across the welds, with limited evidence of heat affected zone softening. Decreased hardness across the heat affected zone directly correlated to the appearance of ferrite. A technique was developed to non-destructively evaluate weld quality based on geometrical criteria. Weld face profilometry data were compared between light optical, metallographic sample, and frequency-modulated continuous-wave laser detection and ranging (FMCW LADAR) methods.

  16. Experimental investigations and statistical analysis of pulsed laser bending of AISI 304 stainless steel sheet

    NASA Astrophysics Data System (ADS)

    Maji, Kuntal; Pratihar, D. K.; Nath, A. K.

    2013-07-01

    This paper presents experimental investigations on pulsed laser bending of sheet metal and statistical analysis to study the effects of process parameters. Laser power, scan speed, spot diameter and pulsed duration were taken as input variables and bending angle was considered as the output. Response surface methodology was used for modeling and optimization of the pulsed laser bending process. The performance of the developed model was validated through the experiments. All the input variables were found to have significant influence on the bending angle. Bending angle increased with the increase of laser power and pulse duration and decreased with the increase of scan speed and spot diameter. The optimum process parameters for the maximum bending angle were also found and verified with experimental data. The effects of pulse frequency, pulse width and pulse energy on bending angle were also investigated through experiments. Bending angle was found to be the maximum for a certain value of pulse frequency. With the increase of pulse width, bending angle increased at constant laser power but decreased at constant pulse energy. Bending angle was seen to increase with the increase of spatial overlapping and decrease with the increase of gap at constant laser power, but it showed optimal values for both the cases at constant line energy. A comparative study between continuous and pulsed laser bending was carried out to study the process efficiency in terms of energy input and produced deformation.

  17. Effect of texture and grain size on the magnetic flux density and core loss of cold-rolled high silicon steel sheets

    NASA Astrophysics Data System (ADS)

    Qin, Jing; Yang, Ping; Mao, Weimin; Ye, Feng

    2015-11-01

    The effects of texture and grain size on the magnetic flux density and core loss (50-20 kHz) of 0.23 mm-thick cold-rolled high silicon steel sheets are investigated by means of electron back-scattered diffraction (EBSD), loss separation, and anisotropy parameter (ε) calculation. A model of the hysteresis loss coefficient kh considering average grain size and ε is established. The magnetic flux density at 800 A/m (B8) is closely related to the volume fraction of η-fiber-oriented grains, while the magnetic flux density at 5000 A/m (B50) is closely related to the volume fractions of γ- and λ-fiber-oriented grains in high silicon steel. The hysteresis loss of high silicon steel can be greatly reduced by increasing the grain size and optimizing the texture of the sheets. Although increases in frequencies decrease the effect of texture on core loss, the effect cannot be ignored. As annealing temperature and time increase, the relative difference in core loss between the rolling direction (RD) and the transverse direction (TD) is maintained at higher frequencies because of increases in grain size, decreases in γ texture, and maintenance of a strong η texture. Texture and grain size jointly affect the high-frequency core loss of high silicon steel.

  18. Copper and nickel hexacyanoferrate nanostructures with graphene-coated stainless steel sheets for electrochemical supercapacitors

    NASA Astrophysics Data System (ADS)

    Wu, Mao-Sung; Lyu, Li-Jyun; Syu, Jhih-Hao

    2015-11-01

    Copper and nickel hexacyanoferrate (CuHCF and NiHCF) nanostructures featuring three-dimensional open-framework tunnels are prepared using a solution-based coprecipitation process. CuHCF shows superior supercapacitive behavior than the NiHCF, due to the presence of numerous macropores in CuHCF particles for facilitating the transport of electrolyte. Both CuHCF and NiHCF electrodes with stainless steel (SS) substrate tend to lose their electroactivity towards intercalation/deintercalation of hydrated potassium ions owing to the partial corrosion of SS. Formation of a protective and conductive carbon layer in between SS and CuHCF (NiHCF) film is of paramount importance for improving the irreversible loss of electroactivity. Thin and compact graphene (GN) layer without observable holes in its normal plane is the most effective way to suppress the corrosion of SS compared with porous carbon nanotube and activated carbon layers. Specific capacitance of CuHCF electrode with GN layer (CuHCF/GN/SS) reaches 570 F g-1, which is even better than that of CuHCF with Pt substrate (500 F g-1) at 1 A g-1. The CuHCF/GN/SS exhibits high stability with 96% capacitance retention over 1000 cycles, greater than the CuHCF with Pt (75%).

  19. Designing the Color of Hot-Dip Galvanized Steel Sheet Through Destructive Light Interference Using a Zn-Ti Liquid Metallic Bath

    NASA Astrophysics Data System (ADS)

    Levai, Gabor; Godzsák, Melinda; Török, Tamas I.; Hakl, Jozsef; Takáts, Viktor; Csik, Attila; Vad, Kalman; Kaptay, George

    2016-07-01

    The color of hot-dip galvanized steel sheet was adjusted in a reproducible way using a liquid Zn-Ti metallic bath, air atmosphere, and controlling the bath temperature as the only experimental parameter. Coloring was found only for samples cooled in air and dipped into Ti-containing liquid Zn. For samples dipped into a 0.15 wt pct Ti-containing Zn bath, the color remained metallic (gray) below a 792 K (519 °C) bath temperature; it was yellow at 814 K ± 22 K (541 °C ± 22 °C), violet at 847 K ± 10 K (574 °C ± 10 °C), and blue at 873 K ± 15 K (600 °C ± 15 °C). With the increasing bath temperature, the thickness of the adhered Zn-Ti layer gradually decreased from 52 to 32 micrometers, while the thickness of the outer TiO2 layer gradually increased from 24 to 69 nm. Due to small Al contamination of the Zn bath, a thin (around 2 nm) alumina-rich layer is found between the outer TiO2 layer and the inner macroscopic Zn layer. It is proven that the color change was governed by the formation of thin outer TiO2 layer; different colors appear depending on the thickness of this layer, mostly due to the destructive interference of visible light on this transparent nano-layer. A complex model was built to explain the results using known relationships of chemical thermodynamics, adhesion, heat flow, kinetics of chemical reactions, diffusion, and optics. The complex model was able to reproduce the observations and allowed making predictions on the color of the hot-dip galvanized steel sample, as a function of the following experimental parameters: temperature and Ti content of the Zn bath, oxygen content, pressure, temperature and flow rate of the cooling gas, dimensions of the steel sheet, velocity of dipping the steel sheet into the Zn-Ti bath, residence time of the steel sheet within the bath, and the velocity of its removal from the bath. These relationships will be valuable for planning further experiments and technologies on color hot-dip galvanization of steel

  20. Designing the Color of Hot-Dip Galvanized Steel Sheet Through Destructive Light Interference Using a Zn-Ti Liquid Metallic Bath

    NASA Astrophysics Data System (ADS)

    Levai, Gabor; Godzsák, Melinda; Török, Tamas I.; Hakl, Jozsef; Takáts, Viktor; Csik, Attila; Vad, Kalman; Kaptay, George

    2016-05-01

    The color of hot-dip galvanized steel sheet was adjusted in a reproducible way using a liquid Zn-Ti metallic bath, air atmosphere, and controlling the bath temperature as the only experimental parameter. Coloring was found only for samples cooled in air and dipped into Ti-containing liquid Zn. For samples dipped into a 0.15 wt pct Ti-containing Zn bath, the color remained metallic (gray) below a 792 K (519 °C) bath temperature; it was yellow at 814 K ± 22 K (541 °C ± 22 °C), violet at 847 K ± 10 K (574 °C ± 10 °C), and blue at 873 K ± 15 K (600 °C ± 15 °C). With the increasing bath temperature, the thickness of the adhered Zn-Ti layer gradually decreased from 52 to 32 micrometers, while the thickness of the outer TiO2 layer gradually increased from 24 to 69 nm. Due to small Al contamination of the Zn bath, a thin (around 2 nm) alumina-rich layer is found between the outer TiO2 layer and the inner macroscopic Zn layer. It is proven that the color change was governed by the formation of thin outer TiO2 layer; different colors appear depending on the thickness of this layer, mostly due to the destructive interference of visible light on this transparent nano-layer. A complex model was built to explain the results using known relationships of chemical thermodynamics, adhesion, heat flow, kinetics of chemical reactions, diffusion, and optics. The complex model was able to reproduce the observations and allowed making predictions on the color of the hot-dip galvanized steel sample, as a function of the following experimental parameters: temperature and Ti content of the Zn bath, oxygen content, pressure, temperature and flow rate of the cooling gas, dimensions of the steel sheet, velocity of dipping the steel sheet into the Zn-Ti bath, residence time of the steel sheet within the bath, and the velocity of its removal from the bath. These relationships will be valuable for planning further experiments and technologies on color hot-dip galvanization of steel

