Showing papers on "Stress corrosion cracking published in 1977"
TL;DR: In this paper, the theory of stress corrosion for slow crack propagation is reviewed in the light of classical Griffith theory of fracture, and it is shown that the effect of decreasing temperature (at progressively shallower levels along the geotherm) would be to decrease the crack velocity by several orders of magnitude if other factors were equal.
Abstract: The theory of stress corrosion for slow crack propagation is reviewed in the light of classical Griffith theory of fracture. Experimental data for stress corrosion cracking for glasses, ceramics, and metals are reviewed. We suggest that stress corrosion cracking plays an important role in the intrusion of magmas and in the transport of magmas upward through the lithosphere. It is shown that the effect of decreasing temperature (at progressively shallower levels along the geotherm) would be to decrease the crack velocity by several orders of magnitude if other factors were equal. We also propose that stress corrosion may be an important process in time-dependent earthquake phenomena such as premonitory behavior and earthquake aftershocks. We suggest that slow cracking in the earth is not seismically detectable but may nevertheless precede the terminal (catastrophic) phase of the fracture that is discerned as an earthquake. The seismically quiet periods before some earthquakes and the seismically quiet regions beneath some volcanoes may in fact be regimes of slow crack propagation. Slow crack propagation in a lithospheric plate may provide access routes for magmas which give rise to prominent linear volcanic chains.
393 citations
Book•
01 Jan 1977
66 citations
TL;DR: Crack growth in a mild steel subjected to various cyclic loading conditions while immersed in a carbonate-bicarbonate solution and held at different potentials may follow intergranular or transgranular growth.
Abstract: Crack growth in a mild steel subjected to various cyclic loading conditions while immersed in a carbonate-bicarbonate solution and held at different potentials may follow intergranular or transgran...
58 citations
TL;DR: In this paper, a long term immersion testing has been carried out of stressed, austenitic steel samples (304S15) in chloride solutions of varying strength, type, temperature and pH.
58 citations
01 Jan 1977
52 citations
TL;DR: In this article, the Alloy 600 material with varying microstructures was fabricated into single U-bend specimens and tested in 343 C. The materials were tested in a laboratory thermal-mechanical processing environment.
Abstract: Laboratory thermal-mechanical processing was used to produce Alloy 600 material with varying microstructures. The materials were fabricated into single U-bend specimens and tested in 343 C...
36 citations
TL;DR: In this article, the properties of commercial steels are outlined showing how these alloys can be divided into general purpose (18Cr-2Mo), moderately severe service (26Cr-1Mo), and premium service (29Cr-4Mo) materials.
Abstract: The new Fe-Cr-Mo ferritic stainless steels are reviewed with an emphasis on corrosion behavior. The properties of commercial steels are outlined showing how these alloys can be divided into general purpose (18Cr-2Mo), moderately severe service (26Cr-1Mo), and premium service (29Cr-4Mo) materials. The stress corrosion cracking (SCC), intergranular corrosion, pitting, crevice corrosion, and general corrosion of the Fe-Cr-Mo ferritic stainless steels in general is discussed. The influence of nickel on the corrosion resistance and toughness of ferritic stainless steels is considered.
35 citations
TL;DR: In this article, a diagnostic investigation has been carried out on some AISI type 316 stainless steel fixation nails that failed during service in the recovery treatment of femoral fractures, and the association of pitting and cracking at the nail edges where the cracking process appears to start together with fractographic features of the ruptured surfaces has led to the belief that pitting in crevice-induced stress corrosion cracking from acid chlorides is the cause of failure.
34 citations
Journal Article•
TL;DR: In this paper, a detailed microscopic examination of incipient i.d. cladding defects in some Maine Yankee Core I fuel rods determined that these defects and clad penetrations in related rods were caused by a PCI mechanism that was promoted by chemical species, i.e., stress corrosion cracking.
