Showing papers on "Stress corrosion cracking published in 1986"
TL;DR: In this article, a review of localized corrosion is presented by a consideration of the four steps involved in localized corrosion: adsorption of the reactive anion on the oxide covered aluminum; chemical reaction of the adsorbed anion with the aluminum ion in the aluminum oxide lattice or the precipitated aluminum hydroxide; thinning of the oxide by dissolution; and direct attack of the exposed metal by the anion, perhaps assisted by anodic potential.
Abstract: Localized corrosion, which usually appears as pitting, crevice corrosion (CC), or certain aspects of stress corrosion cracking (SCC), is a multi-step process. This review is organized by a consideration of the four steps involved in localized corrosion: (1) adsorption of the reactive anion on the oxide covered aluminum; (2) chemical reaction of the adsorbed anion with the aluminum ion in the aluminum oxide lattice or the precipitated aluminum hydroxide; (3) thinning of the oxide by dissolution; and (4) direct attack of the exposed metal by the anion, perhaps assisted by an anodic potential. The experimental work reported in the literature is evaluated within this framework.
279 citations
TL;DR: In this paper, the authors introduce the term strain-induced corrosion cracking (SICC) to describe crack formation involving dynamic straining, but in the absence of obvious, cyclic loading.
64 citations
TL;DR: In this article, scale cracking/healing maps have been developed characterizing the protective capabilities of the oxide scales under tensile strain and the existence of a critical strain rate below which crack healing leads to an instant repair of the cracked scale thuspreventing increased internal corrosion.
Abstract: The healing of cracks in protective oxide scales on four heat-resistant steels has been investigated at 800°C in constant-extension-rate tests, in metallographie and in SEM-examinations. The experimental results suggest the existence of a critical strain rate below which crack healing leads to an instant repair of the cracked scale thuspreventing increased internal corrosion. The existence of this critical strain rate can be explained by model considerations, the results of which are in agreement with the results from the experiments. On the basis of scale cracking data from a previous paper and healing data in the present paper “scale cracking/healing maps” have been developed characterizing the protective capabilities of the oxide scales under tensile strain.
56 citations
TL;DR: In this paper, an analogies in transgranular stress corrosion fracture were found among the three crystal systems reviewed, and it was shown that the slip system geometry has a determining effect on the orientation of the cracking plane.
48 citations
TL;DR: In this paper, the authors defined the functional relationship between the rate of crack growth, expressed as the crack volume strain, and uniaxial compressive stress and found that the traditionally used power and exponential relationships give good correlation for both crack velocity and volume strain rate.
Abstract: Rocks subjected to long-term loading have been known to suffer microcracking. The rate of cracking is sensitive to the type of the applied stress (tensile or compressive), and the magnitude of the stress relative to the instantaneous strength. In addition, crack growth is influenced by the environment (pressure and temperature) including the presence or absence of moisture. For tensile loading, the sensitivity of granite to time-dependent cracking is demonstrated through a fracture mechanics test known as double torsion. The crack velocity versus stress intensity function is established for two environments, room temperature and humidity and room temperature and 100 percent humidity. For compressive loading, time dependent cracking is evaluated from creep tests conducted in uniaxial compression in the same two environments. The rate of cracking is defined by finding the functional relationship between the rate of crack growth, expressed as the rate of crack volume strain, and uniaxial compressive stress. A variety of mathematical functions has been fitted to the obtained data. The traditionally-used power and exponential relationships give good correlation for both crack velocity and crack volume strain rate. The crack volume strain rate versus stress function can be integrated to obtain a lifetime estimate for Lac du Bonnet granite. After 1 000 years of loading in uniaxial compression at room temperature and 100 percent humidity, the strength of this granite could reduce from 225 MPa to 90–100 MPa.
44 citations
TL;DR: In this paper, the authors presented a study of corrosion and stress corrosion cracking of Alloy 600, and the primary purpose of this work is to relate the corrosion susceptibility of the alloy after var...
Abstract: This paper presents a study of corrosion and stress corrosion cracking (SCC) of Alloy 600. The primary purpose of this work is to relate the corrosion susceptibility of the alloy after var...
44 citations
TL;DR: In this paper, the effects of aging treatments on the stress corrosion cracking behavior of Fe8.7Al-29.7Mn-1.04C alloy is discussed.