  1. Experimental investigation of the effect of the material damage induced in sheet metal forming process on the service performance of 22MnB5 steel

    NASA Astrophysics Data System (ADS)

    Zhuang, Weimin; Xie, Dongxuan; Chen, Yanhong

    2016-06-01

    The use of ultra-high strength steels through sheet metal forming process offers a practical solution to the lightweight design of vehicles. However, sheet metal forming process not only produces desirable changes in material properties but also causes material damage that may adversely influence the service performance of the material formed. Thus, an investigation is conducted to experimentally quantify such influence for a commonly used steel (the 22MnB5 steel) based on the hot and cold forming processes. For each process, a number of samples are used to conduct a uniaxial tensile test to simulate the forming process. After that, some of the samples are trimmed into a standard shape and then uniaxially extended until fracture to simulate the service stage. Finally, a microstructure test is conducted to analyze the microdefects of the remaining samples. Based on the results of the first two tests, the effect of material damage on the service performance of 22MnB5 steel is analyzed. It is found that the material damages of both the hot and cold forming processes cause reductions in the service performance, such as the failure strain, the ultimate stress, the capacity of energy absorption and the ratio of residual strain. The reductions are generally lower and non-linear in the former process but higher and linear in the latter process. Additionally, it is found from the microstructure analysis that the difference in the reductions of the service performance of 22MnB5 by the two forming processes is driven by the difference in the micro damage mechanisms of the two processes. The findings of this research provide a useful reference in terms of the selection of sheet metal forming processes and the determination of forming parameters for 22MnB5.

  2. Strong <001> recrystallization texture component in 6.5 wt% Si electrical steel thin sheets by secondary cold rolling and annealing

    NASA Astrophysics Data System (ADS)

    Pan, Hongjiang; Zhang, Zhihao; Mo, Yuanke; Xie, Jianxin

    2016-12-01

    In order to prepare thin sheet with a strong <001> texture component, secondary cold rolling and recrystallization annealing were carried out on a raw sheet of high silicon electrical steel (6.5 wt% Si). The raw sheet was obtained through a process of directional solidification, followed by warm and cold rolling, and annealing. The effects of secondary cold rolling reduction, annealing temperature and holding time on the recrystallization microstructure and texture were investigated. The formation of strong <001> texture component was analyzed. The results showed that the <001> texture component could be enhanced when the sheets were prepared through appropriate secondary cold rolling and annealing. It was ascribed to the cube and Goss recrystallized grains had frequency advantages as well as size advantages during nucleation. Furthermore, the cube and Goss recrystallized grains were easy to grow larger due to the advantage on grain boundary energy and surface energy. The samples prepared through secondary cold rolling with the reduction of 30% and annealing at 1300 °C for 1-5 h exhibited good magnetic properties. The magnetic induction B8 of the samples was 1.335-1.398 T and the core loss P10/50 and P10/400 were 0.383-0.391 W/kg and 5.935-6.422 W/kg, respectively.

  3. Texture and Formability of One-Step and Two-Step Cold-Rolled and Annealed Interstitial Free High-Strength Steel Sheets

    NASA Astrophysics Data System (ADS)

    Humane, M. M.; Minj, R. K.; Peshwe, D. R.; Paretkar, R. K.

    2011-06-01

    In the current experimental investigation, a comparative study has been carried out to understand the development of texture under different conditions, viz. controlled hot-rolled, one-step cold-rolled (CR) and annealed, and two-step cold-rolled and annealed conditions. Mechanical properties were determined and experimental formability limit diagrams (FLDs) were plotted after both one-step and two-step cold-rolled and annealed conditions. From the tabulated data, it was found that hot band texture of 85 to 90 pct deformation was strong and the main orientations were ( {112} )[ {1bar{1}0} ] and ( {332} )[ {bar{1}bar{1}3} ]. One-step cold rolling developed the strong and uniform α-fiber and γ-fiber at 80 pct cold reduction. The strong and uniform new γ-fiber was obtained at the one-step 80 pct CR annealed condition. In addition, the highest drawability was found at the one-step 80 pct CR annealed condition. In two-step cold rolling, orientation ( {223} )[ {1bar{1}0} ] was the main texture component along with extremely strong γ-fiber. Moreover, batch annealing of two-step cold-rolled steel sheets developed exceptionally strong and uniform γ-fiber, and all mechanical properties were enhanced significantly except yield strength. From FLDs, it is observed that the formability properties of interstitial free (IF) high-strength (HS) steel sheets were excellent at both one-step and two-step cold-rolled and annealed conditions. However, the two-step cold-rolling and annealing process was found to be superior to the one-step process. The data of this investigation may be used at the industrial level to design the entire processing of IF-HS steel sheets.

  4. Effect of hot band grain size on development of textures and magnetic properties in 2.0% Si non-oriented electrical steel sheet

    NASA Astrophysics Data System (ADS)

    Lee, K. M.; Huh, M. Y.; Lee, H. J.; Park, J. T.; Kim, J. S.; Shin, E. J.; Engler, O.

    2015-12-01

    The effect of hot band grain size on the development of crystallographic texture and magnetic properties in non-oriented electrical steel sheet was studied. After cold rolling the samples with different initial grain sizes displayed different microstructures and micro-textures but nearly identical macro-textures. The homogeneous recrystallized microstructure and micro-texture in the sample having small grains caused normal continuous grain growth. The quite irregular microstructure and micro-texture in the recrystallized sample with large initial grain size provided a preferential growth of grains in <001>//ND and <113>//ND which were beneficial for developing superior magnetic properties.

  5. Tensile Properties of 17-7 PH and 12 MoV Stainless-Steel Sheet under Rapid-Heating and Constant-Temperature Conditions

    NASA Technical Reports Server (NTRS)

    Manning, Charles R., Jr.; Price, Howard L.

    1961-01-01

    Results are presented of rapid-heating tests of 17-7 PH and 12 MoV stainless-steel sheet heated to failure at temperature rates from about 1 F to 170 F per second under constant-load conditions. Yield and rupture strengths obtained from rapid-heating tests are compared with yield and tensile strengths obtained from short-time elevated-temperature tensile tests (30-minute exposure). A rate-temperature parameter was used to construct master curves from which yield and rupture stresses or temperatures can be predicted. A method for measuring strain by optical means is described.

  6. The Work Softening by Deformation-Induced Disordering and Cold Rolling of 6.5 wt pct Si Steel Thin Sheets

    NASA Astrophysics Data System (ADS)

    Wang, Xianglong; Li, Haoze; Zhang, Weina; Liu, Zhenyu; Wang, Guodong; Luo, Zhonghan; Zhang, Fengquan

    2016-09-01

    As-cast strip of 6.5 wt pct Si steel was fabricated by twin-roll strip casting. After hot rolling at 1323 K (1050 °C), thin sheets with the thickness of 0.35 mm were produced by warm rolling at 373 K (100 °C) with rolling reductions of 15, 25, 35, 45, 55, and 65 pct. Influence of warm rolling reduction on ductility was investigated by room temperature bending test. The measurement of macro-hardness showed that "work softening" could begin when the warm rolling reduction exceeded 35 pct. The room temperature ductility of the thin sheets gradually increased with the increase of warm rolling reductions, and the plastic deformation during bending began to form when the warm rolling reduction was greater than 45 pct, the 65 pct rolled thin sheet exhibited the maximum plastic deformation of about 0.6 pct during bending at room temperature, with a few small dimples having been observed on the fracture surfaces. B2-ordered domains were formed in the 15, 25, 35, 45, and 55 pct rolled specimens, and their average size decreased with the increase of warm rolling reductions. By contrast, no B2-ordered domain could be found in the 65 pct rolled specimen. It had been observed that large-ordered domains could be split into several small parts by the slip of partial super-dislocations during warm rolling, which led to significant decrease of the order degree to cause the phenomenon of deformation-induced disordering. On the basis of these results, cold rolling schedule was developed to successfully fabricate 0.25-mm-thick sheets with good surface qualities and magnetic properties from warm rolled sheets.

