Showing papers on "Stress corrosion cracking published in 1990"
Book•
01 Oct 1990
TL;DR: Water-Formed and Steam-formed Deposits as mentioned in this paper are two types of deposits that are prone to low pH Corrosion during acid cleaning and to dealloying during short-term overheating.
Abstract: Water-Formed and Steam-Formed Deposits. Long-Term Overheating. Short-Term Overheating. Caustic Corrosion. Chelate Corrosion. Low pH Corrosion During Service. Low pH Corrosion During Acid Cleaning. Oxygen Corrosion. Fire-Side Corrosion. Oil Ash Corrosion. Coal Ash Corrosion. Waterfall Corrosion. Cold End Corrosion. Dewpoint Corrosion. Hydrogen Damage. Corrosion Fatigue Cracking. Stress Corrosion Cracking. Erosion. Cavitation. Forming Defects. Welding Defects. Material Deficiency. Graphitic Corrosion. Dealloying.
113 citations
TL;DR: The stress corrosion cracking of a pipeline steel exposed to a carbonate-bicarbonate solution has been studied under various loading conditions, particularly those involving a relatively small amount of carbonate as discussed by the authors.
Abstract: The stress corrosion cracking of a pipeline steel exposed to a carbonate—bicarbonate solution has been studied under various loading conditions, particularly those involving a relatively s...
88 citations
TL;DR: In this paper, the authors used repassivation kinetics of metals to detect passivity breakdown in metals; a step which followed by localized acidification leads to pitting and crevice corrosion.
74 citations
TL;DR: Slow strain rate testing (SSRT) was initially developed as a rapid, ad hoc laboratory method for assessing the propensity for metals and environments to promote stress corrosion cracking as discussed by the authors, and it is now clear, however, that there are good theoretical reasons why strain rate, as opposed to stress per se, will often be the controlling parameter in determining whether or not cracks are nucleated and, if so, are propagated.
Abstract: Slow strain rate testing (SSRT) was initially developed as a rapid, ad hoc laboratory method for assessing the propensity for metals and environments to promote stress corrosion cracking. It is now clear, however, that there are good theoretical reasons why strain rate, as opposed to stress per se, will often be the controlling parameter in determining whether or not cracks are nucleated and, if so, are propagated. The synergistic effects of the time dependences of corrosion-related reactions and microplastic strain provide the basis for mechanistic understanding of stress corrosion cracking in high-pressure pipelines and other structures. However, while this may be readily comprehended in the context of laboratory slow strain tests, its extension to service situations may be less apparent. Nevertheless, laboratory work involving realistic stressing conditions, including low-frequency cyclic loading, shows that strain or creep rates give good correlation with thresholds for cracking and with crac...
66 citations
TL;DR: In this article, a new physical model was proposed to explain the brittle transgranular cracking in a 153°C MgCl2 solution at free corrosion potential, based on the influence of localized anodic dissolution on the enhancement of the plasticity at the crack tip.
Abstract: The ductile f.c.c. 316 alloy is shown to exhibit brittle transgranular (and intergranular) stress corrosion cracking in a 153°C MgCl2 solution at free corrosion potential. Tests on smooth and pre-cracked specimens are performed to identify the mechanisms of fracture. Transgranular cracking is related to both a discontinuous microcleavage mainly on {100} planes and a microshearing on {111} planes. A new physical modelization is proposed to explain the brittle transgranular cracking. It is based on the influence of the localized anodic dissolution on the enhancement of the plasticity at the crack tip. The formation of dislocation pile-ups and the conditions of restricted slip induce a brittle microcracking. The crack propagation is then limited and arrested by the strong effect of relaxation in the ductile 316 alloy. Such a model is discussed as a function of the main factors governing the transgranular stress corrosion cracking sensitivity of ductile f.c.c. single-phase materials.
65 citations
TL;DR: In this paper, the authors reviewed advances in the theory and practice of stress corrosion cracking (SCC) for the period 1965-1990 and concluded that the main developments since 1967 are the recognition of the lack of specificity of SCC environments, the use of slow strain rate and fracture mechanics testing, quantitative SEM fractography, studies of grain boundary structure and composition, transient electrochemistry of bare metal surfaces, measurement and modelling of crack chemistry, elaboration of several SCC models, including slip-dissolution and film induced cleavage, and mitigation by alloy development or anodic
Abstract: Advances in the theory and practice of stress corrosion cracking (SCC) are reviewed for the period 1965–1990. The proceedings of two landmark conferences are used as a basis for discussion: Ohio State University (1967) and Kohler, WI (1988). The discussion is developed around the following topics: metal–environment combinations, testing, fractography, metallurgical aspects, electrochemical aspects and crack chemistry, mechanisms, and prediction and mitigation. It is concluded that the main developments since 1967 are the recognition of the lack of specificity of SCC environments, the use of slow strain rate and fracture mechanics testing, quantitative SEM fractography, studies of grain boundary structure and composition, transient electrochemistry of bare metal surfaces, measurement and modelling of crack chemistry, elaboration of several SCC models, including slip-dissolution and film induced cleavage, and mitigation by alloy development or anodic protection.