44 citations
TL;DR: In this article, the authors investigated the dissolution-repassivation behavior of AISI 304 stainless steel (SS) in 42% MgCl2 at 143 C using a straining electrode technique at different potentials.
Abstract: Dissolution-repassivation behavior of AISI 304 stainless steel (SS) in 42% MgCl2 at 143 C was investigated using a straining electrode technique at different potentials. Dissolution curren...
41 citations
TL;DR: In this article, the authors investigated the stress corrosion cracking behavior of the duplex Fe-10 Al-29 Mn-0.4 C alloy having two phases (α andγ) in an aqueous 20% NaCl solution.
Abstract: The stress corrosion cracking behaviour of the duplex Fe-10 Al-29 Mn-0.4 C alloy having two phases (α andγ) in an aqueous 20% NaCl solution (100° C) has been investigated using both the static constant load and dynamic slow strain rate tests. The constant load test shows that the duplex alloy investigated is immune to stress corrosion cracking in a 20% NaCl solution. However, the slow strain-rate test reveals that this alloy is susceptible to stress corrosion cracking at the stabilized corrosion potential, and also at potentials anodic and cathodic to this potential. Furthermore, the metallographic cross section of this duplex alloy after slow strainrate testing shows that the secondary cracks propagate transgranularly through the ferrite grains at and above the stabilized corrosion potential. However, the cracks propagate transgranularly in both the ferrite and austenite grains and also at the austenite-ferrite grain boundaries when the applied potential is cathodic to the stabilized corrosion potential.
37 citations
TL;DR: In this article, the authors investigated the effectiveness of the heat-sink welding (water cooling) by conducting theoretical analyses and experiments on SUS 304 pipes of different sizes in comparison with the conventional welding.
Abstract: Intergranular stress corrosion cracking may occur in some specific conditions on the inner surface of the welded joints of stainless steel pipes which are furnished in nuclear plants. One of the remedies for this cracking is to convert welding residual stress on this surface into compression. In this research, in order to improve welding residual stress, the authors investigated the effectiveness of the heat-sink welding (water cooling) by conducting theoretical analyses and experiments on SUS 304 pipes of different sizes in comparison with the conventional welding. The mechanisms of production of residual stresses by both methods are clarified and conditions for effective application of the heat-sink welding such as limitation of heat input, procedure of welding are indicated.
34 citations
TL;DR: Alloy 690 exhibited the greatest resistance to SCC of the two alloys, and alloy 600 was immune to IGSCC under all pure water conditions examined, while alloy 690 were both susceptible to cracking in the simulated resin intrusion environment.
Abstract: The relative susceptibilities of alloys 600 and 690 to intergranular stress corrosion cracking (IGSCC) in pure water and a simulated resin intrusion environment at 288 °C were evaluated. A combination of creviced and noncreviced slow-strain-rate, and precracked fracture mechanics tests were employed in the evaluation. Susceptibility was determined as a function of dissolved oxygen content, degree of sensitization, and crevice condition. The results indicated that alloy 600 was susceptible to various degrees of IGSCC in oxygen containing pure water when creviced, and immune to IGSCC when uncreviced. Alloy 690 was immune to IGSCC under all pure water conditions examined. Alloy 600 and alloy 690 were both susceptible to cracking in the simulated resin intrusion environment. Alloy 690, however, exhibited the greatest resistance to SCC of the two alloys.
TL;DR: The flexural strength of mortar specimens in sulfate-solutions has been found to depend significantly on the external load being applied during the sulfate solution exposure of the specimens.
TL;DR: A representative selection of these newer grades is characterised according to crevice corrosion resistance, stress corrosion cracking resistance, and field application experience as mentioned in this paper, and a representative selection is presented in Table 1.
TL;DR: In this article, the effects of heat treatment, carbon content, and microstructure on the resistance of Inconel Alloy 690 to stress corrosion cracking (SCC) under caustic conditions were studied.
Abstract: The effects of heat treatment, carbon content, and microstructure on the resistance of Inconel Alloy 690 to stress corrosion cracking (SCC) under caustic conditions were studied. The resul...
01 Jan 1986
TL;DR: In this paper, the authors presented the papers given at a conference on the corrosion of metals, which included the corrosion properties of low alloy steel in crude oil/brine/CO/sub 2/ mixtures, passive film formation on metals in thionyl chloride electrolytes for lithium batteries and surface chemical processes of clean lithium.