  7. The Work Softening by Deformation-Induced Disordering and Cold Rolling of 6.5 wt pct Si Steel Thin Sheets

    NASA Astrophysics Data System (ADS)

    Wang, Xianglong; Li, Haoze; Zhang, Weina; Liu, Zhenyu; Wang, Guodong; Luo, Zhonghan; Zhang, Fengquan

    2016-06-01

    As-cast strip of 6.5 wt pct Si steel was fabricated by twin-roll strip casting. After hot rolling at 1323 K (1050 °C), thin sheets with the thickness of 0.35 mm were produced by warm rolling at 373 K (100 °C) with rolling reductions of 15, 25, 35, 45, 55, and 65 pct. Influence of warm rolling reduction on ductility was investigated by room temperature bending test. The measurement of macro-hardness showed that "work softening" could begin when the warm rolling reduction exceeded 35 pct. The room temperature ductility of the thin sheets gradually increased with the increase of warm rolling reductions, and the plastic deformation during bending began to form when the warm rolling reduction was greater than 45 pct, the 65 pct rolled thin sheet exhibited the maximum plastic deformation of about 0.6 pct during bending at room temperature, with a few small dimples having been observed on the fracture surfaces. B2-ordered domains were formed in the 15, 25, 35, 45, and 55 pct rolled specimens, and their average size decreased with the increase of warm rolling reductions. By contrast, no B2-ordered domain could be found in the 65 pct rolled specimen. It had been observed that large-ordered domains could be split into several small parts by the slip of partial super-dislocations during warm rolling, which led to significant decrease of the order degree to cause the phenomenon of deformation-induced disordering. On the basis of these results, cold rolling schedule was developed to successfully fabricate 0.25-mm-thick sheets with good surface qualities and magnetic properties from warm rolled sheets.

  8. Effect of Decarburization on Notch Sensitivity and Fatigue-Crack-Propagation Rates in 12 MoV Stainless-Steel Sheet

    NASA Technical Reports Server (NTRS)

    Herrnstein, William H., III; McEvily, Arthur J., Jr.

    1961-01-01

    Tests were conducted in order to determine the effect of surface decarburization on the notch sensitivity and rate of fatigue crack propagation in 12 MoV stainless-steel sheet at room temperature. Three specimen configurations were utilized in the course of the investigation: standard tensile specimen, 9-inch-wide specimens containing fatigue cracks or thread-cut notches of 0.005-inch radius, and 2-inch-wide specimens containing fatigue cracks. The 12 MoV stainless-steel sheet in the normal condition was found to have an ultimate tensile strength of 251 ksi and to be extremely notch sensitive. The material in the decarburized condition was found to have an ultimate tensile strength of 210 ksi and to be considerably stronger than the normal material in the presence of fatigue cracks. Decarburization did not appear to have any significant influence on the rate of fatigue crack propagation in the 2-inch-wide specimens at the stress levels considered. In addition to the tests, two methods for predicting residual static strength and their application to the material are discussed.

  9. 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.

  10. Failure Orientation in Stretch Forming and Its Correlation with a Polycrystal Plasticity-Based Material Model for a Collection of Highly Formable Sheet Steels

    NASA Astrophysics Data System (ADS)

    An, Yuguo; Boterman, Romke; Atzema, Eisso; Abspoel, Michael; Scholting, Marc

    2016-04-01

    Robust design optimization techniques have been developed in recent years within the automotive industry with the aim of reducing scrap rates and improving process stability in sheet metal forming. These new techniques are able to take process variations and other sources of material scatter into account. Among the many material variables and inputs used, the yield criterion is an important aspect and this is used to describe the plastic behavior of sheet metals. To achieve a reliable output in an optimization study, the yield criterion selected must be representative of material response and scatter. However, simple material models that deviate from real material behavior are often used due to a lack of material data, which is usually a requirement when using more complex models. In the present research, a polycrystal plasticity-based CTFP model has been evaluated in stretch forming for a collection of highly formable sheet steel materials. The results demonstrate that the CTFP model can capture the yielding character and also detect the minor deviations presented by different coils. The stretching factor derived from the CTFP model, as opposed to the work hardening and ductility, has a dominant effect on failure for a collection of materials with similar mechanical properties. Results also indicate that plastic deformation causes texture evolution and, consequently, an evolving yield locus. Such changes in the yield locus during deformation have an effect on stretching and friction calibration in FE simulations.

  11. Interfacial Characterization of Dissimilar Joints Between Al/Mg/Al-Trilayered Clad Sheet to High-Strength Low-Alloy Steel

    NASA Astrophysics Data System (ADS)

    Macwan, A.; Jiang, X. Q.; Chen, D. L.

    2015-07-01

    Magnesium (Mg) alloys are increasingly used in the automotive and aerospace sectors to reduce vehicle weight. Al/Mg/Al tri-layered clad sheets are deemed as a promising alternative to improve the corrosion resistance and formability of Mg alloys. The structural application of Al/Mg/Al tri-layered clad sheets inevitably involves welding and joining in the multi-material vehicle body manufacturing. This study aimed to characterize the bonding interface microstructure of the Al/Mg/Al-clad sheet to high-strength low-alloy steel with and without Zn coating using ultrasonic spot welding at different levels of welding energy. It was observed that the presence of Zn coating improved the bonding at the interface due to the formation of Al-Zn eutectic structure via enhanced diffusion. At a higher level of welding energy, characteristic flow patterns of Zn into Al-clad layer were observed with an extensive penetration mainly along some high angle grain boundaries. The dissimilar joints without Zn coating made at a high welding energy of 800 J failed partially from the Al/Fe weld interface and partially from the Al/Mg clad interface, while the joints with Zn coating failed from the Al/Mg clad interface due to the presence of brittle Al12Mg17 phase.

  12. Failure Orientation in Stretch Forming and Its Correlation with a Polycrystal Plasticity-Based Material Model for a Collection of Highly Formable Sheet Steels

    NASA Astrophysics Data System (ADS)

    An, Yuguo; Boterman, Romke; Atzema, Eisso; Abspoel, Michael; Scholting, Marc

    2016-07-01

    Robust design optimization techniques have been developed in recent years within the automotive industry with the aim of reducing scrap rates and improving process stability in sheet metal forming. These new techniques are able to take process variations and other sources of material scatter into account. Among the many material variables and inputs used, the yield criterion is an important aspect and this is used to describe the plastic behavior of sheet metals. To achieve a reliable output in an optimization study, the yield criterion selected must be representative of material response and scatter. However, simple material models that deviate from real material behavior are often used due to a lack of material data, which is usually a requirement when using more complex models. In the present research, a polycrystal plasticity-based CTFP model has been evaluated in stretch forming for a collection of highly formable sheet steel materials. The results demonstrate that the CTFP model can capture the yielding character and also detect the minor deviations presented by different coils. The stretching factor derived from the CTFP model, as opposed to the work hardening and ductility, has a dominant effect on failure for a collection of materials with similar mechanical properties. Results also indicate that plastic deformation causes texture evolution and, consequently, an evolving yield locus. Such changes in the yield locus during deformation have an effect on stretching and friction calibration in FE simulations.

  13. 75 FR 62104 - Certain Stainless Steel Sheet and Strip in Coils From Germany, Japan, the Republic of Korea, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-07

    ... section 751(c) of the Act. See Initiation of Five-Year (``Sunset'') Review, 75 FR ] 30777 (June 2, 2010...-cobalt alloy stainless strip is also excluded from the scope of the orders. This ductile stainless steel strip contains, by weight, 26 to 30 percent chromium, and 7 to 10 percent cobalt, with the remainder...

  14. Measurement of the mechanical properties of car body sheet steels at high strain rates and non ambient temperature

    NASA Astrophysics Data System (ADS)

    Bleck, W.; Larour, P.

    2003-09-01

    Crash behaviour and light weight have become the major design criteria for car bodies. Modem high strength steels offer appropriate solutions for these requirements. The prediction of the crash behaviour in simulation programs requires the information on materials behaviour during dynamic testing. The reduction of the signal waviness and the inertia effects at strain rates above 50s^{-1} are major issues in dynamic tensile testing. Damping techniques or load measurement on the sample itself are the common way to reduce oscillations. Strain measurement from the piston displacement or from optical devices on the specimen itself are also compared. Advantages and drawbacks of those various measurement techniques are presented.

  15. The mechansims by which solute nitrogen affects phase transformations and mechanical properties of automotive dual-phase sheet steel

    NASA Astrophysics Data System (ADS)

    Brown, Tyson W.

