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1

A STUDY OF 17-7 PH STAINLESS STEEL. Period covered: January 1957 to December 1958  

Microsoft Academic Search

The effects of different heat-treatments on mechanical properties and ; microstructures of 17-7 PH stainless steel were studied. The best tensile and ; stress-rupture properties at 600 and 800 deg F were obtained with the TH 950 ; treatment. Long exposure at 800 deg F, either with or without stress, produced ; embrittlement. It was found that original properties may

N. L. Carwile; S. J. Rosenberg

1959-01-01

2

FABRICATION, WELDING AND TESTING OF 17-7 PH STAINLESS STEEL  

Microsoft Academic Search

The fabrication and heat treatment of a scroll, elbows, and transitions ; made from l7-7 PH stainless steel plate in thickhesses varying from one-quarter ; inch to three inches are reported. Inert gas-shielded tungsten-arc welding ; procedures for l7-7 PH stainless steel are presented in detail. The material ; handling and welding techniques necessary to achieve ultra-high quality multipass ;

1958-01-01

3

Metallurgical analysis on a bending failed pump-shaft made of 17-7PH precipitation-hardening stainless steel  

Microsoft Academic Search

Abnormal jump and bending occurred on a shaft used in an erect multiple-grades pump when performing a trial run. The failed shaft is made of 17-7PH stainless steel. Microstructure and mechanical properties of the failed pump-shaft material were examined. Two different microstructural zones were exhibited. One is composed of the tempered martensite coexisting the retained austenite, which is the normal

X. L. Xu; Z. W. Yu

2008-01-01

4

Axial-Load Fatigue Tests on 17-7 PH Stainless Steel Under Constant-Amplitude Loading  

NASA Technical Reports Server (NTRS)

Axial-load fatigue tests were conducted at room temperature on notched and unnotched sheet specimens of 17-7 PH stainless steel in Condition TH 1050. The notched specimens had theoretical stress-concentration factors of 2.32, 4.00, and 5.00. All specimens were tested under completely reversed loading. S-N curves are presented for each specimen configuration and ratios of fatigue strengths of unnotched specimens to those of notched specimens are given. Predictions of the fatigue behavior of notched specimens near the fatigue limit were made.

Leybold, Herbert A.

1960-01-01

5

Cellular Precipitation at a 17-7 PH Stainless Steel Interphase Interface During Low-Temperature Nitridation  

NASA Astrophysics Data System (ADS)

Cellular precipitation of Cr-rich nitrides was observed at an austenite-ferrite interface in 17-7 PH stainless steel after low-temperature nitridation. Fine-scale lamellar rocksalt-structured nitride (MN1-x , M: randomly distributed Fe, Cr, and Al) was identified at the interfaces between austenite and ferrite by local-electrode atom-probe tomography and transmission electron microscopy. The small size and spacing of the nitride lamellae reflect the low mobility of substitutional atoms under the conditions of low-temperature nitridation. Nitrides of the same structure were formed within the ferrite grain as extremely small particles. The face-centered cubic nitride precipitates in the Bain orientation relationship with the ferrite.

Wang, Danqi; Ernst, Frank; Kahn, Harold; Heuer, Arthur H.

2014-04-01

6

Cellular Precipitation at a 17-7 PH Stainless Steel Interphase Interface During Low-Temperature Nitridation  

NASA Astrophysics Data System (ADS)

Cellular precipitation of Cr-rich nitrides was observed at an austenite-ferrite interface in 17-7 PH stainless steel after low-temperature nitridation. Fine-scale lamellar rocksalt-structured nitride (MN1- x , M: randomly distributed Fe, Cr, and Al) was identified at the interfaces between austenite and ferrite by local-electrode atom-probe tomography and transmission electron microscopy. The small size and spacing of the nitride lamellae reflect the low mobility of substitutional atoms under the conditions of low-temperature nitridation. Nitrides of the same structure were formed within the ferrite grain as extremely small particles. The face-centered cubic nitride precipitates in the Bain orientation relationship with the ferrite.

Wang, Danqi; Ernst, Frank; Kahn, Harold; Heuer, Arthur H.

2014-07-01

7

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

NASA Technical Reports Server (NTRS)

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.

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

1961-01-01

8

Irradiation effects on 17-7 PH stainless steel, A-201 carbon steel, and titanium-6-percent-aluminum-4-percent-vanadium alloy  

NASA Technical Reports Server (NTRS)

Irradiation effects on three materials from the NASA Plum Brook Reactor Surveillance Program were determined. An increase of 105 K in the nil-ductility temperature for A-201 steel was observed at a fluence of approximately 3.1 x 10 to the 18th power neutrons/sq cm (neutron energy E sub n greater than 1.0 MeV). Only minor changes in the mechanical properties of 17-7 PH stainless steel were observed up to a fluence of 2 x 10 to the 21st power neutrons/sq cm (E sub n greater than 1.0 MeV). The titanium-6-percent-aluminum-4-percent-vanadium alloy maintained its notch toughness up to a fluence of 1 x 10 to the 21st power neutrons/sq cm (E sub n greater than 1.0 MeV).

Hasse, R. A.; Hartley, C. B.

1972-01-01

9

EFFECT OF PRIOR CREEP ON SHORT-TIME MECHANICAL PROPERTIES OF 17-7PH STAINLESS STEEL (RH 950 CONDITION COMPARED TO TH 1050 CONDITION). Period Covered: January 1, 1958 to March 31, 1959  

Microsoft Academic Search

The effect of creep to 2% in 100 hours at temperatures from 600 to 900 ; deg F was determined on the tension, compression, and tension-impact properties ; of 17-7 PH stainless steel (RH 950 Cond.) at room temperature or the exposure ; temperature. A substantial loss in ductility was observed in room temperature ; tension tests. Material exposed to

J. V. Gluck; J. W. Freeman

1959-01-01

10

Stress Relaxation and Stiffness of 17-7PH Belleville Springs in a Stacked Configuration.  

National Technical Information Service (NTIS)

An investigation was performed to determine the effects of parallel stacking on the stiffness and stress relaxation of 17- 7PH Belleville springs. Parallel stacking refers to Belleville washers stacked with the concave side of all washers in the stack fac...

D. J. Chang G. L. Steckel

2003-01-01

11

Examination of the Excessive Retained Austenite on the Surface of a Section of 17-7 Precipitation Hardening Stainless Steel.  

National Technical Information Service (NTIS)

A 'mishap' section, and other selected sections made from 17-7 precipitation hardening stainless steel were metallurgically examined, and it was concluded that the unusually large amount of retained austenite, greater than 7%, measured on the surface appe...

G. E. Hicho W. J. Boettinger L. Swartzendruber T. R. Shives

1991-01-01

12

Stress-Corrosion Cracking in Martensitic PH Stainless Steels  

NASA Technical Reports Server (NTRS)

Precipitation-hardening alloys evaluated in marine environment tests. Report describes marine-environment stress-corrosion cracking (SCC) tests of three martensitic precipitation hardening (PH) stainless-steel alloys.

Humphries, T.; Nelson, E.

1984-01-01

13

SEMIAUSTENITIC PRECIPITATION-HARDENABLE STAINLESS STEELS  

Microsoft Academic Search

A summary is given of the classification, metallurgy, treatment, and ; properties of the semiaustenitic precipitatson-hardenable stainless steels: 17-7 ; PH, AM 350, AM 355, PH 15-7 Mo, AM 357, and AM 359. (auth);

Ludwigson

1961-01-01

14

Metallurgical Evaluation of 17-4 PH Stainless Steel Castings,  

National Technical Information Service (NTIS)

A metallurgical evaluation was conducted to determine if selected castings of 17-4 PH stainless steel used in head caps on missile weapon systems had been properly heat treated as required by SAE specification AMS-5355D. Optical metallographic analysis an...

G. E. Hicho J. H. Smith

1989-01-01

15

High temperature tensile behavior of a PH stainless steel  

Microsoft Academic Search

High temperature tensile deformation of 15-5 PH stainless steel in peak age and overaged conditions has been studied over the temperature range of 300 to 600°C and different strain rates. Dynamic recrystallization was the main softening mechanism when the alloy deformed at imposed temperature and strain rate region. The apparent activation energy was calculated as 284.8 and 323.1kJ\\/mol for peak

M. Aghaie-Khafri; A. Zargaran

2010-01-01

16

Hot deformation of 15-5 PH stainless steel  

Microsoft Academic Search

The hot deformation behavior of 15-5 PH stainless steel has been studied using hot compression tests over the temperature range of 900–1150°C and strain rates varying between 0.001 and 0.5s?1. The results showed that dynamic recrystallization is the main softening mechanism when the alloy deformed at imposed temperature and strain rate region. Strain rate sensitivity of the material was evaluated

M. Aghaie-Khafri; F. Adhami

2010-01-01

17

Production and aging of highly porous 17-4 PH stainless steel  

Microsoft Academic Search

This study describes production of highly porous 17-4 PH stainless steel for biomedical implant applications by space holder-sintering\\u000a technique. 17-4 PH stainless steel powders were mixed with space holder and then compacted. For designing pore properties,\\u000a both spherical and irregular shaped carbamide with different particle size ranges were used as space holder and removed by\\u000a water leaching. Porous 17-4 PH

Ilven Mutlu; Enver Oktay

18

Optimized postweld heat treatment procedures for 17-4 PH stainless steels  

Microsoft Academic Search

The postweld heat treatment (PWHT) procedures for 17-4 PH stainless steel weldments of matching chemistry was optimized vis-a-vis its microstructure prior to welding based on microstructural studies and room-temperature mechanical properties. The 17-4 PH stainless steel was welded in two different prior microstructural conditions (condition A and condition H 1150) and then postweld heat treated to condition H900 or condition

A. K. Bhaduri; S. Sujith; G. Srinivasan; T. P. S. Gill; S. L. Mannan

1995-01-01

19

50 CFR 17.7 - Raptor exemption.  

Code of Federal Regulations, 2010 CFR

...2009-10-01 2009-10-01 false Raptor exemption. 17.7 Section 17.7...Introduction and General Provisions § 17.7 Raptor exemption. (a) The prohibitions found...17.21 and 17.31 do not apply to any raptor [a live migratory bird of the Order...

2009-10-01

20

50 CFR 17.7 - Raptor exemption.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Raptor exemption. 17.7 Section 17.7...Introduction and General Provisions § 17.7 Raptor exemption. (a) The prohibitions found...17.21 and 17.31 do not apply to any raptor [a live migratory bird of the Order...

2010-10-01

21

COMPRESSIVE STRENGTH OF STAINLESS-STEEL SANDWICHES AT ELEVATED TEMPERATURES  

Microsoft Academic Search

Experimental results are presented from crippling tests of specimens in ; the temperature range from 80 to 1,200 deg F. The specimens included resistance-; welded 177 PH stainless-steel sandwiches with single-corrugated cores, type 301 ; stainless-steel sandwiches with doublecorrugated cores, and brazed 17-7 PH ; stainless-steel sandwiches with honeycomb cores. The experimental strengths are ; compared with predicted buckling and

E. E. Mathauser; R. A. Pride

1959-01-01

22

OBSERVATIONS ON CORROSION RESISTANCE OF HIGH STRENGTH STAINLESS STEELS FOR AIRCRAFT  

Microsoft Academic Search

Stainless steels of the precipitation hardening type are used ; extensively in airframe components. In this paper, compositions and properties ; of several of these alloys are described. The corrosion performances of the ; Armco 17-4 PH and 17-7 PH precipitation hardening alloys are compared with these ; of other hardenable stainless steels. The results of accelerated corrosion tests ;

J. Halbig; O. B. Ellis

1958-01-01

23

Effect of Applied Potentials on Environmental Cracking Behavior of 17-4 PH Stainless Steel Weldments  

Microsoft Academic Search

The effects of anodic, cathodic, and open-circuit potentials (OCP) on the environmental cracking behavior of 17% Cr-4% Ni (17-4 [UNS S17400]) precipitation-hardenable (PH) stainless steel (SS) welds subjected to different thermal treatments were studied. Sheets of 17-4 PH SS 1.5 mm thick and in solution-treated condition were full-penetration welded autogenously using the gas tungsten arc welding process (GTAW). Weldments were

K. S. Raja; K. P. Rao

1995-01-01

24

Pitting Behavior of Type 17-4 PH Stainless Steel Weldments  

Microsoft Academic Search

Electrochemical methods of measuring pitting potentials (E{sub pit}) were used to study the pitting resistance of type 17% Cr-4% Ni (17-4, UNS S17400) precipitation hardenable (PH) stainless steel (SS) weldments. The main objectives were to evaluate the pitting resistance of the base metal, the heat-affected zone (HAZ), and the weld metal portions of 17-4 PH SS welds welded autogenously using

K. S. Raja; K. P. Rao

1995-01-01

25

Metal Injection Molding of PH 13-8 Mo Stainless Steel  

Microsoft Academic Search

Powder metal injection molding has been used for fabrication of near net shape parts from a number of ferrous alloys including carbonyl steels and stainless steels in the 3XX series and PH 17-4. However, no work has been performed to-date on the metal injection molding of PH 13-8 Mo. Because of a special application, this alloy was injection molded and

Dianne Chong

1995-01-01

26

Weldability of 17-4 PH stainless steel in centrifugal compressor impeller applications  

Microsoft Academic Search

Weldability of 17-4 PH stainless steel for centrifugal compressor impeller was considered. Welding tests were carried out on the precipitation-hardened steel of the 17-4 PH type. Possibilities of joining centrifugal compressor impeller parts as important elements of turbo machines were considered. Two means of welding (111) and (114), as well as following heat treatment have been considered. The best results:

J. Nowacki

2004-01-01

27

Failure analysis of holding yokes made of investment cast 17-4 PH stainless steel  

Microsoft Academic Search

Holding yokes made of investment cast 17-4PH stainless steel were too soft (below 20HRC). Optical microscopy of the parts showed that there is a high fraction of retained austenite after oil quench due to high amount of molybdenum found in parts as an impurity. Subzero treatment in liquid nitrogen after solution heat treating was used to convert retained austenite to

Ahmad Reza Etemadi; Peiman Behjati; Armin Emami; Sayyed Majd-al-Din Motiei; Saeed Mirsaeedi

2011-01-01

28

Failure maps for rectangular 17-4PH stainless steel sandwiched foam panels  

Microsoft Academic Search

A new and innovative concept is proposed for designing lightweight fan blades for aircraft engines using commercially available 17-4PH precipitation hardened stainless steel. Rotating fan blades in aircraft engines experience a complex loading state consisting of combinations of centrifugal, distributed pressure and torsional loads. Theoretical failure plastic collapse maps, showing plots of the foam relative density versus face sheet thickness,

S. V. Raj; L. J. Ghosn

2008-01-01

29

SOLID-STATE DIFFUSION BONDING OF INCONEL ALLOY 718 TO 17-4 PH STAINLESS STEEL  

Microsoft Academic Search

Solid-state diffusion bonding of Inconel® alloy 718 to 17-4 PH® stainless steel was studied. Mechanical tests and metallographic examinations were used to evaluate the joint quality. The effect of bonding pressure on the joint integrity was assessed. In all joints, failure occurred nearly without plastic deformation. The thermal residual stress generated from cooling to room temperature was calculated by finite

Zhang Guoge; R. S. Chandel; H. P. Seow

2001-01-01

30

Investigation of hydrogen sulfide stress corrosion cracking of PH 13-8 Mo stainless steel  

Microsoft Academic Search

Slow displacement rate tensile tests were carried out in a saturated H2S solution to investigate the effect of hydrogen embrittlement on notched tensile strength (NTS) and fracture characteristics of aged PH 13-8 Mo stainless steel. Hydrogen diffusivity, permeation flux and apparent hydrogen solubility were determined by an electrochemical permeation method, and correlated with the inherent microstructure of the specimens. All

L. W. Tsay; M. Y. Chi; H. R. Chen; C. Chen

2006-01-01

31

Thermal Fatigue Behavior of Nimonic 80A and PH 15-7 Mo Stainless Steel.  

National Technical Information Service (NTIS)

The thermal fatigue behavior of Nimonic 80A and PH 15-7 Mo stainless steel was investigated. An automatic testing apparatus used in this work is described. Thermal stresses are generated by direct resistance heating and constraint of the specimen. Stresse...

E. Krempl H. Neuber

1965-01-01

32

Effect of Hydrogen on the Fracture Toughness of 17-4PH Stainless Steel.  

National Technical Information Service (NTIS)

Fracture toughness (K/sub c/) of 17-4 PH stainless steel decreased significantly with increased hydrogen test pressure for a variety of heat treatment conditions: solution annealed, underaged, peak-aged, and overaged. Minimum toughness (13 MPa sqrt m) was...

T. L. Capeletti

1976-01-01

33

Physical and mechanical properties of cast 17-4 PH stainless steel  

SciTech Connect

The physical and mechanical properties of an overaged 17-4 PH stainless steel casting have been examined. The tensile and compressive properties of cast 17-4 PH are only influenced to a slight degree by changing test temperature and strain rate. However, both the Charpy impact energy and dynamic fracture toughness exhibit a tough-to-brittle transition with decreasing temperature - this transition being related to a change in fracture mode from ductile, dimple to cleavage-like. Finally, although the overaged 17-4 PH casting had a relatively low room temperature Charpy impact energy when compared to wrought 17-4 PH, its fracture toughness was at least comparable to that of wrought 17-4 PH. This observation suggests that prior correlations between Charpy impact energies and fracture toughness, as derived from wrought materials, must be approached with caution when applied to cast alloys.

Rack, H. J.

1981-02-01

34

High-temperature fatigue crack growth behavior of 17-4 PH stainless steels  

Microsoft Academic Search

The fatigue crack growth (FCG) behavior was investigated for 17-4 PH stainless steels in three heat-treated conditions, i.e., unaged (condition A), peak-aged (condition H900), and overaged (condition H1150), at temperatures ranging from 300 C to\\u000a 500 C. The high-temperature fatigue crack growth rates (FCGRs) of condition H1150 were increased with an increase in temperature.\\u000a However, for conditions A and H900

Kuei-Chang Hsu; Chih-Kuang Lin

2004-01-01

35

Microstructural evolution in a 17-4 PH stainless steel after aging at 400 °C  

Microsoft Academic Search

The microstructure of 17-4 PH stainless steel at various stages of heat treatment, i.e., after solution heat treatment, tempering at 580 C, and long-term aging at 400 C, have been studied by atom probe field\\u000a ion microscopy (APFIM) and transmission electron microscopy (TEM). The solution-treated specimen consists largely of martensite\\u000a with a small fraction of ?-ferrite. No precipitates are present

M. Murayama; K. Hono; Y. Katayama

1999-01-01

36

Hydrogen assisted cracking of palladium modified PH 13-8 Mo stainless steel  

Microsoft Academic Search

We compare the hydrogen assisted cracking resistance of wrought PH 13-8 Mo stainless steel alloyed with 0.4 to 1.0 wt.% palladium to the conventional alloy when aged to yield strengths of 1170--1250 MPa. Pd is found both in solid solution in the martensitic phase and also in the form of randomly distributed, incoherent PdAl precipitates in the modified alloy. Interfacial

J. R. Scully; J. A. Van Den Avyle; M. J. Cieslak; C. R. Hills

1989-01-01

37

Growth of small fatigue cracks in PH 13-8 Mo stainless steel  

Microsoft Academic Search

The growth of small fatigue cracks in PH 13-8 Mo (H1050) stainless steel under constant amplitude loading at different mean\\u000a stresses (R=0.1 and ?1) under generally high cycle fatigue conditions was investigated. Small cracks were allowed to initiate naturally\\u000a at the root of a single edge notch specimen and were monitored using a surface replicating technique. It was found that

A. M. Patel; R. W. Neu; J. A. Pape

1999-01-01

38

Effects of ion implantation on friction and wear of stainless steels. [15-5PH  

Microsoft Academic Search

Friction and wear of 304, 15-5 PH and 440C stainless steels and of pure Fe are shown to be reduced by ion implantation of Ti and C. Mechanically polished samples were ion implanted to fluences of 2 x 10¹⁵ Ti\\/mm² (90 to 180 keV) and 2 x 10¹⁵ C\\/mm² (30 keV); the implantation profiles of the two elements extended to

L. E. Pope; F. G. Yost; D. M. Follstaedt; J. A. Knapp; S. T. Picraux

1982-01-01

39

Effect of hydrogen on the fracture toughness of 17-4 PH stainless steel  

Microsoft Academic Search

Fracture toughness (K\\/sub c\\/) of 17-4 PH stainless steel decreased significantly with increased hydrogen test pressure for a variety of heat treatment conditions: solution annealed, underaged, peak-aged, and overaged. Minimum toughness (13 MPa..sqrt..m) was obtained with peak-aged samples tested in 69.5-MPa hydrogen; toughness was maximum (100 MPa..sqrt..m) for samples tested in helium. Aging treatments increased the hardness from 28 R\\/sub

Capeletti

1976-01-01

40

A comparative study of the fretting fatigue behavior of 4340 steel and PH 13-8 Mo stainless steel  

Microsoft Academic Search

The fretting fatigue behavior of two high strength structural steels, PH 13-8 Mo stainless steel and quenched and tempered 4340 steel, is investigated. Both were heat treated to a similar hardness (43-44 HRC), comparable to the condition used in structural components. Both materials experienced significant reductions in fatigue strength due to fretting, with PH 13-8 Mo stainless steel exhibiting a

J. A. Pape; R. W. Neu

2007-01-01

41

Hot-cracking mechanism in COâ laser beam welds of dissimilar metals involving PH martensitic stainless steels  

Microsoft Academic Search

Autogenous COâ laser beam welds were made between Alloy HP 9-4-20 and both 15-5 PH and PH 13-8 Mo stainless steel. Small scale circular-patch test specimens revealed that the combination involving the Nb-bearing alloy, 15-5 PH, was far more crack susceptible than the combination involving the Nb-free alloy, PH 13-8 Mo. Analytical electron microscopy was used to identify an NbC\\/austenite

Cieslak

1987-01-01

42

PHYSICAL AND MECHANICAL PROPERTIES OF NINE COMMERCIAL PRECIPITATION HARDENABLE STAINLESS STEELS  

Microsoft Academic Search

ABS>The physical and mechanical properties of commercial precipitation-; hardenable stainless steels are presented. The steels covered include the ; martensitic types (Stainless W and 17⁻⁴ PH), the semiaustenitic types (17-7 ; PH, PH 15-7 Mo, AM 350, and AM 355), and the austenitic types (A-286, 17-10 P, ; and HNM). Roomand elevated-temperature tensile and compressive properties, ; stress-rupture and creep

D. A. Roberts; D. B. Roach; A. M. Hall

1959-01-01

43

Hydrogen embrittlement behavior of palladium modified PH 13-8 Mo stainless steel as a function of age hardening  

Microsoft Academic Search

The hydrogen embrittlement (HE) susceptibility of precipitation age hardened stainless steels (17-4 PH, PH 15-5, PH 13-8 Mo, and others) is well established in the literature. Susceptibility is a strong function of strength and hence lower aging temperatures produce alloys which are more prone to HE. Recently it was shown that uniformly distributed PdAl precipitates improve the HE resistance of

J. R. Scully; M. J. Cieslak; J. A. Van Den Avyle

1994-01-01

44

Surface laser alloying of 17-4PH stainless steel steam turbine blades  

NASA Astrophysics Data System (ADS)

As a known high-quality precipitation hardening stainless steel with high strength, high antifatigue, excellent corrosion resistance and good weldability, 17-4PH has been widely used to produce steam turbine blades. However, under the impact of high-speed steam and water droplets, the blades are prone to cavitation, which could lead to lower efficiency, shorter life time, and even accidents. In this article, the 17-4PH blade's surface was alloyed using a high power CO 2 laser. The microstructure and microhardness of hardened 17-4PH were tested by scanning electronic microscope (SEM), X-ray diffraction (XRD), energy disperse spectroscopy (EDS) and a microhardness tester. After laser alloying, the surface layer was denser and the grain refined, while the microhardness of the surface (average 610HV 0.2) was about one times higher than that of the substrate material (330HV 0.2). The friction coefficient of the laser-alloyed 17-4PH layer was much lower than that of the substrate.

Yao, Jianhua; Wang, Liang; Zhang, Qunli; Kong, Fanzhi; Lou, Chenghua; Chen, Zhijun

2008-09-01

45

The Structure and Properties of Diffusion Assisted Bonded Joints in 17-4 PH, Type 347, 15-5 PH and Nitronic 40 Stainless Steels  

NASA Technical Reports Server (NTRS)

Diffusion assisted bonds are formed in 17-4 PH, 15-5 PH, type 347 and Nitronic 40 stainless steels using electrodeposited copper as the bonding agent. The bonds are analyzed by conventional metallographic, electron microprobe analysis, and scanning electron microscopic techniques as well as Charpy V-notch impact tests at temperatures of 77 and 300 K. Results are discussed in terms of a postulated model for the bonding process.

Wigley, D. A.

1981-01-01

46

Post-irradiation characterization of PH13-8Mo martensitic stainless steel  

NASA Astrophysics Data System (ADS)

The irradiation response of PH13-8Mo stainless steel was measured up to 2.5 dpa at 200 and 300 °C irradiation temperatures. The PH13-8Mo, a martensitic precipitation-hardened steel, was produced by Hot Isostatic Pressing at 1030 °C. The fatigue tests (high cycle fatigue and fatigue crack propagation) showed a test temperature dependency but no irradiation effects. Tensile tests showed irradiation hardening (yield stress increase) of approximately 37% for 200 °C irradiated material tested at 60 °C and approximately 32% for 300 °C irradiated material tested at 60 °C. This contradicts the shift in reference temperature ( T0) measured in toughness tests (Master Curve approach), where the ? T0 for 300 °C irradiated is approximately 170 °C and the ? T0 for the 200 °C irradiated is approximately 160 °C. This means that the irradiation hardening of PH13-8Mo steel is not suitable to predict the shift in the reference temperature for the Master Curve approach.

Jong, M.; Schmalz, F.; Rensman, J. W.; Luzginova, N. V.; Wouters, O.; Hegeman, J. B. J.; van der Laan, J. G.

2011-10-01

47

Failure Maps for Rectangular 17-4PH Stainless Steel Sandwiched Foam Panels  

NASA Technical Reports Server (NTRS)

A new and innovative concept is proposed for designing lightweight fan blades for aircraft engines using commercially available 17-4PH precipitation hardened stainless steel. Rotating fan blades in aircraft engines experience a complex loading state consisting of combinations of centrifugal, distributed pressure and torsional loads. Theoretical failure plastic collapse maps, showing plots of the foam relative density versus face sheet thickness, t, normalized by the fan blade span length, L, have been generated for rectangular 17-4PH sandwiched foam panels under these three loading modes assuming three failure plastic collapse modes. These maps show that the 17-4PH sandwiched foam panels can fail by either the yielding of the face sheets, yielding of the foam core or wrinkling of the face sheets depending on foam relative density, the magnitude of t/L and the loading mode. The design envelop of a generic fan blade is superimposed on the maps to provide valuable insights on the probable failure modes in a sandwiched foam fan blade.

Raj, S. V.; Ghosn, L. J.

2007-01-01

48

Mechanical Properties of 17-4PH Stainless Steel Foam Panels  

NASA Technical Reports Server (NTRS)

Rectangular 17-4PH stainless steel sandwiched foam panels were fabricated using a commercial manufacturing technique by brazing two sheets to a foam core. Microstructural observations and ultrasonic nondestructive evaluation of the panels revealed large variations in the quality of the brazed areas from one panel to the next as well as within the same panel. Shear tests conducted on specimens machined from the panels exhibited failures either in the brazed region or in the foam core for the poorly brazed and well-brazed samples, respectively. Compression tests were conducted on the foam cores to evaluate their elastic and plastic deformation behavior. These data were compared with published data on polymeric and metallic foams, and with theoretical deformation models proposed for open cell foams.

Raj, S. V.; Ghosn, L. J.; Lerch, B. a.; Hebsur, M.; Cosgriff, L. M.; Fedor, J.

2007-01-01

49

Failure analysis of a set of stainless steel disc springs  

Microsoft Academic Search

This paper analyses the failure of a set of disc springs, broken in service in a seawater environment and at high temperature. These components were manufactured using a 17-7 PH, UNS S17700 precipitation hardening stainless steel. The morphology of the cracks was intergranular and it was attributed to hydrogen embrittlement due to the hydrogen that entered into the steel during

G. Atxaga; A. Pelayo; A. M. Irisarri

2006-01-01

50

Electroless nickel plating on stainless steels and aluminum  

NASA Technical Reports Server (NTRS)

Procedures for applying an adherent electroless nickel plating on 303 SE, 304, and 17-7 PH stainless steels, and 7075 aluminum alloy was developed. When heat treated, the electroless nickel plating provides a hard surface coating on a high strength, corrosion resistant substrate.

1966-01-01

51

Effect of postweld heat treatment on weld metal impact toughness of a semi-austenitic PH stainless steel  

Microsoft Academic Search

Semi-austenitic precipitation hardened PH stainless steel plates, PH 15-7 Mo (Cu), 6.14 mm thick were autogenously welded using the electron beam welding (EBW) and plasma arc welding (PAW) processes. Impact toughness studies using Charpy V-notch samples (V-notch at the center of the weld metal) showed that EB welds had higher impact toughness than PA welds in various identical postweld heat

N. Sivaramakrishnan; K. S. Raja; K. Prasad Rao

1994-01-01

52

A Fracture Mechanics and Fractographic Study of Fatigue Crack Propagation Resistance in 17-4 PH Stainless Steels.  

National Technical Information Service (NTIS)

A determination of fatigue-crack propagation resistance in heat-treated samples of 17-4 PH stainless steel has been made, together with correlative microscopic observations via electron fractography. Two rolled plates of 1/2-in. thickness were investigate...

T. W. Crooker D. F. Hasson G. R. Yoder

1975-01-01

53

Mitigation of FOD and Corrosion Fatigue Damage in 17-4 PH Stainless Steel Compressor Blades with Surface Treatment  

Microsoft Academic Search

Compressor blades of a military aircraft turbine engine made of 17 -4 PH stainless steel have been reported to have blade edge foreign object damage (FOD), corrosion pitting, and erosion damage that reduce fatigue life. This paper reports the findings of a comprehensive investigation of the effect of residual compressive stresses, imparted by various surface treatments, to improve leading edge

Paul S. Prevéy; N. Jayaraman; Ravi Ravindranath

54

LOW PLASTICITY BURNISHING (LPB) TREATMENT TO MITIGATE FOD AND CORROSION FATIGUE DAMAGE IN 17-4 PH STAINLESS STEEL  

Microsoft Academic Search

The benefits of applying low plasticity burnishing (LPB) to 17-4PH Stainless Steel (H1100) on both the fatigue and corrosion fatigue performance were compared with the shot peened (SP) and low stress ground (LSG) conditions. LPB treatment dramatically improved both the high cycle fatigue (HCF) performance and fatigue strength. The baseline LSG and SP treatments showed similar fatigue strengths of about

Paul S. Prevéy; N. Jayaraman

55

Low Plasticity Burnishing (LPB) Treatment to Mitigate FOD and Corrosion Fatigue Damage in 17-4 PH Stainless Steel.  

National Technical Information Service (NTIS)

The benefits of applying low plasticity burnishing (LPB) to 17-4PH Stainless Steel (H1100) on both the fatigue and corrosion fatigue performance were compared with the shot peened (SP) and low stress ground (LSG) conditions. LPB treatment dramatically imp...

P. S. Prevey, N. Jayaraman, R. Ravindranath

2003-01-01

56

Heat treatment of investment cast PH 13-8 Mo stainless steel: Part II. Isothermal aging kinetics  

Microsoft Academic Search

The hardening response of investment cast PH 13-8 Mo stainless steel has been evaluated by hardness measurements following aging in the temperature range normally specified for this alloy (510 °C to 593 °C). A new relationship between fraction transformed and hardness was developed, and analysis of the data in terms of the kinetics of precipitation, in a manner similar to

C. V. Robino; M. J. Cieslak; P. W. Hochanadel; G. R. Edwards

1994-01-01

57

Weldability, microstructure and properties of precipitation strenghtened martensitic stainless steels. [Custom 450; PH 13-8 Mo  

Microsoft Academic Search

We have investigated the influence of welding on the mechanical properties and corrosion resistance of two precipitation strengthened martensitic stainless steels: Custom 450 and PH 13-8 Mo. The two alloys exhibited very good weld cracking resistance, although the formation of a low melting NbC eutectic constituent did cause some solidification cracking in Custom 450. The effects of aging temperature on

J. A. Brooks; W. R. Cieslak; W. M. Jr. Garrison

1986-01-01

58

Effect of implantation species on the tribological response of stainless steel surfaces. [SS15-5PH  

Microsoft Academic Search

The friction and wear properties of 304 and 15-5 PH stainless steels which were ion implanted with P and with P plus C have been examined and are compared with the properties of the same steels implanted with N and with Ti plus C. While benefits are obtained with the P and the P plus C implantation treatments, the N

L. E. Pope; S. T. Picraux; D. M. Follstaedt; J. A. Knapp; F. G. Yost

1984-01-01

59

On the correlation between fracture toughness and precipitation hardening heat treatments in 15-5PH Stainless Steel  

Microsoft Academic Search

In this study, the fracture toughness, Kq, and the yield strength of precipitation heat-treated Stainless Steel 15-5 PH was determined. Thirty six cylindrical tensile bars and eighteen compact tension C(T) specimens were tested. It was found that the high tolerance for solution heat treatment decreases the Kq value significantly, while the yield strength remains virtually unaltered.

M. Abdelshehid; K. Mahmodieh; K. Mori; L. Chen; P. Stoyanov; D. Davlantes; J. Foyos; J. Ogren; R CLARKJR; O. S. Es-Said

2007-01-01

60

Alloy Shrinkage Factors for the Investment Casting of 17-4PH Stainless Steel Parts  

NASA Astrophysics Data System (ADS)

In this study, alloy shrinkage factors were obtained for the investment casting of 17-4PH stainless steel parts. For the investment casting process, unfilled wax and fused silica with a zircon prime coat were used for patterns and shell molds, respectively. The dimensions of the die tooling, wax pattern, and casting were measured using a coordinate measurement machine (CMM). For all the properties, the experimental data available in the literature did not cover the entire temperature range necessary for process simulation. A comparison between the predicted material property data and measured property data is made. It was found that most material properties were accurately predicted over most of the temperature range of the process. Several assumptions were made, in order to obtain a complete set of mechanical property data at high temperatures. Thermal expansion measurements for the 17-4PH alloy were conducted during heating and cooling. As a function of temperature, the thermal expansion for both the alloy and shell mold materials showed a different evolution on heating and cooling. Thus, one generic simulation was performed with thermal expansion obtained on heating, and another one was performed with thermal expansion obtained on cooling. The alloy dimensions were obtained from the numerical simulation results of the solidification, heat transfer, and deformation phenomena. As compared with experimental results, the numerical simulation results for the shrinkage factors were slightly overpredicted.

Sabau, Adrian S.; Porter, Wallace D.

2008-04-01

61

Effect of applied potentials on environmental cracking behavior of 17-4 PH stainless steel weldments  

SciTech Connect

The effects of anodic, cathodic, and open-circuit potentials (OCP) on the environmental cracking behavior of 17% Cr-4% Ni (17-4 [UNS S17400]) precipitation-hardenable (PH) stainless steel (SS) welds subjected to different thermal treatments were studied. Sheets of 17-4 PH SS 1.5 mm thick and in solution-treated condition were full-penetration welded autogenously using the gas tungsten arc welding process (GTAW). Weldments were given one of two postweld heat treatments: direct aging and solution treatment + aging. Samples were aged at 480 C for 1 h, 510 C for 4 h, and 600 C for 4 h. Environmental cracking tests were conducted using U-bend samples. Samples were tested in 3.5% sodium chloride (NaCl) solution (pH = 2.0) under various applied potentials. The failure time at each potential was taken as the criterion for cracking resistance of the samples. At OCP and at anodic potentials, cracking was found to occur by an active path dissolution mechanism in the heat-affected zone (HAZ). Although the weld metal hardness was more than that of the HAZ, no cracking took place in the weld metal. Solution treating the welds improved their cracking resistance. In contrast, failure occurred within the weld metal at applied cathodic potentials. Therefore, the hardness criterion (the harder the structure, the higher the susceptibility to cracking) was found to be applicable under applied cathodic potentials. The hardest structure obtained by peak aging showed the least cracking resistance under these potentials. To increase the cracking resistance of weld metals under cathodic potentials, solution treating followed by overaging (at 600 C for 4 h) was found to be the best method. However, the same treatment was found to be highly detrimental under anodic and OCP conditions.

Raja, K.S.; Rao, K.P. [Indian Inst. of Tech., Madras (India). Dept. of Metallurgical Engineering

1995-07-01

62

Dry sliding wear in injection molded 17-4 PH stainless steel powder with nickel boride additions  

Microsoft Academic Search

Dry sliding wear behavior of injection molded 17-4 PH stainless steel powder with nickel boride additions has been studied on a pin-on-disc wear tester using an alloy steel pin and disc of hardness 63 HRC. The PIM alloys in the as sintered as well as in the precipitate-hardened conditions were investigated for their wear behavior. Wear rate was found to

H. Özkan Gülsoy

2007-01-01

63

The influence of palladium on the hydrogen-assisted cracking resistance of PH 13-8 Mo stainless steel  

Microsoft Academic Search

We compare the hydrogen-assisted cracking resistance of wrought PH 13-8 Mo stainless steel alloyed with 0.4 to 1.0 wt pct\\u000a palladium to the conventional alloy when aged to yield strengths of 1170 to 1250 MPa. Intergranular hydrogen cracking is suppressed\\u000a with Pd in both static load and constant extension rate tests conducted with electrochemical hydrogen charging. These results\\u000a are analyzed

J. R. Scully; J. A. Van Den Avyle; M. J. Cieslak; A. D. Romig; C. R. Hills

1991-01-01

64

Heat treatment of investment cast PH 13-8 Mo stainless steel: Part II. Isothermal aging kinetics  

Microsoft Academic Search

The hardening response of investment cast PH 13-8 Mo stainless steel has been evaluated by hardness measurements following\\u000a aging in the temperature range normally specified for this alloy (510 ?C to 593 ?C). A new relationship between fraction transformed\\u000a and hardness was developed, and analysis of the data in terms of the kinetics of precipitation, in a manner similar to

C. V. Robino; M. J. Cieslak; P. W. Hochanadel; G. R. Edwards

1994-01-01

65

The influence of palladium on the hydrogen-assisted cracking resistance of PH 13-8 Mo stainless steel  

Microsoft Academic Search

We compare the hydrogen-assisted cracking resistance of wrought PH 13-8 Mo stainless steel alloyed with 0.4 to 1.0 wt pct palladium to the conventional alloy when aged to yield strengths of 1170 to 1250 MPa. Intergranular hydrogen cracking is suppressed with Pd in both static load and constant extension rate tests conducted with electrochemical hydrogen charging. These results are analyzed

J. R. Scully; J. A. van den Avyle; M. J. Cieslak; A. D. Romig; C. R. Hills

1991-01-01

66

The corrosion and corrosion–wear behaviour of plasma nitrided 17-4PH precipitation hardening stainless steel  

Microsoft Academic Search

Plasma surface nitriding of 17-4 PH martensitic precipitation hardening stainless steels was conducted at 350 °C, 420 °C and 500 °C for 10 h using a DC plasma nitriding unit, and the surface properties of the plasma surface engineered samples were systematically evaluated. Experimental results have shown that the surface properties of the plasma nitrided layers in terms of hardness, wear resistance, corrosion behaviour

M. Esfandiari; H. Dong

2007-01-01

67

The microstructure and properties of 17-4PH martensitic precipitation hardening stainless steel modified by plasma nitrocarburizing  

Microsoft Academic Search

17-4PH martensitic precipitation hardening stainless steel was plasma nitrocarburized at 430°C and 460°C for 8h. The nitrocarburized layers were characterized by optical microscope, scanning electron microscope, X-ray diffractometer, microhardness tests, pin-on-disc tribometer and the anodic polarization method in a 3.5% NaCl solution. The results show that the microstructure of plasma nitrocarburized layer is characterized by a compound layer with no

R. L. Liu; M. F. Yan

2010-01-01

68

Heat treatment of investment cast PH 13-8 Mo stainless steel: Part I. Mechanical properties and microstructure  

Microsoft Academic Search

The microstructure of investment cast PH 13-8 Mo stainless steel heat-treated to various conditions was studied using light\\u000a and electron microscopy, electron probe microanalysis, and M?ssbauer spectroscopy. The mechanical properties were investigated\\u000a by using uniaxial tensile testing, hardness testing, and Charpy impact testing. The?-NiAl strengthening precipitates, though detectable by electron diffraction, were difficult to resolve by transmission electron\\u000a microscopy (TEM)

P. W. Hochanadel; G. R. Edwards; C. V. Robino; M. J. Cieslak

1994-01-01

69

Heat treatment of investment cast PH 13-8 Mo stainless steel: Part I. Mechanical properties and microstructure  

Microsoft Academic Search

The microstructure of investment cast PH 13-8 Mo stainless steel heat-treated to various conditions was studied using light and electron microscopy, electron probe microanalysis, and Mössbauer spectroscopy. The mechanical properties were investigated by using uniaxial tensile testing, hardness testing, and Charpy impact testing. The Beta-NiAl strengthening precipitates, though detectable by electron diffraction, were difficult to resolve by transmission electron microscopy

P. W. Hochanadel; G. R. Edwards; C. V. Robino; M. J. Cieslak

1994-01-01

70

Water Droplet Erosion Behavior of High-Power Diode Laser Treated 17Cr4Ni PH Stainless Steel  

NASA Astrophysics Data System (ADS)

This article deals with water droplet erosion (WDE) behavior of high-power diode laser (HPDL) treated 17Cr4Ni PH stainless steel. After HPDL treatment, the water droplet erosion resistance (WDER) of 17Cr4Ni PH stainless steel has not improved. The main reason is the surface hardness, which has not improved after HPDL treatment though the microstructure has become much finer. On the other hand, precipitation hardening of the alloy at 490°C for 3 h has resulted in improved WDER more than twice. This is because of its increased microhardness and improved modified ultimate resilience (MUR), and formation of fine grained microstructure. The WDER has been correlated with MUR, a single mechanical property, based upon microhardness, ultimate tensile strength, and Young's modulus. WDERs of HPDL treated, untreated, and precipitation hardened 17Cr4Ni PH stainless steel samples were determined using a WDE test facility as per ASTM G73-1978. The WDE damage mechanism, compared on the basis of MUR and scanning electron micrographs, is discussed and reported in this article.

Mann, B. S.

2014-05-01

71

Effect of postweld heat treatment on weld metal impact toughness of a semi-austenitic PH stainless steel  

SciTech Connect

Semi-austenitic precipitation hardened PH stainless steel plates, PH 15-7 Mo (Cu), 6.14 mm thick were autogenously welded using the electron beam welding (EBW) and plasma arc welding (PAW) processes. Impact toughness studies using Charpy V-notch samples (V-notch at the center of the weld metal) showed that EB welds had higher impact toughness than PA welds in various identical postweld heat treated (PWHT) conditions. Based on hardness and impact toughness values, the optimal postweld heat treated conditions are recommended. The effect of retained austenite, carbides and delta ferrite on impact toughness of the welds are discussed.

Sivaramakrishnan, N.; Raja, K.S.; Prasad Rao, K. (Indian Inst. of Tech., Madras (India). Dept. of Metallurgical Engineering)

1994-08-01

72

Stress corrosion cracking behaviour of precipitation hardened stainless steels in high purity water environments  

Microsoft Academic Search

The susceptibility of 17-4PH and 17-7PH stainless steels to stress corrosion cracking (SCC) is examined in the present investigation. The specimens were tested in the presence of NaCl and NaOH (20%) at 908C and various pH values. The evaluations were carried out using the CERT test, at a speed of 10-6s-1, supplemented by anodic polarisation and electrochemical noise analysis. The

C. Gaona-Tiburcio; F. Almeraya-Calderón; A. Martínez-Villafañe; R. Bautista-Margulis

2001-01-01

73

Effects of the Process Parameters on the Microstructure and Properties of Nitrided 17-4PH Stainless Steel  

NASA Astrophysics Data System (ADS)

The effects of process parameters on the microstructure, microhardness, and dry-sliding wear behavior of plasma nitrided 17-4PH stainless steel were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and wear testing. The results show that a wear-resistant nitrided layer was formed on the surface of direct current plasma nitrided 17-4PH martensitic stainless steel. The microstructure and thickness of the nitrided layer is dependent on the treatment temperature rather than process pressure. XRD indicated that a single ? N phase was formed during nitriding at 623 K (350 °C). When the temperature increased, the ? N phase disappeared and CrN transformed in the nitrided layer. The hardness measurement demonstrated that the hardness of the stainless substrate steel increased from 320 HV0.1 in the untreated condition increasing to about 1275HV0.1 after nitriding 623 K (350 °C)/600 pa/4 hours. The extremely high values of the microhardness achieved by the great misfit-induced stress fields associated with the plenty of dislocation group and stacking fault. Dry-sliding wear resistance was improved by DC plasma nitriding. The best wear-resistance performance of a nitrided sample was obtained after nitriding at 673 K (350 °C), when the single ? N-phase was produced and there were no CrN precipitates in the nitrided layer.