Abstract: This book presents the papers given at a conference on the corrosion of metals. Topics considered at the conference included the corrosion of low alloy steel in crude oil/brine/CO/sub 2/ mixtures, passive film formation on metals in thionyl chloride electrolytes for lithium batteries, surface chemical processes of clean lithium, corrosion reactions relevant to lithium-sulfur batteries, the growth and breakdown of passive films on metal surfaces, and the initiation of stress corrosion cracking of sensitized type 304 stainless steel.
TL;DR: In this paper, the SCC behavior of Fe-8.7 Al-29.7 Mn-1.04C alloy in a 20% sodium-chloride solution (100°C) has been investigated by the slow strain rate method.
Abstract: The SCC behavior of Fe-8.7 Al-29.7Mn-1.04C alloy in a 20% sodium-chloride solution (100°C) has been investigated by the slow strain rate method. The results showed that the alloy was susceptible to SCC only at the free corrosion potential and at the applied strain rate of 2.8 × 10−7/s. Application of the cathodic potential during the slow strain rate test resulted in the loss of ductility in the alloy which was attributed to the hydrogen induced cracking.
Spannungsriskorrosion von austenitischen FeAlMn-Legierungen in Chloridlosungen
Das Spannungsriskorrosionsverhalten der Legierung Fe-8, 7 Al-29, 7 Mn-1,04 C in 20%iger Natriumchloridlosung von 100°C ist mit Hilfe der „slow strain rate”-Methode untersucht worden. Die Ergebnisse zeigen, das die Legierung bei der Dehngeschwindigkeit 2,8 · 10−7s nur am freien Korrosionspotential anfallig fur Spannungsriskorrosion ist. Im kathodischen Potentialbereich trat unter den Versuchsbedingungen ein Duktilitatsverlust auf, welcher der wasserstoffinduzierten Risbildung zugeschrieben wurde.
Patent•
31 Mar 1986
TL;DR: In this article, a low-alloy steel with excellent stress corrosion cracking resistance is described, which is based on the nickel-chrome-molybdenum (NCCM) alloy.
Abstract: The present invention relates to low alloy steel and specifically to nickel-chrome-molybdenum steel A low alloy steel having excellent stress corrosion cracking resistance containing C : ≦ 040 %, Si : ≦ 015 %, Mn : ≦ 020 %, P : ≦ 0010 %, S : ≦ 0030%, Ni : 050 to 400 %, Cr : 050 to 250 %, Mo : 025 to 400 % and V : ≦ 030 %, said Si, Mn and P being fulfilled with relationship of Si + Mn + 20P ≦ 030 %, the remainder comprising Fe and unavoidable impurities, the prior austenite crystal grain size being in excess of 4 of ASTM crystal grain size number
Patent•
25 Apr 1986
TL;DR: In this article, the authors proposed a method to produce the title oil-well steel at low cost by incorporating a specified combination of Mn, P, and Mo into steel having a specified composition, hot-working and then hardening the steel, and then tempering the steel.
Abstract: PURPOSE: To produce the title oil-well steel at low cost by incorporating a specified combination of Mn, P, and Mo into steel having a specified composition, hot-working and then hardening the steel, and then tempering the steel. CONSTITUTION: The steel contg., by weight, 0.10W0.35% C, ≤0.35% Si, ≤0.005% S, 0.01W0.10% Nb, 0.2W1.5% Cr, ≤0.008% N, ≤0.028% Ti, where -0.005% ≤Ti-3.4N≤0.01%, 0.01W0.10% Al, 0.0007W0.0020% B, ≥0.1% Mo, Mn, P, and the Mo in the ratio so that the yield strength δc obtained by the equation is made higher than the actually desired yield strength YS, and the balance iron is refined. The steel is hot-worked into the desired shape. The steel material is austenitized at a temp. from (Ac 3 point + 20°C) to 1,020°C, and then hardened to obtain the material having ≥90% martensite. The steel material is subsequently tempered at a temp. from 560°C to the Ac 1 point. COPYRIGHT: (C)1987,JPO&Japio
TL;DR: In this article, the effect of P and S on the intergranular corrosion and stress corrosion of Ni has been evaluated with corrosion tests, crack tip corrosion modeling, and modeling.
