Showing papers on "Stress corrosion cracking published in 1988"
12 Apr 1988
TL;DR: In this article, a moisture-diffusion analysis of the plastic, deformation and stress analysis of a package, and measurement of some high-temperature properties of the polyethylene has been carried out.
Abstract: Package cracking that occurs in surface-mount devices that have absorbed moisture has been studied by means of a moisture-diffusion analysis of the plastic, deformation and stress analysis of the package, and measurement of some high-temperature properties of the plastic. The validity of the analysis has been confirmed by a measurement of the deformation of packages heated by infrared radiation. Several packages with different level of moisture saturation and hysteresis of moisture absorption have been heated by soldering and the occurrence of package cracking investigated. The vapor pressure and distribution of moisture content of these packages have been calculated by the present analysis. It was found that generated vapor pressure is lower than saturated vapor pressure and depends on the moisture content at the part of the plastic facing the space in which vapor pressure is generated. This example shows that it is possible to evaluate package cracking by the present analysis method quantitatively. >
179 citations
IBM1
TL;DR: In this article, the authors investigated the process compatibility and potential component reliability problems associated with surface-mount technology and reported major reliability concerns observed during qualification of vendors' surface mount ICs.
Abstract: The process compatibility and potential component reliability problems associated with surface-mount technology are investigated. Major reliability concerns observed during qualification of vendors' surface mount ICs are reported. Moisture-induced package cracking and its implication for the corrosion resistance of the package are discussed. The application of acoustic microscopy techniques such as scanning laser acoustic microscopy (SLAM) and C-mode scanning acoustic microscopy (C-SAM) for examining internal package cracking is described. The concept of threshold (safe) moisture level in a surface-mount package and the proper procedures for determining it are discussed. >
85 citations
TL;DR: In this paper, the effects of interfacial and matrix microstructure on microdeformation and primary side stress corrosion cracking (SCC) of alloy 600 tubing were examined after various tensile deformations.
Abstract: Microdeformation characteristics in alloy 600 tubing have been examined after various tensile deformations. Microstructure developed during processing was found to control subsequent microdeformation behavior. Grain boundary carbides were the most effective source of dislocations, activating at lower macrostrains and continuing to operate at higher macrostrains than other sources. Ledges within grain boundaries, twin boundaries, and matrix carbides also acted as dislocation sources. Most dislocation activity at low strains was confined to planar arrays. A conceptual model is presented to explain the effects of interfacial and matrix microstructure on microdeformation and primary side stress corrosion cracking (SCC) of alloy 600 tubing. Microstructure is linked to intergranular stress corrosion cracking (IGSCC) resistance through its influence on microdeformation behavior and the resultant crack tip stress state. Dislocation source activity at grain interfaces is proposed to be critical in control...
79 citations
TL;DR: In this paper, a detailed analysis of crack growth in pure magnesium in dry air, aqueous, and liquid alkali metal environments is described, and a fractal model of the crack growth is presented.
Abstract: Metallographic and fractographic observations of crack growth in pure magnesium in dry air, aqueous, and liquid alkali metal environments are described. Crack growth in dry air at ambient ...
74 citations
TL;DR: Analyse du potentiel de corrosion de l'acier inoxydable type 304 sensibilite mis sous contraintes dans des solutions contenant de loxygene.
Abstract: Analyse du potentiel de corrosion de l'acier inoxydable type 304 sensibilite mis sous contraintes dans des solutions contenant de l'oxygene. Determination de la relation entre les fluctuations de potentiel et l'amorcage de la fissuration
64 citations
TL;DR: In this article, it was shown that the more extensive pitting that is associated with the more aggressive solutions means that initiation of stress corrosion cracks becomes more difficult, with a consequent increase in threshold stress and a sharp decrease in crack velocity.
54 citations
TL;DR: In this article, the relative effect of 13 anionic species, in conjunction with hydrogen and sodium cations, on the stress corrosion cracking (SCC) behavior of lightly sensitized AISI 304 stainless steel (SS) was investigated in constant extension rate tests (CERTs) at 289 C in water with 2 ppm dissolved oxygen at total conductivity values of ≤ 1 µS/cm.
Abstract: The relative effect of 13 anionic species, in conjunction with hydrogen and sodium cations, on the stress corrosion cracking (SCC) behavior of lightly sensitized AISI 304 stainless steel (SS) was investigated in constant extension rate tests (CERTs) at 289 C in water with 02 ppm dissolved oxygen at total conductivity values of ≤1 µS/cm The results show that the sulfur species, either in acid or sodium form, produce the highest degree of intergranular stress corrosion cracking (IGSCC) relative to the other anions The effect of temperature on SCC behavior was investigated in CERTs over the range of 110 to 320 C in high-purity water and in water containing 01 and 10 ppm sulfate as H2SO4 at a dissolved oxygen concentration of 02 ppm The CERT parameters were correlated with the electrochemical potential of platinum and AISI 304 SS electrodes in the high-temperature environments Maximum IGSCC occurred at temperatures between ∼200 and 250 C in high-purity water, and the addition of sulfate incre
46 citations
TL;DR: In this paper, the effect of cold work on the stress corrosion cracking (SCC) of solution-annealed (nonsensitized) AISI 304 stainless steel (SS) in 288 C oxygenated pure water was studied utilizing crevi...