Wang, Jun; Lin, Yuanhua; Zeng, Dezhi; Yan, Jing; Fan, Hongyuan

2013-04-01

74

Hydrogen embrittlement of PH 13-8 Mo stainless steel-the effect of surface condition  

Microsoft Academic Search

The susceptibility of precipitation hardening 13-8 Mo stainless steel to hydrogen embrittlement (HE) was measured by both post hydrogen charging tensile tests and by time to failure tests while being subjected to hydrogen charging and a static stress below the yield stress. In the former, it was found that the ductility was decreased substantially after only 30 min charging time.

G. T. Murray; H. H. Honegger; T. Mousel

1984-01-01

75

TENSILE PROPERTIES OF FIVE LOW-ALLOY AND STAINLESS STEELS UNDER HIGH HEATING-RATE AND CONSTANT-TEMPERATURE CONDITIONS  

Microsoft Academic Search

High-heating-rate results were obtained for three lowalloy steels: 4340 ; (400 deg F temper), 4130 (800 deg F temper), and 4130 (1050 deg F temper) and two ; stainless steels: 17-7 PH (TH 1050) and 410 (700 deg F temper). Stress levels ; ranging from 10 to 125 ksi and heating rates varying from 40 to 2000 deg F\\/sec ;

W. W. Gerberich; H. E. Martens; R. A. Boundy

1962-01-01

76

TUNGSTEN-ARC WELDING OF 0.002IN. AND 0.005IN. STAINLESS STEEL AND TITANIUM  

Microsoft Academic Search

The cover of The Welding Journal is 0.005 in. thick. That is just right ; for a magazine cover but pretty slim from the staadpoint of welding the same ; thickness of 17--7 PH stainless-steel sheet. To complicate matters, this weld ; must be made without the use of a filler rod because of aerodynamic requirements. ; In addition, the

J. C. Collins; S. P. Jenkins

1958-01-01

77

Effects of Temperature on Microstructure and Wear of Salt Bath Nitrided 17-4PH Stainless Steel  

NASA Astrophysics Data System (ADS)

Salt bath nitriding of 17-4 PH martensitic precipitation hardening stainless steels was conducted at 610, 630, and 650 °C for 2 h using a complex salt bath heat-treatment, and the properties of the nitrided surface were systematically evaluated. Experimental results revealed that the microstructure and phase constituents of the nitrided surface alloy are highly process condition dependent. When 17-4PH stainless steel was subjected to complex salt bathing nitriding, the main phase of the nitrided layer was expanded martensite (?'), expanded austenite (?N), CrN, Fe4N, and (Fe,Cr) x O y . In the sample nitrided above 610 °C, the expanded martensite transformed into expanded austenite. But in the sample nitrided at 650 °C, the expanded austenite decomposed into ?N and CrN. The decomposed ?N then disassembled into CrN and alpha again. The nitrided layer depth thickened intensively with the increasing nitriding temperature. The activation energy of nitriding in this salt bath was 125 ± 5 kJ/mol.

Wang, Jun; Lin, Yuanhua; Fan, Hongyuan; Zeng, Dezhi; Peng, Qian; Shen, Baoluo

2012-08-01

78

43 CFR 17.7 - Procedure for effecting compliance.  

Code of Federal Regulations, 2013 CFR

... NONDISCRIMINATION IN FEDERALLY ASSISTED PROGRAMS OF THE DEPARTMENT OF THE INTERIOR Nondiscrimination on the Basis of Race, Color, or National Origin § 17.7 Procedure for effecting compliance. (a) General. If there appears to...

2013-10-01

79

Sliding wear behaviour of a liquid nitrocarburised precipitation-hardening (PH) stainless steel  

Microsoft Academic Search

A precipitation-hardening stainless steel, of commercial trade name CORRAX, similar to DIN X3CrNiMoAl 13-8-2 grade steel (W.Nr. 1.4534) has been subjected to liquid nitrocarburising in cyanide salt bath to enhance its wear behavior. The wear resistance was evaluated using a pin-on-disk wear testing method with a tungsten carbide counterface against three different steel conditions: nitrocarburised, age-hardened (aged) and solution treated

G Pantazopoulos; T Papazoglou; P Psyllaki; G Sfantos; S Antoniou; K Papadimitriou; J Sideris

2004-01-01

80

Use of the double-loop reactivation test to measure sensitization in aged and welded pH 13-8 Mo martensitic stainless steel  

Microsoft Academic Search

Electrochemical potentiokinetic reactivation (EPR) testing provides quantitative detection of small degrees of sensitization. We have used double-loop (DL-EPR) testing, a method which has been characterized for use on austenitic stainless steels, to measure sensitization resulting from aging or from welding of PH 13-8 Mo martensitic stainless steel. Aging at either 500°C or 620°C results in an increase of the reactivation

W. R. Cieslak; M. J. Cieslak; C. R. Hills

1987-01-01

81

Hydrogen embrittlement of stainless steels by lithium hydride  

Microsoft Academic Search

Tests were made on 304L and 17-7 PH stainless steels in contact with LiH powder. Reduction in area relative to ductility in air decreased for both alloys. It was essential that the LiH be baked in contact with the alloys for the ductility loss to be observed; thermodynamic and kinetic evidence indicated that the LiH was reacting with surface oxides

Anthony W. Thompson

1973-01-01

82

Hydrogen embrittlement of stainless steels by lithium hydride  

Microsoft Academic Search

Tests were made on 304L and 17-7 PH stainless steels in contact with LiH powder. Reduction in area relative to ductility in\\u000a air decreased for both alloys. It was essential that the LiH be baked in contact with the alloys for the ductility loss to\\u000a be observed; thermodynamic and kinetic evidence indicated that the LiH was reacting with surface oxides

Anthony W. Thompson

1973-01-01

83

Hydrogen embrittlement of PH 13-8 Mo stainless steel-the effect of surface condition  

SciTech Connect

The susceptibility of precipitation hardening 13-8 Mo stainless steel to hydrogen embrittlement (HE) was measured by both post hydrogen charging tensile tests and by time to failure tests while being subjected to hydrogen charging and a static stress below the yield stress. In the former, it was found that the ductility was decreased substantially after only 30 min charging time. The strength was markedly reduced after 2 h charging time. In the delayed failure tests, it was found that a localized cold worked surface condition promoted crack formation.

Murray, G.T.; Honegger, H.H.; Mousel, T.

1984-04-01

84

The spinodal decomposition in 17-4PH stainless steel subjected to long-term aging at 350 deg. C  

SciTech Connect

The influence of aging time on the microstructure evolution of 17-4 PH martensitic stainless steel was studied by transmission electron microscopy (TEM). Results showed that the martensite decomposed by a spinodal decomposition mechanism after the alloy was subjected to long-term aging at 350 deg. C. The fine scale spinodal decomposition of {alpha}-ferrite brought about a Cr-enriched bright stripe and a Fe-enriched dark stripe, i.e., {alpha}' and {alpha} phases, separately, which were perpendicular to the grain boundary. The spinodal decomposition started at the grain boundary. Then with prolonged aging time, the decomposition microstructure expanded from the grain boundary to interior. The wavelength of the spinodally decomposed microstructure changed little with extended aging time.

Wang Jun [School of Manufacturing Science and Engineering, Sichuan University, Chengdu, 610065 (China) and National Key Laboratory for Nuclear Fuel and Materials, Nuclear Power Institute of China, P.O. Box 436, Chengdu, 610041 (China)], E-mail: srwangjun@163.com; Zou Hong; Li Cong; Qiu Shaoyu [National Key Laboratory for Nuclear Fuel and Materials, Nuclear Power Institute of China, P.O. Box 436, Chengdu, 610041 (China); Shen Baoluo [School of Manufacturing Science and Engineering, Sichuan University, Chengdu, 610065 (China)

2008-05-15

85

Heat treatment of investment cast PH 13-8 Mo stainless steel: Part II. Isothermal aging kinetics  

NASA Astrophysics Data System (ADS)

The hardening response of investment cast PH 13-8 Mo stainless steel has been evaluated by hardness measurements following aging in the temperature range normally specified for this alloy (510 °C to 593 °C). A new relationship between fraction transformed and hardness was developed, and analysis of the data in terms of the kinetics of precipitation, in a manner similar to that frequently applied to other precipitation-hardenable martensitic steels, yielded low time exponents and a low value for the apparent activation energy. The values of the time exponents were 0.49, 0.37, 0.56, and 0.53 at 510 °C, 538 °C, 566 °C, and 593 °C, respectively, and that for the apparent activation energy was 139 kJ/mole. As has been proposed for other maraging type steels, these estimates suggest that ?-NiAl precipitates along or near dislocations and that growth of the precipitates is dominated by dislocation pipe diffusion. However, these predictions were neither supported nor refuted by transmission electron microscopy (TEM) because of difficulties in imaging the ?-NiAl precipitates at the aging times and temperatures used. Further, analysis of the data using the formalism of Wert and Zener for the growth of precipitates with interfering diffusion fields indicated that the estimates of fraction transformed from hardness data are not fully appropriate for maraging type steels. Consideration of the nature of the Avrami analysis and the electron microscopy results suggests that other phenomena, including dislocation recovery and reversion of martensite to austenite, occur at rates sufficient to convolute the Avrami analysis. It is further suggested that these results cast doubt on the fundamental implications of previous analyses of precipitation kinetics in age-hardening martensitic steels. Although the Avrami analysis was found not to provide a tenable description of the precipitation kinetics, it does provide a reasonable methodology for portrayal of the hardening response of PH 13-8 Mo stainless steel.

Robino, C. V.; Cieslak, M. J.; Hochanadel, P. W.; Edwards, G. R.

1994-04-01

86

Infrared brazing of Ti–6Al–4V and 17-4 PH stainless steel with (Ni)\\/Cr barrier layer(s)  

Microsoft Academic Search

Ti–6Al–4V and 17-4PH stainless steel (17-4PH SS) with (Ni)\\/Cr barrier layer(s) were infrared vacuum brazed using two silver-based braze alloys, 72Ag–28Cu and 63Ag–35.25Cu–1.75Ti (wt.%), respectively. Both Cr (15?m) and Ni (2?m)\\/Cr (15?m) coated 17-4PH SS plates were evaluated in the study. Introducing (Ni)\\/Cr barrier layer(s) can effectively inhibit the interfacial reaction between the 17-4PH SS and the molten braze during

R. K. Shiue; S. K. Wu; J. Y. Shiue

2008-01-01

87

Solution quenched structure of wrought PH 13–8 Mo stainless steel  

Microsoft Academic Search

The solution-quenched structure of wrought PH13-8Mo steel was investigated by transmission electron microscope (TEM) and small-angle neutron scattering (SANS). Retained austenite and primary carbide were observed in the TEM. SANS measurements indicated microstructural inhomogeneities, comprising carbides and atom-clusters of elements having small scattering length, such as, Al, Si, S and P.

J. Mittra; G. K. Dey; D. Sen; A. K. Patra; S. Mazumder; P. K. De

2004-01-01

88

45 CFR 17.7 - Retractions or corrections.  

Code of Federal Regulations, 2013 CFR

... RELEASE OF ADVERSE INFORMATION TO NEWS MEDIA § 17.7 Retractions or corrections...correction in the same manner to all of the media outlets that received the original...correction in the same manner to all of the media outlets that received the original...

2013-10-01

89

Axial-Load Fatigue Properties of PH 15-7 Mo Stainless Steel in Condition TH 1050 at Ambient Temperature and 500 Degrees F.  

National Technical Information Service (NTIS)

Axial-load fatigue tests were conducted on notched and unnotched sheet specimens of PH 15-7 Mo stainless steel in Condition TH 1050. Fatigue lives at three mean stresses at ambient temperature (approx. 80 deg F) and at 500 deg F were determined throughout...

W. Illg C. B. Castle

1964-01-01

90

Ultrasonic Measurement of Elastic Moduli of 17-4 pH Stainless Steel and Uranium -2 Molybdenum from -40 exp 0 C to 800 exp 0 C.  

National Technical Information Service (NTIS)

Young's Modulus, shear modulus, and Poisson's ratio for 17-4 pH stainless steel and uranium -2 molybdenum are calculated from ultrasonic longitudinal and shear velocities determined from -40 exp 0 C to 800 exp 0 C. The ultrasonic velocities were determine...

J. H. Gieske

1980-01-01

91

Mechanism of austenitic transformation in the martensitic stainless steel of type PH 15-5  

Microsoft Academic Search

By dilatometric analysis and TEM experiments, the martensite (M)+austenite (y) transformation and the formation of the precipitates in PH 15-5 alloy were studied between 20 and 1050°C, using heating rate (Rh) , and cooling rate &) = 300OC.h-1. For this heating rate the M+ y transformation develops in two steps. Detailed analysis of the diffusion processes controlling the two stages

H. R. HABIBI BAJGUIRANI

1994-01-01

92

Effect of pH and oxygen on stress corrosion cracking of stainless steel in reactor moderator service.  

National Technical Information Service (NTIS)

Intergranular cracking of Type 304 stainless steel outlet nozzles in reactor moderator service prompted a broad program of laboratory studies to determine the cause of the failures. It was demonstrated that sensitized and pickled Type 304 stainless steel ...

S. P. Rideout

1964-01-01

93

The influence of palladium on the hydrogen-assisted cracking resistance of PH 13-8 Mo stainless steel  

NASA Astrophysics Data System (ADS)

We compare the hydrogen-assisted cracking resistance of wrought PH 13-8 Mo stainless steel alloyed with 0.4 to 1.0 wt pct palladium to the conventional alloy when aged to yield strengths of 1170 to 1250 MPa. Intergranular hydrogen cracking is suppressed with Pd in both static load and constant extension rate tests conducted with electrochemical hydrogen charging. These results are analyzed to elucidate the role of Pd in suppressing intergranular cracking. Palladium is found both in substitutional solid solution in the martensitic phase and also in the form of randomly distributed PdAl precipitates in all Pd-modified alloys. Interfacial segregation of Pd to grain boundaries and lath boundaries is not observed at any levels above a detection limit of approximately 0.5 monolayers. Hydrogen permeation analyses indicate that hydrogen ingress is not inhibited by Pd but that apparent diffusion coefficients are lowered relative to the conventional alloy. Lower diffusion coefficients are consistent with the creation of a strong but reversible hydrogen trap, identified as the uniformly distributed PdAl phase. We hypothesize that PdAl trap sites force a redistribution of trapped hydrogen, which lowers the amount of interfacially segregated hydrogen at prior austenite grain boundaries for the electrochemical conditions applied. These assertions are supported by a simplistic trapping model for PH 13-8 Mo which shows that both the hydrogen trap binding energy and the trap density for the PdAl trapping site are greater than the hydrogen trap binding energy and density for prior austenite grain boundaries.

Scully, J. R.; van den Avyle, J. A.; Cieslak, M. J.; Romig, A. D.; Hills, C. R.

1991-10-01

94

Heat treatment of investment cast PH 13-8 Mo stainless steel: Part I. Mechanical properties and microstructure  

NASA Astrophysics Data System (ADS)

The microstructure of investment cast PH 13-8 Mo stainless steel heat-treated to various conditions was studied using light and electron microscopy, electron probe microanalysis, and Mössbauer spectroscopy. The mechanical properties were investigated by using uniaxial tensile testing, hardness testing, and Charpy impact testing. The ?-NiAl strengthening precipitates, though detectable by electron diffraction, were difficult to resolve by transmission electron microscopy (TEM) in specimens aged at low temperatures (566 °C and below). A high dislocation density was observed in the lath martensitic structure. The higher strength and lower ductility observed at low aging temperatures was attributed to both the high dislocation density and the precipitation of ?-NiAl. When samples were aged at high temperatures (> 566 °C), a lower dislocation density and a reverted austenite fraction on the order of 15 pct were observed. Spherical ?-NiAl precipitates were observed in the overaged condition. The decrease in strength and corresponding increase in ductility observed in samples aged at temperatures above 566 °C were attributed to the reverted austenite and recovery. Mechanical properties were improved when the homogenizing temperature and time were increased. Electron probe microanalysis quantified the increased homogeneity realized by increasing homogenizing temperature and time. Elimination of the refrigeration step, which normally follows the solution treatment, did not degrade the mechanical properties. Mössbauer spectroscopy showed only minor decreases in the fraction of retained austenite when refrigeration followed the solution treatment.

Hochanadel, P. W.; Edwards, G. R.; Robino, C. V.; Cieslak, M. J.

1994-04-01

95

Microstructures of stainless steels exhibiting reduced friction and wear after implantation with Ti and C. [304; 15-5 PH; Nitronic 60; 440C  

Microsoft Academic Search

Implantation of Ti and C into stainless steel discs of Types 304, 15-5 PH, Nitronic 60 and 440C has previously been reported to reduce wear depths by up to approx. 85% and friction by approx. 50% in unlubricated pin-on-disc tests. Our earlier studies relating microstructure to friction and wear results in Type 304 are first summarized: these indicate that the

D. M. Follstaedt; F. G. Yost; L. E. Pope

1983-01-01

96

Nuclear microprobe analysis of wear tracks on ¹⁴N-implanted steels. [15-5 PH and 304 stainless steels  

Microsoft Academic Search

Two nuclear microbeam analysis techniques (3.7 MeV (..cap alpha..,p) and 6 MeV (..cap alpha..,..cap alpha..)) have been used to determine the local areal density of ¹⁴N which remains in wear tracks resulting from pin-on-disc testing of nitrogen implanted 15-5 PH and 304 stainless steels. The microbeam analysis shows that the extent of N migration into the 15-5 substrate was to

B. L. Doyle; D. M. Follstaedt; S. T. Picraux; F. G. Yost; L. E. Pope; J. A. Knapp

1984-01-01

97

Metallurgical Analysis of Crack Initiation of Wire-Cut Electrical Discharge-Machined Spline Actuators Made of 17-4 PH Stainless Steel  

Microsoft Academic Search

Spline actuators made of investment cast 17-4 PH (precipitation hardening) stainless steel were found to contain micro-cracks.\\u000a The cracked actuators were subjected to optical and scanning electron microscopy and hardness testing, which revealed that\\u000a the failure occurred due to fatigue crack initiation and growth after electrical discharge machining (EDM). The rehardened\\u000a layer produced by the EDM remained after machining, and

Ahmad-Reza Etemadi; Bahram Fazel; Armin Emami

98

Influence of hardness on the wear resistance of 17-4 PH stainless steel evaluated by the pin-on-disc testing  

Microsoft Academic Search

Present work aimed at investigating the wear resistance of AISI 630 (UNS S17400) or 17-4 PH stainless steel hardened by precipitation hardening or aging at various hardness levels. The PHs steels are an interesting family of steels for applying in highly stressed parts for its corrosion resistance and relative high hardness, attaining up to 49 HRC by low-temperature aging heat

J. D. Bressan; D. P. Daros; A. Sokolowski; R. A. Mesquita; C. A. Barbosa

2008-01-01

99

The effect of microstructural evolution on hardening behavior of type 17-4PH stainless steel in long-term aging at 350 °C  

Microsoft Academic Search

The effect of microstructural evolution on hardening behavior of 17-4PH stainless steel in long-term aging at 350 °C was studied by X-ray diffraction and transmission electron microscopy. The results showed that there is the matrix of lath martensite and nanometer-sized particles of ?-Cu precipitated from the matrix after the alloy is solution treated and tempered. When the alloy was aged 350 °C

Jun Wang; Hong Zou; Cong Li; Shao-yu Qiu; Bao-luo Shen

2006-01-01

100

Heat treatment of investment cast PH 13-8 Mo stainless steel; Part 2: Isothermal aging kinetics  

SciTech Connect

The hardening response of investment cast PH 13-8 Mo stainless steel has been evaluated by hardness measurements following aging in the temperature range normally specified for this alloy (510 C to 593 C). A new relationship between fraction transformed and hardness was developed, and analysis of the data in terms of the kinetics of precipitation, in a manner similar to that frequently applied to other precipitation-hardenable martensitic steels, yielded low time exponents and a low value for the apparent activation energy. The values of the time exponents were 0.49, 0.37, 0.56, and 0.53 at 510 C, 538 C, 566 C, and 593 C, respectively, and that for the apparent activation energy was 139 kJ/mole. As has been proposed for other maraging type steels, these estimates suggest that [beta]-NiAl precipitates along or near dislocations and that growth of the precipitates is dominated by dislocation pipe diffusion. However, these predictions were neither supported nor refuted by transmission electron microscopy (TEM) because of difficulties in imaging the [beta]-NiAl precipitates at the aging times and temperatures used. Further, analysis of the data using the formalism of Wert and Zener for the growth of precipitates with interfering diffusion fields indicated that the estimates of fraction transformed from hardness data are not fully appropriate for maraging type steels. Consideration of the nature of the Avrami analysis and the electron microscopy results suggests that other phenomena, including dislocation recovery and reversion of martensite to austenite, occur at rates sufficient to convolute the Avrami analysis. It is further suggested that these results cast doubt on the fundamental implications of previous analyses of precipitation kinetics in age-hardening martensitic steels.

Robino, C.V.; Cieslak, M.J. (Sandia National Labs., Albuquerque, NM (United States). Physical and Joining Metallurgy Dept.); Hochanadel, P.W.; Edwards, G.R. (Colorado School of Mines, Golden, CO (United States). Dept. of Metallurgical and Materials Engineering)

1994-04-01

101

Influence of stress and pH on susceptibility of copper-containing type 304 stainless steels to stress corrosion cracking in sulfuric acid  

SciTech Connect

Stress corrosion tests on type 304 (UNS S30400) stainless steels (SS) with 0.3 wt% or 1.3 wt% Cu addition were conducted in hot sulfuric acid-sodium hydroxide solutions under constant loads. Cracking susceptibility, corrosion morphology, average crack growth rate (CGR), and average uniform corrosion rate were examined as functions of pH, sulfate ion concentration, and applied stress. The steel with 0.3 wt% Cu exhibited stress corrosion cracking from pH 0.3 to 2.4, in which range the CGR was greater than the corrosion rate. The steel with 1.3 wt% Cu exhibited pit-like attack, crevice corrosion, pit-like attack with cracking, or cracking, depending upon pH ({minus}0.3 to 0.3) and stress level (150 MPa to 325 MPa).

Asawa, M.; Minoda, D. [Shinshu Univ., Nagano (Japan)

1996-07-01

102

Influence of salt bath nitrocarburizing and post-oxidation process on surface microstructure evolution of 17-4PH stainless steel  

Microsoft Academic Search

The effect of Quench–Polish–Quench complex salt bath heat-treatment (QPQ) on surface microstructure of the 17-4PH stainless steel (SS) was investigated. A bright zone (compound ?-Fe2(N,C)) is formed at the outermost surface of the nitrocarburized sample, followed by a zone (mixture Fe3N\\/Fe4N\\/CrN\\/?-Fe) which is slightly etched. A thin oxides zone (Fe3O4\\/FeO) is formed at the outer surface of the post-oxidized sample,

Gui-jiang Li; Jun Wang; Qian Peng; Cong Li; Ying Wang; Bao-luo Shen

2008-01-01

103

Influence of pH and chloride concentration on the pitting and crevice corrosion behavior of high-alloy stainless steels  

SciTech Connect

Localized corrosion resistance (pitting and crevice corrosion) of two high-alloy stainless steels (superduplex and superaustenitic) was studied in solutions with chloride concentrations of 200, 400, 600, and 6,000 ppm at pH values ranging from 2 to 6.5. Critical temperatures for pitting and crevice corrosion were calculated for these test media using electrochemical techniques (continuous current). From results obtained for cyclic polarization, the critical pitting temperature (CPT) and critical crevice temperature (CCT) of these materials in the different test media were determined. Under the tested conditions, the resistance of these materials to localized corrosion was very high. Only in test conditions of higher aggressivity (6,000 ppm CL{sup {minus}} and pH 6.5), pitting or crevice corrosion was observed. In those cases, values of pitting potential (E{sub pit}) and crevice potential (E{sub cre}) showed little tendency to decrease with an increase in CL{sup {minus}} concentration, temperature, and pH. Moreover, the CPT of these steels was determined in a ferric chloride (FeCl{sub 3}) medium, which corresponds to the standard ASTM G48 practice (Method A).

Pardo, A.; Otero, E.; Merino, M.C.; Lopez, M.D.; Utrilla, M.V.; Moreno, F.

2000-04-01

104

Stress corrosion study of PH13-8Mo stainless steel using the Slow Strain Rate Technique  

NASA Technical Reports Server (NTRS)

The need for a fast and reliable method to study stress corrosion in metals has caused increased interest in the Slow Strain Rate Technique (SSRT) during the last few decades. PH13-8MoH950 and H1000 round tensile specimens were studied by this method. Percent reduction-in-area, time-to-failure, elongation at fracture, and fracture energy were used to express the loss in ductility, which has been used to indicate susceptibility to stress corrosion cracking (SCC). Results from a 3.5 percent salt solution (corrosive medium) were compared to those in air (inert medium). A tendency to early failure was found when testing in the vicinity of 1.0 x 10(-6) mm/mm/sec in the 3.5 percent salt solution. PH13-8Mo H1000 was found to be less likely to suffer SCC than PH13-8Mo H950. This program showed that the SSRT is promising for the SCC characterization of metals and results can be obtained in much shorter times (18 hr for PH steels) than those required using conventional techniques.

Torres, Pablo D.

1989-01-01

105

An investigation of the high-temperature and solidification microstructures of PH 13-8 Mo stainless steel  

Microsoft Academic Search

Differential thermal analysis (DTA), high-temperature water-quench (WQ) experiments, and optical and electron microscopy were used to establish the near-solidus and solidification microstructures in PH 13-8 Mo. On heating at a rate of 0. 33 °C\\/s, this alloy begins to transform from austenite to delta-ferrite at ≈1350 °C. Transformation is complete by ≈1435 °C. The solidus is reached at ≈1447 °C,

M. J. Cieslak; C. R. Hills; P. F. Hlava; S. A. David

1990-01-01

106

An investigation of the high-temperature and solidification microstructures of PH 13-8 Mo stainless steel  

Microsoft Academic Search

Differential thermal analysis (DTA), high-temperature water-quench (WQ) experiments, and optical and electron microscopy were\\u000a used to establish the near-solidus and solidification microstructures in PH 13-8 Mo. On heating at a rate of 0. 33 C\\/s, this\\u000a alloy begins to transform from austenite to ?-ferrite at ?1350 C. Transformation is complete by ?1435 C. The solidus is\\u000a reached at ?1447 C,

M. J. Cieslak; C. R. Hills; P. F. Hlava; S. A. David

1990-01-01

107

Microstructure and dry-sliding wear properties of DC plasma nitrided 17-4 PH stainless steel  

Microsoft Academic Search

An attempt that the precipitation hardening steel 17-4PH was conducted by DC plasma nitriding (DCPN) is made to develop a kind of candidate material for nuclear reactor. Nitriding process performed at temperature?400°C takes effect on creation of the layers composed of S-phase (expanded austenite) and ?N? (expanded martensite). Up to the temperature of 420°C, the S-phase peaks disappear due to

Gui-Jiang Li; Jun Wang; Cong Li; Qian Peng; Jian Gao; Bao-Luo Shen

2008-01-01

108

On the microstructure and phase identification of plasma nitrided 17-4PH precipitation hardening stainless steel  

Microsoft Academic Search

Systematic microstructure characterisation of plasma nitrided (350–500 °C for 10 to 30 h) 17-4PH alloy was carried out using SEM, XRD and TEM. Experimental results have shown that the microstructure and phase constituents of the plasma surface alloyed cases are highly treatment temperature dependent. When treated at low-temperatures (?420 °C), the microstructure is dominated by nitrogen supersaturated martensite (?'N-expanded martensite); Nitrogen S-phase grains

H. Dong; M. Esfandiari; X. Y. Li

2008-01-01

109

Microstructure and dry-sliding wear properties of DC plasma nitrided 17-4 PH stainless steel  

NASA Astrophysics Data System (ADS)

An attempt that the precipitation hardening steel 17-4PH was conducted by DC plasma nitriding (DCPN) is made to develop a kind of candidate material for nuclear reactor. Nitriding process performed at temperature ? 400 °C takes effect on creation of the layers composed of S-phase (expanded austenite) and ?N' (expanded martensite). Up to the temperature of 420 °C, the S-phase peaks disappear due to the transformation occurrence (S-phase ? ?N' + CrN). For the samples nitrided at temperature ? 450 °C, no evidence of ?N' is found owing to a precipitation ( ?N'??+CrN) taking place. For the 480 °C/4 h treated sample, it is the surface microhardness that plays the lead role in the wear rate reduction but the surface roughness; while for the 400 °C/4 h treated sample, it is both of the surface roughness and the S-phase formation. Dry sliding wear of the untreated 17-4PH is mainly characterized by strong adhesion, abrasion and oxidation mechanism. Samples nitrided at 400 °C which is dominated by slight abrasion and plastic deformation exhibit the best dry sliding wear resistance compared to the samples nitrided at other temperatures.

Li, Gui-jiang; Wang, Jun; Li, Cong; Peng, Qian; Gao, Jian; Shen, Bao-luo

2008-05-01

110

An investigation of the high-temperature and solidification microstructures of PH 13-8 Mo stainless steel  

NASA Astrophysics Data System (ADS)

Differential thermal analysis (DTA), high-temperature water-quench (WQ) experiments, and optical and electron microscopy were used to establish the near-solidus and solidification microstructures in PH 13-8 Mo. On heating at a rate of 0. 33 °C/s, this alloy begins to transform from austenite to ?-ferrite at ?1350 °C. Transformation is complete by ?1435 °C. The solidus is reached at ?1447 °C, and the liquidus is ?1493 °C. On cooling from the liquid state at a rate of 0. 33 °C/s, solidification is completed as ?-ferrite with subsequent transformation to austenite beginning in the solid state at ?1364 °C. Insufficient time at temperature is available for complete transformation and the resulting room-temperature microstructure consists of matrix martensite (derived from the shear decomposition of the austenite) and residual ?-ferrite. The residual ?-ferrite in the DTA sample is enriched in Cr (?16 wt pct), Mo (?4 wt pct), and Al (?1. 5 wt pct) and depleted in Ni (?4 wt pct) relative to the martensite (?12. 5 wt pct Cr, ?2 wt pct Mo, ?1 wt pct Al, ?9 wt pct Ni). Solid-state transformation of ? ? ? was found to be quench-rate sensitive with large grain, fully ferritic microstructures undergoing a massive transformation as a result of water quenching, while a diffusionally controlled Widmanstätten structure was produced in air-cooled samples.

Cieslak, M. J.; Hills, C. R.; Hlava, P. F.; David, S. A.

1990-09-01

111

The effect of microstructural evolution on hardening behavior of type 17-4PH stainless steel in long-term aging at 350 deg. C  

SciTech Connect

The effect of microstructural evolution on hardening behavior of 17-4PH stainless steel in long-term aging at 350 deg. C was studied by X-ray diffraction and transmission electron microscopy. The results showed that there is the matrix of lath martensite and nanometer-sized particles of {epsilon}-Cu precipitated from the matrix after the alloy is solution treated and tempered. When the alloy was aged 350 deg. C for 9 months, {alpha}-{alpha}' spinodal decomposition occurred along the grain boundaries and caused an increase in hardness which compensated for the weakening effect due to ripening of the {epsilon}-copper precipitates. Upon further aging to 12 months, the Cr-rich {alpha}'-phase and M{sub 23}C{sub 6} precipitated, both of which strengthened the alloy considerably and led to enhanced hardening despite the continued softening by overaging of the {epsilon}-copper precipitates. With the aging time extended to 15 months, substantial reversed austenite transformed and precipitation of the intermetallic G-phase occurred near the {epsilon}-Cu precipitates in the matrix. The abundant amount of reversed austenite that transformed led to rapid softening.

Wang Jun [School of Materials Science and Engineering, Sichuan University, Chengdu, 610065 (China) and Nuclear Power Institute of China, Chengdu, 610041 (China)]. E-mail: srwangjun@163.com; Zou Hong [Nuclear Power Institute of China, Chengdu, 610041 (China); Li Cong [Nuclear Power Institute of China, Chengdu, 610041 (China); Qiu Shaoyu [Nuclear Power Institute of China, Chengdu, 610041 (China); Shen Baoluo [School of Materials Science and Engineering, Sichuan University, Chengdu, 610065 (China)

2006-12-15

112

Corrosion behavior of austenitic stainless steels as a function of pH for use as bipolar plates in polymer electrolyte membrane fuel cells  

Microsoft Academic Search

Stainless steels (types 304 and 310S) were employed as bipolar plates for polymer electrolyte membrane fuel cells. For the cell operation, the decayed cell voltage was approximately 22mV for the type 310S stainless steel after 1000h operation, while that for type 304 stainless steel was about 46mV. Corrosion products appeared on the cathode side bipolar plate for the type 304

Masanobu Kumagai; Seung-Taek Myung; Shiho Kuwata; Ryo Asaishi; Hitoshi Yashiro

2008-01-01

113

THE EFFECT OF 17-4PH STAINLESS STEEL ON THE LIFETIME OF A PENNZANE® LUBRICATED MICROWAVE LIMB SOUNDER ANTENNA ACTUATOR ASSEMBL Y BALL SCREW FOR THE AURA SPACECRAFT  

Microsoft Academic Search

During ground based life testing of a Microwave Limb Sounder (MLS) Antenna Actuator Assembly (AAA) ball-screw assembly, lubricant darkening and loss w ere noted when approximately 10% of required lifetime was completed. The MLS-AAA ball screw and nut are made from 17-4 PH steel, the nut has 440C stainless steel balls, and the assembly is lubricated with a Pennzane ®

William R. Jones; Mark J. Jansen; Jonathan Lam; Mark Balzer; John Lo; Joseph P. Schepis; Mark Anderson

114

Bladed-shrouded-disc aeroelastic analyses: Computer program updates in NASTRAN level 17.7  

NASA Technical Reports Server (NTRS)

In October 1979, a computer program based on the state-of-the-art compressor and structural technologies applied to bladed-shrouded-disc was developed. The program was more operational in NASTRAN Level 16. The bladed disc computer program was updated for operation in NASTRAN Level 17.7. The supersonic cascade unsteady aerodynamics routine UCAS, delivered as part of the NASTRAN Level 16 program was recorded to improve its execution time. These improvements are presented.

Gallo, A. M.; Elchuri, V.; Skalski, S. C.

1981-01-01

115

The Effect of 17-4 PH Stainless Steel on the Lifetime of a Pennzane(Trademark) Lubricated Microwave Limb Sounder Antenna Actuator Assembly Ball Screw for the AURA Spacecraft  

NASA Technical Reports Server (NTRS)

During ground based life testing of a Microwave Limb Sounder (MLS) Antenna Actuator Assembly (AAA) ball-screw assembly, lubricant darkening and loss were noted when approximately 10 percent of required lifetime was completed. The MLS-AAA ball screw and nut are made from 17-4 PH steel, the nut has 440C stainless steel balls, and the assembly is lubricated with a Pennzane formulation containing a three weight percent lead naphthenate additive. Life tests were done in dry nitrogen at 50 C. To investigate the MLS-AAA life test anomaly, Spiral Orbit Tribometer (SOT) accelerated tests were performed. SOT results indicated greatly reduced relative lifetimes of Pennzane formulations in contact with 17-4 PH steel compared to 440C stainless steel. Also, dry nitrogen tests yielded longer relative lifetimes than comparable ultrahigh vacuum tests. Generally, oxidized Pennzane formulations yielded shorter lifetimes than non-oxidized lubricant. This study emphasizes surface chemistry effects on the lubricated lifetime of moving mechanical assemblies.

Jones, William R., Jr.; Jansen, Mark J.; Chen, Gun-Shing; Lam, Jonathan; Balzer, Mark; Anderson, Mark; Lo, John; Schepis, Joseph P.

2005-01-01

116

Tool wear and tool life in end milling of 15–5 PH stainless steel under different cooling and lubrication conditions  

Microsoft Academic Search

Most of the machining operations on stainless steel alloys are carried out with cutting fluid due to the poor machinability\\u000a of this kind of material. Tool wear mechanisms are directly influenced by the cooling and lubrication condition to which the\\u000a tool is exposed, especially in interrupted cutting processes. This work investigates tool wear mechanisms for an end milling\\u000a operation of

Aldo Braghini Junior; Anselmo Eduardo Diniz; Fernando Teixeira Filho

2009-01-01

117

Corrosion of nickel—chromium deposit on AISI 316L stainless steel in radioactive water with and without fluoride at pH 4  

NASA Astrophysics Data System (ADS)

The electrochemical behavior of samples was studied using potentiodynamic techniques at low scan rates, cyclic voltammetry at high scan rates and electrochemical impedance spectroscopy. The surfaces were examined and analyzed by scanning electron microscopy and X-ray microanalysis, respectively. The results from these different methods are discussed. They show that the deposit is more easily corroded than the AISI 316L stainless steel in presence or absence of fluoride. With fluoride and at the prepassive potentials, the Warburg straight line indicates that there is ionic diffusion in the nickel—chromium deposit oxide. The equivalent circuits for the nickel-chromium are proposed and indicate that the deposit can take part in localized corrosion. The use of high scan rates shows the transient kinetics of the oxide formation in presence of fluoride. With fluoride, the pitting currents are higher for nickel-chromium deposits. The SEM photographs and polarization curves show that the Ni?Cr deposit is locally corroded by fluoride, leading to the possibility of crevice formation under this and in 316L stainless steel.

Bellanger, G.; Rameau, J. J.

1995-10-01

118

Formation of Ge nanoclusters on Si(1 1 1)-7 × 7 surface at high temperature  

NASA Astrophysics Data System (ADS)

We report on Ge nanocluster formation on Si(1 1 1)-7 × 7 surface at elevated substrate temperatures during deposition. The shape and size of the Ge clusters are more uniform than those obtained at room temperature due to an increase in the average mobility of the additional atoms. The Ge clusters have a preferential adsorption site in the faulted halves. Some clusters in the faulted and the unfaulted halves exhibit two different features, which indicate the different adsorption energy and chemical activity of the two half-cells. We also observe some clusters forming in a characteristic star shape at a particular positive bias voltage. The formation mechanism and possible structures are discussed.

Guo, H. M.; Wang, Y. L.; Liu, H. W.; Ma, H. F.; Qin, Z. H.; Gao, H. J.

2004-07-01

119

Estudio de la corrosion bajo tension del acero 17-4PH en medios acuosos usando tecnicas electroquimicas. (Susceptibility of 17-4PH stainless steel to stress corrosion cracking in aqueous environments by electrochemical techniques.).  

National Technical Information Service (NTIS)

The susceptibility of a 17-4PH type steel to Stress Corrosion Cracking (SCC) in low pressure steam turbine environments was assessed using slow strain rate test at 90 Centigrade and at 1.35x10(sup -6) seg(sup -1). Environments tested included different co...

A. C. S. Diaz

1997-01-01

120

Microstructural Evolution and Response to Double-Loop Reactivation Testing of Heat-Treated pH 13-8 Mo Martensitic Stainless Steel.  

National Technical Information Service (NTIS)

The double loop electrochemical potentiokinetic reactivation (DL-EPR) test was used to investigate the intergranular and interlath corrosion susceptibility of pH 13-8 Mo as a function of heat treatment. Degree of sensitization was measured to the ratio of...

W. R. Cieslak M. J. Cieslak C. R. Hills

1987-01-01

121

Microstructural evolution and response to double-loop reactivation testing of heat-treated pH 13-8 Mo martensitic stainless steel  

Microsoft Academic Search

The double loop electrochemical potentiokinetic reactivation (DL-EPR) test was used to investigate the intergranular and interlath corrosion susceptibility of pH 13-8 Mo as a function of heat treatment. Degree of sensitization was measured to the ratio of the peak current on a reverse (reactivation) scan to that on the forward anodic scan. Corrosion morphology was characterized by SEM, and microstructure

W. R. Cieslak; M. J. Cieslak; C. R. Hills

1987-01-01

122

Fatigue Crack Growth under High Pressure of Gaseous Hydrogen in a 15-5PH Martensitic Stainless Steel: Influence of Pressure and Loading Frequency  

NASA Astrophysics Data System (ADS)

In this study, the effect of gaseous hydrogen pressure in relation with the loading frequency on the fatigue crack growth behavior of a precipitation-hardened martensitic stainless steel is investigated. It is found that increasing the hydrogen pressure from 0.09 to 9 MPa induces an enhancement of the fatigue crack growth rates. This enhancement is pronounced particularly at higher stress intensity factor amplitudes at 9 MPa. Meanwhile, decreasing the frequency from 20 to 0.2 Hz under 0.9 MPa of hydrogen reveals a significant increase in the crack growth rates that tends to join the curve obtained under 9 MPa at 20 Hz, but with a different cracking mode. However, it is shown that the degradation in fatigue crack growth behavior derives from a complex interaction between the fatigue damage and the amount of hydrogen enriching the crack tip, which is dependent on the hydrogen pressure, loading frequency, and stress intensity factor level. Scanning electron microscope (SEM) observations of the fracture surfaces are used to support the explanations proposed to account for the observed phenomena.

Sun, Z.; Moriconi, C.; Benoit, G.; Halm, D.; Henaff, G.

2013-03-01

123

Quantitative measurement of fatigue crack initiation and propagation in 304 stainless steel as related to design and nondestructive evaluation. Ph.D. Thesis  

SciTech Connect

The initiation and propagation of short fatigue cracks in 304 stainless steel have been examined through replication techniques and through a mechanical vibration resonant frequency technique, which allows the measurement of elastic modulus and internal friction. Center hole and side notch specimens 6.3 mm thick were used for low cycles fatigue tests. The notches localize the crack initiation sites to facilitate the observation of the cracks and also simulate stress risers in real parts. The cracks initiate at several locations at the notch root inside the notches. These cracks then grow and link up along the surface of the notches and propagate to the specimen surface. The cracks are often nonlinear and link up through a bridging feature. Once the crack has reached the specimen surfaces at the edges of the notch, it propagates through the specimen as a through crack. The crack profile at this point has a small amount of curvature, allowing a measurement of the crack length through surface examination. The stress intensity factor is used as the driving force for the small crack propagation. Justification for the linear elastic fracture mechanics based stress intensity factor is found through examination of the cyclic stress-strain curves. The maximum amount of plastic strain is a factor of five less than the 0.2 percent plastic strain used to define the yield strength. Therefore, there is no gross yielding. The plastic zone size due to the notch was also calculated and found to be smaller than the crack length in most cases. Finally, the elastic plastic fracture mechanics based delta J was calculated for the specimen which experienced the maximum plastic strain. Only a small difference is found between the elastic delta K(exp 2)/E term and delta J. The short cracks grew at stress intensity factors below the long crack threshold. The crack growth rate of the small cracks fit a power law relation commonly called the Paris relation.

Mcguire, S.M.

1993-12-31

124

An STM study of the localized atomic reaction of 1,2- and 1,4-dibromobenzene at Si(1 1 1)-7 × 7  

NASA Astrophysics Data System (ADS)

A comparative study is reported of the thermal reaction of 1,2- and 1,4-dibromobenzene (1,2- and 1,4-diBrPh) on Si(1 1 1)-7 × 7, investigated by STM. Some results are given for the intermediate case of 1,3-diBrPh. The STM images gave evidence of a different pattern of reaction to yield pairs of Br-Si for 1,2-, 1,3- and 1,4-diBrPh. The ratio of pairs of Br-Si to single bromination events was 1:2 for 1,2-diBrPh and 1:3 for 1,4-diBrPh. In many cases organic residue from the bromination reaction, R-Si, was evident in the STM image. The products R-Si and Br-Si were found to be bound to adjacent Si, for both 1,2- and 1,4-diBrPh. The mean Br⋯Br pair separation at the surface depended on the parent molecule, being 7.6 Å for 1,2-diBrPh, 10.3 Å for 1,3-diBrPh, and 11.3 Å for 1,4-diBrPh. These separations are, in each case, about 4 Å greater than the separation of the Br-atoms in the intact parent molecule, which increases systematically down the series. There was a marked decrease in the percentage of R-Si accompanying the Br-Si in going down the series, decreasing from 70% for 1,2- to 20% for 1,4-diBrPh; this was interpreted as being due to a decrease in the percentage of `benzene-mediated' reaction dynamics, in which the benzene ring was bound to the surface. At moderately increased surface temperature (45 °C) the reaction of 1,2- and also 1,4-diBrPh no longer resulted in R-Si formation, suggesting that the dynamics had altered from benzene-mediated to `bromine-mediated'.

Dobrin, Sergey; Rajamma Harikumar, K.; Polanyi, John C.

