Showing papers on "Stress corrosion cracking published in 1993"
TL;DR: In this article, the evolution of mechanical properties in austenitic stainless steels during irradiation is reviewed and the effects of irradiation on fatigue appear to be modest except at high temperature where helium embrittlement becomes important.
362 citations
TL;DR: In this paper, a critical evaluation of mechanistically based modelling of environment-assisted cracking has been made, namely slip-dissolution, anodic reaction-induced cleavage and surface mobility, from both a mechanistic and quantitative perspective.
163 citations
TL;DR: The linearly increasing stress test (list) as discussed by the authors is a load-controlled version of the CERT test, with the essential difference that the list test is load controlled whereas the Cert test is displacement-controlled.
Abstract: This paper presents a new testing apparatus for stress corrosion research. In this linearly increasing stress test (LIST) method, plain un-notched specimens are simultaneously exposed to an environment and subjected to an applied stress increasing linearly at a controlled rate. Experiments are repeated at various applied stress rates and the parameters measured include SCC initiation stress (the stress at which stress corrosion cracks start to propagate), fracture stress and average crack velocity. The LIST test is similar to the constant extension rate test (CERT) test, with the essential difference that the LIST test is load-controlled whereas the CERT test is displacement-controlled. The LIST test is particularly aimed at service conditions of loaded parts and structures; that is, service conditions described as load-controlled. This paper describes the design, construction and operation of the test apparatus and some typical results are given to illustrate its performance. Experiments have been conducted using as-quenched 3.5Ni-Cr-Mo-V turbine rotor steel specimens in aerated distilled water at 90 degrees C at stress rates varying from 0.00034 MPa s-1 to 2.08 MPa s-1.
99 citations
TL;DR: In this paper, Thiosulfate ion was used as a substitute for hydrogen sulfide (H2S) to simulate stress corrosion cracking (SCC) of corrosion-resistant alloys (CRAs) and sulfide stress cracking (SSC) of high-strength, low-alloy steels.
Abstract: Thiosulfate ion was used as a substitute for hydrogen sulfide (H2S) to simulate stress corrosion cracking (SCC) of corrosion-resistant alloys (CRAs) and sulfide stress cracking (SSC) of high-strength, low-alloy steels. Several SCC tests using a variety of stress application techniques showed the brine containing thiosulfate exhibited similar severity to brine containing H2S in regard to SCC when plastic strain was applied to the CRAs. Materials that exhibited SCC susceptibility in brine containing thiosulfate agreed well the SCC susceptibility of those in brine containing H2S. Types 304 (UNS S30400) and 316L (UNS S31603) stainless steels and duplex stainless steel exhibited in both environments. However, high-nickel austenitic alloys such as alloys 904L (UNS N08904) and 825 (UNS N08825) did not. A 10−3 to 10−2 mol/l S2O32− addition in 20% NaCl aqueous solution at 353 K corresponded to H2S of 0.1 to 1 MPa at 473 K. The SSC susceptibilities of high-strength, low-alloy steels in a 10−3 mol/l S2O32− ...
80 citations
01 Jan 1993
76 citations
TL;DR: In this paper, a transgranular stress corrosion cracking (TGSCC) was reported in aqueous 0.21 M K2 CrO4 containing 0.6M NaCl at displacement rates between 5 × 10−5 and 9 × 10 −3 mm s−1.
71 citations
TL;DR: In this article, the effects of small-amplitude cyclic loading on threshold stress, together with the increase of crack nucleation and the decrease of average crack growth rates with increasing test times, were studied in a range of pipeline steels immersed in a carbonate-bicarbonate solution.
Abstract: Stress corrosion cracking (SCC) characteristics of a range of pipeline steels immersed in a carbonate-bicarbonate solution were studied in terms of the deleterious effects of small-amplitude cyclic loading on threshold stress, together with the increase of crack nucleation and the decrease of average crack growth rates with increasing test times. Data were reported on conditions for coalescence or otherwise of adjacent cracks in terms of spatial separation. The time dependence of crack nucleation rates and crack growth in laboratory tests varied with stress. The laboratory rates for crack nucleation and growth likely are applicable in high-pressure gas transmission pipelines in service, but values of the constants in the power law expressions for those rates differed for service conditions. The data showed service condition calculations can be guided by empirically assigning ranges of values for the constants by imposing boundary conditions that relate to service experience. Ranges of values also...