    Dual-phase steels have seen increased use in automotive applications in recent years, in order to meet the goals of weight reduction and occupant safety. Variations in nitrogen content that may be encountered in steel sourced from a basic oxygen furnace process compared to an electric arc furnace process require that dual-phase steel producers understand the ways that nitrogen affects processing and properties. In the current work, the distribution of nitrogen was investigated in a dual-phase steel with a base chemistry of 0.1 C, 2.0 Mn, 0.2 Cr, 0.2 Mo (wt pct) across a range of nitrogen contents (30-159 ppm) with Al (0.2 and 0.08 wt pct), and Ti (0.02 wt pct) additions used for precipitation control of nitrogen amounts. The distribution of nitrogen amongst trapping sites, including precipitates, grain boundaries, dislocations, and interstitial sites (away from other types of defects) was determined from a combination of electrolytic dissolution, internal friction, and three-dimensional atom probe tomography experiments. Various mechanisms by which different amounts and locations of nitrogen affect phase transformations and mechanical properties were identified from quantitative metallography, dilatometric measurement of phase transformations, tensile testing, and nanoindentation hardness testing. Results indicate nitrogen that is not precipitated with Ti or Al (free nitrogen) partitions to austenite (and thus martensite) during typical intercritical annealing treatments, and is mostly contained in Cottrell atmospheres in martensite. Due to the austenite stabilizing effect of nitrogen, the presence of free nitrogen during intercritical annealing leads to a higher austenite fraction in certain conditions. Thus, the presence of free nitrogen in a dual-phase microstructure will lead to an increase in tensile and yield strengths from both an increase in martensite fraction, and an increase in martensite hardness due to solid solution strengthening. Despite the presence

  16. Mechanical Behavior of Lithium-Ion Batteries and Fatigue Behavior of Ultrasonic Weld-Bonded Lap-Shear Specimens of Dissimilar Magnesium and Steel Sheets

    NASA Astrophysics Data System (ADS)

    Lai, Wei-Jen

    The mechanical behaviors of LiFePO4 battery cell and module specimens under in-plane constrained compression were investigated for simulations of battery cells, modules and packs under crush conditions. The experimental stress-strain curves were correlated to the deformation patterns of battery cell and module specimens. Analytical solutions were developed to estimate the buckling stresses and to provide a theoretical basis for future design of representative volume element cell and module specimens. A physical kinematics model for formation of kinks and shear bands in battery cells was developed to explain the deformation mechanism for layered battery cells under in-plane constrained compression. A small-scale module constrained punch indentation test was also conducted to benchmark the computational results. The computational results indicate that macro homogenized material models can be used to simulate battery modules under crush conditions. Fatigue behavior and failure modes of ultrasonic spot welds in lap-shear specimens of magnesium and steel sheets with and without adhesive were investigated. For ultrasonic spot welded lap-shear specimens, the failure mode changes from the partial nugget pullout mode under low-cycle loading conditions to the kinked crack failure mode under high-cycle loading conditions. For adhesive-bonded and weld-bonded lap-shear specimens, the test results show the near interface cohesive failure mode and the kinked crack failure mode under low-cycle and high-cycle loading conditions, respectively. Next, the analytical effective stress intensity factor solutions for main cracks in lap-shear specimens of three dissimilar sheets under plane strain conditions were developed and the solutions agreed well with the computational results. The analytical effective stress intensity factor solutions for kinked cracks were compared with the computational results at small kink lengths. The results indicate that the computational results approach to

  17. Numerical estimation of phase transformations in solid state during Yb:YAG laser heating of steel sheets

    SciTech Connect

    Kubiak, Marcin Piekarska, Wiesława; Domański, Tomasz; Saternus, Zbigniew; Stano, Sebastian

    2015-03-10

    This work concerns the numerical modeling of heat transfer and phase transformations in solid state occurring during the Yb:YAG laser beam heating process. The temperature field is obtained by the numerical solution into transient heat transfer equation with convective term. The laser beam heat source model is developed using the Kriging interpolation method with experimental measurements of Yb:YAG laser beam profile taken into account. Phase transformations are calculated on the basis of Johnson - Mehl - Avrami (JMA) and Koistinen - Marburger (KM) kinetics models as well as continuous heating transformation (CHT) and continuous cooling transformation (CCT) diagrams for S355 steel. On the basis of developed numerical algorithms 3D computer simulations are performed in order to predict temperature history and phase transformations in Yb:YAG laser heating process.

  18. Parametric Study On The CW Nd: YAG Laser Cutting Quality Of 1.25 mm Ultra Low Carbon Steel Sheets Using O2 Assist Gas

    SciTech Connect

    Salem, Hanadi G.; Abbas, Wafaa A.; Mansour, Mohy S.; Badr, Yehia A.

    2007-02-14

    There are many non-linear interaction factors responsible for the performance of the laser cutting process. Identification of the dominant factors that significantly affect the cut quality is important. In the current research, the gas pressure, laser power and scanning speed were selected as the cutting parameters. Effect of the cutting parameters on the cut quality was investigated, by monitoring the variation in hardness, oxide layer width and microstructural changes within the heat affected zone (HAZ). Results revealed that good quality cuts can be produced in ultra low carbon steel thin sheets, using CW Nd:YAG laser at a window of scanning speed ranging from 1100-1500 mm/min at a minimum heat input of 337watts under an assisting O2 gas pressure of 5 bar. Higher laser power resulted in either strengthening or softening in the HAZ surrounding the cut kerf. The oxide layer width is not affected by the energy density input but rather affected by the O2 gas pressure due to exothermal reaction.

  19. Measurement and Analysis of Ultra-Thin Austenitic Stainless Steel Sheet under Biaxial Tensile Loading and In-Plane Reverse Loading

    NASA Astrophysics Data System (ADS)

    Murakoso, Satoko; Kuwabara, Toshihiko

    Biaxial tensile tests of austenitic stainless steel sheet (SUS304) 0.2mm thick have been carried out using cruciform specimens. The specimens are loaded under linear stress paths in a servo-controlled biaxial tensile testing machine. Plastic orthotropy remained coaxial with the principal stresses throughout every experiment. The successive contours of plastic work in biaxial stress space changed their shapes progressively, exemplifying differential work hardening. The geometry of the entire family of the work contours and the directions of plastic strain rates have been precisely measured and compared with those calculated using conventional yield functions. Yld2000-2d [Barlat, F., Brem, J.C., Yoon, J.W., Chung, K., Dick, R.E., Lege, D.J., Pourboghrat, F., Choi, S.H. and Chu, E., International Journal of Plasticity, Vol. 19, (2003), pp. 1297-1319.] with an exponent of 6 was capable of reproducing the general trends of the work contours and the directions of plastic strain rates with good accuracy. Furthermore, in order to quantitatively evaluate the Bauschinger effect of the test material, in-plane tension/compression tests are conducted. It was found that the non-dimensional (σ /σu) - Δɛ /(σu/ E) curves measured during unloading almost fall on a single curve and are not affected by the amount of pre-strain, where σ is the current stress during unloading, σu is the stress immediately before unloading, Δɛ (< 0) is the total strain increment during unloading.

  20. Standard specification for heat-resisting chromium and chromium-nickel stainless steel plate, sheet, and strip for pressure vessels. ASTM standard

    SciTech Connect

    1998-10-01

    This specification is under the jurisdiction of ASTM Committee A-1 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.17 on Flat Stainless Steel Products. Current edition approved Sep. 10, and Nov. 10, 1997, Apr. 10, and Jun. 10, 1998. Published October 1998. Originally published as A 240-40T. Last previous edition A 240/A 240M-97a.

  1. Formability of Aluminum 5182-Polypropylene Sandwich Sheet for Automotive Application

    NASA Astrophysics Data System (ADS)

    Kim, Kee Joo; Kim, Cheol-Woong; Choi, Byung-Ik; Sung, Chang Won; Kim, Heon Young; Won, Si-Tae; Ryu, Ho-Yeun

    The AA5182/polypropylene/AA5182 (AA/PP/AA) sandwich sheet is the material fabricated by adhering two aluminum skins to one polypropylene core. When it has the same flexural rigidity as a steel sheet, it is 65% lighter than the steel sheet and 30% lighter than an aluminum alloy sheet. Therefore, it is notified exclusively as good substitutive materials for a steel body to improve the fuel efficiency. Through AA/PP/AA sandwich sheet, however, it has relatively lower formability than that of the steel sheet for automotive application. In this study, we developed formability evaluation techniques in order to apply AA/PP/AA sandwich sheet for an automotive parts. For this purpose, newly adopting formability evaluations (using limit dome height and plane strain test) were carried out in order to secure the fundamental data for the measurement of sheet metal forming and the establishment of optimum forming conditions of the sandwich sheet. The results showed that there were in good agreements between the old formability evaluation method and the new one which was more simplified than that of the old one. From the results of these formability evaluations, the formability of sandwich sheet was higher than that of aluminum alloy sheet alone which was the skin component for the sandwich sheet. In addition, it was found that sandwich sheet could reduce the weight and could have the same flexural rigidity simultaneously when it was compared to the automotive steel sheet.