57 citations
Journal Article•
TL;DR: Duplex stainless steels are defined and the advantages of second-generation, nitrogen-alloyed grades are explained in this paper, where duplex stainless steel metallurgy, pitting and crevice corrosion resistance, stress corrosion cracking resistance, specifications, mechanical properties, fabrication procedures and applications
Abstract: Duplex stainless steels are defined and the advantages of second-generation, nitrogen-alloyed grades are explained Information is provided on duplex stainless steel metallurgy, pitting and crevice corrosion resistance, stress corrosion cracking resistance, specifications, mechanical properties, fabrication procedures and applications See also abstract number 90051131
53 citations
01 Dec 1990
TL;DR: The work performed by Argonne National Laboratory on fatigue and environmentally assisted cracking (EAC) in light water reactors (LWRs) from April 1995 to December 1995 is summarized in this article.
Abstract: This report summarizes work performed by Argonne National Laboratory on fatigue and environmentally assisted cracking (EAC) in light water reactors (LWRs) from April 1995 to December 1995 Topics that have been investigated include fatigue of carbon and low-alloy steel used in reactor piping and pressure vessels, EAC of Alloy 600 and 690, and irradiation-assisted stress corrosion cracking (IASCC) of Type 304 SS Fatigue tests were conducted on ferritic steels in water that contained various concentrations of dissolved oxygen (DO) to determine whether a slow strain rate applied during different portions of a tensile-loading cycle are equally effective in decreasing fatigue life Crack-growth-rate tests were conducted on compact-tension specimens from several heats of Alloys 600 and 690 in simulated LWR environments Effects of fluoride-ion contamination on susceptibility to intergranular cracking of high- and commercial- purity Type 304 SS specimens from control-tensile tests at 288 degrees Centigrade Microchemical changes in the specimens were studied by Auger electron spectroscopy and scanning electron microscopy to determine whether trace impurity elements may contribute to IASCC of these materials
49 citations
Patent•
15 Oct 1990TL;DR: In this paper, a powder-derived aluminum alloy is provided which contains throughout its se aluminum alloy matrix a fine dispersion of elemental molybdenum particles, which exhibit improved resistance to environmentally-assisted cracking, such as stress corrosion cracking and corrosion fatigue, at room and moderately elevated temperatures.
Abstract: A powder-derived aluminum alloy is provided which contains throughout its se aluminum alloy matrix a fine dispersion of elemental molybdenum particles. The articles formed from the alloy exhibit improved resistance to environmentally-assisted cracking, such as stress corrosion cracking and corrosion fatigue, at room and moderately elevated temperatures. An aluminum alloy powder of a composition usually used to produce high-strength aluminum alloys is blended with molybdenum powder to form a homogeneous powder blend containing up to about 1.0% by weight molybdenum. The powder blend is consolidated, including compacting it and extruding or otherwise hot working it to a total reduction ratio of at least 16 to 1. The hot-worked product is then heat treated in a conventional manner to maximize other desirable properties, such as strength.
41 citations
Book•
01 Apr 1990
TL;DR: McEvily et al. as discussed by the authors present a comprehensive reference work for materials scientists concerned with stress corrosion cracking and corrosion fatigue, which includes over 500 stress/cracking time curves, S/N curves, and other graphical data.