Abstract: Results of three related projects undertaken to elucidate the mechanism of Zircaloy cladding fracture caused by pellet-cladding interaction (PCI) in water reactor fuel rods are described. A detailed microscopic examination of incipient i.d. cladding defects in some Maine Yankee Core I fuel rods determined that these defects and clad penetrations in related rods were caused by a PCI mechanism that was promoted by chemical species, i.e., stress corrosion cracking (SCC). A consideration of the internal fuel rod chemistry and fission product distribution indicates that one potential agent for SCC of Zircaloy cladding is iodine released from CsI deposited on the i.d. surface and another is cadmium metal. A simple analytical model of crack propagation in Zircaloy cladding based on linear elastic fracture mechanics indicates two possible rate-controlling events, depending on the value of the stress intensification K/sub ISCC/. If K/sub ISCC/ for irradiated Zircaloy is very low, i.e., on the order of 2.2 to 3.3 MN/m/sup 3///sup 2/ (2 to 3 ksi ..sqrt..in.), crack growth is relatively easy, and hence the rate-limiting step must be the nucleation of sharp cracks in the cladding i.d. surface. However, if K/sub ISCC/ for irradiated Zircaloy is relatively large, i.e., greater than or equalmore » to 11 MN/m/sup 3///sup 2/ (10 ksi ..sqrt..in.), a high interfacial friction coefficient, for example, caused by fuel-clad bonding, would be required to propagate the i.d. defect.« less
34 citations
TL;DR: In this article, slow strain rate experiments have been performed on Type 304L and 304 stainless steel sheet material in boiling MgCl2 as a function of solution temperature and strain rate.
Abstract: Slow strain rate experiments have been performed on Type 304L and 304 stainless steel sheet material in boiling MgCl2 as a function of solution temperature and strain rate. Additionally, s...
29 citations
TL;DR: In this article, the authors evaluated the resistance of various commercial alloys to stress corrosion cracking (SCC) in 50% NaOH at temperatures in the range 284 to 332 C. The effects of alloy composition, heat treatment, and test temperature on the severity of SCC were examined.
Abstract: The resistance of various commercial alloys to stress corrosion cracking (SCC) in 50% NaOH has been evaluated at temperatures in the range 284 to 332 C. Austenitic alloys tested included Type 300 series stainless steels, Monel Alloy 400, Inconel Alloys 600, 625, 690, Incoloy Alloys 800, 804, 825, Hastelloy Alloy C, and Nickel 201. Other materials tested were Croloy 2¼Cr-1Mo steel, ferritic stainless steels Type 446, 26-1S, and EB 26-1, and commercial purity titanium. The effects of alloy composition, heat treatment, and test temperature on the severity of SCC were examined. Increasing the nickel content increased the resistance of SCC in deaerated 50% NaOH. In an aerated 50% NaOH solution, both high chromium and high nickel contents were necessary to increase stress corrosion resistance. In deaerated 50% NaOH, ferritic alloys exhibited high corrosion rates and displayed structure sensitive cracking behavior. Titanium corroded rapidly but did not crack. The greatest overall resistance to SCC in de...
TL;DR: In this paper, the susceptibility to stress corrosion cracking in caustic solutions of austenitic materials for steam generator tubing, both for liquid metal fast breeders and pressurized water reactors (Type 316, and Alloy 600 and 800) has been compared as a function of: (1) the concentration of the sodium hydroxide solution; (2) the stress level (the actual stress levels for different types of specimens have been carefully evaluated and discussed), and (3) the composition and structure of the metal.
Abstract: The susceptibility to stress corrosion cracking (SCC) in caustic solutions of austenitic materials for steam generator tubing, both for liquid metal fast breeders and pressurized water reactors (Type 316, and Alloys 600 and 800) has been compared as a function of: (1) The concentration of the sodium hydroxide solution; (2) the stress level (the actual stress levels for different types of specimens have been carefully evaluated and discussed), and (3) the composition and structure of the metal (in particular, the grain boundary precipitation in high nickel alloys has been characterized by different techniques). It has been shown that the first two factors have a strong influence on the classification of the alloys, which can be completely reversed when the stress and the caustic concentration change. The possible cracking of Alloy 600 for very low caustic concentrations (4 g/l) suggested the hypothesis that cracking in pure water could be the same phenomenon as caustic cracking. Thermal treatments...
TL;DR: In this article, an improved model was proposed to explain the hot salt stress corrosion cracking (HSSCC) of titanium alloys, where corrosion produced hydrogen from a secondary cathodic reaction is responsible for the premature failure which can occur when tensile stressed titanium alloy are exposed to chloride containing hot salt environments.