  2. In-situ studies on the performance of landfill caps (compacted soil liners, geomembranes, geosynthetic clay liners, capillary barriers)

    SciTech Connect

    Melchior, S.

    1997-12-31

    Since 1986 different types of landfill covers have been studied in-situ on the Georgswerder landfill in Hamburg, Germany. Water balance data are available for eight years. The performance of different carriers has been measured by collecting the leakage on areas ranging from 100 m{sup 2} to 500 m{sup 2}. Composite liners with geomembranes performed best, showing no leakage. An extended capillary barrier also performed well. The performance of compacted soil liners, however, decreased severely within five years due to desiccation, shrinkage and plant root penetration (liner leakage now ranging from 150 mm/a to 200 mm/a). About 50 % of the water that reaches the surface of the liner is leaking through it. The maximum leakage rates have increased from 2 x 10{sup -10} m{sup 3} m{sup -2} s{sup -1} to 4 x 10{sup -8} m{sup 3} m{sup -2} s{sup -1}. Two types of geosynthetic clay liners (GCL) have been tested for two years now with disappointing results. The GCL desiccated during the first dry summer of the study. High percolation rates through the GCL were measured during the following winter (45 mm resp. 63 mm in four months). Wetting of the GCL did not significantly reduce the percolation rates.

  3. Design, construction, and performance of a single geomembrane liner system at a residual waste disposal site in western Pennsylvania

    SciTech Connect

    Khilji, K.H.; Gould, S.E.; Hamel, T.W.; Thomas, W.B.

    1997-11-01

    This paper examines the effectiveness of a single geomembrane-lined deep valley coal ash/coal mine refuse disposal site to maintain ground-water quality after 10 years of operation. The site occupies over 81 hectares (ha) [200 acres (ac)] in western Pennsylvania. The effectiveness of the liner system was evaluated based on an assessment of the site`s ground-water quality. The liner system was designed in 1983. Selection of geosynthetics and drainage materials, interface shear values, and construction control methods were based on laboratory testing, field investigations, slope stability analyses, and construction load analyses. Diligent construction quality control was applied during all aspects of site development. To examine the site`s ground-water quality, the ground-water monitoring network was sampled approximately once every six weeks for one year. Results of statistical analyses show that the liner system is effectively separating disposal site leachate from ground water and that the site is not degrading ground water.

  4. Effect of the removal of the surface layer of a TRIP steel sheet on its phase composition after static tension at various strain rates

    NASA Astrophysics Data System (ADS)

    Terent'ev, V. F.; Slizov, A. K.; Sirotinkin, V. P.; Prosvirnin, D. V.; Kobeleva, L. I.; Eliseev, E. A.; Rybal'chenko, O. V.; Ashmarin, A. A.

    2016-01-01

    The effect of the removal of the surface layer of a thin strip made of austenitic-martensitic VNS9-Sh (23Kh15N5AM3-Sh) TRIP steel on the phase composition of the strip surface is studied after static tension at various strain rates. An increase in the strain rate is shown to increase the austenite content in the surface layer of the metal. The removal of a 10-μm-thick surface layer by electropolishing results in an increase in the austenite content due to the initial nonuniform phase composition of the thin TRIP steel strip across its thickness after cold rolling.

  5. 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.

  6. 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.

  7. Single wall carbon nanotubes deposited on stainless steel sheet substrates as novel counter electrodes for ruthenium polypyridine based dye sensitized solar cells.

    PubMed

    Calogero, Giuseppe; Bonaccorso, Francesco; Maragò, Onofrio M; Gucciardi, Pietro G; Di Marco, Gaetano

    2010-03-21

    We report on the implementation of stainless steel foils coated with dispersed Single Wall Carbon Nanotubes as novel, low cost and highly efficient counter electrodes for dye sensitized solar cells (DSSCs). We use commercially available non purified nanotubes dispersed in water by ultrasonication and drop cast on stainless steel substrates. When implemented on a ruthenium based DSSC we obtain a high short circuit current density (J(sc)= 9.21 mA cm(-2)), a good open circuit voltage (V(oc) = 0.660 V) and a solar energy conversion efficiency of 3.92%. The above cited values are measured under a light flux of 100 mW cm(-2) generated by a solar simulator equipped with a filter AM 1.5. The obtained results are comparable to those attained using a stainless steel counter electrode sputtered with a 2 microm thick platinum film (J(sc) 10.92 mA cm(-2), V(max) = 0.66 V and eta = 4.5%, AM 1.5). PMID:20200718

  8. A Modified Johnson-Cook Model to Predict Stress-strain Curves of Boron Steel Sheets at Elevated and Cooling Temperatures

    NASA Astrophysics Data System (ADS)

    Duc-Toan, Nguyen; Tien-Long, Banh; Dong-Won, Jung; Seung-Han, Yang; Young-Suk, Kim

    2012-02-01

    In order to predict correctly stress-strain curve for tensile tests at elevated and cooling temperatures, a modification of a Johnson-Cook (J-C) model and a new method to determine (J-C) material parameters are proposed. A MATLAB tool is used to determine material parameters by fitting a curve to follow Ludwick and Voce's hardening law at various elevated temperatures. Those hardening law parameters are then utilized to determine modified (J-C) model material parameters. The modified (J-C) model shows the better prediction compared to the conventional one. An FEM tensile test simulation based on the isotropic hardening model for metal sheet at elevated temperatures was carried out via a user-material subroutine, using an explicit finite element code. The simulation results at elevated temperatures were firstly presented and then compared with the measurements. The temperature decrease of all elements due to the air cooling process was then calculated when considering the modified (J-C) model and coded to VUMAT subroutine for tensile test simulation. The modified (J-C) model showed the good comparability between the simulation results and the corresponding experiments.

  9. 75 FR 4779 - Certain Cut-to-Length Carbon-Quality Steel Plate Products From Italy: Preliminary Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-29

    ...-Rolled Flat-Rolled Carbon-Quality Steel Products From Japan, 64 FR 24329 (May 6, 1999). In Nippon Steel... home-market sales database. See Stainless Steel Sheet and Strip in Coils from Taiwan: Preliminary... (August 5, 2008) (Coils from Taiwan), unchanged in Stainless Steel Sheet and Strip in Coils From...

  10. New Method For Joining Stainless Steel to Titanium

    NASA Technical Reports Server (NTRS)

    Emanuel, W. H.

    1982-01-01

    In new process, edge of stainless-steel sheet is perforated, and joined to titanium by resistance seam welding. Titanium flows into perforations, forming a strong interlocking joint. Process creates a quasi-metallurgical bond between the thin sheets of stainless steel and titanium.

  11. 43. WEST TO DETAIL OF WHEELED SHEET METAL WORK STATION ...

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

    43. WEST TO DETAIL OF WHEELED SHEET METAL WORK STATION BEARING ON LEFT CIRCA 1900 ROLLS FOR BENDING STEEL WINDMILL BLADES TO PROPER CURVATURE AND ON RIGHT CIRCA 1900 BEADING MACHINE FOR ADDING STIFFENING CREASES TO THE EDGES OF SHEET METAL PARTS SUCH AS BLADES. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  12. 44. SOUTHWEST TO CIRCA 1900 SHEET METAL BRAKE, THE MACHINE ...

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

    44. SOUTHWEST TO CIRCA 1900 SHEET METAL BRAKE, THE MACHINE USED TO BEND SHEET METAL TO EXACT ANGLES AS IN STEEL WATER TANK MANUFACTURE. IN THE BACKGROUND IS THE INTERIOR WEST WALL OF THE FACTORY, ITS SHELVES BEARING WATER PUMPS, PARTS FOR PUMPS AND WATER SUPPLY EQUIPMENT, AND NEW OLD STOCK MERCHANDISE. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  13. Rehabilitation of Composite Steel Bridges Using GFRP Plates

    NASA Astrophysics Data System (ADS)

    Damatty, A. A.; Abushagur, M.; Youssef, M. A.