Abstract: Use this new book to find the effects of various corrosive media and processing variables on the stress corrosion cracking and corrosion fatigue characteristics of ferrous and nonferrous alloys. There are over 500 stress/cracking time curves, S/N curves, and other graphical data. An extensive introductory article explains stress corrosion cracking, corrosion fatigue, and related test methods and results. Most curves appear independently, and represent a single alloy in a given condition and environment. In cases where the curveAs significance may not be obvious, explanatory text is included. The major alloy groups covered include aluminium, copper, nickel, titanium and other nonferrous alloys. Major sections are devoted to carbon, alloy, stainless and pressure vessel steels, as well as to superalloys. The effect of variables, such as grain size, cooling rate, stress intensity, and temperature are presented, along with numerous environments (e.g. calcium nitrate, dry nitrogen, mineral oil, sodium chloride, sodium hydroxide, wet air, fresh water, sea-water, etc.). Compiled from an exhaustive survey of the published literature, each curve has been carefully reviewed by A.J. McEvily, Jr. Professor, Department of Metallurgy, University of Connecticut. Dr. McEvily received the ASM Fellow citation for significant contributions to the understanding of fatigue crack initiation and growth in metals and alloys. Organized into a single, comprehensive source, this book is a valuable reference work for materials scientists concerned with stress corrosion cracking and corrosion fatigue.
40 citations
TL;DR: In this article, the influence of heat treatments on the intergranular attack (IGA) and IGSCC resistance of lnconel 690 (UNS N06690) were studied.
Abstract: The influence of heat treatments on the intergranular attack (IGA) and intergranular stress corrosion cracking (IGSCC) resistance of lnconel 690 (UNS N06690) were studied. The chromium profiles adjacent to the grain boundary were predicted by thermodynamic and kinetic modeling and benchmarked with experimental results. The relative susceptibilities of alloy 690 with various heat treatments to stress corrosion cracking (SCC) in 0.001 M Na2S2O3 and low pH at room temperature were evaluated. The results of slow strain rate tensile (SSRT) testing showed good IGSCC resistance of alloy 690. The results of the Huey test showed very little weight loss for various heat treatments. The good resistance of IGA and IGSCC for alloy 690 are considered to be attributed to the higher equilibrium chromium concentration at the intergranular carbide–matrix interface.
TL;DR: The hydrogen-induced IGSCC of Alloy 600 in high-temperature, deaerated water or steam has been studied in this paper, showing the formation of closely spaced (0.2μm) bubbles along boundaries and their growth into fine cracks before they open to communicate with the corroding atmosphere.
Abstract: Intergranular stress corrosion cracking (IGSCC) of Alloy 600 in high-temperature, deaerated water or steam has been termed “hydrogen-induced IGSCC.” We believe these cracks are initiated by the nucleation of a high density of bubbles on the grain boundary under the combined action of the applied stress and high pressure methane formed from carbon in solution reacting with hydrogen injected by corrosion. The bubbles then grow together by grain boundary diffusion to give local failure. This is supported by transmission electron microscope (TEM) observations of two-stage replicas, which show the subsurface formation of closely spaced (0.2μm) bubbles along boundaries, and their growth into fine cracks before they open to communicate with the corroding atmosphere. The kinetics are examined and shown to be in quantitative agreement with several experimental observations. This mechanism involves no grain boundary dissolution of the metal, the only role of corrosion being the injection of hydrogen at a high fugacity. It predicts an activation energy roughly equal to that for grain boundary dψusion of nickel in Alloy 600.
Patent•
02 May 1990
TL;DR: In this article, the Al-Zn-Mg series alloy plate material was proposed to offer the plate material excellent in formability as well as strength, stress corrosion cracking resistance and weldability by specifying the kinds and contents of the alloy components.
Abstract: PURPOSE: To offer the plate material excellent in formability as well as strength, stress corrosion cracking resistance and weldability by specifying the kinds and contents of the alloy components in an Al-Zn-Mg series alloy plate material. CONSTITUTION: The Al alloy contains, by weight, 4 to 7% Zn, 0.3 to 3.0% Mg, 0.03 to 0.1% Ag, 0.01 to 1% Fe and 0.05 to 0.2% Ti, furthermore contains one or more kinds among 0.01 to 1.5% Mn, 0.01 to 0.6% Cr, 0.01 to 0.25% Zr and 0.0001 to 0.08% B and the balance Al. Ag improves the stress corrosion cracking resistance and strength, but in the case of more than the upper limit, the weldability is deteriorated. Fe improves the weldability, but in the case of more than the upper limit, the toughness and workability are deteriorated. Ti improves the strength and weldability, but in the case of more than the upper limit, the toughness and workability are deteriorated. Mn, Cr, Zr and B stabilized the structure, but in the case of more than the upper limit, the toughness and workability are deteriorated. COPYRIGHT: (C)1991,JPO&Japio
TL;DR: In this article, the authors investigated the relationship between pitting, stress, and stress corrosion cracking of line pipe steels and found that cracks generally nucleated from pits, whose depths followed a lognormal distribution.