2004-07-01

125

17-4 PH and 15-5 PH  

NASA Technical Reports Server (NTRS)

17-4 PH and 15-5 PH are extremely useful and versatile precipitation-hardening stainless steels. Armco 17-4 PH is well suited for the magnetic particle inspection requirements of Aerospace Material Specification. Armco 15-5 PH and 17-4 PH are produced in billet, plate, bar, and wire. Also, 15-5 PH is able to meet the stringent mechanical properties required in the aerospace and nuclear industries. Both products are easy to heat treat and machine, making them very useful in many applications.

Johnson, Howard T.

1995-01-01

126

THE PHYSICAL METALLURGY OF PRECIPITATION-HARDENABLE STAINLESS STEELS  

Microsoft Academic Search

The present knowledge on the physical metallurgy of precipitation-; hardenable stainless steels is presented. The alloys discussed include the ; martensitic types (Stainless W and 17-4 PH), the semiaustenitic types (177 PH, PH ; 15-7 Mo, AM 350, and AM 355), and the austenitic types (A-286 and HNM). The ; areas of metallurgy common to most or all of these

D. C. Ludwigson; A. M. Hall

1959-01-01

127

Avoid stainless steel failures in FGD systems  

Microsoft Academic Search

Preventing pitting and localized corrosion is the key to success where low maintenance and high reliability are rime considerations in flue-gas desulfurization (FGD) designs. Knowing when to use a stainless steel, and when not to, is crucial. Operating parameters and environmental factors greatly affect alloy performance, especially pH, temperature, and chloride and oxygen levels. Failures of stainless steels can be

J. P. Mills; C. M. Schillmoller

1995-01-01

128

Effect of residual oxygen in Si(1 1 1)-7 × 7 surface on Si+ and Si2+ sputter yields  

Microsoft Academic Search

Effect of the residual oxygen impurity on the secondary ion yields in the sputtering from the Si(1 1 1)-7 × 7 surface bombarded by the 11 keV Ar0 neutral beam has been studied with use of a time-of-flight technique. Even if the oxygen concentration is much less than the detection limit of the present Auger electron spectrometer, not only Si+

Y. Sakuma; N. Shinde; M. Kato; S. Yagi; K. Soda

2007-01-01

129

Pulsed-dosing controls self-assembly: 1-Bromopentane on Si(1 1 1)-7 × 7  

NASA Astrophysics Data System (ADS)

We have constructed a high-pressure fast-pulse dosing system for use with Scanning Tunneling Microscopy (STM). For 1-bromopentane on Si(1 1 1)-7 × 7 at low temperature (100 K) two physisorbed phases were found to co-exist; spaced-out molecules above corner silicon-adatoms in a one-per-corner-hole (OPCH) pattern, and circles of molecules above middle-adatoms. By tuning the parameters of high-pressure fast-pulse dosing, we can choose which of these two patterns, OPCH or circles, to chemically imprint on room temperature silicon.

Eisenstein, Alon; Harikumar, K. R.; Huang, Kai; McNab, Iain R.; Polanyi, John C.; Zabet-Khosousi, Amir

2012-02-01

130

Study of adsorption structure of benzene and toluene on Si(1 1 1)7 × 7 surfaces  

NASA Astrophysics Data System (ADS)

The adsorption of benzene and toluene on Si(1 1 1)7 × 7 was investigated using scanning tunneling microscopy (STM) and theoretical calculations. For both aromatic molecules, bright spots in the STM images and populations of the subunits, each consisting of three reacted adatoms, indicated that an adsorbed molecule is involved in a configuration with an adatom and its adjacent rest atom. The structures of adsorbed benzene and toluene were also examined using theoretical calculations involving the cluster model of Si 30H 28. Several structures were obtained as energetically favorable structures using geometrical optimization calculations. By comparing the binding energies of each structure, the 1,4-cyclohexadiene-like adsorption structure was found to be most energetically favorable for benzene and toluene adsorption. These calculated adsorption structures are in good agreement with the experimental results.

Tomimoto, Hiroyuki; Sekitani, Tetsuji; Sumii, Ryohei; Oda Sako, Erika; Wada, Shin-ichi; Tanaka, Kenichiro

2004-09-01

131

Oxygen reduction on stainless steel  

Microsoft Academic Search

Oxygen reduction was studied on AISI 304 stainless steel in 0.51 m NaCl solution at pH values ranging from 4 to 10. A rotating disc electrode was employed. It was found that oxygen reduction is under mixed activation-diffusion control. The reaction order with respect to oxygen was found to be one. The values of the Tafel slope depend on the

R. Babi?; M. Metikoš-Hukovi?

1993-01-01

132

Ultrasonic Spectroscopy of Stainless Steel Sandwich Panels  

NASA Technical Reports Server (NTRS)

Enhanced, lightweight material systems, such as 17-4PH stainless steel sandwich panels are being developed for use as fan blades and fan containment material systems for next generation engines. In order to improve the production for these systems, nondestructive evaluation (NDE) techniques, such as ultrasonic spectroscopy, are being utilized to evaluate the brazing quality between the 17-4PH stainless steel face plates and the 17-4PH stainless steel foam core. Based on NDE data, shear tests are performed on sections representing various levels of brazing quality from an initial batch of these sandwich structures. Metallographic characterization of brazing is done to corroborate NDE findings and the observed shear failure mechanisms.

Cosgriff, Laura M.; Lerch, Bradley A.; Hebsur, Mohan G.; Baaklini, George Y.; Ghosn, Louis J.

2003-01-01

133

Introduction of the carrot HSP17.7 into potato (Solanum tuberosum L.) enhances cellular membrane stability and tuberization in vitro.  

PubMed

We have examined the ability of a carrot (Daucus carota L.) heat shock protein gene encoding HSP17.7 (DcHSP17.7) to confer enhanced heat tolerance to potato (Solanum tuberosum L.), a cool-season crop. The DcHSP17.7 gene was fused to a 6XHistidine (His) tag to distinguish the engineered protein from endogenous potato proteins and was introduced into the potato cultivar 'Désirée' under the control of the cauliflower mosaic virus (CaMV) 35S promoter. Western analysis showed that engineered DcHSP17.7 was constitutively, but not abundantly, expressed in transgenic potato lines before heat stress. Leaves from multiple regenerated potato lines that contain the transgene exhibited significantly improved cellular membrane stability at high temperatures, compared with wild-type and vector control plants. Transgenic potato lines also exhibited enhanced tuberization in vitro: under a condition of constant heat stress, at 29 degrees C, nodal sections of the transgenic lines produced larger and heavier microtubers at higher rates, compared to the wild type and vector controls. The dry weight and percentages of microtubers that were longer than 5 mm were up to three times higher in the transgenic lines. Our results suggest that constitutive expression of carrot HSP17.7 can enhance thermotolerance in transgenic potato plants. To our knowledge, this is the first study that shows that the thermotolerance of potato can be enhanced through gene transfer. PMID:17086756

Ahn, Yeh-Jin; Zimmerman, J Lynn

2006-01-01

134

Improvement of the thermal stability of sintered Nd-Fe-B magnets by intergranular addition of Dy82.3Co17.7  

NASA Astrophysics Data System (ADS)

In this study, microstructure and magnetic properties of sintered Nd-Fe-B magnets with addition of Dy82.3Co17.7 (wt. %) were investigated. By adding a small amount of Dy82.3Co17.7, the coercivity is improved greatly, and the irreversible loss is decreased sharply. The increase of Curie temperature suggests that Co atoms have entered into the 2:14:1 main phase. Microstructural analysis indicates that a well-developed core-shell structure was formed in the magnets with the addition of Dy82.3Co17.7. The improvement of magnetic properties can be attributed to the microstructural modification and the intrinsic properties' improvement.

Zhang, Xiaofeng; Guo, Shuai; Yan, Changjiang; Cai, Lingwen; Chen, Renjie; Lee, Don; Yan, Aru

2014-05-01

135

Changes in transition temperature of the Si(111)1 × 1?7 × 7 phase transition observed under various oxygen environments  

Microsoft Academic Search

In order to investigate the role of oxygen atoms in the Si(111)1 × 1?7 × 7 phase transition, the transition was examined accurately under extremely high vacuum conditions (< 4 × 10?10 Pa. Transition temperature was measured for the modified-FZ crystal (resisivity; 4 × 104 ? cm) in which the oxygen concentration was 7.0 × 1015 atoms\\/cm3, and for a

Katsuyuki Tsukui; Kazuhiko Endo; Ryu Hasunuma; Osamu Hirabayashi; Nobuaki Yagi; Hajime Aihara; Toshiaki Osaka; Iwao Ohdomari

1995-01-01

136

On the ?? to ? transformation in maraging (grade 350), PH 13-8 Mo and 17-4 PH steels  

Microsoft Academic Search

The martensite to austenite transformation during continuous heating was studied over a range of heating rates for 350 grade maraging steel (M350), PH 13-8 Mo, and 17-4 PH stainless steel using a programmable dilatometer. The ???? transformation splits into two steps at lower heating rates for the M350 and PH 13-8 Mo, whereas occurs in one step for 17-4 PH.

Rajeev Kapoor; I. S. Batra

2004-01-01

137

Growth of epitaxially oriented Ag nanoislands on air-oxidized Si(1 1 1)-(7 × 7) surfaces: Influence of short-range order on the substrate  

NASA Astrophysics Data System (ADS)

Clean Si(1 1 1)-(7 × 7) surfaces, followed by air-exposure, have been investigated by reflection high-energy electron diffraction (RHEED) and scanning tunneling microscopy (STM). Fourier transforms (FTs) of STM images show the presence of short-range (7 × 7) order on the air-oxidized surface. Comparison with FTs of STM images from a clean Si(1 1 1)-(7 × 7) surface shows that only the 1/7th order spots are present on the air-oxidized surface. The oxide layer is ˜2-3 nm thick, as revealed by cross-sectional transmission electron microscopy (XTEM). Growth of Ag islands on these air-oxidized Si(1 1 1)-(7 × 7) surfaces has been investigated by in situ RHEED and STM and ex situ XTEM and scanning electron microscopy. Ag deposition at room temperature leads to the growth of randomly oriented Ag islands while preferred orientation evolves when Ag is deposited at higher substrate temperatures. For deposition at 550 °C face centered cubic Ag nanoislands grow with a predominant epitaxial orientation [1||[1, (1 1 1) Ag || (1 1 1) Si along with its twin [||[1, (1 1 1) Ag || (1 1 1) Si, as observed for epitaxial growth of Ag on Si(1 1 1) surfaces. The twins are thus rotated by a 180° rotation of the Ag unit cell about the Si[1 1 1] axis. It is intriguing that Ag nanoislands follow an epitaxial relationship with the Si(1 1 1) substrate in spite of the presence of a 2-3 nm thick oxide layer between Ag and Si. Apparently the short-range order on the oxide surface influences the crystallographic orientation of the Ag nanoislands.

Roy, Anupam; Bhattacharjee, K.; Ghatak, J.; Dev, B. N.

2012-01-01

138

Stress corrosion cracking evaluation of martensitic precipitation hardening stainless steels  

NASA Technical Reports Server (NTRS)

The resistance of the martensitic precipitation hardening stainless steels PH13-8Mo, 15-5PH, and 17-4PH to stress corrosion cracking was investigated. Round tensile and c-ring type specimens taken from several heats of the three alloys were stressed up to 100 percent of their yield strengths and exposed to alternate immersion in salt water, to salt spray, and to a seacoast environment. The results indicate that 15-5PH is highly resistant to stress corrosion cracking in conditions H1000 and H1050 and is moderately resistant in condition H900. The stress corrosion cracking resistance of PH13-8Mo and 17-4PH stainless steels in conditions H1000 and H1050 was sensitive to mill heats and ranged from low to high among the several heats included in the tests. Based on a comparison with data from seacoast environmental tests, it is apparent that alternate immersion in 3.5 percent salt water is not a suitable medium for accelerated stress corrosion testing of these pH stainless steels.

Humphries, T. S.; Nelson, E. E.

1980-01-01

139

Stress-Corrosion Properties of High-Strength Precipitation-Hardening Stainless Steels in 3.5% Aqueous Sodium Chloride Solution.  

National Technical Information Service (NTIS)

The plane-strain fracture toughness K(Ic) and stress-corrosion threshold K(Iscc) have been determined for the following high-strength, precipitation-hardening steels: 17-7 PH (RH 950, TH 1050), PH 15-7Mo (RH 950, TH 1050), AM 355 (SCT 850, SCT 1000), AM 3...

C. S. Carter D. G. Farwick A. M. Ross J. M. Uchida

1970-01-01

140

Avoid stainless steel failures in FGD systems  

SciTech Connect

Preventing pitting and localized corrosion is the key to success where low maintenance and high reliability are rime considerations in flue-gas desulfurization (FGD) designs. Knowing when to use a stainless steel, and when not to, is crucial. Operating parameters and environmental factors greatly affect alloy performance, especially pH, temperature, and chloride and oxygen levels. Failures of stainless steels can be avoided by understanding their limits in light of these variables. This article will focus on the capabilities of Types 316L, 317L, 317LM, 317LMN, 904L, and 6% Mo stainless steels and their applications, as well as provide details on unique combination of mechanical properties and corrosion resistance of the 22% Cr duplex and 25% Cr super-duplex stainless steels in acid chloride systems. Guidelines will be presented on methods to prevent intergranular corrosion, stress corrosion cracking, and pitting and crevice corrosion, and what process steps can be taken to assure reasonable performance of marginal alloy selections. Emphasis will be on the lime/limestone wet scrubbing process and the quencher/absorber.

Mills, J.P.; Schillmoller, C.M.

1995-11-01

141

pH Protocol  

NSDL National Science Digital Library

The purpose of this resource is to measure the pH of water. Students use either a pH meter or pH paper to measure the pH. If using the pH meter, the meter needs to be calibrated with buffer solutions that have pH values of 4, 7, and 10.

The GLOBE Program, UCAR (University Corporation for Atmospheric Research)

2005-06-02

142

Microstructures and mechanical properties of boride-dispersed precipitation-hardening stainless steels produced by RST  

Microsoft Academic Search

Two commercial precipitation-hardening (PH) stainless steels were modified with 2.64 to 2.86 wt% Ti and 1.2 to 1.3 wt% B via rapid solidification technology (RST) and powder metallurgy (PM). The resulting alloys exhibited improved tensile and yield strengths over their commercial PH stainless steel counterparts at room and elevated temperatures. Ductility improvements at elevated temperatures were also observed. The improved

Steve Hahn; Saul Isserow; Ranjan Ray

1987-01-01

143

Mechanical, Corrosion, and Fatigue Properties of 15-5 PH, Inconel 718, and Rene 41 Weldments.  

National Technical Information Service (NTIS)

Weldments of three hydrofoil strut/foil candidate materials (15-5 PH stainless steel, Inconel 718, and Rene 41) for hydrofoils were prepared. Mechanical, fatigue, corrosion fatigue, and corrosion tests were performed on these materials with various postwe...

H. P. Hack

1975-01-01

144

Electrochemical Studies of Passive Film Stability on Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 Amorphous Metal in Seawater at 90oCElectrochemical Studies of Passive Film Stability on Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 Amorphous Metal in Seawater at 9  

SciTech Connect

An iron-based amorphous metal, Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4} (SAM2X5), with very good corrosion resistance was developed. This material was prepared as a melt-spun ribbon, as well as gas atomized powder and a thermal-spray coating. During electrochemical testing in several environments, including seawater at 90 C, the passive film stability was found to be comparable to that of high-performance nickel-based alloys, and superior to that of stainless steels, based on electrochemical measurements of the passive film breakdown potential and general corrosion rates. This material also performed very well in standard salt fog tests. Chromium (Cr), molybdenum (Mo) and tungsten (W) provided corrosion resistance, and boron (B) enabled glass formation. The high boron content of this particular amorphous metal made it an effective neutron absorber, and suitable for criticality control applications. This material and its parent alloy maintained corrosion resistance up to the glass transition temperature, and remained in the amorphous state during exposure to relatively high neutron doses.

Farmer, J C; Haslam, J; Day, S D; Lian, T; Saw, C K; Hailey, P D; Choi, J S; Rebak, R B; Yang, N; Payer, J H; Perepezko, J H; Hildal, K; Lavernia, E J; Ajdelsztajn, L; Branagan, D J; Buffa, E J; Aprigliano, L F

2007-04-25

145

Method of forming dynamic membrane on stainless steel support  

NASA Technical Reports Server (NTRS)

A suitable member formed from sintered, powdered, stainless steel is contacted with a nitrate solution of a soluble alkali metal nitrate and a metal such as zirconium in a pH range and for a time sufficient to effect the formation of a membrane of zirconium oxide preferably including an organic polymeric material such as polyacrylic acid.

Gaddis, Joseph L. (inventor); Brandon, Craig A. (inventor)

1988-01-01

146

PRECIPITATION-HARDENING STAINLESS STEELS IN WATER-COOLED REACTORS  

Microsoft Academic Search

A study is made of the stress corrosion susceptibiity of unirradiated ; precipitation-hardening stainless steels. This study is made because of the ; failures encouatered with these materials in the Dresden and Vallecltos boiling ; water reactors. Service experience, static steam autoclave tests, and dynamic ; water and steam corrosion loop tests have demonstrated that 17-4 PH in the high-;

M. C. Rowland; W. R. Sr. Smith

1962-01-01

147

Corrosion in stainless steels  

SciTech Connect

Although it is unreasonable to assume that technology will eventually eliminate all corrosion, it is of vital importance to note that many problems could be avoided through failure analysis and corrosion-preventive design. Laboratory analysis and testing often prove to be a wise investment in preventing potential corrosion problems in stainless steels. This article discusses important corrosion modes in stainless steels, including general, pitting, galvanic, and microbiologically induced corrosion, as well as stress corrosion cracking. It also includes descriptions of failure analysis techniques, including visual and stereomicroscopic examination, chemical analysis, metallographic examination, scanning electron microscopy, immersion testing, and electrochemical corrosion testing.

Suess, S.J. [Technimet Corp., New Berlin, WI (United States)

1997-04-01

148

Switch to duplex stainless steels  

Microsoft Academic Search

Duplex stainless steels contain approximately equal proportions of ferrite and austenite. These stainless steels have become an established material of construction in the chemical process industries (CPI). Duplexes offer benefits over austenitic stainless steels and carbon steels because of their higher strength, and good toughness and ductility, in combination with equivalent resistance to general corrosion, as well as better resistance

J. M. A. Quik; M. Geudeke

1994-01-01

149

Fusion weld stainless steels properly  

Microsoft Academic Search

Stainless steels are widely and effectively joined by a variety of welding techniques. There are, however, many different stainless steels, and techniques to produce quality welds differ among the types of alloys. Stainless steels are ferrous alloys containing a minimum of 10% chromium, required to produce the resistance to atmospheric corrosion that is associated with these alloys. Other alloys elements

Bohl

1995-01-01

150

Corrosion of Welded Stainless Steel  

Microsoft Academic Search

Stainless steels are usually chosen for their low corrosion rates and in some cases their resistance to pitting. In addition, when welded stainless steels are used, measures are taken to reduce the susceptibility to sensitization and other forms of corrosion. Additional care may have to be taken when the environmental conditions associated with the use of the stainless steels are

T. Defee; H. G. Wheat; S. Landsberger

151

A vibrational spectroscopic study of the borate mineral ezcurrite Na4B10O17·7H2O - Implications for the molecular structure  

NASA Astrophysics Data System (ADS)

We have studied the boron containing mineral ezcurrite Na4B10O17·7H2O using electron microscopy and vibrational spectroscopy. Both tetrahedral and trigonal boron units are observed. The nominal resolution of the Raman spectrometer is of the order of 2 cm-1 and as such is sufficient enough to identify separate bands for the stretching bands of the two boron isotopes. The Raman band at 1037 cm-1 is assigned to BO stretching vibration. Raman bands at 1129, 1163, 1193 cm-1 are attributed to BO stretching vibration of the tetrahedral units. The Raman band at 947 cm-1 is attributed to the antisymmetric stretching modes of tetrahedral boron. The sharp Raman peak at 1037 cm-1 is from the 11-B component such a mode, then it should have a smaller 10-B satellite near (1.03) × (1037) = 1048 cm-1, and indeed a small peak at 1048 is observed. The broad Raman bands at 3186, 3329, 3431, 3509, 3547 and 3576 cm-1 are assigned to water stretching vibrations. Broad infrared bands at 3170, 3322, 3419, 3450, 3493, 3542, 3577 and 3597 cm-1 are also assigned to water stretching vibrations. Infrared bands at 1330, 1352, 1389, 1407, 1421 and 1457 cm-1 are assigned to the antisymmetric stretching vibrations of trigonal boron. The observation of so many bands suggests that there is considerable variation in the structure of ezcurrite. Infrared bands at 1634, 1646 and 1681 cm-1 are assigned to water bending modes. The number of water bending modes is in harmony with the number of water stretching vibrations.

Frost, Ray L.; López, Andrés; Theiss, Frederick L.; Scholz, Ricardo; Belotti, Fernanda M.

2014-07-01

152

An STM study of the localized atomic reaction of 1,2- and 1,4-dibromoxylene with Si(1 1 1)-7 × 7  

NASA Astrophysics Data System (ADS)

Thermal reactions of 1,2- and 1,4-dibromoxylene (1,2- and 1,4-diBrXy) with Si(1 1 1)-7 × 7 were investigated by STM at room temperature under UHV conditions. Reaction led to the formation of single adsorbed Br-atoms or pairs of Br-atoms, in a ratio approx. 3:1 for both reagents. Experimental results were interpreted in terms of 'parent-mediated' (halogen atom accompanied by organic residue), and 'daughter-mediated' (no accompanying organic residue) reaction dynamics. Both mechanisms contributed to the bromination of the silicon surface in comparable amounts. For pairs of bromine atoms the Br-Br separation had a most probable value of 7.6 Å for 1,2-diBrXy, and 11.5 Å for 1,4-diBrXy. This separation was in each case greater than that in the diBrXy parent molecule by a few angstroms. For parent-mediated reaction the dynamics were revealed in detail by the STM images which gave the vectorial location of the halogen-atom products (distance and angle of the daughter atoms) relative to the prior location and alignment of the adsorbed parent molecule. Both reagents, 1,2- and 1,4-diBrXy, were found to be less reactive than the corresponding dibromobenzenes studied earlier in this laboratory [S. Dobrin et al., Surf. Sci. 561 (2004) 11], in both parent- and daughter-mediated modes.

Dobrin, Sergey; Rajamma Harikumar, K.; Matta, Chérif F.; Polanyi, John C.

2005-04-01

153

VHF and L-band scintillation characteristics over an Indian low latitude station, Waltair (17.7° N, 83.3° E)  

NASA Astrophysics Data System (ADS)

Characteristics of simultaneous VHF (244 MHz) and L-band (1.5 GHz) scintillations recorded at a low-latitude station, Waltair (17.7° N, 83.3° E), during the low sunspot activity year of March 2004 to March 2005, suggest that the occurrence of scintillations is mainly due to two types, namely the Plasma Bubble Induced (PBI), which maximizes during the post sunset hours of winter and equinoctial months, and the Bottom Side Sinusoidal (BSS) type, which maximizes during the post-midnight hours of the summer solstice months. A detailed study on the spectral characteristics of the scintillations at both the frequencies show that the post-sunset scintillations are strong with fast fading (?40 fad/min) and are multiple in nature in scattering, giving rise to steep spectral slopes, whereas the post-midnight scintillations, which occur mostly on the VHF signal with low fading rate (?4 fad/min), are of the BSS type, often showing typical Fresnel oscillations with reduced roll off spectral slopes, indicating that the type of irregularity resembles a thin screen structure giving rise to weak scattering. Using the onset times of several similar scintillation patches across the two satellite (FLEETSAT 73° E, INMARSAT 65° E) ray paths (sub-ionospheric points are separated by 82 km), the East ward movement of the irregularity patches is found to vary from 150 to 250 m/s during the post sunset hours and decrease slowly during the post midnight hours. Further, the east-west extent of the PBI type of irregularities is found to vary from 100 to 500 km, while that of the BSS type extend up to a few thousand kilometers. Keywords. Ionosphere (Ionospheric irregularities; Auroral ionosphere; Electric fields and currents)

Rama Rao, P. V. S.; Tulasi Ram, S.; Niranjan, K.; Prasad, D. S. V. V. D.; Gopi Krishna, S.; Lakshmi, N. K. M.

2005-10-01

154

Gaseous hydrogen embrittlement of PH 13-8 Mo steel  

Microsoft Academic Search

In this study, notched tensile and fatigue crack growth tests in gaseous hydrogen were performed on PH 13-8 Mo stainless steel specimens at room temperature. These specimens were susceptible to hydrogen embrittlement (HE), but at different degrees, depending on the aging conditions or the microstructures of the alloys. In hydrogen, the accelerated fatigue crack growth rate (FCGR) usually accompanied a

Y. S. Ding; L. W. Tsay; M. F. Chiang; C. Chen

2009-01-01

155

Evaluation of Armco PH13-8Mo.  

National Technical Information Service (NTIS)

The PH-13 13-8 Mo is a precipitation hardenable stainless steel. This steel can be heat treated to 225 ksi and has excellent toughness, general corrosion, and stress corrision at this strength level. The fatigue life is comparable to 4330 in both the smoo...

J. M. Uchida

1969-01-01

156

Sensitization of stainless steel  

NASA Technical Reports Server (NTRS)

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

Nagy, James P.

1990-01-01

157

Welding of Stainless Materials  

NASA Technical Reports Server (NTRS)

It would appear that welds in some stainless steels, heat-treated in some practicable way, will probably be found to have all the resistance to corrosion that is required for aircraft. Certainly these structures are not subjected to the severe conditions that are found in chemical plants.

Bull, H; Johnson, Lawrence

1929-01-01

158

Corrosion behavior of 2205 duplex stainless steel  

Microsoft Academic Search

The corrosion behavior of 2205 duplex stainless steel was compared with that of AISI type 316L stainless steel. The 2205 stainless steel is a potential orthodontic bracket material with low nickel content (4 to 6 wt%), whereas the 316L stainless steel (nickel content: 10 to 14 wt%) is a currently used bracket material. Both stainless steels were subjected to electrochemical

Jeffrey A. Platt; Andres Guzman; Arnaldo Zuccari; David W. Thornburg; Barbara F. Rhodes; Yoshiki Oshida; B. Keith Moore

1997-01-01

159

Passivation of stainless steel  

Microsoft Academic Search

This paper, the 19th in a series of articles on the hygienic design of food processing equipment published in TIFS, introduces the first joint EHEDG\\/3-A Update article in the series, a set of guidelines for the hygienic passivation of stainless steel surfaces intended for food-contact use. These guidelines have been prepared on behalf of the US-based 3-A Steering Committee and

R. R Maller

1998-01-01

160

A SURVEY OF THE CORROSION OF MARTENSITIC AND FERRITIC STAINLESS STEELS IN PRESSURIZED WATER  

Microsoft Academic Search

The corrosion resistance of mantensitic and ferritic austenitic ; stainless steels and carbon steels in pressurized water at 500 to 600 deg F is ; compared. Included are specific out-of-pile data for austenitic stainless ; steels, AISI types types 410, 420, 431, and 440C; the ferritic AISI types 430, ; 442, and 446; the precipitation-hardening type 17-4PH; and carbon steels,

R. J. Beaver; C. F. Jr. Leitten

1963-01-01

161

An analysis of grain boundary cohesion in precipitation hardened stainless steel  

Microsoft Academic Search

17-4 precipitation hardened (PH) stainless steel belongs to the family of precipitation hardening martensitic stainless steel (AISI 630), containing 17%Cr, 4%Ni and 4%Cu as the main alloying elements; carbon content in the steel is normally maintained below about 0.05 wt.%. The authors have recently attempted an assessment of 17-4 precipitation hardened martensitic steel in terms of processing steps and heat

R. D. K Misra; R. Rao

1993-01-01

162

Pitting inhibition of stainless steel by surfactants: an electrochemical and surface chemical approach  

Microsoft Academic Search

Pitting corrosion of stainless steels causes tremendous damage in terms of material loss and resulting accidents. Organic surfactants have been tried as pitting inhibitors but the understanding of the inhibition mechanisms is mainly speculative. In the present study the inhibition of the pitting corrosion of 304 stainless steel by N-lauroylsarcosine sodium salt (NLS) in 0.1 M NaCl solutions at neutral pH

Zhenqiang Wei; Paul Duby; P. Somasundaran

2003-01-01

163

Understanding pH  

NSDL National Science Digital Library

The first site related to pH is from the Horiba corporate Web site entitled the Story of pH (1). Visitors can learn what pH is and how it's measured, explore various facts about pH, and read several anecdotes such as "Is the Rain in Our Cities Acidic." The site contains simple text, attractive graphics, and a well-designed layout making it fun and easy for anyone to explore. The second site from the Miami Museum of Science is called the pH Factor (2) kids activity page. This interactive and extensive site contains lessons on testing items for pH, tasting acids and bases, an interactive meter to find the pH of common household items, and much more. Next, is the pH and Water Quality (3) page, which is part of the State of Kentucky Division of Water Web site. The site provides a table of the effects of pH on fish and aquatic life and gives a short description of the most significant environmental impacts of pH. Trout for example, can tolerate a pH range between 4.1 and 9.5 while Mosquito larvae can survive within the 3.3 and 4.7 range. The fourth site from Gardengate Magazine.com is entitled More Soil Stuff: Soil pH (4). Described is the pH range of most soil types, requirements of certain plants, how to test soil for pH, and how to adjust it using sulfur and limestone. Seaworld.org maintains the Understanding the pH Cycle within the Aquarium (5) lesson plan site. The stated objective of the activity is to have students define pH, explain how it affects a tank's water quality, and test the pH level in a classroom aquarium. Although an aquarium is obviously needed, the activity offers a unique and fun way for kids to learn about this basic chemistry concept. About.com offers the next site, which is an interactive pH calculator called pH (6). Users simply enter a pH to get the concentration of Hydrogen ions or, conversely, the Hydrogen ion concentration to get the pH. Another tool to learn about pH and Hydrogen ions is called Acids and Alkalis--the pH Scale (7). Provided by Purchon.com, the interactive pH scale illustrates how the ion concentration changes with pH, common acids associated with each, and whether it is a weak or strong acid or alkali. The last site maintained by the National Park Service is called Acid Rain Lesson Plan: Activity 1 The pH Scale (8). Kids will be able to describe the pH scale and its components, explain why a pH measurement must be accurate, and explain why small changes in pH are important. Everything needed to complete the activity is provided, including a materials list, complete instructions, thinking questions, as well as links for further information.

Brieske, Joel A.

164

High performance stainless steels for critical engineering applications  

Microsoft Academic Search

MIDHANI has been producing special stainless steels for different sectors. Production of these steels has posed challenges\\u000a with respect to control over chemical composition, designing heat treatment parameters to meet the desired properties. The\\u000a most challenging grades have been SS304L, 13-8 PH and 9Cr1Mo steels to name a few. The melting equipments were selected with\\u000a utmost care and processing was

M. Narayana Rao

2010-01-01

165

Comparison of Stainless Steels in Simulated Paper Machine Environments  

Microsoft Academic Search

The localized corrosion behavior of austenitic stainless steels (SS) UNS S30403 and UNS S31603, and duplex SS UNS S31803 was compared in simulated paper machine environments containing chloride, sulfate, and thiosulfate at pH 3 and 65 C. Electrochemical testing of the materials was performed by cyclic polarization scans and scratch tests. Thiosulfate caused a remarkable decrease in repassivation potentials (E{sub

T. M. J. Laitinen; T. M. J

1999-01-01

166

Crack Initiation Mechanisms for Corrosion Fatigue of Austenitic Stainless Steel  

Microsoft Academic Search

Corrosion fatigue tests on annealed type 316 stainless steel showed the maximum stress level for failure in 0.5 M sodium chloride aqueous solution at pH = 4.2 was one-third lower than in air after a similar number of cycles. Crack initiation mechanisms of corrosion fatigue were studied by scanning electron microscopy of prepolished specimen surfaces. Fatigue tests were conducted at

Y. R. Qian; J. R. Cahoon

1997-01-01

167

Switch to duplex stainless steels  

SciTech Connect

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

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

1994-11-01

168

pH Game  

NSDL National Science Digital Library

The purpose of this resource is to teach students about the acidity levels of liquids and other substances around their school so they understand what pH levels tell us about the environment. Students will create mixtures of water samples, soil samples, plants and other natural materials to better understand the importance of pH levels.

The GLOBE Program, UCAR (University Corporation for Atmospheric Research)

2003-08-01

169

Corrosion Resistance of Amorphous Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 coating - a new criticality-controlled material  

SciTech Connect

An iron-based amorphous metal with good corrosion resistance and a high absorption cross-section for thermal neutrons has been developed and is reported here. This amorphous alloy has the approximate formula Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4} and is known as SAM2X5. Chromium (Cr), molybdenum (Mo) and tungsten (W) were added to provide corrosion resistance, while boron (B) was added to promote glass formation and the absorption of thermal neutrons. Since this amorphous metal has a higher boron content than conventional borated stainless steels, it provides the nuclear engineer with design advantages for criticality control structures with enhanced safety. While melt-spun ribbons with limited practical applications were initially produced, large quantities (several tons) of gas atomized powder have now been produced on an industrial scale, and applied as thermal-spray coatings on prototypical half-scale spent nuclear fuel containers and neutron-absorbing baskets. These prototypes and other SAM2X5 samples have undergone a variety of corrosion testing, including both salt-fog and long-term immersion testing. Modes and rates of corrosion have been determined in various relevant environments, and are reported here. While these coatings have less corrosion resistance than melt-spun ribbons and optimized coatings produced in the laboratory, substantial corrosion resistance has been achieved.

Farmer, J C; Choi, J S; Saw, C K; Rebak, R; Day, S D; Lian, T; Hailey, P; Payer, J H; Branagan, D J; Aprigliano, L F

2007-03-28

170

Long-Term Corrosion Tests of Prototypical SAM2X5 (Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4) Coatings  

SciTech Connect

An iron-based amorphous metal with good corrosion resistance and a high absorption cross-section for thermal neutrons has been developed and is reported here. This amorphous alloy has the approximate formula Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4} and is known as SAM2X5. Chromium (Cr), molybdenum (Mo) and tungsten (W) were added to provide corrosion resistance, while boron (B) was added to promote glass formation and the absorption of thermal neutrons. Since this amorphous metal has a higher boron content than conventional borated stainless steels, it provides the nuclear engineer with design advantages for criticality control structures with enhanced safety. While melt-spun ribbons with limited practical applications were initially produced, large quantities (several tons) of gas atomized powder have now been produced on an industrial scale, and applied as thermal-spray coatings on prototypical half-scale spent nuclear fuel containers and neutron-absorbing baskets. These prototypes and other SAM2X5 samples have undergone a variety of corrosion testing, including both salt-fog and long-term immersion testing. The modes and rates of corrosion have been determined in the various environments, and are reported here. While these coatings have less corrosion resistance than melt-spun ribbons and optimized coatings produced in the laboratory, substantial corrosion resistance has been achieved.

Farmer, J C; Choi, J S; Saw, C K; Rebak, R H; Day, S D; Lian, T; Hailey, P D; Payer, J H; Branagan, D J; Aprigliano, L F

2007-05-10

171

Welding tritium exposed stainless steel  

SciTech Connect

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

Kanne, W.R. Jr.

1994-11-01

172

Exercise and Pulmonary Hypertension (PH)  

MedlinePLUS

... International PH News and Projects Let Me Breathe Music Video PATIENTS Patients Newly Diagnosed Request an Envelope ... International PH News and Projects Let Me Breathe Music Video Help spread PH awareness and share PH ...

173

Thermal Fatigue of Stainless Steel.  

National Technical Information Service (NTIS)

Two austenitic steels, 316 Stainless Steel and Alloy 800, have been examined under conditions of both isothermal low cycle fatigue (LCF) and thermomechanical fatigue (TMF). The TMF tests were conducted between 649 abd 360 deg C with a carefully controlled...

J. A. Van Den Avyle R. J. Bourcier W. B. Jones

1987-01-01

174

Brazing titanium to stainless steel  

NASA Technical Reports Server (NTRS)

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

Batista, R. I.

1980-01-01

175

Hydrogen embrittlement of stainless steels  

Microsoft Academic Search

ABSTRACT Stainless steels are specified for hydrogen service when enhanced compatibility, safety, and reliability are required. Prior to consideration of the issues surrounding containment applications, we will review the phenomenology,of hydrogen,effects. The mechanical,response of stainless steels to hydrogen,exposure varies widely as a consequence of composition, thermo-mechanical preparation, joining, and testing methods. Composition dictates phase stability and properties such as the

Neville Reid Moody; Brian P. Somerday; Steven L. Robinson

2004-01-01

176

Characteristics of VHF radiowave scintillations over a solar cycle (1983-1993) at a low-latitude station: Waltair (17.7 deg N, 83.3 deg E)  

NASA Astrophysics Data System (ADS)

The characteristics of VHF radiowave scintillations at 244 MHz (FLEETSAT) during a complete solar cycle (1983-93) at a low-latitude station, Waltair (17.7 deg N, 83.3 deg E), are presented. The occurrence of night-time scintillations shows equinoctial maxima and summer minima in all the epochs of solar activity, and follows the solar activity. The daytime scintillation occurrence is negatively correlated with the solar activity and shows maximum occurrence during the summer months in a period of low solar activity. The occurrence of night-time scintillations is inhibited during disturbed days of high solar activity and enhanced during low solar activity.

Rama Rao, P. V. S.; Jayachandran, P. T.; Sri Ram, P.; Ramana Rao, B. V.; Prasad, D. S. V. V. D.; Bose, K. K.

1997-06-01

177

Weld microstructure development and properties of precipitation-strengthened martensitic stainless steels  

Microsoft Academic Search

The weld microstructural evolution, mechanical properties and solidification cracking susceptibility of three precipitation-strengthened martensitic stainless steels--PH 13-8 Mo, Custom 450 and 15-5 PH--were investigated. Liquid tin quenching of gas tungsten arc welds revealed that all three welds solidified as single-phase ferrite with a high degree of microsegregation. However, during further solidification and cooling almost complete homogenization occurred as a result

J. A. Brooks; W. R. Jr. Garrison

1999-01-01

178

Stainless steel bipolar plates  

NASA Astrophysics Data System (ADS)

In this research, a specific surface modification technology was developed for stainless steel bipolar plates to obtain a corrosion-resistant oxide film. The surface roughness was measured, and an electron spectroscopy analysis (ESCA) was conducted to verify the chemical composition of the surface layer. From the binding energy of the ESCA spectrum, the amounts of chemical shift were used to identify the major chemical compositions. The thickness of the oxide film was analyzed by auger electron spectroscopy (AES). From the results of the ESCA and AES analyses, the effects of the surface modification on the integrity of the surface were evaluated. Uniform corrosion and localized corrosion tests were also conducted to investigate any improvement on the corrosion characteristics. A single cell was assembled for cell performance tests. The surface of the treated plates was bright and smooth. The ESCA and AES analyses showed that the treated plates had a much higher chrome content. The metallurgical structure was dense with substantially less defects. The chemical and electrochemical properties were more stable. The corrosion rates of the treated plates were also much improved, resulting in better electric conductivity, stable cell performance as well as longer cell life.

Lee, Shuo-Jen; Lai, Jian-Jang; Huang, Ching-Han

179

Life prediction on SCC of solution annealed stainless steels under laboratory conditions  

Microsoft Academic Search

The stress corrosion cracking (SCC) behavior of austenitic stainless steels, types 304 and 316 has been investigated in acidic solutions to verify whether or not a parameter for prediction of time to failure can be detected as functions of applied stress and environmental factors (temperature, concentration, pH, anion species) by using a constant load. The results show that the steady

R Nishimura; K Yamakawa

1998-01-01

180

Achievement of a superpolish on bare stainless steel  

SciTech Connect

We report the achievement of a superpolished surface, suitable for x-ray reflection, on bare stainless steel. The rms roughness obtained on various samples varied from 2.2 to 4.2 {angstrom}, as measured by an optical profiler with a bandwidth 0.29-100 mm{sup -1}. The type 17-4 PH precipitation-hardening stainless steel used to make the mirrors is also capable of ultrastability and has good manufactureability. This combination of properties makes it an excellent candidate material for mirror substrates. We describe the successful utilization of this type of steel in making elliptical-cylinder mirrors for a soft-x-ray microprobe system at the Advanced Light Source, and discuss possible for its unusual stability and polishability.

Howells, M.R. [Lawrence Berkeley National Lab., CA (United States); Casstevens, J. [Dallas Optical Systems, Rockwell, TX (United States)

1997-08-01

181

Corrosion and inhibition of stainless steel pitting corrosion in alkaline medium and the effect of Cl ? and Br ? anions  

Microsoft Academic Search

The effect of carbonate anion on the pitting corrosion and inhibition behavior of stainless steel samples (304L SS and 316L SS) has been studied using potentiodynamic and scanning electron microscope (SEM) techniques. The effect of concentration of CO32? ions, pH, potential scanning rate and the composition of stainless steel are discussed. Additions of Cl? and Br? ions into the carbonate

S. A. M. Refaey; F. Taha; A. M. Abd El-Malak

2005-01-01

182

Overlay welding irradiated stainless steel  

NASA Astrophysics Data System (ADS)

An overlay technique developed for welding irradiated stainless steel may be important for repair or modification of fusion reactor materials. Helium, present due to (n,alpha) reactions, is known to cause cracking using conventional welding methods. Stainless steel impregnated with 3 to 220 appm helium by decay of tritium was used to develop a welding process that could be used for repair. The result was a gas metal arc weld overlay technique with low-heat input and low-penetration into the helium-containing material. Extensive metallurgical and mechanical testing of this technique demonstrated substantial reduction of helium embrittlement damage. The overlay technique was applied to irradiated 304 stainless steel containing 10 appm helium. Surface cracking, present in conventional welds made on the same steel at lower helium concentrations, was eliminated. Underbead cracking, although greater than for tritium charged and aged material, was minimal compared to conventional welding methods.

Kanne, W. R.; Chandler, G. T.; Nelson, D. Z.; Franco-Ferreira, E. A.

183

Hydrogen Solubility in Austenitic Stainless Steels  

SciTech Connect

Hydrogen solubility was directly measured in specimens of Types 304L, 21-6-9, and modified A-286 austenitic stainless steels saturated with hydrogen at 69 MPa pressure at 470 K. Nitrogen in Type 21-6-9 stainless steel and precipitate morphology in the modified Type A-286 stainless steel altered the hydrogen solubility. Cold work and surface treatment had only minor effects on hydrogen solubility in the three stainless steels. This reports discusses this study.

Caskey, G.R. Jr.

1981-05-21

184

Ph.D. shortage  

NASA Astrophysics Data System (ADS)

The late 1990s will see a shortage of Ph.D. graduates, according to the Association of American Universities, Washington, D.C. AAU's new comprehensive study, “The Ph.D. Shortage: The Federal Role,” reports that competition for new Ph.D.s is already intense and can only intensify because demand is greater than supply in both academic and nonacademic markets.Doctoral education plays an increasingly important role in U.S. research and development programs. Students have a pivotal part in doing research and enriching it with new ideas. The AAU report says that graduate students are “major determinants of the creativity and productivity of U.S. academic research, the source of more than 50% of the nation's basic research.’ The market for doctoral education extends beyond the university. In 1985, about 43% of all Ph.D.s employed in this country were working outside higher education; the demand for doctorate recipients in nonacademic sectors continues to grow.

185

Composite copper\\/stainless steel coated powders  

Microsoft Academic Search

The present research work concerns the development of new composites based on austenitic stainless steel (SS) or copper (Cu) microsized powders coated with thin nanostructured layers of copper or stainless steels, respectively. A home-manufactured magnetron sputtering system equipped with a powder vibration device was used to coat the powders. A detailed analysis of the coated copper or stainless steel powders

Mariana Matos; José M. Castanho; Maria T. Vieira

2009-01-01

186

Abrasion wear resistance of arc-sprayed stainless steel and composite stainless steel coatings  

Microsoft Academic Search

The abrasion wear resistance of stainless steel and composite stainless steel\\/titanium boride coatings arc sprayed with air\\u000a and argon was evaluated. Stainless steel coatings arc sprayed with air were found to be slightly more resistant than bulk\\u000a stainless steel, whereas those sprayed with argon were slightly less resistant. The wear resistance of composite stainless\\u000a steel\\/titanium diboride coatings was from two

S. Dallaire; J. G. Legoux; H. Levert

1995-01-01

187

Shrinkage Prediction for the Investment Casting of Stainless Steels  

SciTech Connect

In this study, the alloy shrinkage factors were obtained for the investment casting of 17-4PH stainless steel parts. For the investment casting process, unfilled wax and fused silica with a zircon prime coat were used for patterns and shell molds, respectively. Dimensions of the die tooling, wax pattern, and casting were measured using a Coordinate Measurement Machine in order to obtain the actual tooling allowances. The alloy dimensions were obtained from numerical simulation results of solidification, heat transfer, and deformation phenomena. The numerical simulation results for the shrinkage factors were compared with experimental results.