    2005-09-01

    The current study is a part of an extensive research program conducted to assess the use of Glass Fibre Reinforced Plastic (GFRP) sheets in enhancing the flexural capacity of steel beams. The properties of a heavy-duty adhesive system that can be used to bond GFRP sheets to the flanges of steel beams were experimentally determined in a previous study. The excellent performance of a W-shaped steel beam strengthened using GFRP sheets has encouraged the authors to assess the applicability of this technique to composite steel bridges.

  14. An analytical model for volatile organic compound transport through a composite liner consisting of a geomembrane, a GCL, and a soil liner.

    PubMed

    Xie, Haijian; Jiang, Yuansheng; Zhang, Chunhua; Feng, Shijin

    2015-02-01

    An analytical model for volatile organic compounds (VOCs) transport through a composite liner consisting of a geomembrane (GM), a geosynthetic clay liner (GCL), and a soil liner (SL) was developed for the assessment of the performance of this triple liner system. Both advection through the defects of GM and diffusion in the intact GM were considered in the model, and dimensionless analytical solution was obtained. The soil concentration profiles obtained by the proposed analytical solution have a good agreement with those obtained by the finite-layer-based software POLLUTE v7. The effects of leachate head, length of the connected wrinkles, and the interface transmissivity of GM/GCL on the breakthrough curves of the liner system were then investigated. Results show that the 30-year base flux of the liner system for the case with leachate head = 10 m and length of the connected wrinkles = 1,000 m can be over 60 times greater than that of the pure diffusion case. The length of the connected wrinkles of the GM has greater influence on the base flux of the liner system than on the base concentration. The interface transmissivity has negligible effect on the solute breakthrough curves of the liner system for relatively low values of the length of the connected wrinkles (e.g., <100 m). The groundwater protection level achieved by GM/CCL is more effective than that by GM/GCL/SL in the earlier times. However, the steady state base flux for GM/GCL/SL can be seven to eight times lower than that for GM/CCL. The analytical solution can also be used for experimental data fitting, verification of complicated numerical models, and preliminary design of composite liners. PMID:25217284

  15. 77 FR 2032 - Certain Cut-to-Length Carbon-Quality Steel Plate Products From the Republic of Korea: Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-13

    ... as stated in Stainless Steel Sheet and Strip in Coils From Mexico; Preliminary Results of Antidumping Duty Administrative Review, 73 FR 45708, 45714 (August 6, 2008), unchanged in Stainless Steel Sheet and... International Trade Administration Certain Cut-to-Length Carbon-Quality Steel Plate Products From the...

  16. Joining of Thin Metal Sheets by Shot Peening

    NASA Astrophysics Data System (ADS)

    Harada, Yasunori

    2011-01-01

    In shot peening the substrate undergoes large plastic deformation near the surface due to the hit with shots. The plastic flow areas formed by cold working may form the surface layer. Authors have recently proposed new joining methods using shot peening, shot lining and shot caulking. Our approach has been applied to the butt joining of the dissimilar metal sheets. In the present study, joining of thin metal sheets using a shot peening process was investigated to improve the joinability. In the joined section, the edge of sheets is the equally-spaced slits. In this method, the convex edges of the sheet are laid on top of the other sheet. Namely, the two sheets are superimposed in the joining area. When the connection is shot-peened, the material of the convex area undergoes large plastic deformation near the surface due to the collision of shots. In this process, particularly noteworthy is the plastic flow near surface layer. The convex edges of the sheet can be joined to the other sheet, thus two sheets are joined each other. In the experiment, the shot peening treatment was performed by using an air-type peening machine. The shots used were made of high carbon cast steel. Air pressure was 0.6 MPa and peening time was in the range of 30-150s. The peening conditions were controlled in the experiment. The thin sheets were commercial low-carbon steel, stainless steel, pure aluminum, and aluminium alloy. The effects of processing conditions on the joinability were mainly examined. The joint strength increased with the kinetic energy of shots. It was found that the present method was effective for joining of thin metal sheets.

  17. 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.

  18. 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.

  19. Fatigue Strengths of Aircraft Materials: Axial-Load Fatigue Tests on Edge-Notched Sheet Specimens of 2024-T3 and 7075-T6 Aluminum Alloys and of SAE 4130 Steel with Notch Radii of 0.004 and 0.070 inch

    NASA Technical Reports Server (NTRS)

    Grover, H. J.; Hyler, W. S.; Jackson, L. R.

    1959-01-01

    The present report gives results of axial-load fatigue tests on notched specimens of three sheet materials: 2024-T3 and 7075-T6 aluminum alloys and normalized SAE 4130 steel. Two edge-notched specimens were designed and tested, each having a theoretical stress-concentration factor K(sub t) = 4.0. The radii of the notches were 0.004 and 0.070 inch. Tests of these specimens were run at two levels of nominal mean stress: 0 and 20,000 psi. Results of these studies extended information previously reported on tests of specimens with varying notch severity. They afford data on the variation of fatigue-strength reduction with notch radius and on the potential usefulness of Neuber's technical stress-concentration factor K(sub n).

  20. Precision Small Angle Bending of Sheet Metals Using Shear Deformation

    NASA Astrophysics Data System (ADS)

    Hirota, Kenji; Mori, Yorifumi

    This paper deals with a new method to bend sheet metals at a small angle precisely, in which a sheet metal is slightly bent by shear deformation at negative punch-die clearance. Deformation behavior and key factors affecting on the bend angle were studied in detail with pure aluminum sheets. It was proved that the bend angle was changed in proportion to both punch penetration and negative punch-die clearance within a certain range. The same was true for high-strength steel and phosphor bronze, which are difficult to bend precisely by conventional methods due to large springback after unloading. By using this relationship as a control law, four kinds of sheet metals were precisely bent within a few degrees. This method was applied to correct the angular errors in U-bend products of high-strength steel and to bend leaf springs of phosphor bronze at an arbitrary small angle.

  1. ERECTION PLANS (TOP AND BOTTOM), ELEVATION AND SECTIONS FOR STEEL ...

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

    ERECTION PLANS (TOP AND BOTTOM), ELEVATION AND SECTIONS FOR STEEL TRUSS AT SPAN 2, APALACHICOLA RIVER BRIDGE, SHEET 5507-8-E1 - Apalachicola River Bridge, State Route 20 spanning the Apalachicola River, Blountstown, Calhoun County, FL

  2. ERECTION PLANS (TOP AND BOTTOM), ELEVATION AND SECTIONS FOR STEEL ...

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

    ERECTION PLANS (TOP AND BOTTOM), ELEVATION AND SECTIONS FOR STEEL TRUSS AT SPAN 3, APALACHICOLA RIVER BRIDGE, SHEET 5507-8-E2 - Apalachicola River Bridge, State Route 20 spanning the Apalachicola River, Blountstown, Calhoun County, FL

  3. ERECTION PLANS (TOP AND BOTTOM), ELEVATION AND SECTIONS FOR STEEL ...

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

    ERECTION PLANS (TOP AND BOTTOM), ELEVATION AND SECTIONS FOR STEEL TRUSS AT SPAN 5, APALACHICOLA RIVER BRIDGE, SHEET 5505-6-E2 - Apalachicola River Bridge, State Route 20 spanning the Apalachicola River, Blountstown, Calhoun County, FL

  4. ANCHOR SETTING PLAN, WITH DETAILS, FOR STEEL BENTS AT APPROACH ...

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

    ANCHOR SETTING PLAN, WITH DETAILS, FOR STEEL BENTS AT APPROACH SPANS FOR APALACHICOLA RIVER BRIDGE, SHEET 5509-M2 - Apalachicola River Bridge, State Route 20 spanning the Apalachicola River, Blountstown, Calhoun County, FL

  5. ERECTION PLANS (TOP AND BOTTOM), ELEVATION AND SECTIONS FOR STEEL ...

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

    ERECTION PLANS (TOP AND BOTTOM), ELEVATION AND SECTIONS FOR STEEL TRUSS AT SPAN 1, APALACHICOLA RIVER BRIDGE, SHEET 5505-6-E1 - Apalachicola River Bridge, State Route 20 spanning the Apalachicola River, Blountstown, Calhoun County, FL

  6. ERECTION PLANS (TOP AND BOTTOM), ELEVATION AND SECTIONS FOR STEEL ...

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

    ERECTION PLANS (TOP AND BOTTOM), ELEVATION AND SECTIONS FOR STEEL TRUSS AT SPAN 4, APALACHICOLA RIVER BRIDGE, SHEET 5507-8-E3 - Apalachicola River Bridge, State Route 20 spanning the Apalachicola River, Blountstown, Calhoun County, FL

  7. 15. STRESS SHEET. American Bridge Company, New York Office, 30 ...