Abstract: This paper presents observations about the results of an investigation into the relationships between pitting, stress, and stress corrosion cracking of line pipe steels. This work showed that the number of stress corrosion cracks varied exponentially with specimen stress. The cracks generally nucleated from pits, whose depths followed a lognormal distribution. A mathematical analysis of the crack number and pit depth data supports the hypothesis that a crack nucleates from the bottom of a pit when the stress concentration at the bottom of the pit reaches a critical value. The increase in crack number with stress results from the corresponding decrease in the critical pit depth, and hence an increase in the number of critically sized pits. The number of critically sized pits was found to increase exponentially with stress.
TL;DR: In this article, the use of a laser to melt a thin surface layer of sensitized stainless steel is shown to be an effective method for the prevention of intergranular stress corrosion cracking (IGSCC).
Abstract: The use of a laser to melt a thin surface layer of sensitized stainless steel is shown to be an effective method for the prevention of intergranular stress corrosion cracking (IGSCC). The ...
TL;DR: In this paper, the authors investigated the relationship between steady-state elongation rate (iss[m/s]) and time-to-failure (TF) of austenitic stainless steels in acidic chloride and sulfate solutions.
Abstract: Stress corrosion cracking (SCC) of type 304 (UNS S30400) and type 316 (UNS S31600) austenitic stainless steels in acidic chloride and sulfate solutions has been investigated as functions of pH and concentration by using the constant load method. It is found under a constant stress condition of 437 MPa that the logarithmic relationship between steady-state elongation rate (iss[m/s]) and time-to-failure (tf), which were obtained from the corrosion elongation curve (elongation—time), shows a good linear function with a slope of unity in these solutions, irrespective of material (type 304 and type 316), pH, and anion concentration. This result supports that iss becomes the parameter for prediction of time-to-failure as previously reported. It is also found that the ratio of transition time to time-to-failure holds constant with a value of 0.57 ± 0.02 independent of pH, anion species, concentration and material. Furthermore, iss below which no fracture occurs within the laboratory time scale (< 107 se...
TL;DR: In this paper, a correlation between caustic cracking susceptibility and the electrochemical behaviour of A516 steel is demonstrated. But the pore resistance model is also in good agreement with the assumption of the formation of an amorphous iron-aluminum oxide film.
IBM1
TL;DR: In this paper, the authors used indentation cracks in the presence of a HF etch to show stress-corrosion cracking in silicon for the first time, attributed to the initial removal of the native silica layer, and the subsequent lowering of the fracture resistance by passivation of the crack surfaces.
Abstract: Stress‐corrosion cracking—the phenomonon in which the initiation and propagation of cracks is enhanced by a chemically active environment—has previously not been observed in silicon. For example, extensive experiments have shown no effect of water on the fracture properties. However, using indentation cracks in the presence of a HF etch, we have been able to show stress‐corrosion cracking in silicon for the first time. This is attributed to the initial removal of the native silica layer, and the subsequent lowering of the fracture resistance by passivation of the crack surfaces.
TL;DR: In this article, high-strength high-conductivity Cu and Mo-based alloys have been selected as structural materials for the first wall and divertor plates of NET, respectively, and the effects of irradiation on their bulk properties and behaviour: tensile properties, low-cycle fatigue, fracture toughness, irradiation creep, stress corrosion cracking, H-embrittlement and microstructural stability are discussed in terms of the proposed NET operating conditions with a special emphasis on the possible effect of the neutron spectrum.
Patent•
02 Mar 1990TL;DR: A high-strength martensitic stainless steel excellent in corrosion resistance and stress corrosion cracking resistance, the composition of which comprises: under 0.03% carbon, 1% or less silicon, 2.3-7.0% manganese, 8-14% chromium, 0.005-0.15% nitrogen, and the balance of iron except incidental elements as discussed by the authors.
Abstract: A high-strength martensitic stainless steel excellent in corrosion resistance and stress corrosion cracking resistance, the composition of which comprises: under 0.03% carbon, 1% or less silicon, 2.3-7.0% manganese, 8-14% chromium, 0.005-0.2% aluminum, 0.005-0.15% nitrogen, and the balance of iron except incidental elements. The stainless steel can contain nickel, molybdenum, tungsten, copper, vanadium, titanium, niobium, zirconium, tanatalum, hafnium, calcium and rare earth elements under the fixed conditions in addition to the above elements. Heat treatment of the stainless steel comprises: the step of austenitizing at temperatures of 920° C. to 1,100° C., the step of cooling at a cooling rate equal to or higher than the air cooling rate, the step of tempering at temperatures between 580° C. and A cl point, and the step of cooling at a cooling rate equal to or higher than the air cooling rate.