Abstract: The effect of cold work on the stress corrosion cracking (SCC) of solution-annealed (nonsensitized) AISI 304 stainless steel (SS) in 288 C oxygenated pure water was studied utilizing crevi...
44 citations
TL;DR: In this article, a study of grain boundary segregation, intergranular corrosion, and intragranular stress corrosion cracking in austenitic stainless steels was conducted, and the results showed that phosphorus, nitrogen, and sulfur all segregate to grain boundaries in these materials and that they can affect one another's segregation through site compctition.
Abstract: This paper reports a study of grain boundary segregation, intergranular corrosion, and intergranular stress corrosion cracking in austenitic stainless steels. The results show that phosphorus, nitrogen, and sulfur all segregate to grain boundaries in these materials and that they can affect one another's segregation through site compctition. In particular, the results demonstrate that phosphorus segregation can be lowered by the presence of nitrogen and sulfur in the steel. Also, if manganese is present in the steel, sulfur segregation will be greatly decreased as a result of formation of manganese sulfides. Phosphorus, sulfur, and nitrogen will not initiate intergranular corrosion in the modified Strauss test, although if corrosion is initiated by chromium depletion, these elements might enhance the corrosion process. Phosphorus segregation does enhance corrosion in the Huey test, even in steels that have not undergone grain boundary chromium depletion, although there does not appear to be a precise correlation between the depth of corrosion penetration and phosphorus segregation. Intergranular stress corrosion cracking in 288 °C water at a pH of 2.5 and electrochemical potential of OVSHE can occur in these steels even in the absence of chromium depletion if sulfur is present on the grain boundaries. Phosphorus segregation appears to have very little effect.
39 citations
TL;DR: In this article, the authors present the results of a comprehensive study concerning stress corrosion crack growth rates in steam turbine rotor steels exposed to hot water and show that there exists a threshold stress intensity of about 20 MNm−3/2 above which the invariably intergranular stress corrosion cracks grow at a constant, stress independent velocity.
Abstract: This work presents the results of a comprehensive study concerning stress corrosion crack growth rates in steam turbine rotor steels exposed to hot water. The effects of stress intensity, temperature, and dissolved gases in the water have been investigated. Special attention has been given to the influence of impurities and alloying elements in the steel such as P, S, Mn, Si, Mo, and Ni, and to the effect of yield strength and fracture toughness on the growth rates of stress corrosion cracks. The results of this study clearly show that there exists a threshold stress intensity of about 20 MNm−3/2 above which the invariably intergranular stress corrosion cracks grow at a constant, stress-independent velocity. This plateau stress corrosion crack growth rate isnot affected by the oxygen and carbon dioxide concentration in the water. The temperature and the yield strength of the steel have a strong influence on the growth rate of stress corrosion cracks. In contrast, there isno effect of the steel composition within the range investigated, neither of the impurity elements such as P and S, nor of the major alloying elements such as Mn, Si, Mo, and Ni. Steels with low fracture toughness due to temper embrittlement do not exhibit faster stress corrosion crack growth rates in water than nonembrittled steels. No direct relationship between intergranular temper embrittlement and intergranular stress corrosion crack growth in water can be demonstrated.
39 citations
TL;DR: In this article, the effect of nitrogen in duplex stainless steels was investigated for resistance to pitting corrosion and stress corrosion cracking (SCC) in various environments, and it was shown that the increase in nitrogen content increases the resistance of the base metal, which results from the improvement in the resistances of the γ-phase, which has lower chromium and molybdenum contents compared to α-phase.
Abstract: The effect of nitrogen, which is one of the most important elements in duplex stainless steels (SSs), was investigated for resistance to pitting corrosion and stress corrosion cracking (SCC) in various environments. The increase in nitrogen content increases the resistance of the base metal, which results from the improvement in the resistance of the γ-phase, which has lower chromium and molybdenum contents compared to α-phase. Nitrogen is an important element in sustaining the corrosion resistance of the heat affected zone (HAZ), which is heated to 1350 C or higher, because nitrogen promotes the formation of γ-phase during the cooling process after welding and avoids the precipitation of chromium carbides or nitrides at grain boundaries. When the nitrogen content is less than 0.08% in 22%Cr, 5.5%Ni, and 3%Mo base composition, the HAZ has little -γ-phase to lead to the high susceptibility to intergranular corrosion and intergranular stress corrosion cracking (IGSCC) occurs even in a pure CO2-Cl− ...