Sabau, Adrian S [ORNL

2007-01-01

188

IMPROVED STAINLESS STEEL PROCESSING ROUTES  

Microsoft Academic Search

Advanced melting technology is now being employed in the manufacture of stainless steel powders. The new process currently includes electric arc furnace (EAF) technology in concert with Argon Oxygen Decarburization (AOD), High Performance Atomizing (HPA) and hydrogen annealing. The new high performance processing route has allowed Hoeganaes Corporation to provide not only a more consistent product, but has allowed enhanced

Chris Schade; Robert Causton; Tina Cimino-Corey

189

EAF STAINLESS STEEL DUST PROCESSING  

Microsoft Academic Search

During the production of stainless steel iron, between 30 and 70 kg of dust and fine waste is generated per ton of steel. Mintek has developed the EnviroplasTM process for the treatment of solid wastes from the metallurgical industry, especially steel plant dusts, without requiring agglomeration to produce inert slag and at the same time recover metal values such as

G. M. Denton; N. A. Barcza; P. D. Scott; T. Fulton

190

Thermal Fatigue of Stainless Steel.  

National Technical Information Service (NTIS)

Two austenitic steels, 316 Stainless Steel and Alloy 800, have been examined under conditions of both isothermal low cycle fatigue (LCF) and thermomechanical fatigue (TMF). The TMF tests were conducted between 649 and 360 deg 0 C with a carefully controll...

J. A. Van Den Avyle R. J. Bourcier W. B. Jones

1987-01-01

191

The basics of stainless steels  

SciTech Connect

Examines stainless steel vis-a-vis the grades and types available, their corrosion resistance, their physical and mechanical properties, and how they perform during fabrication and welding. Topics include activity and passivity, electrochemistry of corrosion, welding ferritics, welding austenitics, welding precipitation-hardening steels, welding free-machinery steels, soldering, brazing and fasteners.

Redmond, J.D.; Miska, K.H.

1982-10-01

192

Brazing Stainless Steel to Copper  

Microsoft Academic Search

A requiremcnt often encountered in electron tube developmental work is ; the joining of copper to stainless steel. The usual methods of pcrforming such ; brazes require that a protective nickel coating first be applied to the stain ; equent brazing operation be carried out in dry hydrogen. An ; alternative method not requiring hydrogen, prior to nickel plating, or

Morris Liebson

1959-01-01

193

Corrosion behavior of 2205 duplex stainless steel.  

PubMed

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

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

1997-07-01

194

Crack initiation mechanisms for corrosion fatigue of austenitic stainless steel  

SciTech Connect

Corrosion fatigue tests on annealed type 316 stainless steel showed the maximum stress level for failure in 0.5 M sodium chloride aqueous solution at pH = 4.2 was one-third lower than in air after a similar number of cycles. Crack initiation mechanisms of corrosion fatigue were studied by scanning electron microscopy of prepolished specimen surfaces. Fatigue tests were conducted at sufficiently high stresses to cause formation of intensive slip bands. Interaction of the acidic saline solution with the slip bands caused pitting corrosion along the slip bands. A mechanism for crack initiation resulting from pit formation and crack coalescence was suggested to explain the decrease in the maximum stress level for corrosion fatigue of austenitic SS, which exhibited passive behavior and generally good corrosion resistance in 0.5 M NaCl solution at pH = 4.2.

Qian, Y.R. [Beijing Univ. of Aeronautics and Astronautics (China); Cahoon, J.R. [Univ. of Manitoba, Winnipeg, Manitoba (Canada)

1997-02-01

195

Comparative Study on the Corrosion Resistance of Fe-Based Amorphous Metal, Borated Stainless Steel and Ni-Cr-Mo-Gd Alloy  

SciTech Connect

Iron-based amorphous alloy Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4} was compared to borated stainless steel and Ni-Cr-Mo-Gd alloy on their corrosion resistance in various high-concentration chloride solutions. The melt-spun ribbon of this iron-based amorphous alloy have demonstrated a better corrosion resistance than the bulk borated stainless steel and the bulk Ni-Cr-Mo-Gd alloy, in high-concentration chloride brines at temperatures 90 deg. C or higher. (authors)

Lian, Tiangan; Day, Daniel; Hailey, Phillip; Choi, Jor-Shan; Farmer, Joseph [Lawrence Livermore National Laboratory, Livermore, CA, 94550 (United States)

2007-07-01

196

Nickel release from stainless steels.  

PubMed

In 1994, a study of nickel release and allergic contact dermatitis from nickel-plated metals and stainless steels was published in this journal. It was shown that low-sulfur stainless steel grades like AISI 304, 316L or 430 (S < or = 0.007%) release less than 0.03 microgram/cm2/week of nickel in acid artificial sweat and elicit no reactions in patients already sensitized to nickel. In contrast, nickel-plated samples release around 100 micrograms/cm2/week of Ni and high-sulfur stainless steel (AISI 303-S approximately 0.3%) releases about 1.5 micrograms/cm2/week in this acid artificial sweat. Applied on patients sensitized to nickel, these metals elicit positive reactions in 96% and 14%, respectively, of the patients. The main conclusion was that low-sulfur stainless steels like AISI 304, 316L or 430, even when containing Ni, should not elicit nickel contact dermatitis, while metals having a mean corrosion resistance like a high-sulfur stainless steel (AISI 303) or nickel-plated steel should be avoided. The determining characteristic was in fact the corrosion resistance in chloride media, which, for stainless steels, is connected, among other factors, to the sulfur content. Thus, a question remained concerning the grades with an intermediate sulfur content, around 0.03%, which were not studied. They are the object of the study presented in this paper. 3 tests were performed: leaching experiments, dimethylglyoxime and HNO3 spot tests, and clinical patch tests; however, only stainless steels were tested: a low-sulfur AISI 304 and AISI 303 as references and 3 grades with a sulfur content around 0.03%: AISI 304L, AISI 304L added with Ca, AISI 304L+Cu. Leaching experiments showed that the 4 non-resulfurised grades released less than 0.5 microgram/cm2/week in acid sweat while the reulfurized AISI 303 released around or more than 0.5 microgram/cm2/week. This is explained by the poorer corrosion resistance of the resulfurized grade. Yet all these grades had the same reaction to the DMG test (negative result), which shows again its lack of sensitivity. In contrast, the HNO3 spot test distinguished AISI 303 from the non-resulfurized grades. Clinical patch tests again showed that some patients (4%) were intolerant to AISI 303, while none were intolerant to the other grades. Thus, this study confirms that non-resulfurized stainless steels (S < or = 0.03%) like Ni-containing 304 and 304L should not elicit Ni contact dermatitis, while the resulfurized grades (S > 0.1%) should be avoided. PMID:9330816

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

1997-09-01

197

Proton-coupled protein binding: controlling lysozyme/poly(acrylic acid) interactions with pH.  

PubMed

Rational design of protein-polymer composites and their use, under the influence of the stimulus, for numerous applications requires a clear understanding of protein-polymer interfaces. Here, using poly(acrylic acid) (PAA) and lysozyme as model systems, the binding interactions between these macromolecules were investigated by isothermal titration calorimetry. The binding is proposed to require and be governed by "charge neutralization of the protein/polymer interface" and predicted to depend on solution pH. Calorimetric data show strong exothermic binding of lysozyme to PAA with a molar ?H and T?S values of -107 and -95 kcal/mol, respectively, at pH 7 and room temperature. Both ?H and T?S decreased linearly with increasing pH from 3 to 8, and these plots had slopes of -17.7 and -17.5 kcal/mol per pH unit, respectively. The net result was that the binding propensity (?G) was nearly independent of pH but the binding stoichiometry, surprisingly, increased rapidly with increasing pH from 1 lysozyme binding per PAA molecule at pH 3 to 16 lysozyme molecules binding per PAA molecule at pH 8. A plot of stoichiometry vs pH was linear, and consistent with this result, a plot of ln(average size of the protein/polymer complex) vs pH was also linear. Thus, protonation-deprotonation plays a major role in the binding mechanism. "Charge neutralization" of the lysozyme/PAA interface controls the binding stoichiometry as well as the binding enthalpies/entropies in a predictable fashion, but it did not control the binding affinity (?G). The pH dependence of lysozyme binding to PAA, demonstrated here, provides a stimuli-responsive system for protein binding and release from the polymer surface. PMID:24739101

Ghimire, Ananta; Kasi, Rajeswari M; Kumar, Challa V

2014-05-15

198

Thermal fatigue of stainless steel  

Microsoft Academic Search

Two austenitic steels, 316 Stainless Steel and Alloy 800, have been examined under conditions of both isothermal low cycle fatigue (LCF) and thermomechanical fatigue (TMF). The TMF tests were conducted between 649 and 360°C with a carefully controlled triangular waveform. The LCF tests were performed at 649°C and both kinds of tests were subjected to a strain range of 0.5%.

W. B. Jones; R. J. Bourcier; J. A. Van Den Avyle

1987-01-01

199

Thermal fatigue of stainless steel  

Microsoft Academic Search

Two austenitic steels, 316 Stainless Steel and Alloy 800, have been examined under conditions of both isothermal low cycle fatigue (LCF) and thermomechanical fatigue (TMF). The TMF tests were conducted between 649 abd 360°C with a carefully controlled triangular waveform. The LCF tests were performed at 649°C and both kinds of tests were subjected to a strain range of 0.5%.

W. B. Jones; R. J. Bourcier; J. A. Van Den Avyle

1987-01-01

200

Thermal fatigue of stainless steel  

SciTech Connect

Two austenitic steels, 316 Stainless Steel and Alloy 800, have been examined under conditions of both isothermal low cycle fatigue (LCF) and thermomechanical fatigue (TMF). The TMF tests were conducted between 649 and 360/sup 0/C with a carefully controlled triangular waveform. The LCF tests were performed at 649/sup 0/C and both kinds of tests were subjected to a strain range of 0.5%. TMF shortened life to 40% for 316 Stainless Steel and to 5% for Alloy 800. The microstructural evolution occurring in both alloys has been examined and we conclude these do not play a role in the life shortening caused by TMF. The TMF does produce asymmetric hysteresis loops with large tensile peak stresses in tests where the maximum temperature corresponded with the peak compressive stress. The influence of TMF on fatigue crack growth rates has been measured and it was found that TMF accelerated crack growth in Alloy 800 and slowed it down slightly in 316 Stainless Steel. The dominant influence of TMF appears to be in fatigue crack initiation, with the tensile peak stress development driving early crack initiation. 31 refs., 11 figs., 4 tabs.

Jones, W.B.; Bourcier, R.J.; Van Den Avyle, J.A.

1987-12-01

201

Thermal fatigue of stainless steel  

SciTech Connect

Two austenitic steels, 316 Stainless Steel and Alloy 800, have been examined under conditions of both isothermal low cycle fatigue (LCF) and thermomechanical fatigue (TMF). The TMF tests were conducted between 649 abd 360/sup 0/C with a carefully controlled triangular waveform. The LCF tests were performed at 649/sup 0/C and both kinds of tests were subjected to a strain range of 0.5%. TMF shortened life to 40% for 316 Stainless Steel and to 5% for Alloy 800. The microstructural evolution occurring in both alloys has been examined and we conclude these do not play a role in the life shortening caused by TMF. The TMF does produce asymmetric hysteresis loops with large tensile peak stresses in tests where the maximum temperature corresponded with the peak compressive stress. The influence of TMF on fatigue crack growth rates has been measured and it was found that TMF accelerated crack growth in Alloy 800 and slowed it down slightly in 316 Stainless Steel. The dominant influence of TMF appears to be in fatigue crack initiation, with the tensile peak stess development driving early crack initiation.

Jones, W.B.; Bourcier, R.J.; Van Den Avyle, J.A.

1987-01-01

202

Process for Recovering Silver, Copper, and Stainless Steel from Silver Brazed Stainless Steel Sections.  

National Technical Information Service (NTIS)

The patent application describes an electrolytic refining process for recovering silver, copper and stainless steel from stainless steel honey comb sections from military aircraft brazed with a silver based brazing compound, the brazed sections comprising...

B. W. Dunning D. H. Chambers

1977-01-01

203

Effect of acetic NaF solution on the corrosion behavior of stainless steel orthodontic brackets.  

PubMed

This study assessed the effect of acetic NaF solutions on stainless steel orthodontic brackets. Acetic acid was added to a 0.1% NaF solution to make two solutions, one with pH 3.5 and the other with pH 6. For the two different stainless steel brackets (Tomy, Dentaurum) used in this study, they had a similar elemental composition--except with Mo (molybdenum) in the Tomy bracket. The brackets were then immersed in the prepared test solutions for three days and their responses evaluated. In terms of hydrofluoric acid (HF) concentration, the 0.1%/pH 3.5 solution showed a high HF concentration at 227 ppm, while that of 0.1%/pH 6 solution was very low at 7 ppm. In terms of color change and element release, only the Dentaurum brackets in 0.1%/pH 3.5 solution showed an appreciable color change (deltaE* = 4.0) and released a great amount of elements (Fe, Cr, Ni, Mn) after three days. Otherwise, regardless of pH value and product, only minor color change (deltaE* < 1.0) and negligible element release occurred. In terms of surface modification, no visible changes in surface morphology were observed in any product after immersion in test solutions. PMID:16916238

Jang, Hee-Song; Son, Woo-Sung; Park, Soo-Byung; Kim, Hyung-Il; Yong, Hoon Kwon

2006-06-01

204

Hydrogen Solubility in Austenitic Stainless Steels  

Microsoft Academic Search

Hydrogen solubility was directly measured in specimens of Types 304L, 21-6-9, and modified A-286 austenitic stainless steels saturated with hydrogen at 69 MPa pressure at 470 K. Nitrogen in Type 21-6-9 stainless steel and precipitate morphology in the modified Type A-286 stainless steel altered the hydrogen solubility. Cold work and surface treatment had only minor effects on hydrogen solubility in

Caskey; G. R. Jr

1981-01-01

205

Aging degradation of cast stainless steel  

Microsoft Academic Search

A program is being conducted to investigate the significance of in-service embrittlement of cast-duplex stainless steels under light-water reactor operating conditions. Data from room-temperature Charpy-impact tests for several heats of cast stainless steel aged up to 10,000 h at 350, 400, and 450°C are presented and compared with results from other studies. Microstructures of cast-duplex stainless steels subjected to long-term

O. K. Chopra; H. M. Chung

1985-01-01

206

Development of a carburizing stainless steel alloy  

Microsoft Academic Search

A new carburizing stainless steel alloy that resists corrosion, heat, and fatigue has been developed for bearing and gear applications. Pyrowear 675 Stainless alloy is vacuum induction melted and vacuum arc remelted (VIM\\/VAR) for aircraft-quality cleanliness. Test results show that it has corrosion resistance similar to that of AISI Type 440-C stainless, and its rolling fatigue resistance is superior to

Wert

1994-01-01

207

Welding Metallurgy and Weldability of Stainless Steels  

NASA Astrophysics Data System (ADS)

Welding Metallurgy and Weldability of Stainless Steels, the first book in over twenty years to address welding metallurgy and weldability issues associated with stainless steel, offers the most up-to-date and comprehensive treatment of these topics currently available. The authors emphasize fundamental metallurgical principles governing microstructure evolution and property development of stainless steels, including martensistic, ferric, austenitic, duplex, and precipitation hardening grades. They present a logical and well-organized look at the history, evolution, and primary uses of each stainless steel, including detailed descriptions of the associated weldability issues.

Lippold, John C.; Kotecki, Damian J.

2005-03-01

208

Stainless Steel Bipolar Plates Deposited with Multilayer Films for PEMFC Applications  

NASA Astrophysics Data System (ADS)

A chromium nitride (CrN, Cr2N)/chromium (Cr)/indium-tin-oxide (ITO) system and a gold (Au)/titanium (Ti) system were separately deposited using a sputtering method and an E-beam method, respectively, onto stainless steel 316 and 304 plates. The XRD patterns of the deposited stainless steel plates showed the crystalline phase of typical indium-tin oxide and of metallic phases, such as chromium, gold, and the metal substrate, as well as those of external chromium nitride films. The nitride films were composed of two metal nitride phases that consisted of CrN and Cr2N compounds. The surface morphologies of the modified stainless steel bipolar plates were observed using atomic force microscopy and FE-SEM. The chromium nitride (CrN, Cr2N)/chromium (Cr)/indium-tin-oxide (ITO) multilayer that was formed on the stainless steel plates had a surface microstructural morphology that consisted of fine columnar grains 10 nm in diameter and 60 nm in length. The external gold films that were formed on the stainless steel plates had a grain microstructure approximately 100 nm in diameter. The grain size of the external surface of the stainless steel plates with the gold (Au)/titanium (Ti) system increased with increasing gold film thickness. The electrical resistances and water contact angles of the stainless steel bipolar plates that were covered with the multilayer films were examined as a function of the thickness of the ITO film or of the external gold film. In the corrosion test, ICP-MS results indicated that the gold (Au)/titanium (Ti) films showed relatively excellent chemical stability after exposure to H2SO4 solution with pH 3 at 80 °C.

Cho, Hyun; Yun, Young-Hoon

2013-08-01

209

Effect of Plasma Nitriding and Nitrocarburizing on HVOF-Sprayed Stainless Steel Coatings  

NASA Astrophysics Data System (ADS)

In this work, the effects of plasma nitriding (PN) and nitrocarburizing on HVOF-sprayed stainless steel nitride layers were investigated. 316 (austenitic), 17-4PH (precipitation hardening), and 410 (martensitic) stainless steels were plasma-nitrided and nitrocarburized using a N2 + H2 gas mixture and the gas mixture containing C2H2, respectively, at 550 °C. The results showed that the PN and nitrocarburizing produced a relatively thick nitrided layer consisting of a compound layer and an adjacent nitrogen diffusion layer depending on the crystal structures of the HVOF-sprayed stainless steel coatings. Also, the diffusion depth of nitrogen increased when a small amount of C2H2 (plasma nitrocarburizing process) was added. The PN and nitrocarburizing resulted in not only an increase of the surface hardness, but also improvement of the load bearing capacity of the HVOF-sprayed stainless steel coatings because of the formation of CrN, Fe3N, and Fe4N phases. Also, the plasma-nitrocarburized HVOF-sprayed 410 stainless steel had a superior surface microhardness and load bearing capacity due to the formation of Cr23C6 on the surface.

Park, Gayoung; Bae, Gyuyeol; Moon, Kyungil; Lee, Changhee

2013-12-01

210

Experimental investigation of tribological performance of laser textured stainless steel rings  

Microsoft Academic Search

A series of experiments is conducted to examine the frictional characteristics of laser surface-textured, heat-treated 17-4 PH stainless steel specimens. Two dimple shapes are tested: circular and elliptical. The circular dimples are designed with different sizes, dimple densities and dimple depth-to-diameter ratios. It is found that the cavitation pressure (Pcav) in a circular dimple is strongly affected by the operational

Y. Qiu; M. M. Khonsari

2011-01-01

211

Austenitic Stainless Steel EN 1.4404 Corrosion Detection Using Classification Techniques  

Microsoft Academic Search

\\u000a Different methods of classification have been used in this paper to model pitting corrosion behaviour of austenitic stainless\\u000a steel EN 1.4404. This material was subjected to electrochemical polarization tests in aqueous environment of varying chloride\\u000a ion concentration (from NaCl solutions), pH values and temperature in order to determine values of critical pitting potentials\\u000a (Epit) for each condition tested. In this

M. Jiménez-Come; E. Muñoz; R. García; V. Matres; M. Martín; F. Trujillo; I. Turias

212

Corrosion–erosion of nitrogen bearing martensitic stainless steels in seawater–quartz slurry  

Microsoft Academic Search

AISI 410S stainless steel was nitrided at 1473K in N2 atmosphere, direct quenched and tempered at temperatures between 473 and 873K. Martensitic cases with circa 0.52wt.%N at the surface were obtained. Corrosion–erosion tests were carried out in slurries composed by quartz particles and tap or substitute ocean water. The concentration of solids, the impact angle and the pH of solution

A. Toro; A. Sinatora; D. K. Tanaka; A. P. Tschiptschin

2001-01-01

213

Accelerated determination of the resistance of stainless steels to crevice corrosion in sea water  

SciTech Connect

The authors assess a wide range of stainless chromium steels used in platforms and other offshore facilities for their resistance or susceptibility to crevice as well as electrochemical and pitting corrosion in sea water and discuss an electrochemical method, based on the effect of the pH value on the solution potential, which they find determines corrosion resistance under the given conditions more quickly and efficiently than existing methods.

Korovin, Yu.M.

1987-03-01

214

Friction and wear of stainless steels implanted with Ti and C  

Microsoft Academic Search

Friction and wear tests were completed on Fe and stainless steels of the type 304, 15-5 pH, Nitronic 60, and 440C implanted with Ti and C. Samples were mechanically polished prior to ion implantation to fluences of 2 x 10¹⁷ Ti\\/cm² (90 to 180 keV) and 2 x 10¹⁷ C\\/cm² (30 keV); the implantation profiles of the two elements overlapped

F. G. Yost; L. E. Pope; D. M. Follstaedt; J. A. Knapp; S. T. Picraux

1981-01-01

215

Effect of ion implantation species on the tribological response of stainless steel surfaces  

Microsoft Academic Search

The friction and wear properties of 304 and 15–5 PH stainless steels which were ion implanted with P and with P plus C have\\u000a been examined and are compared with the properties of the same steels implanted with N and with Ti plus C. While benefits\\u000a are obtained with the P and the P plus C implantation treatments, the N

L. E. Pope; S. T. Picraux; D. M. Follstaedt; J. A. Knapp; F. G. Yost

1985-01-01

216

Corrosion–erosion behavior of TiN-coated stainless steels in aqueous slurries  

Microsoft Academic Search

The corrosion–erosion resistance of TiN-coated AISI 304 and AISI 420 stainless steels in aqueous slurries was studied. TiN films with a thickness of 0.6?m were obtained by using the pulsed-arc plasma-assisted physical vapour deposition technique. The corrosion–erosion experiments were performed in a test machine in which the impingement velocity, impact angle, concentration of solids and pH of the solution were

Diana López; Carlos Sánchez; Alejandro Toro

2005-01-01

217

Improvement of the forgability of 17-4 precipitation hardening stainless steel by ausforming  

Microsoft Academic Search

The ausforming process for 17-4 precipitation hardening (17-4PH) stainless steel is compared with the conventional warm-forging process, from the point of both the forgeability and the properties of the forged material. The forgeability is evaluated by upsetting, forward rod extrusion and backward can extrusion. The forging force required in ausforming is about half that required in conventional warm-forging: it especially

Sachihiro Isogawa; Hiroaki Yoshida; Yuzo Hosoi; Yasuhisa Tozawa

1998-01-01

218

Electrodeposition of polypyrrole on 316L stainless steel for corrosion prevention  

Microsoft Academic Search

The electrosynthesis of polypyrrole films onto 316L stainless steel from near neutral and alkaline solutions containing molybdate and nitrate is reported. The corrosion behavior of the coated electrodes was investigated in NaCl solutions by electrochemical techniques and scanning electron microscopy. The polymer formed potentiostatically in a solution of pH 12 is the most efficient in terms of adhesion and corrosion

M. B. González; S. B. Saidman

2011-01-01

219

High frequency stage I corrosion fatigue of austenitic stainless steel (316L)  

Microsoft Academic Search

High frequency (123 Hz) fatigue crack propagation studies were conducted under rising ?K conditions (R-ratio = 0.22) on single edge notch specimens of austenitic stainless steel (type 316L) that contained an annealed precrack.\\u000a Tests were conducted in near neutral (pH 5.5) solutions of 1 M NaCl and 1 M NaCl + 0.01 M Na2S2O3 under potentiostatically controlled conditions and in

Clinton Fong; Desmond Tromans

1988-01-01

220

Helium bubble growth in 316 stainless steel  

Microsoft Academic Search

A systematic TEM investigation has been made of helium bubble growth in type 316 stainless steel. Commercial stainless steel samples have been vacuum annealed following room temperature helium implantation to a concentration of 5 × 1026 He m. The bubble growth kinetics have been determined by measuring the mean bubble radius at annealing times in the range 1 to 200

T. R. Armstrong; P. J. Goodhew

1983-01-01

221

The energy benefit of stainless steel recycling  

Microsoft Academic Search

The energy used to produce austenitic stainless steel was quantified throughout its entire life cycle for three scenarios: (1) current global operations, (2) 100% recycling, and (3) use of only virgin materials. Data are representative of global average operations in the early 2000s. The primary energy requirements to produce 1 metric ton of austenitic stainless steel (with assumed metals concentrations

Jeremiah Johnson; B. K. Reck; T. Wang; T. E. Graedel

2008-01-01

222

PRECIPITATION HARDENING P\\/M STAINLESS STEELS  

Microsoft Academic Search

Applications requiring high strength stainless steels are growing rapidally. Precipitation- hardening stainless steels have seen limited use in powder metallurgy despite their high strength. Strengthening of these alloys is achieved by adding elements such as copper and niobium, which form intermetallic precipitates during aging. The precipitation-hardening grades exhibit corrosion resistance levels comparable with those of the chromium-nickel (300 series) grades.

Chris Schade; Pat Stears; Alan Lawley; Roger Doherty

223

Diffusion brazing nickel-plated stainless steel  

NASA Technical Reports Server (NTRS)

To bond parts, sandwich assembly is made up of aluminum core, aluminum face sheet with brazing alloy interface, and nickel plated stainless steel part. Sandwich is placed between bottom and top glide sheet that is placed in stainless steel retort where assembly is bonded at 580 C.

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

1976-01-01

224

THE DUCTILITY OF BRAZED STAINLESS STEEL JOINTS  

Microsoft Academic Search

The ductility of Type 310 stainless steel T-joints brazed with GE-62 ; brazing alloy was measured. The measure of ductility was taken as the plastic ; axial strain required to crack braze fillets in T-section tensile specimens. At ; elevated temperatures, the ductility of as-brazed joints approximated that of the ; stainless steel, but at room temperature the brazed joints

H. A. Saller; J. T. Stacy; N. S. Eddy

1953-01-01

225

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

PubMed Central

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

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

2012-01-01

226

Behavior of type 304 and type 316 austenitic stainless in 55% lithium bromide heavy brine environments  

SciTech Connect

Cylindrical tensile specimens of AISI type 304 (UNS S30400) and type 316 (UNS S31600) stainless steels (SS) were tested under constant-load conditions in 55% lithium bromide (LiBr) heavy brines at temperatures of 120 C and 140 C. Elongation and open-circuit potential (OCP) were recorded during the tensile test. Potentiodynamic polarization measurements were conducted, and the failed surface fractures were examined by scanning electron microscopy. The tested SS were subjected to stress corrosion under the test environments. Sensitivity was affected strongly by pH values. In LiBr brine of pH = 11.6, the passivation processes were more effective than in brine of pH = 6 [approximately] 8. Because of effective passivation behavior in brine of pH = 11.6, lower values of [delta]l[sub 0] were measured, indicating lower dislocation relaxation processes and high resistance to stress corrosion cracking.

Itzhak, D.; Elias, O. (Ben-Gurion Univ., Beer-Sheva (Israel). Dept. of Materials Engineering)

1994-02-01

227

A porous stainless steel membrane system for extraterrestrial crop production  

NASA Technical Reports Server (NTRS)

A system was developed in which nutrient flow to plant roots is controlled by a thin (0.98 or 1.18 mm) porous (0.2 or 0.5 microns) stainless steel sheet membrane. The flow of nutrient solution through the membrane is controlled by adjusting the relative negative pressure on the nutrient solution side of the membrane. Thus, the nutrient solution is contained by the membrane and cannot escape from the compartment even under microgravity conditions if the appropriate pressure gradient across the membrane is maintained. Plant roots grow directly on the top surface of the membrane and pull the nutrient solution through this membrane interface. The volume of nutrient solution required by this system for plant growth is relatively small, since the plenum, which contains the nutrient solution in contact with the membrane, needs only to be of sufficient size to provide for uniform flow to all parts of the membrane. Solution not passing through the membrane to the root zone is recirculated through a reservoir where pH and nutrient levels are controlled. The size of the solution reservoir depends on the sophistication of the replenishment system. The roots on the surface of the membrane are covered with a polyethylene film (white on top, black on bottom) to maintain a high relative humidity and also limit light to prevent algal growth. Seeds are sown directly on the stainless steel membrane under the holes in the polyethylene film that allow a pathway for the shoots.

Koontz, H. V.; Prince, R. P.; Berry, W. L.; Knott, W. M. (Principal Investigator)

1990-01-01

228

Mechanism of dissimilar metal crevice corrosion of superferritic stainless steels  

SciTech Connect

Superferritic stainless steels (SS) can suffer from dissimilar metal crevice (DMC) corrosion when part of a crevice with certain other stainless alloys. For example, UNS S44735 is attacked when part of a crevice with type 316 SS (UNS S30400). To understand this phenomenon better, solutions which form inside such crevices were collected and analyzed with ion chromatography and capillary electrophoresis for their metal ion content. These analyses provided the data required to design bulk solutions for electrochemical kinetics measurements. Electrochemical measurements in these simulated crevice solutions were compared to measurements made in simple hydrochloric acid solutions. The simulated crevice solutions were much more aggressive toward the materials than the simple HCl solutions. The superferritic SS was depassivated more easily in the simulated crevice solutions and exhibited a much larger active-to-passive transition in these solutions. In HCl solutions of the same pH, the superferritic SS passivated quite easily and could be depassivated only with great difficulty. These results were used to rationalize the observations of DMC corrosion of UNS S44735 when part of a crevice with type 316 SS and the failure of electrochemical measurements in simple HCl solutions to predict this attack. The origin of the specificity of the alloys that cause DMC corrosion of UNSS44735 was explained in terms of the effect of alloyed molybdenum on electrode kinetics of these alloys in the critical crevice solution. The roles of ohmic drop and chloride ion concentration on the initiation and propagation of DMC corrosion also were considered.

Salamat, G.; Juhl, G.A.; Kelly, R.G. [Univ. of Virginia, Charlottesville, VA (United States)

1995-11-01

229

Brazing of 14-5 PH steel and WC-Co sinterson considerable dimension surfaces  

Microsoft Academic Search

Purpose: of this paper is study of structure properties of considerable surfaces vacuum brazed joints of WC-Co sinters and precipitation hardened stainless steel of 14-5 PH using copper and silver-copper as the brazing filler metal. Design\\/methodology\\/approach: the joints are used in large dimension spinning nozzles of a die for polyethylene granulation, in that considerable strength and ductility of the joints

J. Nowacki

230

The pH Game.  

ERIC Educational Resources Information Center

Describes a game that can be used to teach students about the acidity of liquids and substances around their school and enable them to understand what pH levels tell us about the environment. Students collect samples and measure the pH of water, soil, plants, and other natural material. (DDR)

Chemecology, 1996

1996-01-01

231

Coping with PH over the Long Term  

MedlinePLUS

... International PH News and Projects Let Me Breathe Music Video PATIENTS Patients Newly Diagnosed Request an Envelope ... International PH News and Projects Let Me Breathe Music Video Help spread PH awareness and share PH ...

232

LOCAL BUCKLING OF COLD-FORMED STAINLESS STEEL SECTIONS  

Microsoft Academic Search

Research at the University of Sydney, in the stainless steel area has for the last three years concentrated on the local buckling strength of stainless steel plates with application to cold-formed sections. The research has encompassed tests on single stainless steel plates, and the finite element modelling of stainless steel plates. Research was also carried out to determine the stress-strain

K J R Rasmussen; P Bezkorovainy; M R Bambach

233

Plasma immersion ion implantation of stainless steel: austenitic stainless steel in comparison to austenitic-ferritic stainless steel  

Microsoft Academic Search

It has been shown previously in the literature that plasma immersion ion implantation (PHI) can increase the wear resistance of austenitic stainless steel without losing its corrosion resistance. In this work, the effect of PHI treatment on the microstructure and the properties of an austenitic (X6CrNiTi1810, AISI 321) and a duplex austenitic-ferritic (X2CrNiMoN2253, AISI 318) stainless steel has been studied

C. Blawert; A. Weisheit; B. L. Mordike; R. M. Knoop

1996-01-01

234

Nonmetallic Inclusions in JBK-75 Stainless Steel.  

National Technical Information Service (NTIS)

Stainless steel alloys that are chemically complex, such as A-286 or JBK-75, are designed to improve such high-temperature properties as strength. This is accomplished by precipitating secondary phases during aging. Such multicomponent systems, however, c...

A. W. Brewer R. W. Krenzer J. H. Doyle D. H. Riefenberg

1977-01-01

235

Citric Acid Passivation of Stainless Steel.  

National Technical Information Service (NTIS)

Passivation is a process for cleaning and providing corrosion protection for stainless steel. Currently, on Kennedy Space Center (KSC), only parts passivated with nitric acid are acceptable for use. KSC disposes of approximately 125gal of concentrated nit...

C. Carl C. Larson D. Yasensky J. Reali

2010-01-01

236

Hydrogen compatibility handbook for stainless steels  

SciTech Connect

This handbook compiles data on the effects of hydrogen on the mechanical properties of stainless steels and discusses this data within the context of current understanding of hydrogen compatibility of metals. All of the tabulated data derives from continuing studies of hydrogen effects on materials that have been conducted at the Savannah River Laboratory over the past fifteen years. Supplementary data from other sources are included in the discussion. Austenitic, ferritic, martensitic, and precipitation hardenable stainless steels have been studied. Damage caused by helium generated from decay of tritium is a distinctive effect that occurs in addition to the hydrogen isotopes protium and deuterium. The handbook defines the scope of our current knowledge of hydrogen effects in stainless steels and serves as a guide to selection of stainless steels for service in hydrogen.

Caskey, G.R. Jr.

1983-06-01

237

Tritiated Water Interaction with Stainless Steel.  

National Technical Information Service (NTIS)

Experiments conducted to study tritium permeation of stainless steel at ambient and elevated temperatures revealed that HT converts relatively quickly to HTO. Further, the HTO partial pressure contributes essentially equally with elemental tritium gas in ...

G. R. Longhurst

2007-01-01

238

Development of a carburizing stainless steel alloy  

SciTech Connect

A new carburizing stainless steel alloy that resists corrosion, heat, and fatigue has been developed for bearing and gear applications. Pyrowear 675 Stainless alloy is vacuum induction melted and vacuum arc remelted (VIM/VAR) for aircraft-quality cleanliness. Test results show that it has corrosion resistance similar to that of AISI Type 440-C stainless, and its rolling fatigue resistance is superior to that of AISI M50 (UNS K88165). In contrast to alloy gear steels and Type 440C, Pyrowear 675 maintains case hardness of HRC 60 at operating temperatures up to 200 C (400 F). Impact and fracture toughness are superior to that of other stainless bearing steels, which typically are relatively brittle and can break under severe service. Toughness is also comparable or superior to conventional noncorrosion-resistant carburizing bearing steels, such as SAE Types 8620 and 9310.

Wert, D.E. (Carpenter Technology Corp., Reading, PA (United States))

1994-06-01

239

Stress corrosion cracking of duplex stainless steels in caustic solutions  

NASA Astrophysics Data System (ADS)

Duplex stainless steels (DSS) with roughly equal amount of austenite and ferrite phases are being used in industries such as petrochemical, nuclear, pulp and paper mills, de-salination plants, marine environments, and others. However, many DSS grades have been reported to undergo corrosion and stress corrosion cracking in some aggressive environments such as chlorides and sulfide-containing caustic solutions. Although stress corrosion cracking of duplex stainless steels in chloride solution has been investigated and well documented in the literature but the SCC mechanisms for DSS in caustic solutions were not known. Microstructural changes during fabrication processes affect the overall SCC susceptibility of these steels in caustic solutions. Other environmental factors, like pH of the solution, temperature, and resulting electrochemical potential also influence the SCC susceptibility of duplex stainless steels. In this study, the role of material and environmental parameters on corrosion and stress corrosion cracking of duplex stainless steels in caustic solutions were investigated. Changes in the DSS microstructure by different annealing and aging treatments were characterized in terms of changes in the ratio of austenite and ferrite phases, phase morphology and intermetallic precipitation using optical micrography, SEM, EDS, XRD, nano-indentation and microhardness methods. These samples were then tested for general and localized corrosion susceptibility and SCC to understand the underlying mechanisms of crack initiation and propagation in DSS in the above-mentioned environments. Results showed that the austenite phase in the DSS is more susceptible to crack initiation and propagation in caustic solutions, which is different from that in the low pH chloride environment where the ferrite phase is the more susceptible phase. This study also showed that microstructural changes in duplex stainless steels due to different heat treatments could affect their SCC susceptibility. Annealed and water quenched specimens were found to be immune to SCC in caustic environment. Aging treatment at 800°C gave rise to sigma and chi precipitates in the DSS. However, these sigma and chi precipitates, known to initiate cracking in DSS in chloride environment did not cause any cracking of DSS in caustic solutions. Aging of DSS at 475°C had resulted in '475°C embrittlement' and caused cracks to initiate in the ferrite phase. This was in contrast to the cracks initiating in the austenite phase in the as-received DSS. Alloy composition and microstructure of DSS as well as solution composition (dissolved ionic species) was also found to affect the electrochemical behavior and passivation of DSS which in turn plays a major role in stress corrosion crack initiation and propagation. Corrosion rates and SCC susceptibility of DSS was found to increase with addition of sulfide to caustic solutions. Corrosion films on DSS, characterized using XRD and X-ray photoelectron spectroscopy, indicated that the metal sulfide compounds were formed along with oxides at the metal surface in the presence of sulfide containing caustic environments. These metal sulfide containing passive films are unstable and hence breaks down under mechanical straining, leading to SCC initiations. The overall results from this study helped in understanding the mechanism of SCC in caustic solutions. Favorable slip systems in the austenite phase of DSS favors slip-induced local film damage thereby initiating a stress corrosion crack. Repeated film repassivation and breaking, followed by crack tip dissolution results in crack propagation in the austenite phase of DSS alloys. Result from this study will have a significant impact in terms of identifying the alloy compositions, fabrication processes, microstructures, and environmental conditions that may be avoided to mitigate corrosion and stress corrosion cracking of DSS in caustic solutions.

Bhattacharya, Ananya

240

High-Power Diode Laser-Treated 13Cr4Ni Stainless Steel for Hydro Turbines  

NASA Astrophysics Data System (ADS)

The cast martensitic chromium nickel stainless steels such as 13Cr4Ni, 16Cr5Ni, and 17Cr4Ni PH have found wide application in hydro turbines. These steels have adequate corrosion resistance with good mechanical properties because of chromium content of more than 12%. The 13Cr4Ni stainless steel is most widely used among these steels; however, lacks silt, cavitation, and water impingement erosion resistances (SER, CER, and WIER). This article deals with characterizing 13Cr4Ni stainless steel for silt, cavitation, and water impingement erosion; and studying its improved SER, CER, and WIER behavior after high-power diode laser (HPDL) surface treatment. The WIER and CER have improved significantly after laser treatment, whereas there is a marginal improvement in SER. The main reason for improved WIER and CER is due to its increased surface hardness and formation of fine-grained microstructure after HPDL surface treatment. CER and WIER of HPDL-treated 13Cr4Ni stainless steel samples have been evaluated as per ASTM G32-2003 and ASTM G73-1978, respectively; and these were correlated with microstructure and mechanical properties such as ultimate tensile strength, modified ultimate resilience, and microhardness. The erosion damage mechanism, compared on the basis of scanning electron micrographs and mechanical properties, is discussed and reported in this article.

Mann, B. S.

2014-04-01

241

High-Power Diode Laser-Treated 13Cr4Ni Stainless Steel for Hydro Turbines  

NASA Astrophysics Data System (ADS)

The cast martensitic chromium nickel stainless steels such as 13Cr4Ni, 16Cr5Ni, and 17Cr4Ni PH have found wide application in hydro turbines. These steels have adequate corrosion resistance with good mechanical properties because of chromium content of more than 12%. The 13Cr4Ni stainless steel is most widely used among these steels; however, lacks silt, cavitation, and water impingement erosion resistances (SER, CER, and WIER). This article deals with characterizing 13Cr4Ni stainless steel for silt, cavitation, and water impingement erosion; and studying its improved SER, CER, and WIER behavior after high-power diode laser (HPDL) surface treatment. The WIER and CER have improved significantly after laser treatment, whereas there is a marginal improvement in SER. The main reason for improved WIER and CER is due to its increased surface hardness and formation of fine-grained microstructure after HPDL surface treatment. CER and WIER of HPDL-treated 13Cr4Ni stainless steel samples have been evaluated as per ASTM G32-2003 and ASTM G73-1978, respectively; and these were correlated with microstructure and mechanical properties such as ultimate tensile strength, modified ultimate resilience, and microhardness. The erosion damage mechanism, compared on the basis of scanning electron micrographs and mechanical properties, is discussed and reported in this article.

Mann, B. S.

2014-06-01

242

Embrittlement of austenitic stainless steel welds  

Microsoft Academic Search

The microstructure of type-308 austenitic stainless steel weld metal containing γ and δ and ferrite is shown. Typical composition of the weld metal is Cr-20.2, Ni-9.4, Mn-1.7, Si-0.5, C-0.05, N-0.06 and balance Fe (in wt %). Exposure of austenitic stainless steel welds to elevated temperatures can lead to extensive changes in the microstructural features of the weld metal. On exposure

S. A. David; J. M. Vitek

1997-01-01

243

NIOBIUM TO STAINLESS STEEL BRAZE TRANSITION DEVELOPMENT  

Microsoft Academic Search

We present results of an R&D program to develop and test a reliable cryogenic leak-tight, copper-brazed transition between niobium and stainless steel for use in superconducting niobium cavities. We have chosen to make the integral helium container that houses a niobium cavity of stainless steel rather than titanium both for ease of fabrication and also for low cost. Other techniques

J. D. Fuerst; W. F. Toter; K. W. Shepard

2003-01-01

244

Philip Prorok, PhD  

Cancer.gov

Philip Prorok, PhD, mirum est notare quam littera gothica, quam nunc putamus parum claram, anteposuerit litterarum formas humanitatis per seacula quarta decima et quinta decima. Eodem modo typi, qui nunc nobis videntur parum clari, fiant sollemnes in futurum.

245

Electrochemical codeposition of sol-gel films on stainless steel: controlling the chemical and physical coating properties of biomedical implants.  

PubMed

The electrochemically assisted codeposition of sol-gel thin films on stainless steel is described. Specifically, electrodeposition of films based on aminopropyltriethoxysilane (APTS), and its codeposition with propyltrimethoxysilane (PrTMOS) and phenyltrimethoxysilane (PhTMOS) has been accomplished by applying negative potentials. The latter increases the concentration of hydroxyl ions on the stainless steel surface and thus catalyzes the condensation and deposition of the sol-gel films. The films were characterized by profilometry, electrochemical impedance spectroscopy (EIS), alternating current voltammetry (ACV), goniometry, atomic force microscopy (AFM) and scanning electron microscopy (SEM). AFM and SEM analysis of codeposited APTS:PrTMOS films disclosed the structural changes induced by altering the deposition solution composition and the applied potential. Codeposited APTS:PhTMOS did not show any structural differences from their electrodeposited homopolymers, while Nano Scratch Test clearly revealed the changes in the elastic and adhesion properties, suggesting the formation of an APTS:PhTMOS composite. EIS of the films showed good resistance towards penetration of hydrophilic species, such as hexacyanoferrate. ACV measurements of the homo and codeposits showed the decrease of the interfacial capacity as a result of the electrochemical deposition. In essence, controllable sol-gel films with tunable chemical and physical properties based on controlling the combination of the precursors, pH and electrochemical properties can be electrodeposited on conducting surfaces. The application of this approach has been demonstrated by coating a stainless steel coronary stent. PMID:20877869

Okner, Regina; Favaro, Gregory; Radko, Anna; Domb, Abraham Jacob; Mandler, Daniel

2010-12-14

246

PhEDEx Data Service  

NASA Astrophysics Data System (ADS)

The PhEDEx Data Service provides access to information from the central PhEDEx database, as well as certificate-authenticated managerial operations such as requesting the transfer or deletion of data. The Data Service is integrated with the "SiteDB" service for fine-grained access control, providing a safe and secure environment for operations. A plug-in architecture allows server-side modules to be developed rapidly and easily by anyone familiar with the schema, and can automatically return the data in a variety of formats for use by different client technologies. Using HTTP access via the Data Service instead of direct database connections makes it possible to build monitoring web-pages with complex drill-down operations, suitable for debugging or presentation from many aspects. This will form the basis of the new PhEDEx website in the near future, as well as providing access to PhEDEx information and certificate-authenticated services for other CMS dataflow and workflow management tools such as CRAB, WMCore, DBS and the dashboard. A PhEDEx command-line client tool provides one-stop access to all the functions of the PhEDEx Data Service interactively, for use in simple scripts that do not access the service directly. The client tool provides certificate-authenticated access to managerial functions, so all the functions of the PhEDEx Data Service are available to it. The tool can be expanded by plug-ins which can combine or extend the client-side manipulation of data from the Data Service, providing a powerful environment for manipulating data within PhEDEx.