Abstract: The effect of P and S on the intergranular corrosion and stress corrosion of Ni has been evaluated with corrosion tests, crack tip corrosion modeling and stress corrosion tests, and modeling. Tests were conducted in I N H2SO4 at 25 °C over anodic potentials of +0.3 V to 2.0 V (SCE). Corrosion tests were conducted on Ni + P and Ni + S alloys and Ni samples ion implanted with P and S. The corrosion results showed that both P and S reduce passivity in Ni and enhance the corrosion rate but that P is oxidized and dissolves in the electrolyte while S remains on the surface. This difference in surface behavior of P and S was used to explain the difference in intergranular corrosion (IGC) and inter-granular stress corrosion cracking (IGSCC) behavior of Ni + P and Ni + S. The active crevice and crack walls with Ni + S is thought to reduce the concentration gradient and hence the transport of Ni+2 from tip to mouth which in turn reduces the crack tip corrosion rate. By comparison of the geometry, potential dependence and rates of IGC and IGSCC of Ni + P it was concluded that IGSCC was not controlled solely by anodic dissolution but that a mechanical contribution was involved. Strain assisted corrosion was ruled out while a corrosion assisted intergranular fracture process was shown to be feasible.
TL;DR: In this article, slow strain rate tests were conducted on solution annealed and sensitized AISI 304 stainless steels with varying nitrogen and carbon contents to study their susceptibility to stress corrosion cracking (SCC).
Abstract: Slow strain rate tests (SSRTs) were conducted on solution annealed and sensitized AISI 304 stainless steels (SSs) with varying nitrogen and carbon contents to study their susceptibility to stress corrosion cracking (SCC). The tests were conducted in deaerated 0.1 M Na2SO4 at 250 C at a strain rate of 2×10−6/s and an applied potential of 0 VH. For the sensitized SS containing 0.05 wt% carbon, susceptibility to intergranular stress corrosion cracking (IGSCC) decreased with nitrogen additions up to ∼ 0.16 wt%. Scanning electron microscopy (SEM) showed that a transition from IGSCC to transgranular stress corrosion cracking (TGSCC) occurred at greater nitrogen contents. Potentiodynamic polarization curves measured in the above environment were identical for both the solution annealed and sensitized conditions, but the latter showed slightly greater current densities (CDs). Nitrogen additions had no influence on anodic polarization characteristics. No changes were noted in the polarization curves, whic...
TL;DR: In this article, the process of stress corrosion cracking was studied in a range of six commercial hardwood species and four standard types of sawblade steel, and the combined effects of corrosion and wear of these steels produced an average loss of material of 5 g/m2/h in weight and 0.001 mm/H in thickness.
Abstract: The process of stress corrosion cracking was studied in a range of six commercial hardwood species and four standard types of sawblade steel. The combined effects of corrosion and wear of these steels produced an average loss of material of 5 g/m2/h in weight and 0.001 mm/h in thickness. The interaction between timber species and types of steel was significant at the 0.1% probability level. Timbers and steels were ranked by Duncan's multiple-range test according to their corrosion properties, which differed at the 5% probability level. Such a classification of sawblade steels and timbers has an immediate, practical use.
TL;DR: In this paper, a large program was performed to evaluate crack growth at representative environmental conditions for both conventional and vacuum deaeration startup practices, and five alloys were studied: types 304 and 316 nuclear grade stainless steel, Inconel 600, carbon steel, and A508-2 low alloy steel.
Abstract: During startup of a boiling water reactor (BWR), the water chemistry and temperature are constantly changing. Special operational practices can be performed to control the dissolved oxygen level using, for example, vacuum deaeration. To assess the impact of startup practice on environmental cracking in the structural materials used in the BWR, a large program was performed to evaluate crack growth at representative environmental conditions for both conventional and vacuum deaeration startup practices. Five alloys were studied: types 304 and 316 nuclear grade stainless steel, Inconel 600, carbon steel, and A508-2 low alloy steel. Tests were performed using fracture mechanics type specimens with constant load crack growth measured at appropriate stress intensity levels. The program intent was to compare the crack growth rates for the two practices. The results show that normal startup and startup deaeration environments had varied effects. Sensitized type 304 stainless steel exhibited a decrease in crack growth rate and concomitant decrease in severity of intergranular fracture morphology at the low temperatures under deaeration. In contrast, the type 316 nuclear grade displayed very little influence of startup deaeration due to its inherent resistance to stress corrosion cracking. Inconel 600 showed up to a factor of five reduction inmore » crack growth rate in the deaeration environment.« less
TL;DR: In this paper, it was shown that if a transport process is provided for the iodide to obtain access to the zirconium surface, CsI is capable of causing SCC of Zircaloy fuel cladding.