Abstract: An improved model explains the hot salt stress corrosion cracking (HSSCC) of titanium alloys. Basically, corrosion produced hydrogen from a secondary cathodic reaction is responsible for the premature failure which can occur when tensile stressed titanium alloys are exposed to chloride containing hot salt environments. The electrochemical model is consistent with all observations and data which have been reported and verified by earlier HSSCC investigators. Examination of the mechanism provides an explanation why titanium alloy components in aircraft gas turbine engines probably have not failed by HSSCC in service. Microstructural factors are involved in the cracking process. Optically observable microstructures probably should not be used in discussing the relative susceptibility of titanium alloys to HSSCC.
01 Dec 1977
TL;DR: In this article, the susceptibility to stress corrosion cracking in caustic solutions of austenitic materials for steam generator tubing, both for liquid metal fast breeders and pressurized water reactors (Type 316, and Alloy 600 and 800) has been compared as a function of the concentration of the sodium hydroxide solution; the stress level (the actual stress levels for different types of specimens have been carefully evaluated and discussed); and the composition and structure of the metal (in particular, the grain boundary precipitation in high nickel alloys has been characterized by different techniques).
Abstract: The susceptibility to stress corrosion cracking (SCC) in caustic solutions of austenitic materials for steam generator tubing, both for liquid metal fast breeders and pressurized water reactors (Type 316, and Alloys 600 and 800) has been compared as a function of: (1) The concentration of the sodium hydroxide solution; (2) the stress level (the actual stress levels for different types of specimens have been carefully evaluated and discussed); and (3) the composition and structure of the metal (in particular, the grain boundary precipitation in high nickel alloys has been characterized by different techniques). It has been shown that the first two factors have a strong influence on the classification of the alloys, which can be completely reversed when the stress and the caustic concentration change. The possible cracking of Alloy 600 for very low caustic concentrations (4 g/l) suggested the hypothesis that cracking in pure water could be the same phenomenon as caustic cracking. Thermal treatments (such as 16 hours at 700/sup 0/C) can significantly improve the behavior of Alloy 600 in caustic solutions.
TL;DR: In this paper, modified Streicher and 288 C (550 F) electrochemical caustic stress corrosion tests were performed on Alloy 600 to determine the relationship between acid intergranular attack susceptibili...
Abstract: Modified Streicher and 288 C (550 F) electrochemical caustic stress corrosion tests were performed on Alloy 600 to determine the relationship between acid intergranular attack susceptibili...
TL;DR: Stress corrosion cracking of CDA 443 admiralty brass was studied in sodium sulfate solutions over a pH range of 1.3 to 12.7 at open circuit and controlled potentials using a slow strain rate technique as discussed by the authors.
Abstract: Stress corrosion cracking (SCC) of CDA 443 admiralty brass was studied in sodium sulfate solutions over a pH range of 1.3 to 12.7 at open circuit and controlled potentials using a slow strain rate technique. This study negates the view that SCC of brass only occurs in the presence of ammonia or its derivatives. SCC of brass occurs over a wide pH range depending on the oxidizing condition represented by the anodic potential. (FS)
TL;DR: Iodine stress corrosion cracking of Zircaloy-2 cladding under static tensile stress has been studied over the temperature range of 250~450°C as mentioned in this paper, and the lowest iodine concentration required to cause cracking was 0.15 mg iodine per cm3 free volume in test ampoule at 300°C, and 1.1 mg/cm' at 350°C.
Abstract: Iodine stress corrosion cracking of Zircaloy-2 cladding under static tensile stress has been studied over the temperature range of 250~450°C. The lowest iodine concentration required to cause cracking was 0.15 mg iodine per cm3 free volume in test ampoule at 300°C, and 1.1 mg/cm' at 350°C. The minimum circumferential plastic strain to cause failure was about 0.4% for specimen tubes possessing high cracking susceptibility. Softer tubes tolerate more circumferential deformation before they failed. This is attributed to greater margin retained for work hardening, rather than to smaller residual tensile hoop stress. Cracking was also inhibited by the presence of oxygen in the iodine atmosphere, the threshold partial pressures being 28 torr at 300°C and 9 torr at 350°C. Scanning electron micrographs of the fractured surfaces revealed brittle transgranular fracture carrying river patterns on part of the cleavage facets.