TL;DR: In this article, the repassivation kinetics of AISI 304 austenitic stainless steel were studied in 0.5 M Na2SO4 solution, 1 M HCl solution and 1 M NaCl solution, at room temperature and at various electrode potentials.
01 Aug 1988-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, acoustic emission measurements have been made for anodic-dissolution, cathodic-hydrogen-and gaseous hydrogen-induced subcritical crack growth, and the results suggest that AE could potentially be useful for life prediction of components susceptible to environment-assisted crack growth.
Abstract: Acoustic emission (AE) measurements have been made for anodic-dissolution-, cathodic-hydrogen- and gaseous-hydrogen-induced subcritical crack growth. Measurements have been made on iron with segragated phosphorus and silicon, nickel with segregated phosphorus, type 304 stainless steel heat treated to produce high and medium degrees of sensitization and a tool steel. Intergranular fracture was the primary crack extension mode; however, the event rate per unit of crack extension correlated with the fraction of transgranular fracture. Emission from ligament fracture behind the advancing intergranular crack front is thought to be the source of the AE. These results suggest that AE could potentially be useful for life prediction of components susceptible to environment-assisted crack growth, although the results are very preliminary and need further substantiation.
TL;DR: In this paper, the transgranular stress corrosion cracking (TGSCC) of α-brass (Cu-30 Zn) in cupric ammonia solutions occurs by extremely localized ductile fracture.
TL;DR: In this article, the effect of both NaNO2 concentration (0.01-1.0 M) and solution pH (6.2-12.0) on SCC was evaluated.
TL;DR: In this paper, the transient anodic behavior of α-brass in sodium nitrite solution has been studied using scratching and rapid straining techniques, and the results show that the rapid-straining technique is inappropriate in this environment because the surface film on the brass undergoes a gross mechanical failure when strained.
TL;DR: In this paper, the authors evaluated the stress corrosion cracking behavior of the AlLi Alloy 8090 using the slow strain rate technique, and the alloy was exposed to 0.5 M NaCl under potentiostatic conditions.
Abstract: The stress corrosion cracking (SCC) behavior of the AlLi Alloy 8090 was evaluated using the slow strain rate technique. The alloy was exposed to 0.5 M NaCl under potentiostatic conditions....
TL;DR: In this paper, the data supplied by electrochemical methods such as potentiodynamic polarization curves and potentiostatic anodic transients show that in methanolic solution a region of unstable passivity for Armco iron and Ni-Cr-Mo low alloy steels results from the overlapping of certain ranges of solution composition.
TL;DR: In this article, the stress corrosion cracking susceptibilities of Alloy 600 and 690, AISI 316 NG stainless steel (SS), ASTM A508 carbon steel, and a number of compatible weld metals have been evaluated.
Abstract: The stress corrosion cracking (SCC) susceptibilities of Alloys 600 and 690, AISI 316 NG stainless steel (SS), ASTM A508 carbon steel, and a number of compatible weld metals have been evalu...
TL;DR: In this paper, the repassivation rate kinetics of α-brass in NaNO2 solutions of various concentrations, in borate buffered Na2SO4 solutions, and in sulphide-containing Na2 SO4 solutions were studied.
TL;DR: The carbon solubility, stress corrosion cracking (SCC) resistance, and microstructure of Inconel Alloy 690 was studied and compared to Alloy 600 in this article, showing that Alloy690 exhibited lower carbon-solubility than Alloy 600 and, after a high temperature/short time thermal treatment, displayed greater SCC resistance in 10% NaOH than Alloy600 which had been thermally treated at 1300 F (704 C).
Abstract: The carbon solubility, stress corrosion cracking (SCC) resistance, and microstructure of Inconel Alloy 690 was studied and compared to Alloy 600. Alloy 690 exhibited lower carbon solubility than Alloy 600 and, after a high temperature/short time thermal treatment, displayed greater SCC resistance in 10% NaOH than Alloy 600 which had been thermally treated at 1300 F (704 C) for 15 h.
TL;DR: A small punch (SP) testing apparatus using miniaturized specimens in high temperature and high pressure aqueous solutions was successfully developed to evaluate the resistance to stress corrosion cracking (SCC) and corrosion of candidate structural steels in water-coolant environment under irradiation as discussed by the authors.
TL;DR: In this paper, the corrosion behavior of iron-phosphorus alloys with 0.003-2 wt% phosphorus has been studied in nitrate and sulfate solutions.
TL;DR: A comprehensive overview of the present knowledge concerning stress corrosion crack growth rates is provided in this paper, where several sets of data confirm that ‘fast’ stress corrosion cracks with growth rates between 10−8 and 10−7 m/s and threshold stress intensities around 20 MN m − 3 2 can occur under certain conditions.