TL;DR: In this article, the authors compare the practical utility of both the slow strain rate (SSR) and reverse U-bend (RUB) techniques and propose an accelerated, sensitive technique enabling accurate evaluation of the IGSCC susceptibility and life expectancy of Alloy 600 tubing in high temperature water with and without hydrogen gas.
Patent•
17 May 1986
TL;DR: In this paper, the authors proposed a method to improve the resistance to stress corrosion cracking under the environment contg. H2S, CO2, Cl ions, or the like by composing the inside material and the outside material, of a welded clad steel pipe for a line pipe, of, respectively, Ni-Cr high alloy steel and Mn-contg. low alloy steel.
Abstract: PURPOSE:To improve the resistance to stress corrosion cracking under the environment contg. H2S, CO2, Cl ions, or the like, by composing the inside material and the outside material, of a welded clad steel pipe for a line pipe, of, respectively, Ni-Cr high alloy steel and Mn-contg. low alloy steel. CONSTITUTION:In manufacturing the welded clad steel pipe which is to be used under the environment exposed to petroleum, natural gas, or the like, contg. corrosive components such as wet H2S, CO2, Cl ions, or the like, while it is still in the same state as is welded at the pipe manufacture stage, the inside and the outside materials of the pipe are composed of high alloy steel and low alloy steel, respectively: the high alloy steel consists of =40% and 2%<=Mo+0.5W<=5%; the low alloy steel consists of 0.02-0.25% C, 0.01-1% Si, 0.5-2.5% Mn, <0.025% P, <0.015% S, and <0.1% sol.Al, or further contains specified small amounts of Cu, Cr, Ni, Mo, Nb, V, Ti, and B.
Patent•
07 Jul 1986
TL;DR: In this paper, a process for improving resistance of control rod guide tube split pins in nuclear reactors to stress corrosion cracking was proposed, comprising heating the split pin to a critical elevated temperature level, cooling at least the surface portions of the split subject to corrosion cracking and then permitting the splitpin to come to ambient temperature.
Abstract: A process for improving resistance of control rod guide tube split pins in nuclear reactors to stress corrosion cracking comprising heating the split pin to a critical elevated temperature level, cooling at least the surface portions of the split subject to stress corrosion cracking and then permitting the split pin to come to ambient temperature.
TL;DR: In this paper, the authors determined the dislocation density in the surface layer and dislocation densities in the interior of Naval brass at a rate of 10 −5 s −1 in 0.1 M CuSO 4.
TL;DR: In this article, the threshold stress intensities for stress corrosion cracking (SCC) and hydrogen induced cracking (HIC) under modes III and I loading were measured and compared and it was found that both SCC and HIC under Mode III loading initiated and propagated on the planes inclined at 45 deg to the notch plane, differing from that under Mode I loading.
Abstract: Stress corrosion cracking (SCC) of high-strength steel in aqueous environment and hydrogen induced cracking (HIC) during dynamic charging under Mode III loading were investigated. The threshold stress intensities for SCC and HIC under Modes III and I were measured and compared. It was found that both SCC and HIC under Mode III loading initiated and propagated on the planes inclined at 45 deg to the notch plane, differing from that under Mode I loading. The fracture surfaces, however, revealed intergranular facets, similar to that under Mode I loading. The addition of thiourea decreased the threshold value for SCC under Mode III and Mode I loading, which was still higher than that for dynamic charging. The threshold values of both SCC and HIC under Mode III were larger than that under Mode I,i.e., KIIIH> KIH, KIIISCC > KISCC. Based upon the fracture mechanics analysis, this difference is attributed to the different equilibrium hydrogen concentration between Modes III and I loading. These results give strong evidence that the SCC mechanism in high strength steel under Mode III loading is also related to hydrogen induced cracking.