TL;DR: In this article, the effects of chemical environments upon the mechanical properties of zirconium alloys are investigated. But the authors focus on the Zircaloy-2 alloy, which is used to contain fissionable fuel in water-cooled nuclear reactors.
Abstract: EFFECTS of chemical environments upon the mechanical properties of zirconium alloys are of great interest because such alloys are used to contain fissionable fuel in water-cooled nuclear reactors. Particular interest attaches to stress corrosion cracking or liquid metal embrittlement because both of these phenomena are known to produce non-ductile fractures in otherwise ductile materials. Rosenbaum et al. reported iodine stress corrosion cracking of Zircaloy-2 some years ago1,2, and this phenomenon has been extensively investigated by others3–5. Zircaloy-2 is an alloy of zirconium containing by weight about 1.5% tin, 0.15% iron, 0.1% chromium, 0.05% nickel and 0.12% oxygen. Cox has reported embrittilement of Zircaloy by mercury or liquid caesium at room temperature3. However, the phenomenon of liquid metal embrittlement is known to be favoured by low temperatures6, and Zircaloy nuclear fuel cladding operates in the vicinity of 300 °C.
TL;DR: In this paper, the susceptibility of various implant alloys to different types of corrosion was determined, with special emphasis on the compound design of joint endoprostheses, and it was shown that these combine the advantages of cast moving parts with those of forged anchorage shafts.
TL;DR: In this article, a constant strain rate test of Type 304 stainless steel was carried out in high temperatures with varying chloride ion concentrations up to 100 ppm and a strain rate of 5 x 10−4 minute−1 was obtained.
Abstract: Constant strain rate tests of Type 304 stainless steel were continued in high temperatures with varying chloride ion concentrations up to 100 ppm. A strain rate of 5 x 10−4 minute−1 was em...
01 Jun 1977
TL;DR: In this paper, a study of the corrosion and SCC of copper and alpha-phase Cu-Zn alloys in 1N ammoniacal solutions was made, and the corrosion process in non-tarnishing solutions is under concentration polarization, being controlled by the transport of the main cathodic species (cupric complex ions) to the surface, and established the reversible potential, the exchange current density and the Tafel slope for the main anodic reaction, copper dissolution.
Abstract: : A study has been made of the corrosion and SCC of copper and alpha-phase Cu-Zn alloys in 1N ammoniacal solutions. Potentiostatic experiments confirmed that the corrosion process in non-tarnishing solutions is under concentration polarization, being controlled by the transport of the main cathodic species (cupric complex ions) to the surface, and established the reversible potential, the exchange current density and the Tafel slope for the main anodic reaction, copper dissolution. The conditions for tarnish formation and the nature of this cuprous-oxide layer were also studied. Potentiostatic studies of the potential dependence of SCC of annealed Cu-30Zn established that the critical potential for cracking corresponds to the reversible potential for copper dissolution. Moreover, SCC was shown to be predominantly intergranular in potential ranges where tarnishing occurs and transgranular in non-tarnishing ranges. These and other observations lend support to our view that inter- and transgranular SCC involve different mechanisms. The former is considered to occur by the film-rupture model. The mechanism of transgranular cracking has not been established, but fractographic and accoustic-emission studies of both Cu-30Zn and Admiralty Metal indicated that this form of cracking occurs by discontinuous cleavage on (110) planes. (Author)
Patent•
30 Mar 1977TL;DR: In this article, a chromium-nickel austenitic stainless steel with improved resistance to intergranular stress corrosion cracking has been provided for applications involving exposure to high-temperature and high-pressure water and attack by chlorides.
Abstract: There is provided a chromium-nickel austenitic stainless steel having improved resistance to intergranular stress corrosion cracking. The steel has low carbon and phosphorus content or carbon and phosphorus in solid solution fixed by niobium addition. Further resistance to transgranular stress corrosion cracking is realized with a low molybdenum content. The steel is particularly useful in applications involving exposure to high-temperature and high-pressure water and attack by chlorides.