01 Jun 1988
TL;DR: In this paper, the effects of welding on the degradation modes of three austenitic alloys: Types 304L and 316L stainless steels and Alloy 825 are surveyed.
Abstract: This volume surveys the effects of welding on the degradation modes of three austenitic alloys: Types 304L and 316L stainless steels and Alloy 825. These materials are candidates for the fabrication of containers for the long-term storage of high-level nuclear waste. The metallurgical characteristics of fusion welds are reviewed here and related to potential degradation modes of the containers. Three specific areas are discussed in depth: (1) decreased resistance to corrosion in the forms of preferential corrosion, sensitization, and susceptibility to stress corrosion cracking, (2) hot cracking in the heat-affected zone and the weld zone, and (3) formation of intermetallic phases. The austenitic alloys are ranked as follows in terms of overall weldability: Alloy 825 (best) > Type 316L stainless steel > Type 304L stainless steel (worst). 108 refs., 31 figs., 7 tabs.
TL;DR: In this article, an extensive effort is underway to improve the understanding of IASCC and to mitigate the problem in the BWR by alloy impurity control and hydrogen water chemistry.
Abstract: Irradiation-assisted stress corrosion cracking (IASCC) is a form of intergranular stress corrosion cracking (IGSCC) that has occurred infrequently during the last two decades in in-core components of nonsensitized austenitic stainless steel. IASCC is apparently a time-dependent phenomenon, which does not manifest itself until a minimum residence time or threshold fast neutron fluence has been attained in an appropriate material/environment combination. Until now, IASCC has been observed in components that are readily removable, such as fuel rod and absorber tube cladding. The problem is being mitigated in the BWR by alloy impurity control. Hydrogen water chemistry is another highly promising remedy currently under qualification. An extensive effort is underway to improve our understanding of IASCC.
TL;DR: In this paper, the authors developed a stainless steel with superior resistance to intergranular stress corrosion cracking (IGSCC), intergranul corrosion (IGC), and pitting corrosion.
Abstract: As a part of a study to develop a stainless steel (SS) with superior resistance to intergranular stress corrosion cracking (IGSCC), intergranular corrosion (IGC), and pitting corrosion, an...
TL;DR: In this paper, stress corrosion cracking (SCC) and hydrogen-induced cracking (HIC) of AISI 321 stainless steel (SS) under Mode II loading were investigated with notched specimens.
Abstract: Stress corrosion cracking (SCC) and hydrogen-induced cracking (HIC) of AISI 321 stainless steel (SS) under Mode II loading were investigated with notched specimens. The results showed that...
TL;DR: In this article, the authors proposed to use high Cr and Mo ferritic stainless steels, or the two phase, or duplex, ferritic-austenitic steels.
Abstract: Conventional 18Cr–8Ni austenitic stainless steels have excellent resistance to corrosion in mildly aggressive environments, good mechanical properties, and are readily weldable. They are therefore used in a wide range of areas, including the food, petrochemical, and pharmaceutical industries. A major disadvantage to the use of austenitic stainless steels however is the drastically reduced resistance to pitting or crevice attack in aqueous environments containing chlorides. Furthermore, at temperatures above 65°C they are susceptible to failure from chloride stress corrosion cracking (SCC). Improvements in pitting or SCC resistance may be achieved by alloying additions, producing the high alloy austenitic stainless steels. Alternative solutions are to employ high Cr and Mo ferritic stainless steels, or the two phase, or duplex, ferritic–austenitic stainless steels. The choice of alloy depends on several factors, such as mechanical properties, economics, and weldability. The last property may be cri...
TL;DR: In an attempt to elucidate the mechanism of cracking for reactor pressure vessel (RPV) steels in high temperature water, slow strain rate tests (SSRTs) and polarization measurements have been conducted on a series of FeCMnX alloys, where X was either Cr, Ni, Mo, or Si as mentioned in this paper.
Abstract: In an attempt to elucidate the mechanism of cracking for reactor pressure vessel (RPV) steels in high temperature water, slow strain rate tests (SSRTs) and polarization measurements have been conducted on a series of FeCMnX alloys, where X was either Cr, Ni, Mo, or Si (typical alloying elements for RPV steels) and on some relevant commercial alloys The SSRTs were performed in 250 C water at a series of applied potentials On the criterion of the minimum potential at which cracking will occur, nickel and chromium retard cracking, whereas molybdenum enhances cracking The mechanism of cracking is discussed in terms of the maximum crack velocities observed and typical anodic current densities (CDs) observed in polarization studies The existing data suggests that the rate controlling mechanism for cracking is anodic dissolution at the crack tip, but that the observed crack growth rates might only be explained by the involvement of a significant contribution from mechanical tearing in the fracture p