Egeland, Ricky; Wildish, Tony; Huang, Chih-Hao

2010-04-01

247

Analysis of Stainless Steel Sandwich Panels with a Metal Foam Core for Lightweight Fan Blade Design  

NASA Technical Reports Server (NTRS)

The quest for cheap, low density and high performance materials in the design of aircraft and rotorcraft engine fan and propeller blades poses immense challenges to the materials and structural design engineers. The present study investigates the use of a sandwich foam fan blade mae up of solid face sheets and a metal foam core. The face sheets and the metal foam core material were an aerospace grade precipitation hardened 17-4 PH stainless steel with high strength and high toughness. The resulting structures possesses a high stiffness while being lighter than a similar solid construction. The material properties of 17-4 PH metal foam are reviewed briefly to describe the characteristics of sandwich structure for a fan blade application. A vibration analysis for natural frequencies and a detailed stress analysis on the 17-4 PH sandwich foam blade design for different combinations of kin thickness and core volume are presented with a comparison to a solid titanium blade.

Min, James B.; Ghosn, Louis J.; Lerch, Bradley A.; Raj, Sai V.; Holland, Frederic A., Jr.; Hebsur, Mohan G.

2004-01-01

248

CORROSION OF STAINLESS STEEL IN ACIDIC NITRATE WASTE SOLUTIONS FROM PROCESSING STAINLESS STEEL REACTOR FUELS  

Microsoft Academic Search

The influence of the surface state on steel corrosion in high ; temperature steam and water is studied. The autoclave tests were continued for ; stainless steel grade 304 and undertaken for Creusot 1.2 MD07 boilerplate steel. ; Regarding the stainless steel, complete results for the tests in water at 300 deg ; C and partial results for the tests

D. N. Hess; L. Rice; B. Willis; E. S. Snavely; W. E. Clark

1963-01-01

249

High Mn austenitic stainless steel  

DOEpatents

An austenitic stainless steel alloy includes, in weight percent: >4 to 15 Mn; 8 to 15 Ni; 14 to 16 Cr; 2.4 to 3 Al; 0.4 to 1 total of at least one of Nb and Ta; 0.05 to 0.2 C; 0.01 to 0.02 B; no more than 0.3 of combined Ti+V; up to 3 Mo; up to 3 Co; up to 1W; up to 3 Cu; up to 1 Si; up to 0.05 P; up to 1 total of at least one of Y, La, Ce, Hf, and Zr; less than 0.05 N; and base Fe, wherein the weight percent Fe is greater than the weight percent Ni, and wherein the alloy forms an external continuous scale including alumina, nanometer scale sized particles distributed throughout the microstructure, the particles including at least one of NbC and TaC, and a stable essentially single phase FCC austenitic matrix microstructure that is essentially delta-ferrite-free and essentially BCC-phase-free.

Yamamoto, Yukinori (Oak Ridge, TN) [Oak Ridge, TN; Santella, Michael L (Knoxville, TN) [Knoxville, TN; Brady, Michael P (Oak Ridge, TN) [Oak Ridge, TN; Maziasz, Philip J (Oak Ridge, TN) [Oak Ridge, TN; Liu, Chain-tsuan (Knoxville, TN) [Knoxville, TN

2010-07-13

250

Semiconducting properties of passive films formed on stainless steels: Influence of the alloying elements  

SciTech Connect

Passive films formed on stainless steels in a borate buffer solution (pH 9.2) have been investigated by capacitance measurements and photoelectrochemistry. The study was carried out on films formed on AISI type 304 and 316 stainless steels and high purity alloys with differing chromium, nickel, and molybdenum contents. Complementary research by Auger analysis shows that the passive films are composed essentially of an inner chromium region in contact with the metallic substrate and an outer iron oxide region developed at the film/electrolyte interface. The semiconducting properties of the passive films are determined by those of the constituent chromium and iron oxides which are of p-type and n-type, respectively. Thus the influence of the alloying elements on the semiconducting properties of the passive films is explained by changes in the electronic structure of each of these two oxide regions.

Hakiki, N.E.; Belo, M.D.C. [CNRS, Vitry-sur-Seine (France). Centre d`Etudes de Chimie Metallurgique; Simoes, A.M.P.; Ferreira, M.G.S. [Inst. Superior Tecnico, Lisboa (Portugal). Dept. de Engenharia Quimica

1998-11-01

251

Metal dissolution and maximum stress during SCC process of ferritic (type 430) and austenitic (type 304 and type 316) stainless steels in acidic chloride solutions under constant applied stress  

Microsoft Academic Search

By using a constant load method and inductive coupled plasma (ICP) spectrometer, the metal dissolution and maximum stress (?mair) of type 430 ferritic stainless, and type 304 and type 316 austenitic stainless steels during stress corrosion cracking (SCC) process were investigated under a constant applied stress condition in 0.82 kmol\\/m3 hydrochloric acid (HCl) and 0.82 kmol\\/m3 acidic chloride (pH 1.0)

Rokuro Nishimura; Yasuaki Maeda

2004-01-01

252

Kawasaki Steel Technical Report No. 14, March 1986. Special Issue on Stainless Steels.  

National Technical Information Service (NTIS)

Table of Contents: Manufacturing process and properties of stainless steels; Progress in stainless steel production by top and bottom blown converter; Production of high grade stainless steels; New equipment for improvement of stainless steel casting qual...

1986-01-01

253

Radka Stoyanova, PhD  

Cancer.gov

Dr. Radka Stoyanova, PhD has extensive background in developing approaches to best utilize imaging techniques in cancer research, diagnosis and treatment, as well as in developing approaches for the analysis, mining, and interpretation of "big data" generated by high-throughput approaches such as genomics, proteomics, and metabolomics. She received her Masters Degree in Mathematics from the University of Sofia, Bulgaria. Dr. Stoyanova obtained her doctoral training and PhD degree at the Imperial College London, under the mentorship of Profs.

254

pH Optrode Instrumentation  

NASA Technical Reports Server (NTRS)

pH-sensitive chromophoric reagents immobilized in porous optical fibers. Optoelectronic instrumentation system measures acidity or alkalinity of aqueous nutrient solution. Includes one or more optrodes, which are optical-fiber chemical sensors, in sense, analogous to electrodes but not subject to some of spurious effects distorting readings taken by pH electrodes. Concept of optrodes also described in "Ethylene-Vapor Optrodes" (KSC-11579). pH optrode sensor head, with lead-in and lead-out optical fibers, convenient for monitoring solutions located away from supporting electronic equipment.

Tabacco, Mary Beth; Zhou, Quan

1995-01-01

255

Use of Electrochemical Potential Noise to Detect Initiation and Propagation of Stress Corrosion Cracks in a 17-4 PH Steel  

Microsoft Academic Search

Corrosion potential transients were associated with nucleation and propagation of stress corrosion cracks in a 17-4 precipitation-hardenable (PH) martensitic stainless steel (SS) during slow strain rate tests (SSRT) at 90 C in deaerated sodium chloride (NaCl) solutions, Test solutions included 20 wt% NaCl at pH 3 and 7, similar to normal and faulted steam turbine environments, respectively. Time series were

J. G. Gonzalez-Rodriguez; V. M. Salinas-Bravo; E. G. Garca-Ochoa; A. Diaz-Sanchez

1997-01-01

256

Stress corrosion cracking of type 321 stainless steels in simulated petrochemical process environments containing hydrogen sulfide and chloride  

Microsoft Academic Search

The susceptibility to stress corrosion cracking (SCC) of type 321 stainless steel (type 321s) in a simulated petrochemical process environment containing hydrogen sulfide and chloride (20wt.% NaCl+0.01M Na2S2O3, pH 2) was assessed using the slow strain rate tensile (SSRT) test and static load (U-bend) tests at the free corrosion potentials. In the SSRT, effects of environmental factors, such as chloride

Y. Y. Chen; Y. M. Liou; H. C. Shih

2005-01-01

257

Corrosion of stainless steel coated with TiN, (TiAl)N and CrN in aqueous environments  

Microsoft Academic Search

The corrosion behaviour of TiN, (TiAl)N and CrN coated on 304 stainless steel by physical vapour deposition was examined in borate solution (pH 9.0) and in 0.5 M NaCl solution. The study was performed by using open circuit potential, potentiodynamic polarization and cyclic polarization techniques, complemented with XRD and laser microscopy. The measurements were also performed on the uncoated substrate

M. A. M Ibrahim; S. F Korablov; M Yoshimura

2002-01-01

258

Hydrogen-assisted cracking in a precipitation-hardened stainless steel: effects of heat treatment and displacement rate  

Microsoft Academic Search

The hydrogen embrittlement susceptibility of PH 13-8 Mo stainless steel was evaluated using non-linear fracture mechanics methods. The initiation toughness, Ji, and the resistance to stable crack growth, dJ\\/da, were measured using precracked compact specimens. Specimens were electrochemically charged with hydrogen prior to fracture testing in air. After charging, a monotonically increasing load-line displacement was applied to produce the J-integral

L. M. Young; M. R. Eggleston; H. D. Solomon; L. R. Kaisand

1995-01-01

259

Filtration studies of selected anionic dyes using asymmetric titanium dioxide membranes on porous stainless-steel tubes  

Microsoft Academic Search

Filtration studies using 0.2-?m titanium dioxide membranes fused on porous stainless-steel tubes is reported for solutions containing sodium nitrate alone and in the presence of commercial anionic, direct and acid dyes. Solution pH was adjusted with dilute sodium hydroxide and nitric acid to maintain maximum solubility of all ions and simplify the system. Electrolyte rejections and color rejections were measured

John J. Porter; Regina S. Porter

1995-01-01

260

78 FR 21417 - Drawn Stainless Steel Sinks From China  

Federal Register 2010, 2011, 2012, 2013

...Commerce that imports of drawn stainless steel sinks from China were subsidized...April 2013), entitled Drawn Stainless Steel Sinks from China: Investigation...Doc. 2013-08304 Filed 4-9-13; 8:45 am] BILLING CODE...

2013-04-10

261

Evaluation of 410 Stainless Steel Produced by the Watts Process.  

National Technical Information Service (NTIS)

A preliminary investigation was undertaken to compare the properties obtainable in a 410 stainless steel produced by the Watts Process with those of a conventionally cast 410 stainless steel alloy. Material produced by the Watts Process was subjected to t...

V. J. Colangelo G. P. Lessen

1975-01-01

262

The Corrosion Behavior of Selected Stainless Steels in Soil Environments.  

National Technical Information Service (NTIS)

In order to obtain more definitive information regarding the corrosion and stress corrosion of stainless steels in soil environments, NBS in cooperation with the Committee of Stainless Steel producers, AISI, initiated in 1970 a soil burial program in repr...

W. F. Gerhold E. Escalante B. T. Sanderson

1981-01-01

263

Thermal Linear Expansion of Nine Selected AISI Stainless Steels.  

National Technical Information Service (NTIS)

This technical report reviews the available experimental data and information on the thermal linear expansion of nine AISI stainless steels and presents the recommended values from 10 K to near the melting point of the stainless steels. The nine selected ...

P. D. Desai C. Y. Ho

1978-01-01

264

21 CFR 878.4495 - Stainless steel suture.  

Code of Federal Regulations, 2013 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4495 Stainless steel suture. (a) Identification. A stainless steel...

2013-04-01

265

Casting Stainless-Steel Models Around Pressure Tubes  

NASA Technical Reports Server (NTRS)

Survivability of thin-wall stainless-steel tubing increased to nearly 100 percent. Improves state of art in pressure-model castings and reduces cost associated with machining complete model from stainless-steel blank.

Vasquez, Peter; Micol, John R.

1992-01-01

266

Making pH Tangible.  

ERIC Educational Resources Information Center

Presents a laboratory exercise in which students test the pH of different substances, study the effect of a buffer on acidic solutions by comparing the behavior of buffered and unbuffered solutions upon the addition of acid, and compare common over-the-counter antacid remedies. (MKR)

McIntosh, Elizabeth; Moss, Robert

1995-01-01

267

Sashwati Roy, PhD  

Cancer.gov

Dr. Sashwati Roy is an Associate Professor of Surgery and Director of the Laser Capture Molecular Core at The Ohio State University, Columbus, Ohio. In 1994 she received her PhD degree in Physiology and Environmental Sciences and later completed her postdoctoral training at the University of California, Berkeley. Dr.

268

Karl Krueger, PhD  

Cancer.gov

Dr. Karl Krueger received a PhD in biochemistry from Vanderbilt University and continued his research training at NIH as a postdoctoral fellow before joining the faculty at Georgetown University School of Medicine. His research throughout this period focused on different aspects of drug receptors and their role in the nervous system.

269

Corrosion behavior of sensitized duplex stainless steel.  

PubMed

The present work investigates the corrosion behavior of 2205 duplex stainless steel in 0.9% NaCl solution after various heat-treatments, and compares it to that of 316L austenitic stainless steel. Both stainless steels were heat-treated at 500, 650, and 800 degrees C in air for 1 h, followed by furnace cooling. Each heat-treated sample was examined for their microstructures and Vickers micro-hardness, and subjected to the X-ray diffraction for the phase identification. Using potentiostatic polarization method, each heat-treated sample was corrosion-tested in 37 degrees C 0.9% NaCl solution to estimate its corrosion rate. It was found that simulated sensitization showed an adverse influence on both steels, indicating that corrosion rates increased by increasing the sensitization temperatures. PMID:9713683

Torres, F J; Panyayong, W; Rogers, W; Velasquez-Plata, D; Oshida, Y; Moore, B K

1998-01-01

270

Thermophysical properties of stainless steel foils  

SciTech Connect

Evacuated panel superinsulations with very high center-of-panel thermal resistances are being developed for use in refrigerators/freezers. Attainment of high resistances relies upon the maintenance of low vacuum levels by the use of stainless steel vacuum jackets. However, the metal jackets also present a path for heat conduction around the high resistance fillers. This paper presents results of a study of the impact of metal vacuum jackets on the overall thermal performance of vacuum superinsulations when incorporated into the walls and doors of refrigerators/freezers. Results are presented on measurements of the thermophysical properties of several types and thicknesses of stainless steel foils that were being considered for application in superinsulations. A direct electrical heating method was used for simultaneous measurements of the electrical resistivity, total hemispherical emittance, and thermal conductivity of the foils. Results are also presented on simulations of the energy usage of refrigerators/freezers containing stainless-steel-clad vacuum superinsulations.

Wilkes, K.E.; Strizak, J.P.; Weaver, F.J. [Oak Ridge National Lab., TN (United States); Besser, J.E.; Smith, D.L. [Aladdin Industries, Inc. (United States)

1997-10-01

271

Friction Drilling of Stainless Steels Pipes  

NASA Astrophysics Data System (ADS)

This work describes the experimental study of the friction drilling process in stainless steel by means of an optimization of the machining conditions. For such purpose austenitic stainless steel with different thicknesses were analyzed through controlled tests at different rotation speeds and feed rates. On one hand, the torque and the thrust force were computed and monitorized. On the other hand, the dimensional tolerances of the holes were evaluated, mainly the accuracy of the hole diameter and the burr thickness at different depths. Another topic of interest inherent to this special technique is the temperature level reached during the friction process which is crucial when it comes to development of microstructural transformations.

Fernández, A.; Lopez de Lacalle, L. N.; Lamikiz, A.

2011-01-01

272

Friction Drilling of Stainless Steels Pipes  

SciTech Connect

This work describes the experimental study of the friction drilling process in stainless steel by means of an optimization of the machining conditions. For such purpose austenitic stainless steel with different thicknesses were analyzed through controlled tests at different rotation speeds and feed rates. On one hand, the torque and the thrust force were computed and monitorized. On the other hand, the dimensional tolerances of the holes were evaluated, mainly the accuracy of the hole diameter and the burr thickness at different depths. Another topic of interest inherent to this special technique is the temperature level reached during the friction process which is crucial when it comes to development of microstructural transformations.

Fernandez, A.; Lopez de Lacalle, L. N.; Lamikiz, A. [Dept. of Mechanical Engineering, Univ. of the Basque Country. Alda. Urquijo s/n, 48013 Bilbao (Spain)

2011-01-17

273

Embrittlement of austenitic stainless steel welds  

SciTech Connect

To prevent hot-cracking, austenitic stainless steel welds generally contain a small percent of delta ferrite. Although ferrite has been found to effectively prevent hot-cracking, it can lead to embrittlement of welds when exposed to elevated temperatures. The aging behavior of type-308 stainless steel weld has been examined over a range of temperatures 475--850 C for times up to 10,000 hrs. Upon aging, and depending on the temperature range, the unstable ferrite may undergo a variety of solid state transformations. These phase changes creep-rupture and Charpy impact properties.

David, S.A.; Vitek, J.M.; Alexander, D.J.

1995-06-01

274

Stainless Steel Microstructure and Mechanical Properties Evaluation  

SciTech Connect

A nitrogen strengthened 21-6-9 stainless steel plate was spinformed into hemispherical test shapes. A battery of laboratory tests was used to characterize the hemispheres. The laboratory tests show that near the pole (axis) of a spinformed hemisphere the yield strength is the lowest because this area endures the least “cold-work” strengthening, i.e., the least deformation. The characterization indicated that stress-relief annealing spinformed stainless steel hemispheres does not degrade mechanical properties. Stress-relief annealing reduces residual stresses while maintaining relatively high mechanical properties. Full annealing completely eliminates residual stresses, but reduces yield strength by about 30%.

Switzner, Nathan T

2010-06-01

275

Ultralight Stainless Steel Urban Bus Concept  

SciTech Connect

While stainless steel buses are certainly not new, this study reveals opportunities for substantial improvements in structural performance.The objective of this project was to investigate the mass saving potential of ultra-high strength stainless steel as applied to the structure of a full size urban transit bus.The resulting design for a low floor,hybrid bus has an empty weight less than half that of a conventional transit bus.The reduced curb weight allows for a greater payload,without exceeding legal axle limits. A combination of finite element modeling and dynamic testing of scale models was used to predict structural performance.

J. Bruce Emmons; Leonard J. Blessing

2001-05-14

276

Study of passive films formed on AISI 304 stainless steel by impedance measurements and photoelectrochemistry  

SciTech Connect

Moss-Schottky plots and photoelectrochemical measurements were made on films formed at different potentials on AISI 304 stainless steel in a borate/boric acid solution, pH 9.2. The results allowed the determination of the semiconductive properties and band structure of the films, which account for the existence of two kinds of films depending on the formation potential. For potentials below 0 V (SCE), the results point out for a film with an inverse spinel structure constituted by Cr-substituted magnetite with two donor levels. Above 0 V only one donor level is detected, which should be Fe{sup 2 +} on tetrahedral sites.

Simoes, A.M.P.; Ferreiro, M.G.S. (Dept. de Engenharia Quimica, Instituto Superior Tecnico, 1096 Lisboa Codex (PT)); Rondot, B.; Belo, M. (Centre National de la Recherche Scientifique, 94 - Vitry-sur-Seine (France). Centre d'Etudes de Chimie Metallurgique)

1990-01-01

277

76 FR 87 - Grant of Authority for Subzone Status; ThyssenKrupp Steel and Stainless USA, LLC; (Stainless and...  

Federal Register 2010, 2011, 2012, 2013

...USA, LLC; (Stainless and Carbon Steel Products) Calvert...subzone at the stainless and carbon steel products manufacturing...manufacturing of stainless and carbon steel products at the facility...Secretary, for the purpose of monitoring by the FTZ staff. Signed...

2011-01-03

278

PhET Simulation: Density  

NSDL National Science Digital Library

This simulation provides a highly visual, intuitive way for students to explore how density is related to an object's mass and volume. Using a virtual water tank, users drop various objects to see what floats and what sinks. Use the mouse to submerge the object and see how much fluid it displaces. A scale is provided to measure the mass of the objects, with a density table available for view. Students can easily see why the density formula works, especially when they identify the "mystery" objects. Editor's Note: Scroll down on the page for exemplary lesson plans for grades 6-12 developed by the PhET project specifically to accompany the "Density" simulation. This item is part of a larger collection of simulations developed by the Physics Education Technology project (PhET).

2011-02-16

279

Christos Patriotis, PhD  

Cancer.gov

Dr. Christos Patriotis obtained his MSc in Biochemistry from the University of Sofia, Bulgaria in 1985 and his PhD in Molecular Biology from the Bulgarian Academy of Sciences in 1990. Postdoctoral training focused on signal transduction and tumor cell biology. He joined the faculty at Fox Chase Cancer Center in 1998; his research was directed toward understanding mechanisms of breast and ovarian cancer pathogenesis and identification of biomarkers associated with the early stages of the two types of cancer.

280

Photoelectrochemical analysis on the passive film formed on Fe–20Cr in pH 8.5 buffer solution  

Microsoft Academic Search

The electronic properties of passive film formed on Fe–20Cr stainless steel in pH 8.5 buffer solution were examined by the photocurrent measurements of the film. The passive film on Fe–20Cr exhibited an n-type semiconductor, which was confirmed by anodic photocurrent. The photocurrent spectrum for the passive films formed on Fe–20Cr was almost same in shape to that for the passive

EunAe Cho; HyukSang Kwon; Digby D. Macdonald

2002-01-01

281

The influence of aging treatments on sulfide stress corrosion cracking of PH 13-8 Mo steel welds  

Microsoft Academic Search

Slow displacement rate tensile tests were carried out to study sulfide stress corrosion cracking (SSCC) of PH 13-8 Mo stainless steel welds in a saturated H2S solution. The welds aged in the temperature range of 482–593°C were susceptible to SSCC; the fracture surfaces revealed mainly quasi-cleavage fractures after notched tensile tests. However, the SSCC susceptibility in terms of the percentage

L. W. Tsay; H. H. Chen; M. F. Chiang; C. Chen

2007-01-01

282

Amorphous stainless steel coatings prepared by reactive magnetron-sputtering from austenitic stainless steel targets  

Microsoft Academic Search

Stainless steel films were reactively magnetron sputtered in argon\\/methane gas flow onto oxidized silicon wafers using austenitic\\u000a stainless-steel targets. The deposited films of about 200 nm thickness were characterized by conversion electron Mössbauer\\u000a spectroscopy, magneto–optical Kerr-effect, X-ray diffraction, scanning electron microscopy, Rutherford backscattering spectrometry,\\u000a atomic force microscopy, corrosion resistance tests, and Raman spectroscopy. These complementary methods were used for a detailed

Salvatore Cusenza; Peter Schaaf

2009-01-01

283

Effect of Ph on Human Complement Activity.  

National Technical Information Service (NTIS)

The influence of pH on the haemolytic activity of human complement (HuC') was investigated over the pH range 5.55-8.20. Maximum haemolytic activity of HuC' was observed at pH 6.77 and not at the pH level (7.2) usually used. Adjustment of pH to either the ...

B. J. Fogel W. A. Hook E. H. Fife

1966-01-01

284

Copper metallization of stainless steels. Final report  

SciTech Connect

Stainless steel plates were vacuum metallized with pure copper films 0.004 inch thick. Prior to metallization the surfaces were cleaned with EPA-approved detergents. A thin layer of chromium was sputtered for improved adhesion followed by sputtering of the copper. Results showed excellent adhesion of the sputtered films to the substrates.

Rosenblum, B.Z.

1994-09-01

285

Helium Damage in Austenitic Stainless Steels.  

National Technical Information Service (NTIS)

Helium produced by tritium decay was first shown to embrittle austenitic stainless steel at ambient temperature in tensile specimens of Nitronic-40 steel (Armco, Inc.). A long-term study was initiated to study this form of helium damage in five austenitic...

G. R. Caskey D. A. Mezzanotte D. E. Rawl

1983-01-01

286

Magnetic characterisation of duplex stainless steel  

Microsoft Academic Search

Heat treatment-induced microstructural processes were studied by different non-destructive magnetic and mechanical material testing methods in the present work. A commercial SAF 2507 type superduplex stainless steel was investigated. This alloy contains about 40% metastable ferrite which can decompose to a sigma phase and secondary austenite due to heat treatment. All the mechanical, corrosion resistance and magnetic properties are strongly

I. Mészáros

2006-01-01

287

Materials data handbook: Stainless steel type 301  

NASA Technical Reports Server (NTRS)

A summary of the materials property information for stainless steel type 301 is presented. The scope of the information includes physical and mechanical properties at cryogenic, ambient, and elevated temperatures. Information on material procurement, metallurgy of the alloy, corrosion, environmental effects, fabrication, and bonding is developed.

Muraca, R. F.; Whittick, J. S.

1972-01-01

288

Development of High Performance Stainless Steel Powders  

Microsoft Academic Search

Advanced melting technology is now being employed in the manufacture of stainless steel powders. The new process currently includes electric arc furnace (EAF) technology in concert with Argon Oxygen Decarburization (AOD), High Performance Atomizing (HPA) and hydrogen annealing. The new high performance processing route has allowed the more consistent production of existing products, and has allowed enhanced properties, such as

Christopher Schade; John Schaberl

2007-01-01

289

Forming "dynamic" membranes on stainless steel  

NASA Technical Reports Server (NTRS)

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

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

1979-01-01

290

Materials data handbooks on stainless steels  

NASA Technical Reports Server (NTRS)

Two handbooks which summarize latest available data have been published. Two types of stainless steels, alloy A-286 and Type 301, are described. Each handbook is divided into twelve chapters. Scope of information presented includes physical- and mechanical-property data at cryogenic, ambient, and elevated temperatures.

Muraca, R. F.; Whittick, J. S.

1973-01-01

291

Strain induced martensite formation in stainless steel  

Microsoft Academic Search

The Conversion Electron and X-ray Mössbauer studies of the surface of Type 316 stainless steel at 400 K, 300 K, and 100 K show that both the substitutional and interstitial elements perturb the cubic symmetry at the iron site. The single peak of austenite is a superposition of at least five quadrupole split doublets whose magnitudes and intensities depend on

D. C. Cook

1987-01-01

292

Austenitic stainless steels for cryogenic service  

SciTech Connect

Presently available information on austenitic Fe-Cr-Ni stainless steel plate, welds, and castings for service below 77 K are reviewed with the intent (1) of developing systematic relationships between mechanical properties, composition, microstructure, and processing, and (2) of assessing the adequacy of these data bases in the design, fabrication, and operation of engineering systems at 4 K.

Dalder, E.N.C.; Juhas, M.C.

1985-09-19

293

Precipitate formation in austenitic stainless steel welds  

Microsoft Academic Search

Recent research efforts have revealed many of the factors which control the hotcracking susceptibility of austenitic stainless steel weld metals. It is generally agreed that the segregation of impurity elements to solidification grain boundaries is a primary cause of the hot-cracking tendency of these alloys in that elements such as phosphorus and sulfur form low melting point eutectics with the

M. J. Cieslak; A. M. Ritter

1985-01-01

294

Characterization of Brazing Alloys with Stainless Steels.  

National Technical Information Service (NTIS)

To simulate braze joints, qualitative x-ray mapping of the elemental interactions between brazing alloys and two common types of stainless steels was performed via the electron microprobe. In general both steels, Types 304L and 21-6-9, react with a partic...

D. H. Riefenberg J. H. Doyle R. F. Hillyer W. S. Bennett

1975-01-01

295

VACUUM BRAZING OF STAINLESS STEEL TO BERYLLIUM  

Microsoft Academic Search

A new technique of brazing stainless steel to beryllium results in ; vacuum-tight joints twice as strong as those previously obtained. Pretreatment ; of the component surfaces, as well as the brazing operation itself, is done in a ; furnace capable of maintaining a vacuum of 0.1 mu . (auth)

Whitson

1962-01-01

296

Characterization of brazing alloys with stainless steels  

Microsoft Academic Search

To simulate braze joints, qualitative x-ray mapping of the elemental ; interactions between brazing alloys and two common types of stainless steels was ; performed via the electron microprobe. In general both steels, Types 304L and 21-; 6-9, react with a particular brazing alloy in a similar manner, the exceptions ; being the gold--copper brazing alloys which show deeper penetration

D. H. Riefenberg; J. H. Doyle; R. F. Hillyer; W. S. Bennett

1975-01-01

297

Phase Instability during Fatigue of Stainless Steel.  

National Technical Information Service (NTIS)

This work is a comparative study of the fatigue crack growth rate (FCGR) of two austenitic stainless steels, AISI 301 and AISI 302. The objective was to determine how differences in the austenitic stabilities of the two steels would effect their respectiv...

C. J. Altstetter Z. Khan G. Schuster

1981-01-01

298

Durable nonslip stainless-steel drivebelts  

NASA Technical Reports Server (NTRS)

Two toothed stainless-steel drive belt retains its strength and flexibility in extreme heat or cold, intense radiation, or under high loading. Belt does not stretch or slip and is particularly suited to machinery for which replacement is difficult or impossible.

Bahiman, H.

1979-01-01

299

Martensite Transformation in Antimony Implanted Stainless Steel.  

National Technical Information Service (NTIS)

The authors have used Rutherford backscattering analysis (RBS) and transmission electron microscopy (TEM) and diffraction to investigate austenitic stainless steel crystals implanted at room temperature with 80 keV Sb exp + ions to a fluence of 5 x 10 exp...

E. Johnson, U. Littmark, A. Johansen, C. Christodoulides

1981-01-01

300

Hydrogen Outgassing in Stainless Steel Gun Chambers  

Microsoft Academic Search

Vacuum quality is an important aspect in electron guns. The hydrogen outgassing rate is a determinant of the vacuum quality in stainless steel gun chambers. A low outgassing rate allows for a better vacuum and therefore a longer photocathode lifetime. Low outgassing rates depend on thermal treatments of the chamber. The purpose of this project is to put together a

Melissa Ricketts

2009-01-01

301

Effect of proteins and pH on fretting corrosion and metal ion release.  

PubMed

The objectives of this study were to determine the effect of proteins and protein charge on the corrosion of stainless steel. As Zwitter ions, proteins have a positive charge in solutions acidic to their isoelectric point (pI) and a negative charge in solutions basic to the pI. Fretting corrosion rates of stainless-steel plates and screws as determined by weight loss and metal ion release were studied in saline and protein solutions with the pH adjusted to 3, 5, and 8. Alterations in pH did not affect the corrosion rate in saline solutions. However, alterations of the pH in albumin solutions did affect the corrosion rate. In protein solutions acidic to the isoelectric point the presence of the positively charged albumin did not alter the corrosion rates as compared to that in saline. However, the presence of negatively charged proteins in solutions basic to their isoelectric points decreased the amount of corrosion. Thus, the effect of proteins on fretting corrosion is dependent on the charge on the protein. When the release of nickel was compared to the release of chromium, it was shown that the release was in proportion to the composition of the alloy when fretting corrosion took place in saline. The nickel/chromium ratio in the albumin and gamma globulin solutions was increased relative to that predicted indicating preferential release of nickel in protein solutions. PMID:2451675

Merritt, K; Brown, S A

1988-02-01

302

Silicon strain gages bonded on stainless steel using glass frit for strain sensor applications  

NASA Astrophysics Data System (ADS)

In this paper, a steel pressure sensor using strain gages bonded on a 17–4 PH stainless steel (SS) diaphragm based on glass frit technology is proposed. The strain gages with uniform resistance are obtained by growing an epi-silicon layer on a single crystal silicon wafer using epitaxial deposition technique. The inorganic glass frits are used as the bonding material between the strain gages and the 17–4 PH SS diaphragm. Our results show that the output performances of sensors at a high temperature of 125 °C are almost equal those at room temperature, which indicates that the glass frit bonding is a good method and may lead to a significant advance in the high temperature applicability of silicon strain gage sensors. Finally, the microstructure of the cured organic adhesive and the fired glass frit are compared. It may be concluded that the defects of the cured organic adhesive deteriorate the hysteresis and repeatability errors of the sensors.

Zhang, Zongyang; Cheng, Xingguo; Leng, Yi; Cao, Gang; Liu, Sheng

2014-05-01

303

Mechanism of oxalate ion adsorption on chromium oxide-hydroxide from pH dependence and time evolution of ATR-IR spectra  

NASA Astrophysics Data System (ADS)

A chromium (III) oxide-hydroxide colloid film has been used to model the passive surface of stainless steel in in situ ATR-IR studies of oxalate ion adsorption from aqueous oxalate solutions over a wide pH range. Studies of time and pH dependence of adsorption have been used to reveal a mechanism of adsorption proceeding through ionic, hydrogen bonded and coordinated oxalate species. A Langmuir adsorption constant of 4.5×10 4 M -1 was determined for the surface coordinated oxalate from an adsorption isotherm at pH=3.

Degenhardt, Jens; McQuillan, A. James

1999-09-01

304

Biologics formulation factors affecting metal leachables from stainless steel.  

PubMed

An area of increasing concern and scientific scrutiny is the potential contamination of drug products by leachables entering the product during manufacturing and storage. These contaminants may either have a direct safety impact on the patients or act indirectly through the alteration of the physicochemical properties of the product. In the case of biotherapeutics, trace amounts of metal contaminants can arise from various sources, but mainly from contact with stainless steel (ss). The effect of the various factors, buffer species, solution fill volume per unit contact surface area, metal chelators, and pH, on metal leachables from contact with ss over time were investigated individually. Three major metal leachables, iron, chromium, and nickel, were monitored by inductively coupled plasma-mass spectrometry because they are the major components of 316L ss. Iron was primarily used to evaluate the effect of each factor since it is the most abundant. It was observed that each studied factor exhibited its own effect on metal leachables from contact with ss. The effect of buffer species and pH exhibited temperature dependence over the studied temperature range. The metal leachables decreased with the increased fill volume (mL) per unit contact ss surface area (cm(2)) but a plateau was achieved at approximately 3 mL/cm(2). Metal chelators produced the strongest effect in facilitating metal leaching. In order to minimize the metal leachables and optimize biological product stability, each formulation factor must be evaluated for its impact, to balance its risk and benefit in achieving the target drug product shelf life. PMID:21360314

Zhou, Shuxia; Schöneich, Christian; Singh, Satish K

2011-03-01

305

Effect of corrosion on the isoelectric point of stainless steel  

SciTech Connect

The recently developed adhesion method for determining the isoelectric points (IEP) of conductive metal surfaces was applied in studying the corrosion processes of stainless steel (SS). This technique allowed for characterization of the charge on the metal oxide surface as a function of pH. The magnitude of IEP was found to correlate with the structure of the oxide layer. The exposure of SS to air at 1,000 C reduced the original pH[sub IEP] from 4.15 to 2.8 as a result of the presence of magnetite. Treatment at lower temperatures yielded a significant portion of hematite in the oxide layer and pH[sub IEP] shifted to 3.3. The corrosion of SS in aqueous sodium chloride (NaCl) solution at room temperature, as examined by the proposed electrokinetic method, resulted in the formation of magnetite in the early stage of the process, while hematite and/or lepidocrocite was detected as a final product.

Kallay, N.; Kovacevic, D.; Dedic, I. (Univ. of Zagreb (Croatia). Lab. of Physical Chemistry); Tomasic, V. (Inst. Rugjer Boskovic, Zagreb (Croatia). Dept. of Physical Chemistry)

1994-08-01

306

Thin films of ZnTe electrodeposited on stainless steel  

NASA Astrophysics Data System (ADS)

The electrodeposition of zinc telluride (ZnTe) thin films on stainless steel foil substrates from an aqueous solution containing ZnSO4 (150 mM) and TeO2 (0.5 mM) is performed. For the deposition of stoichiometric films at a bath temperature 80 °C and pH=3.5, the suitable deposition potential is found to be in the range -740 mV to -800 mV against a Ag/AgCl reference electrode. The films structure, surface morphology, chemical composition, optical absorption coefficient, bandgap energy and electrical resistivity are measured and the results are discussed. Films are composed of small crystallites, and their surface texture, which depends on the film stoichiometry, varies with the deposition potential. Films have a resistivity greater than 109 ? cm and a bandgap energy that is measured in the range 2.1 to 2.3 eV. Films annealed in nitrogen for 15 min and at 350 °C show p-type conductivity.

Rakhshani, A. E.; Pradeep, B.

2004-12-01

307

Comparison of stainless steels in simulated paper machine environments  

SciTech Connect

The localized corrosion behavior of austenitic stainless steels (SS) UNS S30403 and UNS S31603, and duplex SS UNS S31803 was compared in simulated paper machine environments containing chloride, sulfate, and thiosulfate at pH 3 and 65 C. Electrochemical testing of the materials was performed by cyclic polarization scans and scratch tests. Thiosulfate caused a remarkable decrease in repassivation potentials (E{sub pp}) and a slight decrease in pitting potentials (E{sub np}) of UNS S30403 and UNS S31603, when compared to the corresponding E{sub pp} and E{sub np} values determined in similar solutions without thiosulfate addition. Pits on UNS S30403 and UNS S31603 steels were enriched in Cr and Cu and depleted in Fe when compared to the base metal. Thiosulfate being present in the solution pits contained also very high amounts of S. Thiosulfate was proposed to be reduced to hydrogen sulfide (H{sub 2}S) inside the pits enhancing the anodic dissolution process of SS. In the case of UNS S31803, test environments had hardly any influence on the determined high E{sub pp} and E{sub np} values. Chloride concentration had to be a minimum of 500 mg/L until any localized corrosion could be observed on UNS S31803.

Laitinen, T.M.J. [VTT Manufacturing Technology (Finland)

1999-09-01

308

Electrocoagulation of simulated reactive dyebath effluent with aluminum and stainless steel electrodes.  

PubMed

Reactive dyebath effluents are ideal candidates for electrocoagulation due to their intensive color, medium strength, recalcitrant COD and high electrolyte (NaCl) content. The present study focused on the treatability of simulated reactive dyebath effluent (COD(o)=300 mg/L; color in terms of absorbance values A(o,436)=0.532 cm(-1), A(o,525)=0.693 cm(-1) and A(o,620)=0.808 cm(-1)) employing electrocoagulation with aluminum and stainless steel electrodes. Optimization of critical operating parameters such as initial pH (pH(o) 3-11), applied current density (J(c)=22-87 mA/cm(2)) and electrolyte type (NaCl or Na(2)SO(4)) improved the overall treatment efficiencies resulting in effective decolorization (99% using stainless steel electrodes after 60 min, 95% using aluminum electrodes after 90 min electrocoagulation) and COD abatement (93% with stainless steel electrodes after 60 min, 86% with aluminum electrodes after 90 min of reaction time). Optimum electrocoagulation conditions were established as pH(o) 5 and J(c)=22 mA/cm(2) for both electrode materials. The COD and color removal efficiencies also depended on the electrolyte type. No in situ, surplus adsorbable organically bound halogens (AOX) formation associated with the use of NaCl as the electrolyte during electrocoagulation was detected. An economical evaluation was also carried out within the frame of the study. It was demonstrated that electrocoagulation of reactive dyebath effluent with aluminum and stainless steel electrodes was a considerably less electrical energy-intensive, alternative treatment method as compared with advanced chemical oxidation techniques. PMID:18849115

Arslan-Alaton, Idil; Kabda?li, I?ik; Vardar, Burcu; Tünay, Olcay

2009-05-30

309

The pH of antiseptic cleansers  

PubMed Central

Background Daily bathing with antiseptic cleansers are proposed by some physicians as an adjunctive management of atopic dermatitis (AD). As atopic skin is sensitive, selection of cleansing products becomes a topic of concern. Objective Our purpose is to evaluate the pH of various antiseptic body cleansers to give an overview for recommendation to patients with AD. Methods Commonly bar and liquid cleansers consisted of antiseptic agents were measured for pH using pH meter and pH-indicator strips. For comparison, mild cleansers and general body cleansers were also measured. Results All cleansing bars had pH 9.8-11.3 except syndet bar that had neutral pH. For liquid cleansers, three cleansing agents had pH close to pH of normal skin, one of antiseptic cleansers, one of mild cleansers and another one of general cleansers. The rest of antiseptic cleansers had pH 8.9-9.6 while mild cleansers had pH 6.9-7.5. Syndet liquid had pH 7 and general liquid cleansers had pH 9.6. Conclusion The pH of cleanser depends on composition of that cleanser. Adding antiseptic agents are not the only factor determining variation of pH. Moreover, benefit of antiseptic properties should be considered especially in cases of infected skin lesions in the selection of proper cleansers for patients with AD.

Kulthanan, Kanokvalai; Varothai, Supenya; Nuchkull, Piyavadee

2014-01-01

310

An analysis of grain boundary cohesion in precipitation hardened stainless steel  

SciTech Connect

17-4 precipitation hardened (PH) stainless steel belongs to the family of precipitation hardening martensitic stainless steel (AISI 630), containing 17%Cr, 4%Ni and 4%Cu as the main alloying elements; carbon content in the steel is normally maintained below about 0.05 wt.%. The authors have recently attempted an assessment of 17-4 precipitation hardened martensitic steel in terms of processing steps and heat treatment with a view to obtain a rationale of the quantitative effects of grain boundary segregation processes. Auger electron spectroscopy (AES) studies enabled an understanding of a striking variation in impact toughness as a function of carbon content to emerge on the basis of Nb-C-P interaction processes. In order to understand the factors responsible for the large variation in the impact toughness of the industrially important 17-4 PH stainless steel, a series of steels with varied % of carbon (0.02 to 0.09 wt %) but about the same levels of the Nb (0.28wt%) and P(0.03 wt%) was selected, since it was felt that Nb/C ratio may play a pivotal role in influencing the impact toughness. Two distinct regimes were delineated (a) a low toughness regime (Nb/C ratio > 6 but less than about 20) characterized by high grain boundary concentration of phosphorus and formation of NbC in the grain interior owing to strong Nb-C interaction, (b) a high toughness regime (Nb/C <6), where grain boundary P is displaced by C through site competition. In this paper the authors attempt thermodynamic analysis in terms of free energy of segregation for the aforementioned two regimes.

Misra, R.D.K (Defence Metallurgical Research Lab., Hyderabad (India)); Rao, R. (Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore (India))

1993-06-15

311

Metallurgical evaluation of recycled stainless steel  

SciTech Connect

Recycled Type 304 stainless steel from both Carolina Metals Inc. (CMI) and Manufacturing Science Corporation (MSC) met all the requirements of ASTM A-240 required by Procurement Specification G-SPP-K-00005 Rev. 4. Mechanical strength and corrosion resistance of the material are adequate for service as burial boxes, overpacks, and drums. Inclusion content of both manufacturer`s material was high, resulting in a corresponding decrease in the corrosion resistance. Therefore, an evaluation of the service conditions should be performed before this material is approved for other applications. These heats of stainless steel are not suitable for fabricating DWPF glass canisters because the inclusion and carbon contents are high. However, MSC has recently installed a vacuum induction furnace capable of producing L grade material with a low inclusion content. Material produced from this furnace should be suitable for canister material if appropriate care is taken during the melting/casting process.

Imrich, K.J.

1997-01-22

312

Radiation Effects in Stainless Steel and Tungsten for use in the ADS Spallation Neutron Source System  

Microsoft Academic Search

Radiation effects have been studied in modified 316L stainless steel and commercially available stainless steel and tungsten by the heavy ion irradiation simulation and positron lifetime techniques. The experimental results show that the radiation resistant property of stainless steel is much better than that of tungsten, and the modified 316L stainless steel is the best among them. The stainless steel

Yongjun Xu; Zhiqiang Wang; Jiazheng Zhu; T. Minamisono; K. Matsuta; Yongnan Zheng; Dongmei Zhou; Guoji Xu; Enpeng Du; Youlin Fu; M. Fukuda; M. Mihara; Shengyun Zhu

2003-01-01

313

Fracture toughness of stainless steel welds  

Microsoft Academic Search

The effects of temperature, composition and weld-process variations on the fracture toughness behavior for Types 308 and 16-8-2 stainless steel (SS) welds were examined using the multiple-specimen J\\/sub R\\/-curve procedure. Fracture characteristics were found to be dependent on temperature and weld process but not on filler material. Gas-tungsten-arc (GTA) welds exhibited the highest fracture toughness, a shielded metal-arc (SMA) weld

1985-01-01

314

Laser surface hardening of austenitic stainless steel  

Microsoft Academic Search

For the purpose of studying the possibilities of increasing the wear resistance, keeping a high level of corrosion strength,\\u000a austenitic stainless steel specimens mainly containing 19.2%Cr and 9.4%Ni were two-step surface alloyed using added materials\\u000a (AMs) with hard particles of carbides (WC), nitrides (TiN), and borides (TiB2). The simultaneous melting of AM and surface layer was performed by a CO2

S. M. Levcovici; D. T. Levcovici; V. Munteanu; M. M. Paraschiv; A. Preda

2000-01-01

315

Welding high-molybdenum superaustenitic stainless steel  

SciTech Connect

A high-molybdenum, nitrogen-enriched, nickel-based filler metal was developed for welding superaustenitic stainless steels. The beneficial effects of high Ni content and nitrogen addition in reducing the solute microsegregation and the precipitation of intermetallic phases were used to design the filler alloy. The weld had a precipitate-free, fully austenitic microstructure and exhibited excellent mechanical properties, and reduced hot-cracking susceptibility and high-chloride pitting-corrosion resistance.