67 citations
TL;DR: In this article, the authors present experimental results from the Linearly Increasing Stress Test (LIST) applied to the stress corrosion cracking (SCC) of as-quenched 4340 and 3.5NiCrMoV turbine rotor steel in aerated distilled water at 90°C.
59 citations
TL;DR: The surface mobility stress-corrosion cracking mechanism is based on the assumption that environmentally induced crack propagation is due to the capture of vacancies by the stressed lattice, at the tip of the crack as discussed by the authors.
50 citations
TL;DR: In this article, the compressive forces generated by voluminous grain boundary corrosion products were investigated by measuring the forces of under-aged, over-aged and peak-aged aluminum-lithium (Al-Li) alloy 8090 (UNS A98091) in plate and sheet form.
Abstract: Exfoliation of aluminum-lithium (Al-Li) alloy 8090 (UNS A98091) in plate and sheet form was studied by measuring the compressive forces generated by voluminous grain boundary corrosion products. The forces were shown to be related closely to grain shape, with more elongated microstructures generating higher forces. Aging treatment of the alloy also was a factor. Corrosion product forces were ranked in the order: under-aged > over-aged > peak-aged. High susceptibility of the over-aged temper in 8090 differed from that of conventional, precipitation-hardened Al alloys and was attributed to the formation of anodic phases in the Li-containing material. Stress corrosion tests were performed on the plate using double-cantilever beam specimens. The sheet was tested under constant load in the through-thickness direction. KISCC values, the limiting values of stress intensity for stress corrosion to occur, were compared with the maximum corrosion product forces and supported the proposition that exfoliatio...
49 citations
TL;DR: In this article, a research program has been undertaken to determine the origins of irradiation-assisted stress corrosion cracking (IASCC) in austenitic alloys in light water reactors, and the effect of impurities on IASCC susceptibility.
TL;DR: In this paper, microscopic fatigue crack propagation (FCP) paths in peak-aged unrecrystallized alloy 2090 are identified as functions of intrinsicda/dN- δK kinetics and environment, and a hydrogen embrittlement mechanism is supported by similar brittle crack paths for low pressure water vapor and the electrolyte, the SGC and 100/110 crystallographic cracking modes, the influence of cyclic plastic zone volume (δK), and the benignancy of O2.
Abstract: Microscopic fatigue crack propagation (FCP) paths in peak-aged unrecrystallized alloy 2090 are identified as functions of intrinsicda/dN- δK kinetics and environment. The FCP rates in longitudinal-transverse (LT)-oriented 2090 are accelerated by hydrogen-producing environments (pure water vapor, moist air, and aqueous NaCl), as defined in Part I. Subgrain boundary cracking (SGC) dominates for δK values where the cyclic plastic zone is sufficient to envelop subgrains. At low δK, when this crack tip process zone is smaller than the subgrain size, environmental FCP progresses on or near 100 or 110 planes, based on etch-pit shape. For inert environments (vacuum and He) and pure O2 with crack surface oxidation, FCP produces large facets along 111 oriented slip bands. This mode does not change with δK, and T1 decorated subgrain boundaries do not affect an expectedda/dN- δK transition for the inert environments. Rather, the complex dependence ofda/dN on δK is controlled by the environmental contribution to process zone microstructure-plastic strain interactions. A hydrogen embrittlement mechanism for FCP in 2090 is supported by similar brittle crack paths for low pressure water vapor and the electrolyte, the SGC and 100/110 crystallographic cracking modes, the influence of cyclic plastic zone volume (δK), and the benignancy of O2. The SGC may be due to hydrogen production and trapping at T1 bearing sub-boundaries after process zone dislocation transport, while crystallographic cracking may be due to lattice decohesion or hydride cracking.
TL;DR: In this paper, the effects of coarsening of porosity within dealloyed layers have been investigated from the viewpoint of the film-induced cleavage model of SCC.