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

    15. STRESS SHEET. American Bridge Company, New York Office, 30 Church Street, sheet no. C516, dated March 12, 1928, approved March 16, 1928, order no. F5073. For U.S. Steel Products Company, Pacific Coast Depot. For Southern Pacific Company, Pacific Lines, 1st crossing, Napa River, near Napa, Western Division, customer's order no. 8873-P-28746. Various scales. - Napa River Railroad Bridge, Spanning Napa River, east of Soscol Avenue, Napa, Napa County, CA

  8. Structural Biology Fact Sheet

    MedlinePlus

    ... Home > Science Education > Structural Biology Fact Sheet Structural Biology Fact Sheet Tagline (Optional) Middle/Main Content Area What is structural biology? Structural biology is a field of science focused ...

  9. Zika Virus Fact Sheet

    MedlinePlus

    ... 2014 Fact sheets Features Commentaries 2014 Multimedia Contacts Zika virus Fact sheet Updated 6 September 2016 Key facts ... and last for 2-7 days. Complications of Zika virus disease After a comprehensive review of evidence, there ...

  10. Investigation into springback characteristics of two HSS sheets during cold v-bending

    NASA Astrophysics Data System (ADS)

    Fang, Gang; Gao, Wei-Ran

    2013-12-01

    Considering the safety and the light-weight structure, there is an increasing requirement of high strength steel (HSS) sheets in the automotive industry. The high-precise prediction of the springback depends on constitutive equations and their corresponding material parameters. In order to investigate the springback of HSS sheets, DP590 and B280VK, their constitutive behaviors were analyzed based on the sheet tension tests. With respect to the constitutive equation, the Voce model is more proper to two hot-rolled steels, DP590 and B280VK, than the Swift model. Two steels are all saturated hardening, and the degree of hardening decreases with the strain. The cold v-banding tests of two HSS sheets were carried out for evaluation of springback characteristics. Results of v-bending experiments showed that the springback angle increases with the bending along 45°, 90° and 0° to the rolling direction of steel in turn.

  11. 117. JOB NO. 1347M, SHEET 5, 1930, ADDITION FOR PRESSED ...

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

    117. JOB NO. 1347-M, SHEET 5, 1930, ADDITION FOR PRESSED STEEL DEPARTMENT FOR FORD MOTOR COMPANY; NORTH ELEVATIONS DETAILS - Ford Motor Company Long Beach Assembly Plant, Assembly Building, 700 Henry Ford Avenue, Long Beach, Los Angeles County, CA

  12. 116. JOB NO. 1347M, SHEET 4, 1930, ADDITION FOR PRESSED ...

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

    116. JOB NO. 1347-M, SHEET 4, 1930, ADDITION FOR PRESSED STEEL DEPARTMENT FOR THE FORD MOTOR COMPANY; ELEVATIONS, DETAILS - Ford Motor Company Long Beach Assembly Plant, Assembly Building, 700 Henry Ford Avenue, Long Beach, Los Angeles County, CA

  13. Investigation into springback characteristics of two HSS sheets during cold v-bending

    SciTech Connect

    Fang, Gang; Gao, Wei-Ran

    2013-12-16

    Considering the safety and the light-weight structure, there is an increasing requirement of high strength steel (HSS) sheets in the automotive industry. The high-precise prediction of the springback depends on constitutive equations and their corresponding material parameters. In order to investigate the springback of HSS sheets, DP590 and B280VK, their constitutive behaviors were analyzed based on the sheet tension tests. With respect to the constitutive equation, the Voce model is more proper to two hot-rolled steels, DP590 and B280VK, than the Swift model. Two steels are all saturated hardening, and the degree of hardening decreases with the strain. The cold v-banding tests of two HSS sheets were carried out for evaluation of springback characteristics. Results of v-bending experiments showed that the springback angle increases with the bending along 45°, 90° and 0° to the rolling direction of steel in turn.

  14. 36. PHOTOGRAPHY OF W.P.A. PROJECT (MINNEAPOLIS CITY ENGINEER) STRAIN SHEET ...

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

    36. PHOTOGRAPHY OF W.P.A. PROJECT (MINNEAPOLIS CITY ENGINEER) STRAIN SHEET (4 x 5 negative) - Steel Arch Bridge, Hennepin Avenue spanning west channel of Mississippi River, Minneapolis, Hennepin County, MN

  15. 41. DRAW SPAN OVER PASSAIC RIVER 18M110; Sheet No. 34 ...

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

    41. DRAW SPAN OVER PASSAIC RIVER 18-M-110; Sheet No. 34 Details of Center Casting and Steel Ring Scale 1-1/2'=1'; February 1897 - Jackson Street Bridge, Spanning Passaic River, Newark, Essex County, NJ

  16. Effect of initial texture on secondary recrystallization of grain-oriented electrical steel

    SciTech Connect

    Iwanaga, I.; Iwayama, K.; Takahasi, N. . Yawata R and D Lab.); Masui, H.; Harase, J. . Steel Research Labs.)

    1994-04-01

    The effect of initial texture before cold rolling on secondary recrystallization of grain-oriented electrical steel was investigated using thin cast sheets and conventional hot-rolled sheets and conventional hot-rolled sheets as initial materials. The main texture component of the surface layer of thin cast sheets is random, while that of the hot-rolled sheets is [110] <001>. It was found that the optimum cold reduction for achieving a strong [110] <001> texture during secondary recrystallization was 95% and 90% for thin cast sheets and hot-rolled sheets, respectively.

  17. 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.

  18. Modern processes of production of thin sheets and strips by continuous casting

    NASA Astrophysics Data System (ADS)

    Smirnov, A. N.

    2012-06-01

    The history of the development of producing thin sheets and strips by continuous casting methods is considered. The mechanism of this sheet formation during casting of steel in a two-roll continuous caster is described. The advantages of this process over the corresponding traditional technologies are discussed.

  19. 75 FR 39663 - Stainless Steel Bar From Brazil: Final Results of Antidumping Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-12

    ... Antidumping Duty Administrative Review, 73 FR 75398, 75399 (December 11, 2008), and Stainless Steel Sheet and... Steel Bar From Brazil, 59 FR 66914 (December 28, 1994). These deposit requirements shall remain in... International Trade Administration Stainless Steel Bar From Brazil: Final Results of Antidumping...

  20. TRP 9904 - Constitutive Behavior of High Strength Multiphase Sheel Steel Under High Strain Rate Deformation

    SciTech Connect

    David Matlock; John Speer

    2005-03-31

    The focus of the research project was to systematically assess the strain rate dependence of strengthening mechanisms in new advanced high strength sheet steels. Data were obtained on specially designed and produced Duel Phase and TRIP steels and compared to the properties of automotive steels currently in use.

  1. 75 FR 12514 - Stainless Steel Bar From Brazil: Preliminary Results of Antidumping Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-16

    ... Brazil. See Antidumping Duty Orders: Stainless Steel Bar from Brazil, India and Japan, 60 FR 9661... Review, 73 FR 75398, 75399 (December 11, 2008) (SSPC from Belgium), and Stainless Steel Sheet and Strip... International Trade Administration Stainless Steel Bar From Brazil: Preliminary Results of Antidumping...

  2. A Collaborative Design Curriculum for Reviving Sheet Metal Handicraft

    ERIC Educational Resources Information Center

    Chan, Patrick K. C.

    2015-01-01

    Galvanised sheet metal was a popular and important material for producing handmade home utensils in Hong Kong from the 1930s onwards. It was gradually replaced by new materials like stainless steel and plastic because similar goods made with these are cheaper, more standardised, more durable and of much better quality. The handicrafts behind sheet…

  3. 10. Photographic copy of linen drawing of original construction (sheet ...

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

    10. Photographic copy of linen drawing of original construction (sheet 1 of 4, in possession of DM & IR Bridge Engineer, Procter, Minnesota). Steel plan detailing truss elevation, foundation locations and sizes, railroad track layout and typical approach span bents. - Elwood Bridge, Carrying St. Louis County Road 696 over DM & IR Railyard, Proctor, St. Louis County, MN

  4. Corrosion behavior of HVOF coated sheets

    NASA Astrophysics Data System (ADS)

    Yilbas, B. S.; Abdul-Aleem, B. J.; Khalid, M.