Ogawa, T. [Saitama Inst. of Technology, Ohsato-Okabe, Saitama (Japan). Dept. of Mechanical and Environmental Engineering; Koseki, T. [Nippon Steel Corp., Futtsu-Shintomi, Chiba (Japan). Steel Research Lab.

1996-02-01

316

Thermophysical properties of stainless steel foils  

Microsoft Academic Search

Evacuated panel superinsulations with very high center-of-panel thermal resistances are being developed for use in refrigerators\\/freezers. Attainment of high resistances relies upon the maintenance of low vacuum levels by the use of stainless steel vacuum jackets. However, the metal jackets also present a path for heat conduction around the high resistance fillers. This paper presents results of a study of

K. E. Wilkes; J. P. Strizak; F. J. Weaver; J. E. Besser; D. L. Smith

1997-01-01

317

Hydrogen solubility in austenitic stainless steels  

Microsoft Academic Search

The effects of thermomechanical treatment and surface condition on hydrogen solubility in Types 304L, 21-6-9, and modified A-286 austenitic stainless steels were determined. Three thermomechanical treatments were studied: annealed, 100% cold-worked, and high-energy rate forged (HERFed). Solubility in the modified Type A-286 was less in the HERFed specimens than in solution-annealed specimens. 8 refs.

G. R. Jr. Caskey; R. D. Jr. Sisson

1981-01-01

318

Hydrogen solubility in austenitic stainless steels  

SciTech Connect

The effects of thermomechanical treatment and surface condition on hydrogen solubility in Types 304L, 21-6-9, and modified A-286 austenitic stainless steels were determined. Three thermomechanical treatments were studied: annealed, 100% cold-worked, and high-energy rate forged (HERFed). Solubility in the modified Type A-286 was less in the HERFed specimens than in solution-annealed specimens. 8 refs.

Caskey, G.R. Jr.; Sisson, R.D. Jr.

1981-11-01

319

Constitutive modeling of ferritic stainless steel  

Microsoft Academic Search

In this work, constitutive models, including phenomenological and crystal plasticity, were used to simulate the anisotropy\\u000a behavior and texture evolution of two ferritic stainless steel sheets, AISI409L and AISI430. Uniaxial tension, hydraulic bulge\\u000a and disk compression tests were performed to characterize the mechanical properties of the two materials, and to determine\\u000a the yield surfaces at different amounts of plastic work.

Le Xu; Frédéric Barlat; Deok Chan Ahn

2010-01-01

320

Corrosion of Stainless Steel During Acetate Production  

Microsoft Academic Search

Corrosion of types 304, 304L, 316, and 316L stainless steel (SS) during the esterification of acetic acid and alcohol or glycol ether was investigated. The catalyst for this reaction, sulfuric acid or para-toluene sulfonic acid (PTSA), was shown to cause more corrosion on reactor equipment than CHâCOOH under the process conditions commonly practiced in industry. The corrosive action of the

J. S. Qi; G. C. Lester

1996-01-01

321

Strain induced martensite formation in stainless steel  

Microsoft Academic Search

The Conversion Electron and X-ray M?ssbauer studies of the surface of Type 316 stainless steel at 400 K, 300 K, and 100 K\\u000a show that both the substitutional and interstitial elements perturb the cubic symmetry at the iron site. The single peak of\\u000a austenite is a superposition of at least five quadrupole split doublets whose magnitudes and intensities depend on

D. C. Cook

1987-01-01

322

Strain induced martensite formation in stainless steel  

Microsoft Academic Search

The Conversion Electron and X-ray Mössbauer studies of the surface of Type 316 stainless steel at 400 K, 300 K, and 100 K\\u000a show that both the substitutional and interstitial elements perturb the cubic symmetry at the iron site. The single peak of\\u000a austenite is a superposition of at least five quadrupole split doublets whose magnitudes and intensities depend on

D. C. Cook

1987-01-01

323

Partial replacement of chromium in stainless steel  

Microsoft Academic Search

The Bureau of Mines, U.S. Department of the Interior, conducted research on the partial replacement of chromium in stainless\\u000a steel. The alloys examined contain 8 to 9 pct Cr, 11 to 14 pct Ni, and additions of up to 5 pct Mo, 2 pct Cu, and 2 pct V\\u000a for corrosion-resistant applications and up to 5 pct Si and 2

M. L. Glenn; S. J. Bullard; D. E. Larson; S. C. Rhoads

1985-01-01

324

The impedance of stainless-steel electrodes  

Microsoft Academic Search

The resistive and capacitive properties of stainless-steel electrodes in contact with saline solutions of various concentrations\\u000a were investigated over a frequency range extending from 20 to 10 kHz by using a variable-length conductivity cell. With a\\u000a low current density, the series-equivalent resistance and capacitance of a single electrode-electrolyte interface were found\\u000a to vary almost inversely as the square root of

L. A. Geddes; C. P. Da Costa; G. Wise

1971-01-01

325

Effect of ferrite on cast stainless steels  

SciTech Connect

Premature failure of stainless steel castings in bleach washing service is attributed to poor casting quality high porosity and to a high ferrite content, which makes the castings susceptible to corrosion by hot acid chloride solutions. A survey of the chemical compositions and ferrite contents of corrosion-resistant castings in bleach plants at three pulp mills found high [delta]-ferrite levels in the austenitic matrix due to the improper balance between austenite and ferrite stabilizers.

Nadezhdin, A.; Cooper, K. (Noranda Technology Centre, Pointe Claire, Quebec (Canada)); Timbers, G. (James Maclaren Inc., Quebec (Canada). Kraft Pulp Division)

1994-09-01

326

Softened-Stainless-Steel O-Rings  

NASA Technical Reports Server (NTRS)

In fabrication of O-ring of new type, tube of 304 stainless steel bent around mandril into circle and welded closed into ring. Ring annealed in furnace to make it soft and highly ductile. In this condition, used as crushable, deformable O-ring seal. O-ring replacements used in variety of atmospheres and temperatures, relatively inexpensive, fabricated with minimum amount of work, amenable to one-of-a-kind production, reusable, and environmentally benign.

Marquis, G. A.; Waters, William I.

1993-01-01

327

Defining and Teaching pH  

Microsoft Academic Search

The 1909 definition of pH given in most general chemistry textbooks conflicts with the modern, operationally-defined pH scale that underlies laboratory measurement and relates to activities. At an elementary level, pH and the algebra of equilibria can be simply and correctly taught, without logarithms, in terms of the latter scale.

Richard F. Burton

2007-01-01

328

Cast Stainless Steel Ferrite and Grain Structure  

SciTech Connect

In-service inspection requirements dictate that piping welds in the primary pressure boundary of light-water reactors be subject to a volumetric examination based on the rules contained within the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, Section XI. The purpose of the inspection is the reliable detection and accurate sizing of service-induced degradation and/or material flaws introduced during fabrication. The volumetric inspection is usually carried out using ultrasonic testing (UT) methods. However, the varied metallurgical macrostructures and microstructures of cast austenitic stainless steel piping and fittings, including statically cast stainless steel and centrifugally cast stainless steel (CCSS), introduce significant variations in the propagation and attenuation of ultrasonic energy. These variations complicate interpretation of the UT responses and may compromise the reliability of UT inspection. A review of the literature indicated that a correlation may exist between the microstructure and the delta ferrite content of the casting alloy. This paper discusses the results of a recent study where the goal was to determine if a correlation existed between measured and/or calculated ferrite content and grain structure in CCSS pipe.

Ruud, Clayton O.; Ramuhalli, Pradeep; Meyer, Ryan M.; Mathews, Royce; Diaz, Aaron A.; Anderson, Michael T.

2012-09-01

329

PhET Simulation: Sound  

NSDL National Science Digital Library

This interactive simulation allows users to analyze the properties of sound waves. Frequency and amplitude can be controlled, and users can enable audio tones to explore how pitch is related to frequency. Other options allow users to experiment with constructive and destructive interference by moving positions of speakers and listeners. Tools are also provided to measure wavelengths of various frequencies. Experimenting with interference from a wall and exploring sound in environments without air pressure are also possible. This simulation is part of a large and growing collection developed by the Physics Educational Technology Project using research-based principles. See the Related Materials below for a link to clicker questions and tutorials designed specifically for this simulation by the PhET team.

2008-10-29

330

Decontaminating and Melt Recycling Tritium Contaminated Stainless Steel  

SciTech Connect

The Westinghouse Savannah River Company, Idaho National Engineering Laboratory, and several university and industrial partners are evaluating recycling radioactively contaminated stainless steel. The goal of this program is to recycle contaminated stainless steel scrap from US Department of Energy national defense facilities. There is a large quantity of stainless steel at the DOE Savannah River Site from retired heavy water moderated Nuclear material production reactors (for example heat exchangers and process water piping), that will be used in pilot studies of potential recycle processes. These parts are contaminated by fission products, activated species, and tritium generated by neutron irradiation of the primary reactor coolant, which is heavy (deuterated) water. This report reviews current understanding of tritium contamination of stainless steel and previous studies of decontaminating tritium exposed stainless steel. It also outlines stainless steel refining methods, and proposes recommendations based on this review.

Clark, E.A.

1995-04-03

331

Evaluation of filler metals for high-strength stainless steels  

Microsoft Academic Search

Weldments were produced in types 316, 17-14CuMo, and high strength 14Cr-16Ni-2Mo stainless steel base metals with four filler metals-alloy 82, 17-14CuMo stainless steel, controlled residual element CRE 16-8-2 stainless steel, and alloy 556. The welds were evaluated on the basis of microstructure, strength, and ductility. All of the base metals were prone to hot cracking, but steels high in phosphorus

R. W. Swindeman; G. M. Goodwin; J. F. King; C. D. Lundin; C. Y. P. Qiao

1991-01-01

332

Radiation-induced outgassing from Type 304 stainless steel  

Microsoft Academic Search

A Type 304 stainless-steel vacuum system has been designed and constructed to study radiation-induced outgassing when this material is exposed to ⁶°Co gamma radiation. An analytical model has been developed that predicts the outgassing from Type 304 stainless steel to be 5 x 10⁻¹° Pa.l\\/cm².s per Mrad\\/h. Experiments determined the value for Type 304 stainless steel after bakeout at 300°C

T. P. Toepker; J. N. Anno

1979-01-01

333

Laves intermetallics in stainless steel-zirconium alloys  

Microsoft Academic Search

Laves intermetallics have a significant effect on properties of metal waste forms being developed at Argonne National Laboratory. These waste forms are stainless steel-zirconium alloys that will contain radioactive metal isotopes isolated from spent nuclear fuel by electrometallurgical treatment. The baseline waste form composition for stainless steel-clad fuels is stainless steel-15 wt.% zirconium (SS-15Zr). This article presents results of neutron

D. P. Abraham; S. M. McDeavitt; J. W. Jr. Richardson

1997-01-01

334

Sinter-hardening process applicable to stainless steels  

Microsoft Academic Search

Purpose: of this paper was to describe sintered duplex stainless steels manufactured in sinter-hardening process and its usability in field of stainless steels. Design\\/methodology\\/approach: In presented study duplex stainless steels were obtained through powder metallurgy starting from austenitic, ferritic base powders by controlled addition of alloying elements, such as Cr, Ni, Mo and Cu. In the studies apart from the

L. A. Dobrza?ski a; Z. Brytan; M. Rosso

335

Mouse inflammatory response to stainless steel corrosion products  

Microsoft Academic Search

Corrosion occurs regularly following long-term implantation of stainless steel. Little is known about the inflammatory and immunological potential of stainless steel corrosion products. AISI 316L stainless steel was anodically dissolved in a physiologically solution, HBSS, through a chronoamperometric process by imposing an external constant current of 0.5 mA. The solution, containing 245 µg of Fe, 112 µg of Cr, 75

R. B. Tracana; J. P. Sousa; G. S. Carvalho

1994-01-01

336

Soil pH and Fertilizers  

NSDL National Science Digital Library

This Web site by the Mississippi State University Extension Service discusses why fertilizers are added to soils. The Web site begins by introducing the concept of the pH of the soil and how nutrients are affected by this pH level. Students can then learn about the pH logarithmic scale and about the factors that affect soil pH. At the end of the site, users will find a clear and concise table concerning different fertilizer materials characteristics including their speed of reaction and effect on pH in soils.

337

Soils - Part 4: Soil pH  

NSDL National Science Digital Library

Soil pH is defined and its implications for crop production are described in this lesson. How are soil pH and buffer pH determined? How are these assessments used in lime recommendations? The factors that influence pH variations in soils, the chemistry involved in changing the pH of a soil, and the benefits associated with liming acid soils will be discussed.[This lesson, as well as the other nine lessons in the Soils series, is taken from the "Soils Home Study Course," published in 1999 by the University of Nebraska Cooperative Extension.

338

Comportamento anodico do aco inoxidavel ferritico AISI 430 em solucoes aquosas contendo ions cloreto ou ions sulfato. (Anodic behaviour of the stainless steel AISI 430 in aqueous solutions of chloride and sulphate ions).  

National Technical Information Service (NTIS)

The kinetics of the dissolution of stainless steel AISI 430 in the presence of chloride and sulphate ions has been studied in terms of the ion concentration, the pH variation, and the velocity of the working electrode. The experimental method utilized was...

M. Z. Sebrao

1982-01-01

339

Surface-protein interactions on different stainless steel grades: effects of protein adsorption, surface changes and metal release.  

PubMed

Implantation using stainless steels (SS) is an example where an understanding of protein-induced metal release from SS is important when assessing potential toxicological risks. Here, the protein-induced metal release was investigated for austenitic (AISI 304, 310, and 316L), ferritic (AISI 430), and duplex (AISI 2205) grades in a phosphate buffered saline (PBS, pH 7.4) solution containing either bovine serum albumin (BSA) or lysozyme (LSZ). The results show that both BSA and LSZ induce a significant enrichment of chromium in the surface oxide of all stainless steel grades. Both proteins induced an enhanced extent of released iron, chromium, nickel and manganese, very significant in the case of BSA (up to 40-fold increase), whereas both proteins reduced the corrosion resistance of SS, with the reverse situation for iron metal (reduced corrosion rates and reduced metal release in the presence of proteins). A full monolayer coverage is necessary to induce the effects observed. PMID:23378148

Hedberg, Y; Wang, X; Hedberg, J; Lundin, M; Blomberg, E; Wallinder, I Odnevall

2013-04-01

340

Localized corrosion of 316L stainless steel in tritiated water containing aggressive radiolytic and decomposition products at different temperatures  

NASA Astrophysics Data System (ADS)

Tritium is one of the more important radionuclides used in nuclear industry as plutonium and uranium. The tritium in tritiated water always causes difficulties in nuclear installations, including equipment corrosion. Moreover, with tritiated water there are, in addition, the radiolytic and decomposition products such as hydrogen peroxide formed during decay, chloride ions produced by degradation of organic seals and oils used for tightness and pumping, and acid pH produced by excitation of nitrogen in air by the ? - particle. Highly concentrated tritiated water releases energy and its temperature is about 80 °C, moreover heating is necessary in the tritium processes. These conditions highly facilitate the corrosion of stainless steels by pitting and crevice attack. Corrosion tests were performed by electrochemical analysis methods and by visual inspection of the surface of stainless steel.

Bellanger, G.

2008-02-01

341

76 FR 43981 - Circular Welded Austenitic Stainless Pressure Pipe From the People's Republic of China: Final...  

Federal Register 2010, 2011, 2012, 2013

...Austenitic Stainless Pressure Pipe from the People's Republic...austenitic stainless pressure pipe not greater than 14 inches in...specifications; (2) boiler, heat exchanger, superheater, refining...Jiuli Welded Stainless Steel Pipe Co., Ltd.'', dated...

2011-07-22

342

77 FR 60478 - Control of Ferrite Content in Stainless Steel Weld Metal  

Federal Register 2010, 2011, 2012, 2013

...NRC-2012-0231] Control of Ferrite Content in Stainless Steel Weld Metal AGENCY...DG-1279, ``Control of Ferrite Content in Stainless Steel Weld Metal.'' This...considers acceptable for controlling ferrite content in stainless steel weld metal....

2012-10-03

343

Influence of Gold Plating of Stainless Steel Pins on the Tensile Strength of Dental Amalgam  

Microsoft Academic Search

Neither gold plating of stainless steel pins nor mercury wetting of gold-plated stainless steel pins caused an increase in tensile strength of amalgam that was significantly higher than that caused by plain stainless steel pins in amalgam.

M. S. Bapna; A. A. Lugassy

1971-01-01

344

76 FR 76437 - Certain Welded Stainless Steel Pipe From Korea and Taiwan  

Federal Register 2010, 2011, 2012, 2013

...Review)] Certain Welded Stainless Steel Pipe From Korea and Taiwan Determination...orders on certain welded stainless steel pipe from Korea and Taiwan would be likely...entitled Certain Welded Stainless Steel Pipe from Korea and Taiwan,...

2011-12-07

345

Processes of bioadhesion on stainless steel surfaces and cleanability: A review with special reference to the food industry.  

PubMed

Biofouling of equipment surfaces in the food industry is due initially to physico-chemical adhesion processes, and subsequently to the proliferation of microbes within an extracellular polymer matrix. Two physico-chemical theories can be applied to predict simple cases of bacterial adhesion. However, these models are limited in their applicability owing to the complexity of bacterial surfaces and the surrounding medium. Various factors that can affect the bacterial adhesion process have been listed, all directly linked to the solid substratum, the suspension liquid or the microorganism. For stainless steel surfaces, it is important to take into account the grade of steel, the type of finish, surface roughness, the cleaning procedures used and the age of the steel. Regarding the suspension fluid within which adhesion takes place, pH, ionic composition and the presence of macromolecules are important variables. In addition, the adhering microorganisms have extremely complex surfaces and many factors must be taken into account when conducting adhesion tests, such as the presence of cell appendages, the method of culture, the contact time between the microorganism and the surface, and exopolymer synthesis. Research on biofilms growing on stainless steel has confirmed results obtained with other materials, regarding resistance to disinfectants, the role of the extracellular matrix and the process by which the biofilm forms. However, it appears that the bactericidal activity of disinfectants on biofilms differs according to the type of surface on which they are growing. The main cleaners and disinfectants used in the food industry are alkaline and acid detergents, peracetic acid, quaternary ammonium chlorides and iodophors. The cleanability and disinfectability of stainless steel surfaces have been compared with those of other materials. According to the published research findings, stainless steel is comparable in its biological cleanability to glass, and significantly better than polymers, aluminium or copper. Moreover, microorganisms in a biofilm developing on a stainless steel surface can be killed with lower concentrations of disinfectant than those on polymer surfaces. PMID:22115182

Boulané-Petermann, L

1996-01-01

346

Gaseous hydrogen embrittlement of PH 13-8 Mo steel  

NASA Astrophysics Data System (ADS)

In this study, notched tensile and fatigue crack growth tests in gaseous hydrogen were performed on PH 13-8 Mo stainless steel specimens at room temperature. These specimens were susceptible to hydrogen embrittlement (HE), but at different degrees, depending on the aging conditions or the microstructures of the alloys. In hydrogen, the accelerated fatigue crack growth rate (FCGR) usually accompanied a reduced notched tensile strength (NTS) of the specimens, i.e., the faster the FCGR the lower the NTS. It was proposed that the same fracture mechanism could be applied to these two different types of specimens, regardless of the loading conditions. Rapid fatigue crack growth and high NTS loss were found in the H800 (426 °C under-aged) and H900 (482 °C peak-aged) specimens. The HE susceptibility of the steel was reduced by increasing the aging temperature above 593 °C, which was attributed to the increased amount of austenite in the structure. Extensive quasi-cleavage fracture was observed for the specimens that were deteriorated severely by HE.

Ding, Y. S.; Tsay, L. W.; Chiang, M. F.; Chen, C.

2009-04-01

347

40 CFR 17.7 - Allowable fees and other expenses.  

Code of Federal Regulations, 2013 CFR

...based upon the prevailing market rates for the kind and quality of services furnished, except that...prevailing rate for similar services in the community in which the attorney...witness ordinarily performs services; (2) The time...

2013-07-01

348

Online PH measurement technique in seawater desalination  

NASA Astrophysics Data System (ADS)

The measurement technology of pH is essential in seawater desalination. Glass electrode is the main pH sensor in seawater desalination. Because the internal impedance of glass electrode is high and the signal of pH sensor is easy to be disturbed, a signal processing circuit with high input impedance was designed. Because of high salinity of seawater and the characteristic of glass electrode, ultrasonic cleaning technology was used to online clean pH sensor. Temperature compensation was also designed to reduce the measurement error caused by variety of environment temperature. Additionally, the potential drift of pH sensor was analyzed and an automatic calibration method was proposed. In order to online monitor the variety of pH in seawater desalination, three operating modes were designed. The three modes are online monitoring mode, ultrasonic cleaning mode and auto-calibration mode. The current pH in seawater desalination was measured and displayed in online monitoring mode. The cleaning process of pH sensor was done in ultrasonic cleaning mode. The calibration of pH sensor was finished in auto-calibration mode. The result of experiments showed that the measurement technology of pH could meet the technical requirements for desalination. The glass electrode could be promptly and online cleaned and its service life was lengthened greatly.

Wang, Haibo; Wu, Kaihua; Hu, Shaopeng

2009-11-01

349

Functional photoacoustic microscopy of pH  

NASA Astrophysics Data System (ADS)

pH is a tightly regulated indicator of metabolic activity. In mammalian systems, imbalance of pH regulation may result from or result in serious illness. Even though the regulation system of pH is very robust, tissue pH can be altered in many diseases such as cancer, osteoporosis and diabetes mellitus. Traditional high-resolution optical imaging techniques, such as confocal microscopy, routinely image pH in cells and tissues using pH sensitive fluorescent dyes, which change their fluorescence properties with the surrounding pH. Since strong optical scattering in biological tissue blurs images at greater depths, high-resolution pH imaging is limited to penetration depths of 1mm. Here, we report photoacoustic microscopy (PAM) of commercially available pH-sensitive fluorescent dye in tissue phantoms. Using both opticalresolution photoacoustic microscopy (OR-PAM), and acoustic resolution photoacoustic microscopy (AR-PAM), we explored the possibility of recovering the pH values in tissue phantoms. In this paper, we demonstrate that PAM was capable of recovering pH values up to a depth of 2 mm, greater than possible with other forms of optical microscopy.

Chatni, M. Rameez; Yao, Junjie; Danielli, Amos; Favazza, Christopher P.; Maslov, Konstantin I.; Wang, Lihong V.

2012-02-01

350

COMPARISON OF THE CORROSION OF CARBON STEEL, STAINLESS STEE, INCONEL-X, MONEL AND STELLITE IN THE KER MOCK-UP TUBES WITH OUT-OF-REACTOR LOOPS  

Microsoft Academic Search

Water corrosion tests were run on carbon steel (A-212), stainless steel ; (304), Monel, Inconel-X, and Stellite-12 in KER-1 and KER-2 in-reactor ; recirculating loops with the NPR as the reactor. The water was adjusted to pH 10 ; and 4.3 with LiOH and HâPOâ, respectively. The data were compared ; with those obtained in small out-of-reactor corrosion test loops

Larrick

1960-01-01

351

Adhesion measurements and chemical and microstructural characterization at interfaces of titanium nitride and titanium aluminum nitride coatings on stainless steel, inconel and titanium alloys  

Microsoft Academic Search

To assess the adhesion of nitride coatings on metal alloys, Ti 6Al-4V, 17-4 PH stainless steel and Inconel 718 alloy substrates were coated with titanium nitride (TiN) using both cathodic arc and electron beam evaporation. Titanium aluminum nitride ((Ti,Al)N) was also deposited using cathodic arc evaporation. X-ray photoelectron, Auger electron, and energy dispersive x-ray spectroscopies were used in tandem with

Robert Dallas James

1997-01-01

352

Open circuit potentials of metallic chromium and austenitic 304 stainless steel in aqueous sulphuric acid solution and the influence of chloride ions on them  

Microsoft Academic Search

Open circuit potential measurements and cyclic voltammetry of chromium and 304 stainless steel in deaerated aqueous H2SO4 solution of pH 1, without and containing NaCl in the concentration range 1–4 M revealed that chromium exhibits two stable open circuit potentials both having the character of a Wagner–Traud corrosion potential. One, Ecorr.1, was established on the passive surface formed by previously

Bore Jegdi?; Dragutin M. Draži?; Jovan P. Popi?

2008-01-01

353

Helium damage in austenitic stainless steels  

SciTech Connect

Helium produced by tritium decay was first shown to embrittle austenitic stainless steel at ambient temperature in tensile specimens of Nitronic-40 steel (Armco, Inc.). A long-term study was initiated to study this form of helium damage in five austenitic alloys. Results from this study have been analyzed by the J-integral technique and show a decrease in ductile fracture toughness with increasing He-3 concentration. Sustained-load cracking tests indicate that the stress intensity required to initiate and propagate a crack also decreases with increasing He-3 concentration. 9 figures, 3 tables.

Caskey, G.R. Jr.; Mezzanotte, D.A. Jr.; Rawl, D.E. Jr.

1983-01-01

354

Durable icephobic coating for stainless steel.  

PubMed

In this work, we present a modification of a stainless steel surface to impart superhydrophobic properties to it that are robust with respect to mechanical stresses associated with cyclic icing/deicing treatment, as well as to long-term contact with aqueous media and high humidity. The durability of the superhydrophobic state is ensured by the texture with multimodal roughness stable against mechanical stresses and a 2D polymer network of fluorooxysilane chemically bound to the texture elements. The designed superhydrophobic coating is characterized by contact angles exceeding 155° and a maximum rolling angle of 42° after 100 icing/deicing cycles. PMID:23470194

Boinovich, Ludmila B; Emelyanenko, Alexandre M; Ivanov, Vladimir K; Pashinin, Andrei S

2013-04-10

355

Superplastic deformation in two microduplex stainless steels  

SciTech Connect

The deformation behavior and mechanisms of superplastic flow in two microduplex stainless steels (SuperDux64 and Nitronic 19D) were studied at {similar_to}0.7T{sub m}. The two steels differed in initial grain size by a factor of 3. Both steels exhibited solute-drag-controlled grain boundary sliding in a high temperature {gamma}+{delta} phase field. In a lower temperature {gamma}+{sigma} phase field, the fine-grained steel ({bar L}=5{mu}m) exhibited climb-controlled grain boundary sliding and the coarser- grained steel ({bar L}=15{mu}m) exhibited solute-drag-controlled slip creep.

Lesuer, D.R.; Nieh, T.G.; Syn, C.K. [Lawrence Livermore National Lab., CA (United States); Taleff, E.M. [Texas Univ., Austin, TX (United States)

1996-09-01

356

Gas Atomization of Stainless Steel - Slow Motion  

SciTech Connect

Stainless steel liquid atomized by supersonic argon gas into a spray of droplets at ~1800ºC. Atomization of metal requires high pressure gas and specialized chambers for cooling and collecting the powders without contamination. The critical step for morphological control is the impingement of the gas on the melt stream. The video is a black and white high speed video of a liquid metal stream being atomized by high pressure gas. This material was atomized at the Ames Laboratory's Materials Preparation Center http://www.mpc.ameslab.gov

None

2011-01-01

357

Dynamic regulation of gastric surface pH by luminal pH  

PubMed Central

In vivo confocal imaging of the mucosal surface of rat stomach was used to measure pH noninvasively under the mucus gel layer while simultaneously imaging mucus gel thickness and tissue architecture. When tissue was superfused at pH 3, the 25 ?m adjacent to the epithelial surface was relatively alkaline (pH 4.1 ± 0.1), and surface alkalinity was enhanced by topical dimethyl prostaglandin E2 (pH 4.8 ± 0.2). Luminal pH was changed from pH 3 to pH 5 to mimic the fasted-to-fed transition in intragastric pH in rats. Under pH 5 superfusion, surface pH was relatively acidic (pH 4.2 ± 0.2). This surface acidity was enhanced by pentagastrin (pH 3.5 ± 0.2) and eliminated by omeprazole, implicating parietal cell H,K-ATPase as the dominant regulator of surface pH under pH 5 superfusion. With either pH 5 or pH 3 superfusion (a) gastric pit lumens had the most divergent pH from luminal superfusates; (b) qualitatively similar results were observed with and without superfusion flow; (c) local mucus gel thickness was a poor predictor of surface pH values; and (d) no channels carrying primary gastric gland fluid through the mucus were observed. The model of gastric defense that includes an alkaline mucus gel and viscous fingering of secreted acid through the mucus may be appropriate at the intragastric pH of the fasted, but not fed, animal. J. Clin. Invest. 103:605–612 (1999)

Chu, Shaoyou; Tanaka, Shin; Kaunitz, Jonathan D.; Montrose, Marshall H.

1999-01-01

358

Functional photoacoustic microscopy of pH  

Microsoft Academic Search

pH is a tightly regulated indicator of metabolic activity. In mammalian systems, an imbalance of pH regulation may result from or result in serious illness. In this paper, we report photoacoustic microscopy (PAM) of a commercially available pH-sensitive fluorescent dye (SNARF-5F carboxylic acid) in tissue phantoms. We demonstrated that PAM is capable of pH imaging in absolute values at tissue

Muhammad Rameez Chatni; Junjie Yao; Amos Danielli; Christopher P. Favazza; Konstantin I. Maslov; Lihong V. Wang

2011-01-01

359

The PH20 Protein in Human Spermatozoa  

Microsoft Academic Search

PH-20 is a sperm plasma-membrane protein that has been shown to have hyaluronidase activity in several mammalian species including nonhuman primates. In this investigation, the PH-20 protein was characterized in noncapacitated human sperm and in capacitated human sperm. Two forms of PH-20 were ob- served in immunoblots of sodium dodecylsulfate polyacrylamide-gel electrophoresis (SDS PAGE) using a polyclonal antibody to recom-

KHALIDA SABEUR; GARY N. CHERR; ASHLEY I. YUDIN; PAUL PRIMAKOFF; MING-WEN LI; JAMES W. OVERSTREET

360

The pH of estuarine waters  

Microsoft Academic Search

The emf measurements for the TRIS buffer in seawater have been used to define buffer solutions that can be used to determine the pH on a free or total proton scale for estuarine waters. The pH is related to the stoichiometric dissociation constant (K*) of TRISH I-, the concentration of buffer (mTRrs) and salinity (5) by pH = pK* +

FRANK J. MILLERO

1986-01-01

361

Microstructural characterization of titanium to 304 stainless steel brazed joints  

Microsoft Academic Search

The formation of intermetallic compounds in brazed joints between titanium and 304 stainless steel is of major concern, since they considerably degrade the joint properties. This research examined the vacuum brazing of commercially pure titanium to 304 stainless steel using two different silver-copper brazing filler metals. Pure copper and silver were used to prepare the brazing filler metals in these

P. R. C. Camargo; S. Liu; R. E. Trevisan

1993-01-01

362

Dissimilar metal friction welding of austenitic–ferritic stainless steels  

Microsoft Academic Search

Continuous drive friction welding studies on austenitic–ferritic stainless steel combination has been attempted in this investigation. Parameter optimization, microstructure–mechanical property correlation and fracture behaviour is a major contribution of the study. Sound welds are obtained at certain weld parameter combinations only. The mechanical properties of dissimilar metal welds are comparable to those of ferritic stainless steel welds. Evaluation of the

V. V. Satyanarayana; G. Madhusudhan Reddy; T. Mohandas

2005-01-01

363

Plasma processing for inducing bioactivity in stainless steel orthopaedic screws  

Microsoft Academic Search

The work presented in this paper is centred on applying plasma processing for inducing bioactivity (ability of a material to bond with bone) in otherwise bioinert stainless steel screws commonly used in orthopaedic surgery. As-received cortical stainless steel screws were hydroxylated using a patented two-step plasma process developed by the authors. The bioactivity of the screws thus processed was investigated

Sunil Kumar; Darren Simpson; Roger St. C. Smart

2007-01-01

364

Electrochemical etching of stainless steel through laser masking  

Microsoft Academic Search

A new micro patterning process without the need for a mask is proposed in this paper. It is a combination of laser masking and electrochemical etching. In electrochemical etching through laser masking (EELM), selective electrochemical dissolution of stainless steel is achieved in a 2 M sodium nitrite electrolyte. The micro-patterned surface layer of stainless steel is formed by laser marking

Hong Shik Shin; Do Kwan Chung; Min Soo Park; Bo Hyun Kim; Chong Nam Chu

2010-01-01

365

HVEM studies of helium embrittlement in stainless steel  

Microsoft Academic Search

In fast neutron irradiation environments, transmutation reactions occur in stainless steel which produce helium. The dissolved helium in the metal, along with the fast neutron-induced displacement damage leads to a premature integranular failure. A brittle intergranular fracture normally occurs in stainless steel at elevated temperature. The radiation environment apparently lowers the transition temperature between transgranular and intergranular failure. Helium embrittlement

J. A. Jr

1980-01-01

366

Microbiologically influenced corrosion of high molybdenum austenitic stainless steel  

Microsoft Academic Search

Extensive literature exists documenting laboratory and field studies of corrosion of the 300 series stainless steels by bacteria. There is, however, little data confirming similar microbiologically influenced corrosion (MIC) of higher alloy stainless steels, which are thought by some to be immune. This paper presents a case history of a UNS NO8904 (904L) heat exchanger where marine bacterial attack was

P. J. B. Scott; M. Davies

1989-01-01

367

Thermal desorption study of selected austenitic stainless steels  

Microsoft Academic Search

Residual hydrogen in stainless steel results in a steady outgassing from vacuum chamber walls, hindering the achievement of ultrahigh vacuum conditions. The total content, the binding states, and the diffusivity of residual hydrogen in austenitic stainless steels, which together define the room temperature hydrogen outgassing rate, have been investigated by thermal desorption spectroscopy (TDS). Seven different steel types have been

J.-P. Bacher; C. Benvenuti; P. Chiggiato; M.-P. Reinert; S. Sgobba; A.-M. Brass

2003-01-01

368

Magnetic properties of the UNS S39205 duplex stainless steel  

Microsoft Academic Search

Duplex stainless steels (DSS) present a fine microstructure of paramagnetic austenite and ferromagnetic ferrite. In this work the microstructures of UNS S39205 (old S31803) duplex stainless steel (DSS) samples were modified by high temperature treatment at 1300°C in vacuum followed by four different cooling rates and thermal aging at 475°C for three different times. Magnetic properties (saturation magnetization, remanence, coercive

S. S. M Tavares; P. D. S Pedrosa; J. R Teodósio; M. R da Silva; J. M Neto; S Pairis

2003-01-01

369

Barnacle cement: An etchant for stainless steel 316L?  

Microsoft Academic Search

Localized corrosion of stainless steel beneath the barnacle-base is an unsolved issue for the marine industry. In this work, we clearly bring out for the first time the role of the barnacle cement in acting as an etchant, preferentially etching the grain boundaries, and initiating the corrosion process in stainless steel 316L. The investigations include structural characterization of the cement

R. Sangeetha; R. Kumar; M. Doble; R. Venkatesan

2010-01-01

370

VIEW OF PRECISION EQUIPMENT USED IN STAINLESS COMPONENT MANUFACTURING. THE ...  

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

VIEW OF PRECISION EQUIPMENT USED IN STAINLESS COMPONENT MANUFACTURING. THE FACILITY WAS DESCRIBED AS THE MOST MODERN NON-NUCLEAR MANUFACTURING BUILDING IN THE U.S. DEPARTMENT OF ENERGY COMPLEX, WITH MANY PRECISION INSTRUMENTS. (9/21/83) - Rocky Flats Plant, Stainless Steel & Non-Nuclear Components Manufacturing, Southeast corner of intersection of Cottonwood & Third Avenues, Golden, Jefferson County, CO

371

Surface hardening of ductile cast iron using stainless steel  

Microsoft Academic Search

A surface hardening technique for improving the wear resistance of ductile cast iron (DI) is proposed by fabricating molten DI with stainless steel. The essential idea is concerned with using the chromium source in stainless steel and the carbon source in DI to form chromium carbides. It was demonstrated that the surface of the fabricated DI consisted of firstly a

Ma Qian; Shoji Harada; Yoshihito Kuroshima; Hideaki Nagayoshi

1996-01-01

372

TESTS OF COLD-FORMED STAINLESS STEEL TUBULAR COLUMNS  

Microsoft Academic Search

The paper summarises a series of tests on cold-formed stainless steel tubular structures recently conducted in Singapore and Hong Kong. The tubular structures consist of circular, square and rectangular hollow sections subjected to compressive axial force. The experimental investigation focused on the strength and behaviour of stainless steel columns. The test strengths were compared with design strengths calculated using the

Ben Young

373

Coating method enables low-temperature brazing of stainless steel  

NASA Technical Reports Server (NTRS)

Gold coated stainless steel tubes containing insulated electrical conductors are brazed at a low temperature to a copper coated stainless steel sealing block with a gold-copper eutectic. This produces an effective seal without using flux or damaging the electrical conductors.

Seaman, F. D.

1965-01-01

374

Sigma phase precipitation in duplex stainless steel 2205  

Microsoft Academic Search

Sigma phase precipitation is known to embrittle duplex stainless steel. Accordingly, heat treatment and welding must be performed carefully. Nucleation and diffusional growth of sigma phase in the duplex stainless steel 2205 have been analysed in order to ensure the high toughness shown in previous studies for both base and weld material. A quasi-static growth model has been modified in

Henrik Sieurin; Rolf Sandström

2007-01-01

375

Toward Improved Ductility and Toughness of Soft Martensitic Stainless Steel  

Microsoft Academic Search

This paper details the factors affecting mechanical properties of soft martensitic stainless steel castings that have lower carbon contents and increased nickel contents of up to 6% compared with normal martensitic stainless steel castings. The effect of alloying elements and impurities on the microstructural features and tempering characteristics was considered in detail, with special reference to reverted austenite and temper

Yoshitaka IWABUCHI

376

Kinetics of chemical interactions between zirconium alloys and stainless steels.  

National Technical Information Service (NTIS)

The chemical interaction kinetics of reactor core component zirconium alloys and stainless steels at high temperatures was examined. Interaction of as-received and preoxidized Zr1%Nb with X18H10T stainless steel used in WWER type nuclear reactors, and als...

J. Frecska L. Maroti L. Matus

1995-01-01

377

The partitioning of alloying elements in vacuum arc remelted, Pd-modified PH 13-8 Mo alloys  

NASA Astrophysics Data System (ADS)

The partitioning of alloying elements in as-solidified PH 13-8 Mo stainless steel containing up to 1.02 wt pct Pd has been investigated. The as-solidified structure is composed of two major phases, martensite and ferrite. Electron probe microanalysis reveals that Mo, Cr, and Al partition to the ferrite phase while Fe, Ni, Mn, and Pd partition to the martensite (prior austenite) during solidification and cooling from the solidus. In addition to bulk segregation between phases, precipitation of the intermetallic, PdAI, in the retained ferrite is observed. Precipitation of the normal hardening phase, ?-NiAl, is also observed in the retained ferrite. Partition ratios of the various alloying elements are determined and are compared with those observed previously in duplex Fe-Cr-Ni stainless steel solidification structures. The martensite start temperature (Ms) was observed to decrease with increasing Pd concentration.

Cieslak, M. J.; Vandenavyle, J. A.; Carr, M. J.; Hills, C. R.; Semarge, R. E.

1988-12-01

378

Evaluation of the stress corrosion behavior of selected stainless steels  

SciTech Connect

The objective of this investigation was to determine the stress corrosion behavior of selected stainless steels in several fluorinating environments. The possibility of stress corrosion cracking or pitting which could substantially reduce the serviceability of the stainless steels was the primary concern. Laboratory testing indicated that stress corrosion cracking or other forms of localized attack of the austenitic stainless steels tested (304, 304-L, 316, and 316-L) would not occur in the dry gas environments investigated. AISI 316 and 316-L stainless steels exhibited no significant corrosion in any of the test environments. Stressed 304 and 304-L stainless steels exhibited increased general corrosion and pitting when moisture was added to the fluorinating environment. 3 refs., 1 fig., 3 tabs.

Dorning, R.E. II

1983-11-05

379

Environment-Assisted Cracking in Custom 465 Stainless Steel  

NASA Astrophysics Data System (ADS)

The influence of cold work and aging on the environment-assisted cracking (EAC) behavior and mechanical properties of Custom 465 stainless steel (SS) was studied. Four sets of specimens were made and tested. All specimens were initially solution annealed, rapidly cooled, and refrigerated (SAR condition). The first specimen set was steel in the SAR condition. The second specimen set was aged to the H1000 condition. The third specimen set was 60 pct cold worked, and the fourth specimen set was 60 pct cold worked and aged at temperatures ranging from 755 K to 825 K (482 °C to 552 °C) for 4 hours in air. The specimens were subsequently subjected to EAC and mechanical testing. The EAC testing was conducted, using the rising step load (RSL) technique, in aqueous solutions of NaCl of pH 7.3 with concentrations ranging from 0.0035 to 3.5 pct at room temperature. The microstructure, dislocation substructure, and crack paths, resulting from the cold work, aging, or subsequent EAC testing, were examined by optical microscopy, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The aging of the cold-worked specimens induced carbide precipitation within the martensite lath, but not at the lath or packet boundaries. In the aged specimens, as aging temperature rose, the threshold stress intensity for EAC (KIEAC), elongation, and fracture toughness increased, but the strength and hardness decreased. The KIEAC also decreased with increasing yield strength and NaCl concentration. In the SAR and H1000 specimens, the EAC propagated along the prior austenite grain boundary, while in the cold-worked and cold-worked and aged specimens, the EAC propagated along the martensite lath, and its packet and prior austenite grain boundaries. The controlling mechanism for the observed EAC was identified to be hydrogen embrittlement.

Lee, E. U.; Goswami, R.; Jones, M.; Vasudevan, A. K.

2011-02-01

380

Flux-free ultrasonic soldering of aluminum and stainless steel  

NASA Astrophysics Data System (ADS)

Flux-free ultrasonic soldering of 2024 Alclad and 304 stainless steel was conducted to determine the conditions to produce the highest joint shear strength in lap joints. Prior to this time, ultrasonic energy was always applied directly to the molten liquid pool to promote excellent coupling and fluxing by a mechanism of cavitation of the substrate. In this study, the ultrasonic energy was applied to a solid aluminum manifold (heated to the soldering temperature) and further transmitted through the aluminum or stainless steel test sheets to form a lap joint containing solder. Fundamental studies on aluminum and stainless steel samples revealed that the oxide removal and subsequent solder wetting resulted from the erosion of the substrate surface by the cavitation action caused by the ultrasonic vibrations. Although aluminum was successfully joined by the ultrasonic soldering, stainless steel could not be ultrasonically soldered regardless of the surface preparation. Therefore, it may be impractical to chemically clean stainless steel and expect any wetting without a strong fluxing agent. In fact, the results showed that practical soldering of stainless steel could only be achieved by plating the stainless steel substrate surfaces prior to soldering. The Al2O3 oxidation reaction is far more stable than the Cr2O3 reaction, however, the results imply that the rate of oxide formation and growth after chemical cleaning of stainless steel was several times faster than that for aluminum and the applied ultrasonic vibrations were not able to remove the thicker Cr 2O3 from the stainless steel substrate surfaces. with the results of this research, it is now possible to transmit ultrasonic energy through a solid to joint aluminum or stainless steel in a lap joint, it is also more feasible to optimize the most effective soldering variables for increasing the reliability and integrity of an ultrasonic soldering operation.

Faridi, Hamid Reza

381

Citric Acid Passivation of Stainless Steel  

NASA Technical Reports Server (NTRS)

Passivation is a process for cleaning and providing corrosion protection for stainless steel. Currently, on Kennedy Space Center (KSC), only parts passivated with nitric acid are acceptable for use. KSC disposes of approximately 125gal of concentrated nitric acid per year, and receives many parts from vendors who must also dispose of used nitric acid. Unfortunately, nitric acid presents health and environmental hazards. As a result, several recent industry studies have examined citric acid as an alternative. Implementing a citric acid-based passivation procedure would improve the health and environmental safety aspects of passivation process. However although there is a lack of published studies that conclusively prove citric acid is a technically sound passivation agent. In 2007, NASA's KSC Materials Advisory Working Group requested the evaluation of citric acid in place of nitric acid for passivation of parts at KSC. United Space Alliance Materials & Processes engineers have developed a three-phase test plan to evaluate citric acid as an alternative to nitric acid on three stainless steels commonly used at KSC: UNS S30400, S41000, and S17400. Phases 1 and 2 will produce an optimized citric acid treatment based on results from atmospheric exposure at NASA's Beach Corrosion Facility. Phase 3 will compare the optimized solution(s) with nitric acid treatments. If the results indicate that citric acid passivates as well or better than nitric acid, NASA intends to approve this method for parts used at the Kennedy Space Center.