TL;DR: The mechanical stress improvement process (MSIP) has been extensively applied to prevent stress corrosion cracking in BWR plants as discussed by the authors, which involves a slight permanent contraction of the pipe on one side of the weldment, and the resulting plastic flow redistributes the residual as-welded stresses and generates beneficial compressive stresses at the inner pipe surface.
Patent•
19 Oct 1990TL;DR: In this paper, a primary cooling circuit for cooling a nuclear reactor has wetted mechanically stressed nickel base alloy components such as Alloy 600 tubes in steam generators having oxidized surfaces comprising 1-10 w/o zinc, which tubes are inhibited against primary water stress corrosion cracking.
Abstract: A primary coolant circuit for cooling a nuclear reactor has wetted mechanically stressed nickel base alloy components such as Alloy 600 tubes in steam generators having oxidized surfaces comprising 1-10 w/o zinc, which tubes are inhibited against primary water stress corrosion cracking. The crack initiation times may be delayed by a factor of two in pressurized water nuclear reactors.
Patent•
15 Feb 1990TL;DR: A high-strength martensitic stainless steel excellent in corrosion resistance and stress corrosion cracking resistance, the composition of which comprises: 0.1% or less carbon, 1% of or less silicon, 2% of manganese, 8-14% chromium, 1.2-4.5% copper, 0.005-0.15% nitrogen and the balance of iron except incidental elements.
Abstract: A high-strength martensitic stainless steel excellent in corrosion resistance and stress corrosion cracking resistance, the composition of which comprises: 0.1% or less carbon, 1% or less silicon, 2% or less manganese, 8-14% chromium, 1.2-4.5% copper, 0.005-0.2% aluminum, 0.01-0.15% nitrogen, and the balance of iron except incidental elements. The stainless steel can contain nickel, molybdenum, tungsten, vanadium, titanium, niobium, etc. under the fixed conditions in addition to the above elements. The heat treatment of the stainless steel comprises: the step of austenitizing at temperatures of 920° C. to 1,000° C., the step of cooling at a cooling rate equal to or higher than the air cooling rate, the step of tempering at temperatures between 580° C. and A cl point, and the step of cooling at a cooling rate higher than the air cooling rate.
TL;DR: In this paper, the surface mobility-SCC mechanism for stress corrosion cracking susceptibility of Ag-30Cd and Ag-15Pd alloys was investigated in I M KCl, KBr, Kl and Na 2 SO 4 solutions.
TL;DR: In this article, the authors compared the predicted and measured crack velocities of Magdowski and Speidel for steels in hot water, covering a wide range of temperatures, yield strength and impurity levels, with the Surface-Mobility Stress-Corrosion-Cracking Mechanism predictions.
Patent•
26 Dec 1990
TL;DR: In this article, the authors proposed to improve the strength, solderability, stress relaxing properties, corrosion resistance and stress corrosion cracking resistance by mixing a Cu-Zn alloy with a specified amt of Si or furthermore with Sn and Ni.
Abstract: PURPOSE: To improve the strength, solderability, stress relaxing properties, corrosion resistance and stress corrosion cracking resistance by mixing a Cu-Zn alloy with a specified amt. of Si or furthermore with Sn and Ni. CONSTITUTION: The compsn. of a copper alloy for electronic parts is constituted of, by weight, 5 to 25% is Zn, 0.01 to 3% Si and the balance Cu with inevitable impurities. If required, this alloy is furthermore mixed with 0.05 to 3% Ni and moreover incorporated with 0.001 to 2% of one or ≥ two kinds among P, Al, Fe, Pb, As, Sb, B, Co, Cr, Mn, Te, In, Zr, Hf, Be, Mg, Ag, Cd and Ge. The grain size of this copper alloy is preferably regulated to ≤15μm. By this compsn., stress corrosion cracking resistance which is a defect of the conventional brass can be improved. COPYRIGHT: (C)1992,JPO&Japio
TL;DR: In this paper, the electrochemical behavior of the passive film during S.C. phenomena is studied and the phase of the phase maximum corresponds to the beginning of the cracks propagation.
TL;DR: Slow strain rate tests have been performed on annealed type 316 (UNS S31600) stainless steel in 5 ppm chloride content water at temperatures from 100 to 300°C under various applied potenti...
Abstract: Slow strain rate tests have been performed on annealed type 316 (UNS S31600) stainless steel in 5 ppm chloride content water at temperatures from 100 to 300°C under various applied potenti...