    2003-12-01

    High velocity oxygen-fuel (HVOF) thermal spray coating finds application in industry due to its superior resistance to corrosion and thermal loading. In the HVOF process, the metallic powders at elevated temperature are sprayed at supersonic speed onto a substrate material. The powder granules sprayed impact onto each other, forming a mechanical bonding across the coating layer. In most of the cases, the distances among the particles (powder granules sprayed) are not the same, which in turn results in inhomogeneous structure across the coating layer. Moreover, the rate of oxidation of the powder granules during the spraying process varies. Consequently, the electrochemical response of the coating layer surfaces next to the base material and free to atmosphere differs. In the current study, the electrochemical response of a coating sheet formed during HVOF thermal spraying was investigated. NiCrMoNb alloy (similar to Inconel 625) wass used for the powder granules. Thermal spraying was carried out onto a smooth surface of stainless steel workpiece (without grid blasting), and later the coating layer was removed from the surface to obtain the coating sheet for the electrochemical tests. It was found that the corrosion rate of the smooth surface (surface next to the stainless steel surface before its removal) is considerably larger than that corresponding to the rough surface (free surface) of the coating sheet, and no specific patterns were observed for the pit sites.

  5. Perforating Thin Metal Sheets

    NASA Technical Reports Server (NTRS)

    Davidson, M. E.

    1985-01-01

    Sheets only few mils thick bonded together, punched, then debonded. Three-step process yields perforated sheets of metal. (1): Individual sheets bonded together to form laminate. (2): laminate perforated in desired geometric pattern. (3): After baking, laminate separates into individual sheets. Developed for fabricating conductive layer on blankets that collect and remove ions; however, perforated foils have other applications - as conductive surfaces on insulating materials; stiffeners and conductors in plastic laminates; reflectors in antenna dishes; supports for thermal blankets; lightweight grille cover materials; and material for mockup of components.

  6. Titanium Sheet Fabricated from Powder for Industrial Applications

    SciTech Connect

    Peter, William H; Muth, Thomas R; Chen, Wei; Yamamoto, Yukinori; Jolly, Brian C; Stone, Nigel; Cantin, G.M.D.; Barnes, John; Paliwal, Muktesh; Smith, Ryan; Capone, Joseph; Liby, Alan L; Williams, James C; Blue, Craig A

    2012-01-01

    In collaboration with Ametek and Commonwealth Scientific and Industrial Research Organization (CSIRO), Oak Ridge National Laboratory has evaluated three different methods for converting titanium hydride-dehydride (HDH) powder into thin gauge titanium sheet from a roll compacted preform. Methodologies include sintering, followed by cold rolling and annealing; direct hot rolling of the roll-compacted sheet; and hot rolling of multiple layers of roll compacted sheet that are encapsulated in a steel can. All three methods have demonstrated fully consolidated sheet, and each process route has the ability to produce sheet that meets ASTM B265 specifications. However, not every method currently provides sheet that can be highly formed without tearing. The degree of sintering between powder particles, post processing density, and the particle to particle boundary layer where compositional variations may exist, have a significant effect on the ability to form the sheet into useful components. Uniaxial tensile test results, compositional analysis, bend testing, and biaxial testing of the titanium sheet produced from hydride-dehydride powder will be discussed. Multiple methods of fabrication and the resulting properties can then be assessed to determine the most economical means of making components for industrial applications.

  7. Self-Pierce Riveting Through 3 Sheet Metal Combinations

    NASA Astrophysics Data System (ADS)

    Andersson, Roger; Jonason, Paul; Pettersson, Tommy

    2011-05-01

    One way to reduce the CO2 emissions in automotives is to reduce the weight of the Body-In-White. One easy to achieve the weight reduction is to replace steel sheet materials with Al alloys, which is 3 times lighter. One issue is the joining process, especially with combinations between steel grades and AL alloys. Example of combination of mixed material combinations (Al-steel) might be found in the door structure. The reason is because of the AL alloys worthier crash performance so the automotive manufacturer might want to use crash impact beams made by high strength steels in a AL intensive door structure. The joining process between aluminum and steel are problematic due it's not possible to use traditional spot-welding technologies due to the materials total difference in microstructure characteristics as well thermal properties. To overcome this issue then mechanical as well adhesion joining are frequently used. This paper describes a development process and subsequently analysis of a self-pierce rivet (SPR) process between 3 sheet metal combinations. The multi-material combinations in this study were a combination of ultra high strength steels sheets (DP1000) and a Al-alloy (AA 6014). The analysis of the SPR process, in sense of mechanical strengths, has been done by peel- and shear tests. To reduce the amount of future physical tests a virtual FE-model has been developed for the process. This FE model of the process has been subsequently used to analyze the mechanical strength during plastic deformation. By using inverse analysis a correct contact algorithm has been evaluated that would predict the binding force between the rivet and sheet under a deformation process. With this new virtual model it will not only possible to analyze and develop the SPR process but also to achieve the final strength of the joint.

  8. Self-Pierce Riveting Through 3 Sheet Metal Combinations

    SciTech Connect

    Andersson, Roger; Jonason, Paul; Pettersson, Tommy

    2011-05-04

    One way to reduce the CO{sub 2} emissions in automotives is to reduce the weight of the Body-In-White. One easy to achieve the weight reduction is to replace steel sheet materials with Al alloys, which is 3 times lighter. One issue is the joining process, especially with combinations between steel grades and AL alloys. Example of combination of mixed material combinations (Al-steel) might be found in the door structure. The reason is because of the AL alloys worthier crash performance so the automotive manufacturer might want to use crash impact beams made by high strength steels in a AL intensive door structure. The joining process between aluminum and steel are problematic due it's not possible to use traditional spot-welding technologies due to the materials total difference in microstructure characteristics as well thermal properties. To overcome this issue then mechanical as well adhesion joining are frequently used. This paper describes a development process and subsequently analysis of a self-pierce rivet (SPR) process between 3 sheet metal combinations. The multi-material combinations in this study were a combination of ultra high strength steels sheets (DP1000) and a Al-alloy (AA 6014). The analysis of the SPR process, in sense of mechanical strengths, has been done by peel- and shear tests. To reduce the amount of future physical tests a virtual FE-model has been developed for the process. This FE model of the process has been subsequently used to analyze the mechanical strength during plastic deformation. By using inverse analysis a correct contact algorithm has been evaluated that would predict the binding force between the rivet and sheet under a deformation process. With this new virtual model it will not only possible to analyze and develop the SPR process but also to achieve the final strength of the joint.

  9. Friction Stir Lap Welding of Magnesium Alloy to Steel: A Preliminary Investigation

    NASA Astrophysics Data System (ADS)

    Jana, S.; Hovanski, Y.; Grant, G. J.

    2010-12-01

    An initial study was made to evaluate the feasibility of joining magnesium alloy AZ31 sheet to galvanized steel sheet in a lap configuration using friction stir welding (FSW). Two different automotive sheet steels were used for comparative evaluation of the dissimilar joining potential: a 0.8 mm thick, electrogalvanized (EG) mild steel, and a 1.5 mm thick hot-dipped galvanized (HDG) high-strength, low-alloy (HSLA) steel. These steels were joined to 2.33 mm thick AZ31B magnesium sheet. A single FSW tool design was used for both dissimilar welds, and the process parameters were kept the same. The average peak load for the AZ31-1.5 mm steel weld joint in lap shear mode was found to be 6.3 ± 1.0 kN. For the AZ31-0.8 mm steel weld, joint strength was 5.1 ± 1.5 kN. Microstructural investigation indicates melting of the Zn coating present on the steel sheets, and subsequent alloying with the Mg sheet resulted in the formation of a solidified Zn-Mg alloy layer.

  10. Silicon sheet technologies

    SciTech Connect

    Ciszek, T.F.

    1982-09-01

    A classification of silicon sheet growth methods by meniscus geometry permits them to be discussed in three groups: short meniscus techniques, high meniscus techniques, and extended meniscus or large solid/liquid interface area techniques. A second parameter, meniscus shaper interaction with the liquid silicon, is also instrumental in determining the characteristics of the various sheet processes. The current status of each process is discussed in the context of meniscus geometry and shaper/melt interaction. One aspect of sheet growth, surface area generation rate, is quantitatively compared with combined ingot growth and wafering surface area generation rates.