Yasensky, David; Reali, John; Larson, Chris; Carl, Chad

2009-01-01

382

Cast alumina forming austenitic stainless steels  

DOEpatents

An austenitic stainless steel alloy consisting essentially of, in terms of weight percent ranges 0.15-0.5C; 8-37Ni; 10-25Cr; 2.5-5Al; greater than 0.6, up to 2.5 total of at least one element selected from the group consisting of Nb and Ta; up to 3Mo; up to 3Co; up to 1W; up to 3Cu; up to 15Mn; up to 2Si; up to 0.15B; up to 0.05P; up to 1 total of at least one element selected from the group consisting of Y, La, Ce, Hf, and Zr; <0.3Ti+V; <0.03N; and, balance Fe, where the weight percent Fe is greater than the weight percent Ni, and wherein the alloy forms an external continuous scale comprising alumina, and a stable essentially single phase FCC austenitic matrix microstructure, the austenitic matrix being essentially delta-ferrite free and essentially BCC-phase-free. A method of making austenitic stainless steel alloys is also disclosed.

Muralidharan, Govindarajan; Yamamoto, Yukinori; Brady, Michael P

2013-04-30

383

Embrittlement of austenitic stainless steel welds  

SciTech Connect

The microstructure of type-308 austenitic stainless steel weld metal containing {gamma} and {delta} and ferrite is shown. Typical composition of the weld metal is Cr-20.2, Ni-9.4, Mn-1.7, Si-0.5, C-0.05, N-0.06 and balance Fe (in wt %). Exposure of austenitic stainless steel welds to elevated temperatures can lead to extensive changes in the microstructural features of the weld metal. On exposure to elevated temperatures over a long period of time, a continuous network of M{sub 23}C{sub 6} carbide forms at the austenite/ferrite interface. Upon aging at temperatures between 550--850 C, ferrite in the weld has been found to be unstable and transforms to sigma phase. These changes have been found to influence mechanical behavior of the weld metal, in particular the creep-rupture properties. For aging temperatures below 550 C the ferrite decomposes spinodally into {alpha} and {alpha}{prime} phases. In addition, precipitation of G-phase occurs within the decomposed ferrite. These transformations at temperatures below 550 C lead to embrittlement of the weld metal as revealed by the Charpy impact properties.

David, S.A.; Vitek, J.M. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

1997-12-31

384

Dislocation substructure in fatigued duplex stainless steel  

SciTech Connect

Cyclic plastic straining of crystalline materials results in the formation of specific dislocation structures. Considerable progress in mapping and understanding internal dislocation structures has been achieved by studying single crystal behavior: however, most structural materials have a polycrystalline structure and investigations of polycrystals in comparison to single crystal behavior of simple metals prove to be very useful in understanding more complex materials. There are some classes of materials, however, with complicated structure which do not have a direct equivalent in single crystalline form. Moreover, the specific dimensions and shapes of individual crystallites play an important role both in the cyclic stress-strain response of these materials and in the formation of their interior structure in cyclic straining. Austenitic-ferritic duplex stainless steel, which is a kind of a natural composite, is a material of this type. The widespread interest in the application of duplex steels is caused by approximately doubled mechanical properties and equal corrosion properties, when compared with classical austenitic stainless steels. Fatigue resistance of these steels as well as the surface damage evolution in cyclic straining have been studied; however, much less is known about the internal substructure development in cyclic straining. In this study the dislocation arrangement in ferritic and austenitic grains of the austenitic-ferritic duplex steel alloyed with nitrogen and cyclically strained with two strain amplitudes, is reported and compared to the dislocation arrangement found in single and polycrystals of austenitic and ferritic materials of a similar composition and with the surface relief produced in cyclic plastic straining.

Polak, J. (Ecole Centrale de Lille, Villeneuve d'Ascq (France). Lab. de Mecanique de Lille Inst. of Physical Metallurgy, Brno (Czechoslovakia). Academy of Sciences); Degallaix, S. (Ecole Centrale de Lille, Villeneuve d'Ascq (France). Lab. de Mecanique de Lille); Kruml, T. (Inst. of Physical Metallurgy, Brno (Czechoslovakia). Academy of Sciences)

1993-12-15

385

Anthropogenic carbon and ocean pH  

NASA Astrophysics Data System (ADS)

The burning of fossil fuels and forests increases atmospheric CO2 content, which drives a CO2 flux into the ocean, and thereby makes the ocean more acidic. The effects of increased CO2 and decreased ocean pH may individually and in combination have significant consequences for marine biota We present ocean pH change results from ocean geochemistry and ocean general circulation models for both atmospheric CO2 change scenarios and ocean carbon sequestration scenarios. Unsurprisingly, the pH decrease in the ocean reflects the spatial and temporal distribution of anthropogenic carbon. However, the pH response of the ocean depends sensitively on the rate at which carbon is added to the ocean. When CO2 changes occur over hundreds of thousands of years and longer, ocean carbonate-ion concentration is buffered by interaction with carbonate sediments, buffering ocean pH. However, when CO2 changes occur over decades and centuries, ocean alkalinity remains roughly constant, tending to make ocean pH relatively sensitive to changes in ocean carbon content. A doubling of atmospheric CO2 over a few centuries would decrease ocean pH by ~0.3 units. This is roughly the magnitude of pH variation over the past ~50 million years inferred from boron isotopes. There is no evidence of such rapid pH variation of this magnitude in the geologic record (with possible exceptions for rare catastrophic events). If CO2 is emitted as per the IPCC IS92a ``Business as Usual'' scenario, or even as per most of the proposed CO2 stabilization scenarios, ocean pH may decrease by an amount and at a rate not experienced by the Earth for the past few tens of millions of years. The biological consequences of such pH changes are uncertain at present.

Caldeira, K.; Wickett, M. E.; Duffy, P. B.; Barry, J. P.

2001-12-01

386

Experimental Study of Fouling and Cleaning of Sintered Stainless Steel Membrane in Electro-Microfiltration of Calcium Salt Particles  

PubMed Central

Sintered stainless steel (SSS) microfiltration membranes, which served as electrode directly, were used for the experiment of separating Alamin, a calcium salt and protein containing particles, found in dairy processing. Fouling and cleaning of the SSS membranes under the application of an external electric field were studied. The imposed electric field was found, diverging the pH of permeate and retentate. This in turn altered the solubility of the calcium salt and impacted the performance of electro microfiltration membrane. Using electric field as an enhanced cleaning-in-place (CIP) method in back flushing SSS membrane was also studied.

Qin, Frank G. F.; Mawson, John; Zeng, Xin An

2011-01-01

387

Microstructural evolution in 13Cr–8Ni–2.5Mo–2Al martensitic precipitation-hardened stainless steel  

Microsoft Academic Search

The microstructure of 13Cr–8Ni–2.5Mo–2Al martensitic precipitation-hardened (PH) stainless steel has been investigated using transmission electron microscopy, three-dimensional atom probe and small-angle X-ray scattering. A high number density (?1023–25m?3) of ultra-fine (1–6nm) ?-NiAl precipitates are formed during aging at 450–620°C, which are spherical in shape and dispersed uniformly with perfect coherency with the matrix. As the annealing temperature increases, the size

D. H. Ping; M. Ohnuma; Y. Hirakawa; Y. Kadoya; K. Hono

2005-01-01

388

A XPS study of the Mo effect on passivation behaviors for highly controlled stainless steels in neutral and alkaline conditions  

NASA Astrophysics Data System (ADS)

The objective of this work is to study the effect of Mo additions on film passive properties of three different stainless steels (SS) types (austenitic, ferritic and duplex alloys). A comparison between Mo containing (3 wt% Mo) and free Mo (0 wt% Mo) grades of highly controlled laboratory heats was done considering their passive film formed in different aggressive conditions, from neutral to alkaline pH. The presence of oxidized Mo on the passive layer was confirmed by X-ray photoelectron Spectroscopy (XPS). The presence of Mo within the passive film improved the passivity breakdown potential for the duplex and ferritic SS, but seemed to have no effect for austenitic SS.

Mesquita, Thiago J.; Chauveau, Eric; Mantel, Marc; Nogueira, Ricardo P.

2013-04-01

389

Hydrogen embrittlement of type 410 stainless steel in sodium chloride, sodium sulfate, and sodium hydroxide environments at 90 C  

SciTech Connect

Susceptibility of martensitic type 410 (UNS S41000) stainless steel (SS) to environmental cracking was evaluated at 90 C in concentrated sodium chloride, sodium sulfate and sodium hydroxide solutions, all of which are environments related to steam turbine conditions, using the slow strain rate testing (SSRT) technique. In NaCl, the effects of solution pH, concentration, and anodic and cathodic polarization were investigated. Tests were supplemented by detailed electron fractography and hydrogen permeation measurements. A clear correlation was found between the degree of embrittlement and the amount of hydrogen permeating the steel, suggesting a hydrogen-induced cracking mechanism.

Gonzalez-Rodriguez, J.G.; Salinas-Bravo, V.M. [Inst. de Investigaciones Electricas, Cuernavaca (Mexico). Dept. Fisico Quimica Aplicada; Martinez-Villafane, A. [Centro de Investigaciones en Materiales Avanzados Leon Tolstoi, Chihuahua (Mexico)

1997-06-01

390

Response to the "Responsive PhD"  

ERIC Educational Resources Information Center

In June 2005, 50 graduate school deans gathered at Princeton to address the fact that the number of new PhDs conferred each year far exceeds the number of tenure-track academic jobs on offer. Under the auspices of the Woodrow Wilson National Fellowship Foundation's Responsive PhD Project, these deans spoke passionately about how American…

Huyssen, David

2007-01-01

391

pH. Agricultural Lesson Plans.  

ERIC Educational Resources Information Center

This lesson plan is intended for use in conducting classes on the effect of pH on plant growth. Presented first are an attention step/problem statement and a series of questions and answers designed to convey general information about soil pH and its effect on plants. The following topics are among those discussed: acidity and alkalinity; the…

Southern Illinois Univ., Carbondale. Dept. of Agricultural Education and Mechanization.

392

CALCULATING THE PH OF CALCIUM CARBONATE SATURATION  

EPA Science Inventory

Two new expressions for the pH of saturation (pH subs) were derived. One is a simplified equation developed from an aqueous carbonate equilibrium system in which correction for ionic strength was considered. The other is a more accurate quadratic formula that involves computerize...

393

Analysis of Stainless Steel Sandwich Panels with a Metal Foam Care for Lightweight Fan Blade Design  

NASA Technical Reports Server (NTRS)

The quest for cheap, low density and high performance materials in the design of aircraft and rotorcraft engine fan and propeller blades poses immense challenges to the materials and structural design engineers. Traditionally, these components have been fabricated using expensive materials such as light weight titanium alloys, polymeric composite materials and carbon-carbon composites. The present study investigates the use of P sandwich foam fan blade made up of solid face sheets and a metal foam core. The face sheets and the metal foam core material were an aerospace grade precipitation hardened 17-4 PH stainless steel with high strength and high toughness. The stiffness of the sandwich structure is increased by separating the two face sheets by a foam core. The resulting structure possesses a high stiffness while being lighter than a similar solid construction. Since the face sheets carry the applied bending loads, the sandwich architecture is a viable engineering concept. The material properties of 17-4 PH metal foam are reviewed briefly to describe the characteristics of the sandwich structure for a fan blade application. A vibration analysis for natural frequencies and P detailed stress analysis on the 17-4 PH sandwich foam blade design for different combinations of skin thickness and core volume %re presented with a comparison to a solid titanium blade.

Min, James B.; Ghosn, Louis J.; Lerch, Bradley A.; Raj, Sai V.; Holland, Frederic A., Jr.; Hebsur, Mohan G.

2004-01-01

394

Biotherapeutic formulation factors affecting metal leachables from stainless steel studied by design of experiments.  

PubMed

Trace amounts of metals are inevitably present in biotherapeutic products. They can arise from various sources. The impact of common formulation factors such as protein concentration, antioxidant, metal chelator concentration and type, surfactant, pH, and contact time with stainless steel on metal leachables was investigated by a design of experiments approach. Three major metal leachables, iron, chromium, and nickel were monitored by inductively coupled plasma-mass spectrometry. It was observed that among all the tested factors, contact time, metal chelator concentration, and protein concentration were statistically significant factors with higher temperature resulting in higher levels of leached metals. Within a pH range of 5.5-6.5, solution pH played a minor role for chromium leaching at 25°C. No statistically significant difference was observed due to type of chelator, presence of antioxidant, or surfactant. In order to optimize a biotherapeutic formulation to achieve a target drug product shelf life with acceptable quality, each formulation component must be evaluated for its impact. PMID:22246735

Zhou, Shuxia; Evans, Brad; Schöneich, Christian; Singh, Satish K

2012-03-01

395

Frequently Asked Questions for Parents of Children with PH  

MedlinePLUS

... International PH News and Projects Let Me Breathe Music Video Families Patients Newly Diagnosed Request an Envelope ... International PH News and Projects Let Me Breathe Music Video Help spread PH awareness and share PH ...

396

Smart pH cuvette for optical monitoring of pH of biological samples  

NASA Astrophysics Data System (ADS)

A Smart pH Cuvette is developed by coating the inner surface with pH sensitive thin film. The coating is a hydroscopic sol-gel material doped with colorimetric pH indicator dye sensitive to the pH of analyte solutions in biological range. Ocean optics miniaturized spectrometers are used for signal detection and analysis, along with multimode optical fibers. This new pH sensing arrangement yields an inexpensive solution for monitoring the pH of samples for biological applications. The Smart pH Cuvettes provide a resolution of 0.01 pH units, an accuracy of 1% of the reading, and 90% response in less than 10 seconds.

Guenther, Derek A.; Shahriari, Mahmoud R.

2010-02-01

397

Role of structural orientation on the susceptibility of 2205 duplex stainless steel to hydrogen embrittlement  

NASA Astrophysics Data System (ADS)

Relationship between the microstructure directionality of delta ferrite and austenite islands and the crack morphology, crack velocity and time to failure of the mechanically notched duplex stainless samples tested in hydrogen bearing environment was assessed in aqueous solution of 3.5% seawater. A number of UNS S32205 duplex stainless steel samples were mechanically notched in perpendicular and transverse directions with respect to the austenite and ferrite rolling direction were subjected to slow tensile strain at 21.2 nm/s while undergoing cathodic charging in aqueous solution of 3.5% seawater. In order to assess the role of hydrogen content on embrittlement the hydrogen charging was conducted at various cathodic potentials of -800 mV/SCE to -1300 mV/SCE at two different pH (6.7 and 3.5). Generally, the longitudinal samples showed lower susceptibility to hydrogen embrittlement compared with the transverse samples. The results also confirm that long austenite island can act as an obstacle for propagated crack owing to its low diffusivity and high solubility to the hydrogen.

Sharrfeddin, A.; Musa, S. M.; Elshawesh, F. M.

2012-09-01

398

Constituents and pH changes in protein rich hyaluronan solution affect the biotribological properties of artificial articular joints.  

PubMed

The relationship between the coefficient of friction and pH value or protein constituents of lubricating fluid, together with viscosity, were studied within a bearing surface model for artificial joint, ultra-high molecular weight polyethylene (UHMWPE) against stainless steel (SUS), using a mechanical spectrometer. Four lubricants were tested in this study: sodium hyaluronate (HA), HA with albumin, HA with gamma-globulin, and HA with (L)alpha-dipalmitoyl phosphatidylcholine ((L)alpha-DPPC). The coefficient of friction between UHMWPE and SUS in HA with albumin or HA with gamma-globulin varied from 0.035 to 0.070 depending on angular velocity and pH. The coefficient of friction in HA or HA with (L)alpha-DPPC varied from 0.023 to 0.045 depending on angular velocity and pH. The variation in pH for HA with albumin had a large effect on the coefficient of friction at low range of angular velocity with viscosity independence. The variation in pH for HA with gamma-globulin had a large effect on the coefficient of friction with viscosity dependence at high angular velocity. The addition of (L)alpha-DPPC showed a small effect on the coefficient of friction at low angular velocity. This study confirms that the presence of albumin in the lubricant promotes pH dependence and viscosity independence of the tribological properties at low speed while the presence of globulin promotes pH and viscosity independence at low speed and promotes pH and viscosity dependence at high speed in the lubrication of UHMWPE against SUS. This study supports the clinical hypothesis that the effect of constituents and pH changes in periprosthetic fluid for the lubrication is a clue toward resolving many complications after total joint replacement. PMID:11448695

Kitano, T; Ateshian, G A; Mow, V C; Kadoya, Y; Yamano, Y

2001-08-01

399

78 FR 34644 - Stainless Steel Plate in Coils From Belgium: Preliminary Results of Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013

...A-423-808] Stainless Steel Plate in Coils From Belgium: Preliminary Results of Antidumping...duty order on stainless steel plate in coils (steel plate) from Belgium, covering...order is certain stainless steel plate in coils. Stainless steel is alloy steel...

2013-06-10

400

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

Federal Register 2010, 2011, 2012, 2013

...A-351-825] Stainless Steel Bar From Brazil: Final Results of Antidumping Duty Administrative...order on certain stainless steel bar from Brazil. The review covers one producer/exporter...order on certain stainless steel bar from Brazil. See Stainless Steel Bar From...

2010-07-12

401

76 FR 1599 - Stainless Steel Bar From Brazil: Final Results of Antidumping Duty Administrative Review  

Federal Register 2010, 2011, 2012, 2013

...A-351-825] Stainless Steel Bar From Brazil: Final Results of Antidumping Duty Administrative...duty order on stainless steel bar from Brazil. The review covers one producer/exporter...order on stainless steel bar (SSB) from Brazil. See Stainless Steel Bar From...

2011-01-11

402

Final Report, Volume 1, Metallurgical Evaluation of Cast Duplex Stainless Steels and their Weldments  

Microsoft Academic Search

Duplex stainless steels (DSS) are being specified for chloride containing environments due to their enhanced pitting and stress corrosion cracking resistance. They exhibit improved corrosion performance over the austenitic stainless steels. Duplex stainless steels also offer improved strength properties and are available in various wrought and cast forms. Selected grades of duplex stainless steel castings and their welds, in comparison

Songqing Wen; Carl Lundin; Greg Batten

2005-01-01

403

Kinetics of Pseudomonas aeruginosa adhesion to 304 and 316-L stainless steel: role of cell surface hydrophobicity.  

PubMed Central

Fifteen different isolates of Pseudomonas aeruginosa were used to study the kinetics of adhesion to 304 and 316-L stainless steel. Stainless steel plates were incubated with approximately 1.5 X 10(7) CFU/ml in 0.01 M phosphate-buffered saline (pH 7.4). After the plates were rinsed with the buffer, the number of adhering bacteria was determined by a bioluminescence assay. Measurable adhesion, even to the electropolished surfaces, occurred within 30 s. Bacterial cell surface hydrophobicity, as determined by the bacterial adherence to hydrocarbons test and the contact angle measurement test, was the major parameter influencing the adhesion rate constant for the first 30 min of adhesion. A parabolic relationship between the CAM values and the logarithm of the adhesion rate constants (In k) was established. No correlation between either the salt aggregation or the improved salt aggregation values and the bacterial adhesion rate constants could be found. Since there was no significant correlation between the bacterial electrophoretic mobilities and the In k values, the bacterial cell surface charge seemed of minor importance in the process of adhesion of P. aeruginosa to 304 and 316-L stainless steel.

Vanhaecke, E; Remon, J P; Moors, M; Raes, F; De Rudder, D; Van Peteghem, A

1990-01-01

404

THE CLEANING OF 303 STAINLESS STEEL  

SciTech Connect

The sulfur found on the surfaces of stainless steel 303 (SS303) after nitric acid passivation originated from the MnS inclusions in the steel. The nitric acid attacked and dissolved these MnS inclusions, and redeposited micron-sized elemental sulfur particles back to the surface. To develop an alternative passivation procedure for SS303, citric and phosphoric acids have been evaluated. The experimental results show neither acid causes a significant amount of sulfur deposit. Thus, these two acids can be used as alternatives to nitric acid passivation for NIF applications. For SS303 previously passivated by nitric acid, NaOH soak can be used as a remedial cleaning process to effectively remove the sulfur deposits.

Shen, T H

2004-04-20

405

Wear evaluation of high interstitial stainless steel  

SciTech Connect

A new series of high nitrogen-carbon manganese stainless steel alloys are studied for their wear resistance. High nitrogen and carbon concentrations were obtained by melting elemental iron-chromium-manganese (several with minor alloy additions of nickel, silicon, and molybdenum) in a nitrogen atmosphere and adding elemental graphite. The improvement in material properties (hardness and strength) with increasing nitrogen and carbon interstitial concentration was consistent with previously reported improvements in similar material properties alloyed with nitrogen only. Wear tests included: scratch, pin-on-disk, sand-rubber-wheel, impeller, and jet erosion. Additions of interstitial nitrogen and carbon as well as interstitial nitrogen and carbide precipitates were found to greatly improve material properties. In general, with increasing nitrogen and carbon concentrations, strength, hardness, and wear resistance increased.

Rawers, J.C.; Tylczak, J.H.

2008-07-01

406

MOCVD deposition of YSZ on stainless steels  

NASA Astrophysics Data System (ADS)

Yttria stabilized zirconia was deposited on stainless steel using the metal-organic chemical vapor deposition (MOCVD) technique, from ?-diketonate precursors. The variation of the evaporation temperatures of yttrium and zirconium precursor allowed to control the level of Y within the film. Over the temperature range 125-150 °C, the Y content increased from 2.5 to 17.6 at.%. X-ray diffraction (XRD) analyses evidenced tetragonal phase of zirconia when the Y content was below 8 at.%, and cubic phase for higher concentration. Sputtered neutral mass spectrometry (SNMS) profiles confirmed that the control and stability of Y precursor temperature were of major importance to guarantee the homogeneity of the deposited films.

Chevalier, S.; Kilo, M.; Borchardt, G.; Larpin, J. P.

2003-01-01

407

Automatic welding of stainless steel tubing  

NASA Technical Reports Server (NTRS)

The use of automatic welding for making girth welds in stainless steel tubing was investigated as well as the reduction in fabrication costs resulting from the elimination of radiographic inspection. Test methodology, materials, and techniques are discussed, and data sheets for individual tests are included. Process variables studied include welding amperes, revolutions per minute, and shielding gas flow. Strip chart recordings, as a definitive method of insuring weld quality, are studied. Test results, determined by both radiographic and visual inspection, are presented and indicate that once optimum welding procedures for specific sizes of tubing are established, and the welding machine operations are certified, then the automatic tube welding process produces good quality welds repeatedly, with a high degree of reliability. Revised specifications for welding tubing using the automatic process and weld visual inspection requirements at the Kennedy Space Center are enumerated.

Clautice, W. E.

1978-01-01

408

Radiation resistant austenitic stainless steel alloys  

DOEpatents

An austenitic stainless steel alloy, with improved resistance to radiation-induced swelling and helium embrittlement, and improved resistance to thermal creep at high temperatures, consisting essentially of, by weight percent: from 16 to 18% nickel; from 13 to 17% chromium; from 2 to 3% molybdenum; from 1.5 to 2.5% manganese; from 0.01 to 0.5% silicon; from 0.2 to 0.4% titanium; from 0.1 to 0.2% niobium; from 0.1 to 0.6% vanadium; from 0.06 to 0.12% carbon; from 0.01 to 0.03% nitrogen; from 0.03 to 0.08% phosphorus; from 0.005 to 0.01% boron; and the balance iron, and wherein the alloy may be thermomechanically treated to enhance physical and mechanical properties. 4 figs.

Maziasz, P.J.; Braski, D.N.; Rowcliffe, A.F.

1987-02-11

409

Radiation resistant austenitic stainless steel alloys  

DOEpatents

An austenitic stainless steel alloy, with improved resistance to radiation-induced swelling and helium embrittlement, and improved resistance to thermal creep at high temperatures, consisting essentially of, by weight percent: from 16 to 18% nickel; from 13 to 17% chromium; from 2 to 3% molybdenum; from 1.5 to 2.5% manganese; from 0.01 to 0.5% silicon; from 0.2 to 0.4% titanium; from 0.1 to 0.2% niobium; from 0.1 to 0.6% vanadium; from 0.06 to 0.12% carbon; from 0.01% to 0.03% nitrogen; from 0.03 to 0.08% phosphorus; from 0.005 to 0.01% boron; and the balance iron, and wherein the alloy may be thermomechanically treated to enhance physical and mechanical properties.

Maziasz, Philip J. (Oak Ridge, TN); Braski, David N. (Oak Ridge, TN); Rowcliffe, Arthur F. (Oak Ridge, TN)

1989-01-01

410

Magnetic characterisation of duplex stainless steel  

NASA Astrophysics Data System (ADS)

Heat treatment-induced microstructural processes were studied by different non-destructive magnetic and mechanical material testing methods in the present work. A commercial SAF 2507 type superduplex stainless steel was investigated. This alloy contains about 40% metastable ferrite which can decompose to a sigma phase and secondary austenite due to heat treatment. All the mechanical, corrosion resistance and magnetic properties are strongly influenced by this microstructural changes. This study had two aims: to understand better the kinetics of the ferrite decomposition process and to study the application possibilities of the applied magnetic measurements. This paper presents an application possibility of the nonlinear harmonics analysis measurement and demonstrates the possibility to find a quantitative correlation between measured harmonics and mechanical properties obtained from destructive tests.

Mészáros, I.

2006-02-01

411

Refractory metal to stainless steel joints  

NASA Astrophysics Data System (ADS)

The joining of Nb-1Zr to austenitic type 316 stainless steel (316SS) was investigated. Sound welds were produced on sheet metals (1.5-mm thickness) by lap welding 316SS over Nb-1Zr using the gas tungsten arc process. Satisfactory strength and ductility of the welding joints were found in tensile tests at room temperature and at 1000 K. Investigation of thermocyclic effects showed that there was a small degradation in the mechanical properties of the joint after the completion of 100 cycles from 300 to 1000 to 300 K under vacuum. When the base metal was strengthened to cause failure of the weld, cracks were found to propagate along the Nb-1Zr-intermetallic interface or across the fusion zone. This result suggests that both the boundary between the Nb-1Zr-intermetallic and the Nb contaminated resolidified molten metal have less toughness than the surrounding regions.

Chen, Shaofeng; Zee, Ralph H.; Chin, Bryan A.

412

Materials compatibility of hydride storage materials with austenitic stainless steels  

SciTech Connect

This task evaluated the materials compatibility of LaNi[sub 5-x]Al[sub x] (x= 0.3, 0.75) hydrides and palladium coated kieselguhr with austenitic stainless steel in hydrogen and tritium process environments. Based on observations of retired prototype hydride storage beds and materials exposure testing samples designed for this study, no materials compatibility problem was indicated. Scanning electron microscopy observations of features on stainless steel surfaces after exposure to hydrides are also commonly found on as-received materials before hydriding. These features are caused by either normal heat treating and acid cleaning of stainless steel or reflect the final machining operation.

Clark, E.A.

1992-09-21

413

Materials compatibility of hydride storage materials with austenitic stainless steels  

SciTech Connect

This task evaluated the materials compatibility of LaNi{sub 5-x}Al{sub x} (x= 0.3, 0.75) hydrides and palladium coated kieselguhr with austenitic stainless steel in hydrogen and tritium process environments. Based on observations of retired prototype hydride storage beds and materials exposure testing samples designed for this study, no materials compatibility problem was indicated. Scanning electron microscopy observations of features on stainless steel surfaces after exposure to hydrides are also commonly found on as-received materials before hydriding. These features are caused by either normal heat treating and acid cleaning of stainless steel or reflect the final machining operation.

Clark, E.A.

1992-09-21

414

An examination of chromium substitution in stainless steels  

NASA Astrophysics Data System (ADS)

A series of lower Cr stainless steels containing various levels of Mo, Si, Cu, V, N, and Ni were examined. In less severe environments it was possible to achieve corrosion resistance comparable to 18-8 type stainless steels in alloys containing about 9 pct Cr, along with additions of Ni, Mo, Cu, and V. The hot working behavior, weldability, and mechanical properties appear comparable to conventional grades of stainless. Alloys of this type could be used in decorative, aqueous, and some industrial applications, but should not be adequate for more severe environments.

Floreen, S.

1982-11-01

415

EFFECT OF PH ON HUMAN MYCOPLASMA STRAINS.  

PubMed

Shepard, Maurice C. (U.S. Naval Medical Field Research Laboratory, Camp Lejeune, N.C.), and Carl D. Lunceford. Effect of pH on human Mycoplasma strains. J. Bacteriol. 89:265-270. 1965.-The optimal reaction of culture media for the cultivation of T-strain Mycoplasma of human origin was investigated. By use of a recently modified tryptic digest medium, the optimal reaction in either agar or fluid medium was found to be pH 6.0. In contrast, human classic (large-colony) Mycoplasma could be cultivated in agar or fluid medium over a rather broad pH range, and the influence of the reaction of the medium appeared to be primarily species-dependent. M. salivarium, for example, grew best in agar from pH 5.5 through 6.5. M. pneumoniae (Easton's agent) yielded largest colony numbers in agar and highest titers in broth at pH 8.0. In the case of T-strain Mycoplasma, both maximal colony numbers in agar and highest titers in fluid media were achieved at a reaction of pH 6.0. In addition, largest colony size of T-strain Mycoplasma was also achieved in agar at pH 6.0, and averaged 50 to 100% larger than that obtained by cultivation at pH 8.0 with the same medium. Although T-strains will develop in agar media over a pH range of from 5.0 through 10.0, the extremely small colony size and poor staining properties resulting from growth in an alkaline medium make their recognition in agar cultures difficult. Aerobic cultivation of T-strains was first achieved in agar adjusted to pH 5.5 to 6.0. In fluid medium, multiplication of T-strains occurred only within the limits of pH 5.0 through 8.0, with highest titers being reached at pH 6.0. Greater attention to the reaction of complete Mycoplasma media is stressed. PMID:14255688

SHEPARD, M C; LUNCEFORD, C D

1965-02-01

416

Functional photoacoustic microscopy of pH  

PubMed Central

pH is a tightly regulated indicator of metabolic activity. In mammalian systems, an imbalance of pH regulation may result from or result in serious illness. In this paper, we report photoacoustic microscopy (PAM) of a commercially available pH-sensitive fluorescent dye (SNARF-5F carboxylic acid) in tissue phantoms. We demonstrated that PAM is capable of pH imaging in absolute values at tissue depths of up to 2.0 mm, greater than possible with other forms of optical microscopy.

Chatni, Muhammad Rameez; Yao, Junjie; Danielli, Amos; Favazza, Christopher P.; Maslov, Konstantin I.; Wang, Lihong V.

2011-01-01

417

Effect of Prior Processing on the Performance of PH 13-8 Mo Stainless Steel Helicopter Components  

Microsoft Academic Search

The purpose of this investigation was to determine the root cause of the differences noted in the fatigue test\\u000a data of main rotor spindle assembly retaining rods fabricated from three different vendors, as part of a “Second\\u000a Source” evaluation process. ARL performed dimensional verification, accessed overall workmanship, and\\u000a measured the respective surface roughness of the rods in an effort to

Marc S. Pepi; Scott M. Grendahl; Victor K. Champagne

2001-01-01

418

Colorimetric Determination of pH.  

ERIC Educational Resources Information Center

Presented is an activity in which the pH of a solution can be quantitatively measured using a spectrophotometer. The theory, experimental details, sample preparation and selection, instrumentation, and results are discussed. (CW)

Tucker, Sheryl; And Others

1989-01-01

419

Mary Fennell, PhD Chair  

Cancer.gov

NCI Community Cancer Centers Program Evaluation Oversight Committee Roster CHAIR Mary Fennell, Ph.D. Chair, Department of Sociology and Community Health Brown University Box 1916, 211 Maxcy Hall 112 George Street Providence, RI 02912

420

Paul Pinsky, PhD, MPH  

Cancer.gov

Division of Cancer Prevention Staff Paul Pinsky, PhD, MPH Acting ChiefEarly Detection Research Group Location Division of Cancer PreventionNational Cancer Institute9609 Medical Center Drive, Room 5E444 Rockville, MD 20850 Phone

421

Aqueous-Solution pH Scales  

Microsoft Academic Search

The parallel existence of two forms of pH scale is considered, which is unique for the international metrological community. The basic advantages and shortcomings are considered for the multireference NIST scale and the single-reference BSI one.

O. V. Karpov; I. I. Maksimov; A. L. Seifer

2000-01-01

422

Effect of Deformation Rate on JBK-75 Stainless Steel Forgings.  

National Technical Information Service (NTIS)

A parametric study was conducted to evaluate the effect of forging rate and forging temperature on the strength and microstructure of a precipitation-hardened, austenitic stainless steel forging. High and low forging rates were achieved using a high energ...

B. C. Odegard

1987-01-01

423

Carburisation of Stainless Steel Caused by Oil in Sodium.  

National Technical Information Service (NTIS)

The primary objectives of this work were to investigate the kinetics of austenitic stainless steel carburization in sodium caused by oil in sodium, and to measure the corresponding 'sodium carbon activity' (a quantitative measure of sodium steel carburisa...

M. R. Hobdell G. Skyrme

1988-01-01

424

Ultrasonics permits brazing complex stainless steel assembly without flux  

NASA Technical Reports Server (NTRS)

Ultrasonic vibration of an assembly of stainless steel instrumentation tubes ensures brazing without flux. Vibration with an ultrasonic transducer permits the brazing material to flow down each tube in contact with a seal plug installed in a pressure vessel wall.

Baker, W. H.

1967-01-01

425

3. INTERIOR VIEW OF SMOKEHOUSE UNIT; NOTE STAINLESS STEEL NOZZLES ...  

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

3. INTERIOR VIEW OF SMOKEHOUSE UNIT; NOTE STAINLESS STEEL NOZZLES THAT INTRODUCED SMOKE INTO UNIT; FLOOR IS UNPAINTED STEEL - Rath Packing Company, Smokehouse-Hog Chilling Building, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

426

Stress corrosion cracking evaluation of precipitation-hardening stainless steel  

NASA Technical Reports Server (NTRS)

Accelerated test program results show which precipitation hardening stainless steels are resistant to stress corrosion cracking. In certain cases stress corrosion susceptibility was found to be associated with the process procedure.

Humphries, T. S.; Nelson, E. E.

1970-01-01

427

Fabrication of stainless steel clad tubing. [gas pressure bonding  

NASA Technical Reports Server (NTRS)

The feasibility of producing stainless steel clad carbon steel tubing by a gas pressure bonding process was evaluated. Such a tube product could provide substantial chromium savings over monolithic stainless tubing in the event of a serious chromium shortage. The process consists of the initial assembly of three component tubesets from conventionally produced tubing, the formation of a strong metallurgical bond between the three components by gas pressure bonding, and conventional cold draw and anneal processing to final size. The quality of the tubes produced was excellent from the standpoint of bond strength, mechanical, and forming properties. The only significant quality problem encountered was carburization of the stainless clad by the carbon steel core which can be overcome by further refinement through at least three different approaches. The estimated cost of clad tubing produced by this process is greater than that for monolithic stainless tubing, but not so high as to make the process impractical as a chromium conservation method.

Kovach, C. W.

1978-01-01

428

Continuous Cooling Thermal Cycle Effects on Sensitization in Stainless Steel.  

National Technical Information Service (NTIS)

Work for the study was directed towards quantifying sensitization development (defined as grain boundary chromium depletion) in high carbon Type 304 and 316 stainless steel (SS) subjected to linear heating to a given peak temperature followed by linear co...

D. G. Atteridge C. A. Cedeno

1991-01-01

429

Stretch Forming of Very Long Stainless Steel Skins.  

National Technical Information Service (NTIS)

Precipitation hardening FV 520 stainless steel was stretch formed in the fully softened (austenitic) and the cold rolled and transformed (martensitic) conditions using the H.S.A. 250T stretching machine; the skins were subjected to various heat treatments...

N. Padley J. Fray

1967-01-01

430

Deformation Processing of Precipitation-Hardenable Stainless Steels.  

National Technical Information Service (NTIS)

The report covers the state of the art of both primary and secondary fabrication methods for the precipitation-hardenable stainless steels. Methods currently employed for primary fabrication of these alloys include rolling, extrusion, forging, and drawing...

A. F. Gerds D. E. Strohecker F. W. Boulger

1965-01-01

431

Tubular transition joint between zircaloy-2 and stainless steel  

Microsoft Academic Search

The solid-state diffusion bonding process is employed to manufacture a tubular transition joint between Zircaloy-2 and stainless steel. The joint is found to be metallurgically compatible, mechanically strong and also leak-tight.

K. Bhanumurthy; J. Krishnan; G. B. Kale; R. K. Fotedar; A. R. Biswas; R. N. Arya

1995-01-01

432

Stainless-steel elbows formed by spin forging  

NASA Technical Reports Server (NTRS)

Large seamless austenitic stainless steel elbows are fabricated by spin forging /rotary shear forming/. A specially designed spin forging tool for mounting on a hydrospin machine has been built for this purpose.

1964-01-01

433

Sensitization and IGSCC susceptibility prediction in stainless steel pipe weldments.  

National Technical Information Service (NTIS)

An analytical model, based on prediction of chromium depletion, has been developed for predicting thermomechanical effects on austenitic stainless steel intergranular stress corrosion cracking (IGSCC) susceptibility. Model development and validation is ba...

D. G. Atteridge J. W. Simmons M. Li S. M. Bruemmer

1991-01-01

434

Laves intermetallics in stainless steel-zirconium alloys.  

National Technical Information Service (NTIS)

Laves intermetallics have a significant effect on properties of metal waste forms being developed at Argonne National Laboratory. These waste forms are stainless steel-zirconium alloys that will contain radioactive metal isotopes isolated from spent nucle...

D. P. Abraham S. M. McDeavitt J. W. Richardson

1997-01-01

435

Surface modified stainless steels for PEM fuel cell bipolar plates  

DOEpatents

A nitridation treated stainless steel article (such as a bipolar plate for a proton exchange membrane fuel cell) having lower interfacial contact electrical resistance and better corrosion resistance than an untreated stainless steel article is disclosed. The treated stainless steel article has a surface layer including nitrogen-modified chromium-base oxide and precipitates of chromium nitride formed during nitridation wherein oxygen is present in the surface layer at a greater concentration than nitrogen. The surface layer may further include precipitates of titanium nitride and/or aluminum oxide. The surface layer in the treated article is chemically heterogeneous surface rather than a uniform or semi-uniform surface layer exclusively rich in chromium, titanium or aluminum. The precipitates of titanium nitride and/or aluminum oxide are formed by the nitriding treatment wherein titanium and/or aluminum in the stainless steel are segregated to the surface layer in forms that exhibit a low contact resistance and good corrosion resistance.

Brady, Michael P. (Oak Ridge, TN) [Oak Ridge, TN; Wang, Heli (Littleton, CO) [Littleton, CO; Turner, John A. (Littleton, CO) [Littleton, CO

2007-07-24

436

Analysis of Vapor-Aluminum-Diffused Stainless Steels.  

National Technical Information Service (NTIS)

The Bureau of Mines analyzed vapor-aluminum-diffused stainless steels prior to conducting corrosion measurements in severely sulfidizing environments. These studies were conducted in response to the national need to better control the environmental and ec...

L. L. Oden M. P. Krug R. A. McCune

1982-01-01

437

Emissivity of Sodium Wetted and Oxidized Type 304 Stainless Steel.  

National Technical Information Service (NTIS)

The emissivity of sodium wetted and oxidized Type 304 stainless steel was determined to provide data for calculating the heat flow through Liquid Metal Fast Breeder Reactor (LMFBR) reflector plates, located above the sodium pool, to the reactor closure he...

N. L. Haines R. E. Craig D. R. Forsyth E. H. Novendstern

1980-01-01

438

Electrochemical Behavior of Stainless Steels in Natural Seawater.  

National Technical Information Service (NTIS)

The detailed electrochemical reactions on stainless steels in natural seawater cannot be predicted without an understanding of the composition of the biofilm. Electrochemical reactions are influenced by biofilm formation and the chemical microenvironment ...

B. Little R. Ray P. Wagner

1990-01-01

439

Evaluation of the Stress Corrosion Behavior of Selected Stainless Steels.  

National Technical Information Service (NTIS)

The objective of this investigation was to determine the stress corrosion behavior of selected stainless steels in several fluorinating environments. The possibility of stress corrosion cracking or pitting which could substantially reduce the serviceabili...

R. E. Dorning

1983-01-01

440

Heat effects upon annealing plastically deformed 304L stainless steel  

Microsoft Academic Search

In order to determine the heat effects on the ..cap alpha..' ..-->.. ..gamma.. reversion, recovery, and recrystallization, calorimetric measurements were performed on plastically deformed 304L stainless steels. Hardness and magnetic measurements and optical microscopy observations were also made. (DLC)

R. K. Stout; C. R. Brooks

1976-01-01

441

Investigations of thiosulfate accumulation on 304 stainless steel in neutral solutions by radioactive labeling, electrochemistry, Auger electron and X-ray photoelectron spectroscopy methods  

SciTech Connect

Thiosulfate accumulation on 304 stainless steel in near neutral solutions (pH {approximately}5.6) was studied using in situ techniques: electrochemistry and radiochemistry, as well as by Auger electron spectroscopy depth profiling and angle-resolved x-ray photoelectron spectroscopy in ultrahigh vacuum. It was found that thiosulfate accumulation is an irreversible process and occurs over a broad electrode potential range. Thiosulfate surface concentration is very small, below {minus}1.0 V vs. Ag/AgCl reference. In the potential range from {minus}1.0 to 0.50 V the surface concentration increases linearly with potential, reaches a maximum at {minus}0.30 V, and at even more positive potentials, decreases to a slightly lower level. Ultrahigh vacuum spectroscopic measurements indicate that the irreversible surface behavior can be attributed to thiosulfate incorporation into the substrate passive film. The present data obtained with 304 stainless steel are compared to previous results published from this laboratory on thiosulfate adsorption on 316 stainless steel, and the role of molybdenum surface enrichment in the thiosulfate accumulation reversibility is discussed. The effect of chloride on thiosulfate accumulation was also investigated. At high concentration of chloride, thiosulfate is desorbed from the surface due to chloride-induced dissolution of the stainless steel. At very negative potentials, the thiosulfate surface concentration increases upon chloride addition, most probably due to the surface microroughening caused by chloride adsorption.

Thomas, A.E.; Kolics, A.; Wieckowski, A. [Univ. of Illinois, Urbana, IL (United States)

1997-02-01

442

Effect of the hydrogen peroxide formed in tritiated water on the behavior of 316L stainless steel  

NASA Astrophysics Data System (ADS)

The tritiated water used (at a concentration of 20 mg cm -3) contains radiolytic hydrogen peroxide and dissolved oxygen. In the plants for the reprocessing of this water, the pH necessarily has various values, and consequently we used two different pH, 4 and 11, in our studies. The free corrosion potential of the stainless steel, as well as the redox potential of the tritiated water taken immediately from stock are in the transpassive region. This results from the concentrations of the dissolved radiolytic species. If these are decomposed in the voltametric scans, these potentials shift to the prepassive region. This will show the importance of the concentration of radiolytic H 2O 2 on the corrosion of 316L stainless steel. Scanning electron microscope examinations show, that at the free corrosion potential of the steel located in transpassive region, small cracks are formed over all of the oxidized surface. Pits and cavities are also found, the latter tend to be located on the grain boundaries.

Bellanger, G.

1994-06-01

443

Inertia welding of 1100 aluminum to Type 316 stainless steel  

SciTech Connect

This work describes development done for inertia welds of 1100 aluminum of approximately an H-18 work hardened condition, to Type 316 stainless steel. The welding was done with a Caterpillar Model 90 inertia welding machine. Rod diameters were 0.625 inch for the stainless steel and 1.00 inch for the aluminum. A broad range of weld parameters, as well as various steel surface geometries, were investigated for this work.

Yashan, D.; Tsang, S.; Doughty, M.W.

1986-01-01

444

Characterization of borided AISI 316L stainless steel implant  

Microsoft Academic Search

The present study reports on characterization of borided AISI 316L stainless steel implant. Boronizing heat treatment was performed on a cylindrical bar of AISI 316L austenitic surgical stainless steel with a diameter of 2mm and a length of 10mm using slurry salt bath consisting of borax, boric acid and ferro-silicon. The susbstrate AISI 316L was essentially containing 0.022wt% C, 0.79wt%

I. Özbek; B. A. Konduk; C. Bindal; A. H. Ucisik

2002-01-01

445

Embrittlement of cast stainless steels in LWR systems  

Microsoft Academic Search

Mechanical property data from Charpy-impact and J-R curve tests are presented for several experimental and commercial heats, as well as reactor-aged material of CF-3, CF-8, and CF-8M grades of cast stainless steel. The effects of material variables on the embrittlement of cast stainless steels are evaluated. The chemical composition and ferrite morphology have a strong effect on the extent and

O. K. Chopra; H. M. Chung

1989-01-01

446

PROPERTIES OF URANIUM DIOXIDE-STAINLESS STEEL DISPERSION FUEL PLATES  

Microsoft Academic Search

The physical and mechanical properties of GCRE-type fuel elements were ;\\u000a determined from room temperature to 1650 deg F. The fuel elements were prepared ;\\u000a by cladding Type 318 stainless steel sheet to a core containing 15 to 35 wt.% UO\\/;\\u000a sub 2\\/ in either prealloyed Type 318 stainless steel or elemental iron-18 wt.% ;\\u000a chromium-14 wt. % nickel-2.5 wt.