TL;DR: In this paper, a study of the chemistry of the intergranular dissolution of zirconium has been made in a range of iodine/organic solutions, and it is concluded that competition reactions between the various components of the solution and transient chemical species in solution control the extent of the dissolution step.
Abstract: A study of the chemistry of the intergranular dissolution of zirconium has been made in a range of iodine/organic solutions. This process is the second of the 3 stages through which the stress corrosion cracking (SCC) of the Zircaloys proceeds. The first being cracking or breakdown of the surface oxide film and the last a relatively fast transgranular propagation process. From a study of the effects of various additives on the time to failure of smooth split-ring specimens, together with fractography of the resulting cracks, it is concluded that competition reactions between the various components of the solution and transient chemical species in solution control the extent of the intergranular dissolution step. A comparison with published chemical reaction rates suggests a hypothesis whereby this dissolution process proceeds via solvated electron and low valence zirconium intermediates. Additives which react rapidly with solvated electrons, or which complex with the lower valence states of zirco...
TL;DR: In this paper, the effects of aerated and deaerated water, strain rate, and heat treatment on stress-elongation curves and their fracture modes were discussed, and the sensitivity of Type 304 stainless steel to SCC was evaluated by the constant strain rate technique.
Abstract: Constant strain rate tests of Type 304 stainless steel were conducted in high temperature water. Effects of aerated and deaerated water, strain rate, and heat treatment on stress-elongation curves and their fracture modes are discussed. Dissolved oxygen accelerated intergranular stress corrosion cracking (SCC) of sensitized Type 304 stainless steels in high temperature water. In high temperature water environments, the sensitivity of Type 304 stainless steel to SCC could be evaluated by the constant strain rate technique. For the environments, a strain rate of 5 × 10−4 minute−1 was found to be acceptable as an accelerated test.
TL;DR: In this paper, a gamma prime strengthened nickel-base alloy was given five different heat treatments to form microstructures ranging from solution annealed to overaged, and the results suggest that the stress corrosion resistance of other nickel base alloys could be significantly improved by suitable heat treatments.
Abstract: A gamma prime strengthened nickel-base alloy was given five different heat treatments to form microstructures ranging from solution annealed to overaged. Stress corrosion tests in 50 pct NaOH and undeaerated water solutions at 316°C showed that material that was overaged sufficiently to produce homogeneous plastic deformation possessed greatly increased resistance to stress corrosion cracking. The results suggest that the stress corrosion resistance of other nickel-base alloys could be significantly improved by suitable heat treatments.
TL;DR: In this article, a contoured double cantilever beam specimen developed for linear elastic fracture mechanics (LEFM) studies was used in a stress corrosion cracking study of the Al Alloy RR 58.
TL;DR: In this paper, a fracture mechanics approach to the study of stress corrosion cracking in cold drawn prestressing tendon has been made, and the results showed that the effect of stress relief on stress corrosion susceptibility was investigated.
Abstract: Precracked specimens have been developed to enable a fracture mechanics approach to be made to the study of stress corrosion cracking in cold drawn prestressing tendon.Stress corrosion has been shown to occur in realistic environments and the effect of chloride contamination investigated. Values for KIc, KIscc and crack propagation velocity have also been obtained, and limited experiments carried out to determine the effect of stress relief on stress corrosion susceptibility.
TL;DR: In this paper, the influence of alloying and environmental factors on protective film stability was found to be associated with their influence on oxide film Cr, Fe, Si, and Ni contents, suggesting a cracking mechanism involving propagation by strain assisted localized corrosion.
Abstract: Studies showed that the immunity to stress corrosion cracking (SCC) conferred by some alloying variations in the standard boiling 45% MgCl2 test and other standard tests is only a conditional immunity produced by film destabilization and by delocalization of corrosion favoring blunt pitting over cracking. In such cases, immunity can be nullified simply by altering environmental conditions to promote relocalization of corrosion. Cl− concentration, Cl− cation type, and additives that influence corrosion kinetics all influence SCC susceptibility through their effects on overall film stability and localization of corrosion. The influence of alloying and environmental factors on protective film stability was found to be associated with their influence on oxide film Cr, Fe, Si, and Ni contents. Crack morphologies produced under conditions of varying film stability were suggestive of a cracking mechanism involving propagation by strain assisted localized corrosion.