S. J. Paprocki; D. L. Keller; J. M. Fackelmann

1959-01-01

447

Micro Machine Parts Fabricated from Aqueous Based Stainless Steel Slurry  

Microsoft Academic Search

\\u000a A fabrication process of stainless steel micro components from metallic powder is reported. The process consists of two stages.\\u000a In the first stage, high quality SU-8 master moulds and their negative replicas from soft moulds are produced using photolithography\\u000a and soft moulding techniques respectively. The second stage includes preparation of stainless steel slurry, filling the soft\\u000a mould, obtaining the green

Mohamed Imbaby; Isaac Chang; Kyle Jiang

448

Application of Cost-Effective Stainless Steel for Automotive Components  

Microsoft Academic Search

High-strength nickel free austenitic stainless steel material as a light-weight substitute for commercial automotive deep drawn steel has been studied with an automotive bumper as an example. The stainless steel gave a weight saving as high as 50% at the same cost that of deep drawn steels. The study examines the techno-economic merits of value engineering automotive material. The bumper

K. Hariharan; G. Balachandran; M. Sathya Prasad

2009-01-01

449

The technology of chromium oxide passivation on stainless steel surface  

Microsoft Academic Search

A complete chromium oxide (Cr[sub 2]O[sub 3]) passivation technology has been developed for stainless steel surfaces for use in high purity gas-delivery systems and process chambers. Starting with an electrochemical buffing (ECB) to add to electro-polished (EP) SUS316L stainless steel material, an optimal thermal treatment was found by using a gas mixture of 10% hydrogen, 1--10 ppm oxygen and argon

Tadahiro Ohmi; Atsushi Ohki; Masakazu Nakamura; Koji Kawada; Tsuyoshi Watanabe; Yoshinori Nakagawa; Shinji Miyoshi; Shinji Takahashi; M. S. K. Chen

1993-01-01

450

Probing the duplex stainless steel phases via magnetic force microscopy  

NASA Astrophysics Data System (ADS)

Duplex stainless steels are austenitic-ferritic alloys used in many applications, thanks to their excellent mechanical properties and high corrosion resistance. In this work, chemical analyses, x-ray diffraction, and magnetic force microscopy (MFM) were employed to characterize the solution annealed and aged duplex stainless steel. The samples exhibited no changes in lattice parameters and the MFM technique proved successful in clearly imaging the magnetic domain structure of the ferrite phase.

Gheno, S. M.; Santos, F. S.; Kuri, S. E.

2008-03-01

451

Phase formation at bonded vanadium and stainless steel interfaces  

Microsoft Academic Search

The interface between vanadium bonded to stainless steel was studies to determine whether a brittle phase formed during three joining operations. Inertia friction welds between V and 21-6-9 stainless steel were examined using TEM. In the as-welded condition, a continuous, polygranular intermetallic layer about 0.25 μm thick was present at the interface. This layer grew to about 50 μm thick

Summers

1992-01-01

452

Corrosion fatigue of surgical stainless steel in synthetic physiological solution.  

PubMed

Fatigue tests conducted both in air and synthetic physiological solution show that the fatigue strength of surgical stainless steel in synthetic physiological solution is about 10% lower than the strength in air for a given endurance level. It is proposed that surgical stainless steel which is normally passive in physiological solution suffers corrosion fatigue because of susceptibility to crevice corrosion which occurs at extrusions and intrusions (crevices) on the surface thereby shortening the crack initiation time and the fatigue life. PMID:7348709

Cahoon, J R; Holte, R N

1981-03-01

453

Characterization of blasted austenitic stainless steel and its corrosion resistance  

Microsoft Academic Search

It is known that the corrosion resistance of stainless steel is deteriorated by blasting, but the reason for this deterioration\\u000a is not clear. A blasted austenitic stainless steel plate (JIS-SUS304) has been characterized with comparison to the scraped\\u000a and non-blasted specimens. The surface roughness of the blasted specimen is larger than that of materials finished with #180\\u000a paper. A martensite

F. Otsubo; K. Kishitake; T. Akiyama; T. Terasaki

2003-01-01

454

Interaction of bending and axial compression of stainless steel members  

Microsoft Academic Search

The paper deals with the buckling behaviour of stainless steel members with the main focus on developing design formulae for use in the latest version of the European Standard EN 1993-1-4: Eurocode 3–Design of steel structures–Part 1–4: General rules — Supplementary rules for stainless steel. Brussels; 2005.It is based on numerical simulations of single span members of various section type, which

R. Greiner; M. Kettler

2008-01-01

455

Long-Term Corrosion Testing of Thermal Spray Coatings of Amorphous Metals: Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 and Fe48Mo14Cr15Y2C15B6  

SciTech Connect

Amorphous alloys identified as SAM2X5 (Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4}) and SAM1651 (Fe{sub 48}Mo{sub 14}Cr{sub 15}Y{sub 2}C{sub 15}B{sub 6}) have been produced as melt-spun ribbons, drop-cast ingots and thermal-spray coatings. Chromium (Cr), molybdenum (Mo) and tungsten (W) additions provided corrosion resistance, while boron (B) enabled glass formation. Earlier electrochemical studies of melt-spun ribbons and ingots of these amorphous alloys demonstrated outstanding passive film stability. More recently thermal-spray coatings of these amorphous alloys have been made and subjected to long-term salt-fog and immersion tests. Good corrosion resistance has been observed during salt-fog testing. Corrosion rates were measured in situ with linear polarization, while simultaneously monitoring the open-circuit corrosion potentials. Reasonably good performance was observed. The sensitivity of these measurements to electrolyte composition and temperature was determined. The high boron content of SAM2X5 also made it an effective neutron absorber, and suitable for criticality control applications.

Farmer, J; Day, D; Lian, T; Saw, C; Hailey, P; Payer, J; Aprigliano, L; Beardsley, B; Branagan, D

2007-07-09

456

Quantification of corrosion resistance of a new-class of criticality control materials: thermal-spray coatings of high-boron iron-based amorphous metals - Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4  

SciTech Connect

An iron-based amorphous metal, Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4} (SAM2X5), with very good corrosion resistance was developed. This material was produced as a melt-spun ribbon, as well as gas atomized powder and a thermal-spray coating. Chromium (Cr), molybdenum (Mo) and tungsten (W) provided corrosion resistance, and boron (B) enabled glass formation. The high boron content of this particular amorphous metal made it an effective neutron absorber, and suitable for criticality control applications. Earlier studies have shown that ingots and melt-spun ribbons of these materials have good passive film stability in these environments. Thermal spray coatings of these materials have now been produced, and have undergone a variety of corrosion testing, including both atmospheric and long-term immersion testing. The modes and rates of corrosion have been determined in the various environments, and are reported here.

Farmer, J C; Choi, J S; Shaw, C K; Rebak, R; Day, S D; Lian, T; Hailey, P; Payer, J H; Branagan, D J; Aprigliano, L F

2007-03-28

457

Solidification behavior of austenitic stainless steel filler metals  

SciTech Connect

Thermal analysis and interrupted solidification experiments on selected austenitic stainless steel filler metals provided an understanding of the solidification behavior of austenitic stainless steel welds. The sequences of phase separations found were for type 308 stainless steel filler metal, L + L + delta + L + delta + ..gamma.. ..-->.. ..gamma.. + delta, and for type 310 stainless steel filler metal, L ..-->.. L + ..gamma.. ..-->.. ..gamma... In type 308 stainless steel filler metal, ferrite at room temperature was identified as either the untransformed primary delta-ferrite formed during the initial stages of solidification or the residual ferrite after Widmanstaetten austenite precipitation. Microprobe and scanning transmission electron microscope microanalyses revealed that solute extensively redistributes during the transformation of primary delta-ferrite to austenite, leading to enrichment and stabilization of ferrite by chromium. The type 310 stainless steel filler metal investigated solidifies by the primary crystallization of austenite, with the transformation going to completion at the solidus temperature. In our samples residual ferrite resulting from solute segregation was absent at the intercellular or interdendritic regions.

David, S.A.; Goodwin, G.M.; Braski, D.N.

1980-02-01

458

Nickel release from nickel-plated metals and stainless steels.  

PubMed

Nickel release from nickel-plated metals often induces allergic contact dermatitis, but, for nickel-containing stainless steels, the effect is not well-known. In this paper, AISI 304, 316L, 303 and 430 type stainless steels, nickel and nickel-plated materials were investigated. 4 tests were performed: patch tests, leaching experiments, dimethylglyoxime (DMG) spot tests and electrochemical tests. Patch tests showed that 96% of the patients were intolerant to Ni-plated samples, and 14% to a high-sulfur stainless steel (303), while nickel-containing stainless steels with a low sulfur content elicited no reactions. Leaching experiments confirmed the patch tests: in acidic artificial sweat, Ni-plated samples released about 100 micrograms/cm2/week of nickel, while low-sulfur stainless steels released less than 0.03 microgram/cm2/week of nickel, and AISI 303 about 1.5 micrograms/cm2/week. Attention is drawn to the irrelevance of the DMG spot test, which reveals Ni present in the metal bulk but not its dissolution rate. Electrochemical experiments showed that 304 and 316 grades remain passive in the environments tested, while Ni-plated steels and AISI 303 can suffer significant cation dissolution. Thus, Ni-containing 304 and 316 steels should not induce contact dermatitis, while 303 should be avoided. A reliable nitric acid spot test is proposed to distinguish this grade from other stainless steels. PMID:7842681

Haudrechy, P; Foussereau, J; Mantout, B; Baroux, B

1994-10-01

459

X-ray attenuation properties of stainless steel (u)  

SciTech Connect

Stainless steel vessels are used to enclose solid materials for studying x-ray radiolysis that involves gas release from the materials. Commercially available stainless steel components are easily adapted to form a static or a dynamic condition to monitor the gas evolved from the solid materials during and after the x-ray irradiation. Experimental data published on the x-ray attenuation properties of stainless steel, however, are very scarce, especially over a wide range of x-ray energies. The objective of this work was to obtain experimental data that will be used to determine how a poly-energetic x-ray beam is attenuated by the stainless steel container wall. The data will also be used in conjunction with MCNP (Monte Carlos Nuclear Particle) modeling to develop an accurate method for determining energy absorbed in known solid samples contained in stainless steel vessels. In this study, experiments to measure the attenuation properties of stainless steel were performed for a range of bremsstrahlung x-ray beams with a maximum energy ranging from 150 keV to 10 MeV. Bremsstrahlung x-ray beams of these energies are commonly used in radiography of engineering and weapon components. The weapon surveillance community has a great interest in understanding how the x-rays in radiography affect short-term and long-term properties of weapon materials.

Wang, Lily L [Los Alamos National Laboratory; Berry, Phillip C [Los Alamos National Laboratory

2009-01-01

460

INVESTIGATIONS OF CREEP BEHAVIOR OF STRUCTURAL JOINTS UNDER CYCLIC LOADS AND TEMPERATURES  

Microsoft Academic Search

Eighty-two structural joint specimens were tested to evaluate the ; effects of cyclic loads and cyclic temperatures on creep and rupture. The ; specimens included riveted points of 2024-T3 clad aluminum alloy, and riveted and ; spot-welded joints of 17-7 PH (TH 1050) stainless steel. The results of these ; tests show a wide variance but indicate certain trends which

L. Mordfin; N. Halsey; G. E. Greene

1959-01-01

461

HIGH-TEMPERATURE-RESISTANT CERAMIC ADHESIVES  

Microsoft Academic Search

Ceramic adhesives were developed for bonding metal in the operational ; range 500 to lOOO F. When glassybond adhesives were suitably prepared and ; properly applied to types 302 and 17-7 PH stainless-steel specimens, shear ; strengths of the order of 2000 psi were obtained at a test temperature of 8OO ; F, and shear strengths of more than 8OO

HENRY G. LEFORT; DWIGHT G. BENNETT

1958-01-01

462

DETERMINATION OF TENSILE, COMPRESSIVE, BEARING, AND SHEAR PROPERTIES OF SHEET STEELS AT ELEVATED TEMPERATURES. Period covered : January 1957 to May 1958  

Microsoft Academic Search

The tensile, compressive, bearing, and shear properties of the following ; sheet metals were determined at various temperatures after exposure times of ; from1\\/2 hour tc 1000 hours at the test temperature: A-286 austeaitic alloy, ; quenched and tempered; 17-7 PH stain less steel, RH 950 condition; Thermold J ; alloy steel, quenched and tempered; Type 420 stainless steel, quenched

J. R. Kattus; J. B. Preston; H. L. Lessley

1958-01-01

463

ESTUDIO DE LA ROTURA DE UN CONJUNTO DE ARANDELAS  

Microsoft Academic Search

This paper analyses the failure of a set of washers, broken in service in a seawater environment and a high temperature. These parts were manufactured using a 17-7 PH, UNS S17700 precipitation hardening stainless steel. The morphology of the cracks was intergranular and it was attributed to hydrogen embrittlement due to the hydrogen that entered into the steel during the

G. Atxaga; A. Pelayo; Irisarri FUNDACIÓN; San Sebastián

464

Characteristics of Interdiffusion between 17-4 PH Steel and Nickel  

NASA Astrophysics Data System (ADS)

The characteristics of interdiffusion between precipitation-hardened 17-4 PH grade stainless steel and nickel were studied in the temperature range of 900 °C to 1100 °C, using diffusion couples of these two materials. The diffusion coefficients of the major diffusing elements Fe, Ni, Cr, and Cu were evaluated for this multicomponent system. The diffusion paths plotted on the Fe-Ni-Cr isotherm showed a flat “S” shape, suggesting insignificant interaction among the diffusing species. The temperature dependence of the diffusion coefficients for each element was evaluated, and the activation energies for diffusion were determined. The asymmetric nature of concentration variation of the elements at the diffusion zone was observed and was explained by the difference in diffusivities of the diffusing species. The activation energy for diffusion of Ni was found to be lower than that of Fe and Cr.

Laik, A.; Gawde, P. S.; Bhanumurthy, K.; Kale, G. B.

2008-04-01

465

Phase Transformations in Cast Duplex Stainless Steels  

SciTech Connect

Duplex stainless steels (DSS) constitute both ferrite and austenite as a matrix. Such a microstructure confers a high corrosion resistance with favorable mechanical properties. However, intermetallic phases such as {sigma} and {chi} can also form during casting or high-temperature processing and can degrade the properties of the DSS. This research was initiated to develop time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams of two types of cast duplex stainless steels, CD3MN (Fe-22Cr-5Ni-Mo-N) and CD3MWCuN (Fe-25Cr-7Ni-Mo-W-Cu-N), in order to understand the time and temperature ranges for intermetallic phase formation. The alloys were heat treated isothermally or under controlled cooling conditions and then characterized using conventional metallographic methods that included tint etching, and also using electron microscopy (SEM, TEM) and wavelength dispersive spectroscopy (WDS). The kinetics of intermetallic-phase ({sigma} + {chi}) formation were analyzed using the Johnson-Mehl-Avrami (MA) equation in the case of isothermal transformations and a modified form of this equation in the case of continuous cooling transformations. The rate of intermetallic-phase formation was found to be much faster in CD3MWCuN than CD3MN due mainly to differences in the major alloying contents such as Cr, Ni and Mo. To examine in more detail the effects of these elements of the phase stabilities; a series of eight steel castings was designed with the Cr, Ni and Mo contents systematically varied with respect to the nominal composition of CD3MN. The effects of varying the contents of alloying additions on the formation of intermetallic phases were also studied computationally using the commercial thermodynamic software package, Thermo-Calc. In general, {sigma} was stabilized with increasing Cr addition and {chi} by increasing Mo addition. However, a delicate balance among Ni and other minor elements such as N and Si also exists. Phase equilibria in DSS can be affected by local composition fluctuations in the cast alloy. This may cause discrepancy between thermodynamic prediction and experimental observation.

Yoon-Jun Kim

2004-12-19

466

Phase transformations in cast duplex stainless steels  

NASA Astrophysics Data System (ADS)

Duplex stainless steels (DSS) constitute both ferrite and austenite as a matrix. Such a microstructure confers a high corrosion resistance with favorable mechanical properties. However, intermetallic phases such as sigma (sigma) and chi (chi) can also form during casting or high-temperature processing and can degrade the properties of the DSS. This research was initiated to develop time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams of two types of cast duplex stainless steels, CD3MN (Fe-22Cr-5Ni-Mo-N) and CD3MWCuN (Fe-25Cr-7Ni-Mo-W-Cu-N), in order to understand the time and temperature ranges for intermetallic phase formation. The alloys were heat treated isothermally or under controlled cooling conditions and then characterized using conventional metallographic methods that included tint etching, and also using electron microscopy (SEM, TEM) and wavelength dispersive spectroscopy (WDS). The kinetics of intermetallic-phase (sigma + chi) formation were analyzed using the Johnson-Mehl-Avrami (JMA) equation in the case of isothermal transformations and a modified form of this equation in the case of continuous cooling transformations. The rate of intermetallic-phase formation was found to be much faster in CD3MWCuN than CD3MN due mainly to differences in the major alloying contents such as Cr, Ni and Mo. To examine in more detail the effects of these elements of the phase stabilities, a series of eight steel castings was designed with the Cr, Ni and Mo contents systematically varied with respect to the nominal composition of CD3MN. The effects of varying the contents of alloying additions on the formation of intermetallic phases were also studied computationally using the commercial thermodynamic software package, Thermo-Calc. In general, a was stabilized with increasing Cr addition and chi by increasing Mo addition. However, a delicate balance among Ni and other minor elements such as N and Si also exists. Phase equilibria in DSS can be affected by local composition fluctuations in the cast alloy. This may cause discrepancy between thermodynamic prediction and experimental observation.

Kim, Yoon-Jun

467

MRF with adjustable pH  

NASA Astrophysics Data System (ADS)

Deterministic final polishing of high precision optics using sub-aperture processing with magnetorheological finishing (MRF) is an accepted practice throughout the world. A wide variety of materials can be successfully worked with aqueous (pH 10), magnetorheological (MR) fluids, using magnetic carbonyl iron (CI) and either ceria or nanodiamond nonmagnetic abrasives. Polycrystalline materials like zinc sulfide (ZnS) and zinc selenide (ZnSe) are difficult to polish at pH 10 with MRF, due to their grain size and the relatively low stiffness of the MR fluid lap. If microns of material are removed, the grain structure of the material begins to appear. In 2005, Kozhinova et al. (Appl. Opt. 44 4671-4677) demonstrated that lowering pH could improve MRF of ZnS. However, magnetic CI particle corrosion rendered their low pH approach unstable and unsuitable for commercial implementation. In 2009, Shafrir et al. described a sol-gel coating process for manufacturing a zirconia-coated CI particle that protects the magnetic core from aqueous corrosion (Appl. Opt .48 6797-6810). The coating process produces free nanozirconia polishing abrasives during the coating procedure, thereby creating an MR polishing powder that is "self-charged" with the polishing abrasive. By simply adding water, it was possible to polish optical glasses and ceramics with good stability at pH 8 for three weeks. The development of a corrosion resistant, MR polishing powder, opens up the possibility for polishing additional materials, wherein the pH may be adjusted to optimize effectiveness. In this paper we describe the CI coating process, the characterization of the coated powder, and procedures for making stable MR fluids with adjustable pH, giving polishing results for a variety of optical glasses and crystalline ceramics.

Jacobs, Stephen D.

2011-09-01

468

POTENSI KURKUMIN SEBAGAI PENUNJUK pH SEMULAJADI UNTUK PEMBANGUNAN SENSOR OPTIK pH  

Microsoft Academic Search

The potential of curcumin reagent as a natural pH indicator for the development of an optical pH sensor was discussed in this study. Curcumin has been chosen because it has never been reported before for use in the development of an optical pH sensor. Curcumin is a colouring constituent of tumeric that giving yellow pigmentation. Curcumin showed clear colour changes

Rosmawani Mohammad; Musa Ahmad; Jamaluddin Mohd Daud

2007-01-01

469

Novel optical pH sensor for high and low pH values  

Microsoft Academic Search

The development of an optical pH sensor based on immobilization of mixture of two dyes on a triacetylcellulose membrane is described. The sensor has a useful pH range at low and high pH values, where glass electrodes show acidic and alkaline errors, respectively. Application of a back-propagation artificial neural network (ANN) model extends the measuring range of the proposed optode

Afsaneh Safavi; Mozhgan Bagheri

2003-01-01

470

Ruminal pH regulation and nutritional consequences of low pH  

Microsoft Academic Search

Volatile fatty acids (VFA) and lactic acid can build up in the rumen and reduce ruminal pH. Low ruminal pH for prolonged periods each day can affect feed intake, microbial metabolism and feed digestion, and has also been related to inflammation, diarrhea and milk fat depression. This paper considers aspects of pH regulation, as well as the effects of ruminal

J. Dijkstra; J. L. Ellis; E. Kebreab; A. B. Strathe; S. Lopez; A. Bannink

2012-01-01

471

Austenitic stainless steel for high temperature applications  

DOEpatents

This invention describes a composition for an austenitic stainless steel which has been found to exhibit improved high temperature stress rupture properties. The composition of this alloy is about (in wt. %): 12.5 to 14.5 Cr; 14.5 to 16.5 Ni; 1.5 to 2.5 Mo; 1.5 to 2.5 Mn; 0.1 to 0.4 Ti; 0.02 to 0.08 C; 0.5 to 1.0 Si; 0.01 maximum, N; 0.02 to 0.08 P; 0.002 to 0.008 B; 0.004-0.010 S; 0.02-0.05 Nb; 0.01-0.05 V; 0.005-0.02 Ta; 0.02-0.05 Al; 0.01-0.04 Cu; 0.02-0.05 Co; 0.03 maximum, As; 0.01 maximum, O; 0.01 maximum, Zr; and with the balance of the alloy being essentially iron. The carbon content of the alloy is adjusted such that wt. % Ti/(wt. % C+wt. % N) is between 4 and 6, and most preferably about 5. In addition the sum of the wt. % P+wt. % B+wt. % S is at least 0.03 wt. %. This alloy is believed to be particularly well suited for use as fast breeder reactor fuel element cladding.

Johnson, Gerald D. (Kennewick, WA); Powell, Roger W. (Pasco, WA)

1985-01-01

472

Corrosion of stainless steel during acetate production  

SciTech Connect

Corrosion of types 304, 304L, 316, and 316L stainless steel (SS) during the esterification of acetic acid and alcohol or glycol ether was investigated. The catalyst for this reaction, sulfuric acid or para-toluene sulfonic acid (PTSA), was shown to cause more corrosion on reactor equipment than CH{sub 3}COOH under the process conditions commonly practiced in industry. The corrosive action of the catalyst occurred only in the presence of water. Thus, for the batch processes, corrosion occurred mostly during the initial stage of esterification, where water produced by the reaction created an aqueous environment. After water was distilled off, the corrosion rate declined to a negligible value. The corrosion inhibitor copper sulfate, often used in industrial acetate processes, was found to work well for a low-temperature process (< 95 C) such as in production of butyl acetate, but it accelerated corrosion in the glycol ether acetate processes where temperatures were > 108 C. Process conditions that imparted low corrosion rates were determined.

Qi, J.S.; Lester, G.C. [Occidental Chemical Corp. Technology Center, Grand Island, NY (United States)

1996-07-01

473

Characterization of stainless steel 304 tubing  

SciTech Connect

Earlier studies have shown that stainless steel 304 (SS304) containing martensite is susceptible to hydrogen embrittlement. This generated concern regarding the structural integrity of SS304 tubing we use in the W87 pit tube. During surveillance operations, the pit tube undergoes a series of bending and straightening as it goes through a number of surveillance cycles. This motivated the study to characterize austenitic SS304 tubing obtained from Rocky Flats. The tubes continued to display structural soundness even after numerous repeated bending and straightening cycles. The minimum and maximum number of bends to failure occurred after 13 and 16 cycles, respectively. After 5 bends, both the inner and outer surfaces of the tubing showed no microcracks. When the bent tubing samples were pressurized and tested using deuterium at 74{degrees}C and at {approximately}78{degrees}C, they failed away from the bent area. Thus deuterium embrittlement of the bent SS304 tubing should not be a problem. Moreover, to increase our 95% confidence level to 5 bends, we are planning to perform at least four additional bends to failure tests.

Sunwoo, A.J.; Brooks, M.A.; Kervin, J.E.

1995-10-16

474

NanoComposite Stainless Steel Powder Technologies  

SciTech Connect

Oak Ridge National Laboratory has been investigating a new class of Fe-based amorphous material stemming from a DARPA, Defense Advanced Research Projects Agency initiative in structural amorphous metals. Further engineering of the original SAM materials such as chemistry modifications and manufacturing processes, has led to the development of a class of Fe based amorphous materials that upon processing, devitrify into a nearly homogeneous distribution of nano sized complex metal carbides and borides. The powder material is produced through the gas atomization process and subsequently utilized by several methods; laser fusing as a coating to existing components or bulk consolidated into new components through various powder metallurgy techniques (vacuum hot pressing, Dynaforge, and hot isostatic pressing). The unique fine scale distribution of microstructural features yields a material with high hardness and wear resistance compared to material produced through conventional processing techniques such as casting while maintaining adequate fracture toughness. Several compositions have been examined including those specifically designed for high hardness and wear resistance and a composition specifically tailored to devitrify into an austenitic matrix (similar to a stainless steel) which poses improved corrosion behavior.

DeHoff, R.; Glasgow, C. (MesoCoat, Inc.)

2012-07-25

475

PhET Simulation: Build An Atom  

NSDL National Science Digital Library

This simulation is designed to help learners visualize atomic structure, as they drag protons, neutrons, and electrons to construct an atom. As particles are moved into place in the nucleus or the electron orbits, the simulation automatically displays the net charge, mass number, atomic symbol, and name of the element. After practicing with atom-building, users can test their skills against the clock in a game with four levels of increasing difficulty. See Related Materials for a lesson plan and student guide developed by the PhET project specifically for use with Build An Atom. The atom building simulation, which must be open and displayed to complete this activity, is available from PhET at: Build An Atom. This lesson is part of PhET (Physics Education Technology Project), a large collection of free interactive simulations for science education.

476

PhET Teacher Activities: Modeling Isotopes  

NSDL National Science Digital Library

This lesson plan was created specifically to accompany the PhET simulation "Isotopes and Atomic Mass". Appropriate for grades 7-10, it provides explicit guidance for modeling atoms and their variant isotopes. As students add neutrons to the nuclear model, they can see a relationship between the stability of the atom and its abundance in nature. The model makes it easy to visualize that atoms of one element always have the same number of protons, but can have various numbers of neutrons. It will help students differentiate Atomic Number (number of protons in the nucleus) from Mass Number (the number of protons and neutrons. The isotope simulation, which must be open and displayed to complete this activity, is available from PhET at: Isotopes and Atomic Mass. This lesson is part of PhET (Physics Education Technology Project), a large collection of free interactive simulations for science education.

Marrero, Robert

2011-07-18

477

Stainless steel tube-based cell cryopreservation containers.  

PubMed

This study focused on increasing the freezing rate in cell vitrification cryopreservation by using a cryopreservation container possessing rigid mechanical properties and high heat-transfer efficiency. Applying a fast freezing rate in vitrification cryopreservation causes a rapid temperature change in the cryopreservation container and has a substantial impact on mechanical properties; therefore, a highly rigid cryopreservation container that possesses a fast freezing rate must be developed. To produce a highly rigid cryopreservation container possessing superior heat transfer efficiency, this study applies an electrochemical machining (ECM) method to an ANSI 316L stainless steel tube to treat the surface material by polishing and roughening, thereby increasing the freezing rate and reducing the probability of ice crystal formation. The results indicated that the ECM method provided high-quality surface treatment of the stainless steel tube. This method can reduce internal surface roughness in the stainless steel tube, thereby reducing the probability of ice crystal formation, and increase external surface roughness, consequently raising convection heat-transfer efficiency. In addition, by thinning the stainless steel tube, this method reduces heat capacity and thermal resistance, thereby increasing the freezing rate. The freezing rate (3399 ± 197 °C/min) of a stainless steel tube after interior and exterior polishing and exterior etching by applying ECM compared with the freezing rate (1818 ± 54 °C/min) of an original stainless steel tube was increased by 87%, which also exceeds the freezing rate (2015 ± 49 °C/min) of an original quartz tube that has a 20% lower heat capacity. However, the results indicated that increasing heat-transferring surface areas and reducing heat capacities cannot effectively increase the freezing rate of a stainless steel tube if only one method is applied; instead, both techniques must be implemented concurrently to improve the freezing rate. PMID:23993919

Shih, Wei-Hung; Yu, Zong-Yan; Wu, Wei-Te

2013-12-01

478

CRCHD Principal Investigator: Campbell, Janis, Ph.D.  

Cancer.gov

CRCHD Principal Investigator: Campbell, Janis, Ph.D.  Back to CRCHD Ongoing Research CNP Project Listing Janis Campbell, Ph.D. CNP Project Listing CNP Pilot Projects Project Investigator Biography Campbell, Janis, Ph.D. University of

479

CRCHD Principal Investigator: Paula A. Espinoza, Ph.D.  

Cancer.gov

CRCHD Principal Investigator: Paula A. Espinoza, Ph.D.  Back to CRCHD Ongoing Research CNP Project Listing Paula A. Espinoza, Ph.D. CNP Project Listing CNP Pilot Projects Project Investigator Biography Paula A. Espinoza, Ph.D. University

480

PhET Simulations: Quantum Phenomena  

NSDL National Science Digital Library

This is a collection of simulations from the PhET project in Quantum and Modern Physics. The simulations cover a range of topics including the photoelectric effect, wave interference, lasers, blackbody radiation, tunneling, the Stern-Gerlach experiment, nuclear physics, and applications of quantum mechanics. Each simulation provides a user interface that allows learners to explore the physical systems. These resources are part of the PhET project that has created a large collection of research-validated physics, chemistry, and math simulations.

Project, Physics E.

2008-07-13

481

PhEt - Physics Education Technology  

NSDL National Science Digital Library

PhEt is a free website of over sixty interactive simulations that provides opportunities for students to learn physics and chemistry through exploration and virtual labs. A browsable teacher-contributed collection of homework assignments, lectures, activities, and concept questions is available. Additional contributions designed to be used in conjunction with the PhET simulations may be submitted. Simulations can be run in three different ways: on line, by downloading one or more simulations at a time, or by a download of the entire website to your computer. Many simulations have been translated into different languages.

482

Differential genotoxicity of diphenyl diselenide (PhSe)2 and diphenyl ditelluride (PhTe)2.  

PubMed

Organoselenium compounds have been pointed out as therapeutic agents. In contrast, the potential therapeutic aspects of tellurides have not yet been demonstrated. The present study evaluated the comparative toxicological effects of diphenyl diselenide (PhSe)2 and diphenyl ditelluride (PhTe)2 in mice after in vivo administration. Genotoxicity (as determined by comet assay) and mutagenicicity were used as end-points of toxicity. Subcutaneous administration of high doses of (PhSe)2 or (PhTe)2 (500 µmol/kg) caused distinct genotoxicity in mice. (PhSe)2 significantly decreased the DNA damage index after 48 and 96 h of its injection (p < 0.05). In contrast, (PhTe) caused a significant increase in DNA damage (p < 0.05) after 48 and 96 h of intoxication. (PhSe)2 did not cause mutagenicity but (PhTe)2 increased the micronuclei frequency, indicating its mutagenic potential. The present study demonstrated that acute in vivo exposure to ditelluride caused genotoxicity in mice, which may be associated with pro-oxidant effects of diphenyl ditelluride. In addition, the use of this compound and possibly other related tellurides must be carefully controlled. PMID:24711962

Meinerz, Daiane Francine; Allebrandt, Josiane; Mariano, Douglas O C; Waczuk, Emily P; Soares, Felix Antunes; Hassan, Waseem; Rocha, João Batista T

2014-01-01

483

Sintered Intermetallic Reinforced 434L Ferritic Stainless Steel Composites  

NASA Astrophysics Data System (ADS)

The present study examines the effect of aluminide (Ni3Al, Fe3Al) additions on the sintering behavior of ferritic 434L stainless steels during solid-state sintering (SSS) and supersolidus liquid-phase sintering (SLPS). 434L stainless steel matrix composites containing 5 and 10 wt pct of each aluminide were consolidated at 1200 °C (SSS) and 1400 °C (SLPS). The effects of sintering and aluminide additions on the densification, microstructural evolution, mechanical, tribological, and corrosion behavior of sintered ferritic (434L) stainless steels were investigated. The performances of the 434L-aluminide composites were compared with the straight 434L stainless steels processed at similar conditions. Supersolidus sintering resulted in significant improvement in densification, mechanical, wear, and corrosion resistance in both straight 434L and 434L-aluminide composites. Fe3Al additions to 434L stainless steels result in improved wear resistance without significant degradation of corrosion resistance in 3.56 wt pct NaCl solution.

Upadhyaya, A.; Balaji, S.

2009-03-01

484

[Restoration of composite on etched stainless steel crowns. (1)].  

PubMed

Object of investigation The retention of composite resin to etched stainless steel crowns was tested as a possible method for restoring primary anterior teeth. Method employed 1) SEM observation Stainless steel crowns (Sankin Manufacture Co.) were etched with an aqua resia to create surface roughness and undercut to retain the composite resin to the crowns. Etching times were 1, 2, 3, 5, 8, 10 and 20 minutes, then washed in a 70% alcohol solution using an ultrasonic washer and dried. A total of 96 etched samples and non etched control samples were observed through the scanning electron microscope (Hitachi 520). 2) Shear bond strength test Stainless steel crowns were etched in an aqua resia from 1 to 20 minutes, then washed and dried. Composite resin (Photo Clearfil A, Kuraray Co.) with the bonding agent was placed on the crowns and the shear bond strength was tested in 56 samples using an Autograph (DCS-500, Shimazu). Results 1) SEM observation showed that the etching surface of stainless steel crowns created surface roughness and undercut. The most desirable surface was obtained in the 3 to 5 minute etching time specimens. 2) The highest bond strength was obtained in a 3 minute etching specimen. It was 42.12 MPa, although 29.26 MPa in mean value. Conclusion Etching with an aqua resia increased the adherence of composite resin to the surface of stainless steel crowns. PMID:2133964

Goto, G; Zang, Y; Hosoya, Y

1990-01-01

485

Work of adhesion of dairy products on stainless steel surface  

PubMed Central

The adhesion of the solids presents in food can difficult the process of surface cleaning and promotes the bacterial adhesion process and can trigger health problems. In our study, we used UHT whole milk, chocolate based milk and infant formula to evaluate the adhesion of Enterobacter sakazakii on stainless steel coupons, and we determine the work of adhesion by measuring the contact angle as well as measured the interfacial tension of the samples. In addition we evaluated the hydrophobicity of stainless steel after pre-conditioning with milk samples mentioned. E. sakazakii was able to adhere to stainless steel in large numbers in the presence of dairy products. The chocolate based milk obtained the lower contact angle with stainless steel surface, higher interfacial tension and consequently higher adhesion work. It was verified a tendency of decreasing the interfacial tension as a function of the increasing of protein content. The preconditioning of the stainless steel coupons with milk samples changed the hydrophobic characteristics of the surfaces and became them hydrophilic. Therefore, variations in the composition of the milk products affect parameters important that can influence the procedure of hygiene in surface used in food industry.

Bernardes, Patricia Campos; Araujo, Emiliane Andrade; dos Santos Pires, Ana Clarissa; Queiroz Fialho Junior, Jose Felicio; Lelis, Carini Aparecida; de Andrade, Nelio Jose

2012-01-01

486

Investigation of the diffusion kinetics of borided stainless steels  

NASA Astrophysics Data System (ADS)

In this study, the kinetics of borides formed on AISI 420, AISI 304 and AISI 304L stainless steels was investigated. Boronizing treatment was carried out using Ekabor-II powders at the processing temperatures of 1123, 1173 and 1223 K for 2, 4 and 6 h. The phases of the boride layers of borided AISI 420, AISI 304 and AISI 304L stainless steels were FeB, Fe2B, CrB and NiB, respectively. The thickness of the boride layer formed on the borided steels ranged from 4.6 to 64 ?m depending on the boriding temperature, boriding time and alloying elements of the stainless steels. Depending on the chemical composition, temperature and layer thickness, the activation energies of boron in AISI 420, AISI 304 and AISI 304L stainless steels were found to be 206.161, 234.641 and 222.818 kJ/mol, respectively. The kinetics of growth of the boride layers formed on the AISI 420, AISI 304 and AISI 304L stainless steels and the thickness of the boride layers were investigated.

Kayali, Yusuf

2013-12-01

487

pH & Rate of Enzymatic Reactions.  

ERIC Educational Resources Information Center

A quantitative and inexpensive way to measure the rate of enzymatic reaction is provided. The effects of different pH levels on the reaction rate of an enzyme from yeast are investigated and the results graphed. Background information, a list of needed materials, directions for preparing solutions, procedure, and results and discussion are…

Clariana, Roy B.

1991-01-01

488

Effect of Ph on Human Mycoplasma Strains.  

National Technical Information Service (NTIS)

The optimal reaction of culture media for the cultivation of T-strain Mycoplasma of human origin was investigated. By use of a recently modified tryptic digest medium, the optimal reaction in either agar or fluid medium was found to be pH 6.0. In contrast...

M. C. Shepard C. D. Lunceford

1964-01-01

489

The Economic Contribution of PhDs  

ERIC Educational Resources Information Center

This paper looks at what the value of a doctorate is, both to employers in particular and to society and the economy at large. Given the emphasis many universities and funding agencies/governments are putting upon the development of PhD programmes, this is an issue deserving attention. The paper tries to show how two separate but interrelated…

Casey, Bernard H.

2009-01-01

490

Monitoring fetal pH by telemetry  

NASA Technical Reports Server (NTRS)

Telemetry unit has been developed for possible use in measuring scalp-tissue pH and heart rate of unborn infant. Unit radius data to receiver as much as 50 ft. away. Application exists during hours just prior to childbirth to give warning of problems that might require cesarean delivery.

Blum, A.; Donahoe, T.; Jhabvala, M. D.; Ryan, W.

1980-01-01

491

First-Principles pH Theory  

NASA Astrophysics Data System (ADS)

Despite being one of the most important macroscopic measures and a long history even before the quantum mechanics, the concept of pH has rarely been mentioned in microscopic theories, nor being incorporated computationally into first-principles theory of aqueous solutions. Here, we formulate a theory for the pH dependence of solution formation energy by introducing the proton chemical potential as the microscopic counterpart of pH in atomistic solution models. Within the theory, the general acid-base chemistry can be cast in a simple pictorial representation. We adopt density-functional molecular dynamics to demonstrate the usefulness of the method by studying a number of solution systems including water, small solute molecules such as NH3 and HCOOH, and more complex amino acids with several functional groups. For pure water, we calculated the auto- ionization constant to be 13.2 with a 95 % accuracy. For other solutes, the calculated dissociation constants, i.e., the so- called pKa, are also in reasonable agreement with experiments. Our first-principles pH theory can be readily applied to broad solution chemistry problems such as redox reactions.

Kim, Yong-Hyun; Zhang, S. B.

2006-03-01

492

The Ph.D. Value Proposition  

ERIC Educational Resources Information Center

Atlanta University launched its doctor of arts in humanities (DAH) programs almost 40 years ago, and, since the 1988 merger with Clark College, Clark Atlanta University has continued to award the degrees. This fall, for the first time, its students will be able to earn Ph.D.s in humanities instead. In DAH programs around the country, there's been…

Cooper, Kenneth J.

2012-01-01

493

Teaching Physics Using PhET Simulations  

ERIC Educational Resources Information Center

PhET Interactive Simulations (sims) are now being widely used in teaching physics and chemistry. Sims can be used in many different educational settings, including lecture, individual or small group inquiry activities, homework, and lab. Here we will highlight a few ways to use them in teaching, based on our research and experiences using them in…

Wieman, C. E.; Adams, W. K.; Loeblein, P.; Perkins, K. K.

2010-01-01

494

Corrosion Behavior of Stainless Steels and Copper Alloys Exposed to Natural Seawater  

National Technical Information Service (NTIS)

The corrosion behavior of stainless steels, titanium, and copper alloys exposed to flowing Pacific Ocean water was characterized using surface analytical and electrochemical techniques. Biofilm formation on stainless steels and titanium resulted in thin f...

B. J. Little F. B. Mansfeld

1991-01-01

495

Microstructural Analysis of Austenitic Stainless Steel Welds and Their Modification During Laser Welding.  

National Technical Information Service (NTIS)

The microstructure of austenitic stainless steel weld metal containing a duplex structure was fully characterized and its mode of formation explained. Four distinct ferrite morphologies were identified in type 308 stainless steel weld metal: vermicular, l...

S. A. David J. M. Vitek W. H. Smith

1982-01-01

496

78 FR 62583 - Welded Stainless Pressure Pipe From Malaysia, Thailand, and the Socialist Republic of Vietnam...  

Federal Register 2010, 2011, 2012, 2013

...Determination,'' ``Welded Stainless Steel Pressure Pipe From Thailand...Determination,'' and ``Welded Stainless Steel Pressure Pipe From Vietnam: Amended...2013-24709 Filed 10-21-13; 8:45 am] BILLING CODE...

2013-10-22

497

Aluminum and stainless steel tubes joined by simple ring and welding process  

NASA Technical Reports Server (NTRS)

Duranel ring is used to join aluminum and stainless steel tubing. Duranel is a bimetal made up of roll-bonded aluminum and stainless steel. This method of joining the tubing requires only two welding operations.

Townhill, A.

1967-01-01

498

New explosive welding technique to weld aluminum alloy and stainless steel plates using a stainless steel intermediate plate  

SciTech Connect

Various aluminum alloys and stainless steel were explosively welded using a thin stainless steel intermediate plate inserted between the aluminum alloy driver and stainless steel base plates. At first. the velocity change of the driver plate with flying distance is calculated using finite-difference analysis. Since the kinetic energy lost by collision affects the amount of the fused layer generated at the interface between the aluminum alloy and stainless steel, the use of a thin stainless steel intermediate plate is effective for decreasing the energy dissipated by the collision. The interfacial zone at the welded interface is composed of a fine eutectic structure of aluminum and Fe[sub 4]Al[sub 13], and the explosive welding, process of this metal combination proceeds mainly by intensive deformation of the aluminum alloy. The weldable region for various aluminum alloys is decided by the change in collision velocity and kinetic energy lost by collision, and the weldable region is decreased with the increase in the strength of the aluminum alloy.

Hokamoto, K.; Fujita, M. (Kumamoto Univ. (Japan). Dept. of Mechanical Engineering); Izuma, T. (Asahi Chemical Industry Co., Ltd., Siga (Japan))

1993-10-01

499

Practical handbook of stainless steels and nickel alloys  

SciTech Connect

This new handbook is an up-to-date technical guide to the grades, properties, fabrication characteristics, and applications of stainless steels and nickel alloys. The individual chapters were written by industry experts and focus on the key properties and alloy characteristics important in material selection and specification as well as the practical factors that influence the development and application of these materials. The contents include: alloy grades and their welding and fabrication characteristics and their application; monel metal; iron-based and nickel-based alloys; ferritic, austenitic, superaustenitic, and martensitic stainless steels; hastelloys; alloys 20, G, and 825; AOD and new refining technology; duplex stainless steels; 6-Mo alloys; corrosion-resistant castings; specification cross-reference tables; trade names; hardness conversions; list of common abbreviations.

Lamb, S. [ed.

1999-07-01

500

Bacterial adhesion on ion-implanted stainless steel surfaces  

NASA Astrophysics Data System (ADS)

Stainless steel disks were implanted with N +, O + and SiF 3+, respectively at the Surrey Ion Beam Centre. The surface properties of the implanted surfaces were analyzed, including surface chemical composition, surface topography, surface roughness and surface free energy. Bacterial adhesion of Pseudomonas aeruginosa, Staphylococcus epidermidis and Staphylococcus aureus, which frequently cause medical device-associated infections was evaluated under static condition and laminar flow condition. The effect of contact time, growth media and surface properties of the ion-implanted steels on bacterial adhesion was investigated. The experimental results showed that SiF 3+-implanted stainless steel performed much better than N +-implanted steel, O +-implanted steel and untreated stainless steel control on reducing bacterial attachment under identical experimental conditions.

Zhao, Q.; Liu, Y.; Wang, C.; Wang, S.; Peng, N.; Jeynes, C.

2007-08-01