TL;DR: In this article, the effect of heat treatment on the sensitization and SCC behavior of Alloy 600 and Alloy 690 was studied to understand how heat treatment affects the sensitivity of these alloys.
TL;DR: The isothermal time-temperature-sensitization diagrams of two nitrogen containing austenitic-type stainless steels (SS) namely 316 LN-B (0.019 C, 0.16 N) and 316 L N-C (0,027 C,0.19 N) have been established as mentioned in this paper.
Patent•
22 Jan 1993
TL;DR: In this paper, a steel pipe is subjected to accelerated cooling to complete its bainitic transformation, is heated in the temp. and is thereafter tempered at the Ac1 transformation point or below.
Abstract: PURPOSE:To produce a high strength steel pipe excellent in sulfide stress corrosion cracking resistance by forming a steel pipe in such a manner that the componental compsn. and seamless rolling temp. are specified, completing its bainitic transformation and executing hardening and tempering at specified temps. CONSTITUTION:A billet contg., by weight; 0.15 to 0.4%, C, 0.1 to 1% Si, 0.3 to 1% Mn, 0.1 to 1.5% Cr, 0.1 to 1% Mo, =two kinds among 0.01 to 0.05% Nb, 0.01 to 0.5% V and 0.01 to 0.03% Ti, and the balance Fe with inevitable impurities is subjected to seamless rolling so as to regulate the final finish temp. into the recrystallization temp. + or -50 deg.C and is worked into a steel pipe. This steel pipe is subjected to accelerated cooling to complete its bainitic transformation, is heated in the temp. range of the Ac3 transformation point (790 to 830 deg.C) to the Ac3 transformation point+<100 deg.C, is hardened from the same temp. and is thereafter tempered at the Ac1 transformation point or below.
TL;DR: In this article, pre-exposure tests on unstressed specimens of IMI 125 (lowoxygen, commercially pure titanium) in MeOH/HCl solutions revealed that intergranular anodic dissolution was occurring.
TL;DR: In this article, the effect of chromium, phosphorus, silicon and sulfur on the stress corrosion cracking of 304L stainless steel in CERT tests in high purity water or argon at 288°C following irradiation with 3.4 MeV protons at 400°C to 1 dpa, has been investigated using ultrahigh purity alloys (UHP) with controlled impurity additions.
TL;DR: In this paper, the authors investigated the stress corrosion cracking (SCC) behavior of two high nitrogen steels, P900 and P900N, in 1 wt% NaCl solution under an applied potential condition.
TL;DR: In this paper, the authors investigated the SCC susceptibility of type 304 and type 316 stainless steels as a function of chloride ion concentration in 0.82 kmol m −3 pure sulfuric acid solution at 353 K under a constant stress of 392 MPa.
TL;DR: In this article, a small diameter pipe is welded to a plate and TIG cladding is melted on the inner surface of the pipe to protect it from stress corrosion cracking due to environmentally-induced changes in nuclear power plant components.
Patent•
17 Dec 1993
TL;DR: In this paper, the fabrication of components from a face centered cubic alloy, wherein the alloy is cold worked and annealed, is carried out in a number of separate steps, each step being followed by an annealing step.
Abstract: In the fabrication of components from a face centered cubic alloy, wherein the alloy is cold worked and annealed, the cold working is carried out in a number of separate steps, each step being followed by an annealing step. The resultant product has a grain size not exceeding 30 microns, a 'special' grain boundary fraction not less than 60 %, and major crystallographic texture intensities all being less than twice that of random values. The product has a greatly enhanced resistance to intergranular degradation and stress corrosion cracking, and possesses highly isotropic bulk properties.
TL;DR: In this article, the corrosion behavior of commercial austenitic stainless steels and nickel-based alloys in 38wt% KOH solutions was investigated between 120° and 180°C under hydrogen and oxygen overpressure.
TL;DR: In this paper, the effects of heat treatment and applied potential on the stress corrosion cracking (SCC) behavior of Alloy 600 in thiosulfate solution were investigated, and it was shown that the susceptibility of IGSCC was strongly affected by the applied potential.
TL;DR: In this paper, the authors investigated the mechanism of stress corrosion cracking (SCC) of Cu-30Au in 0.6 M NaCl and showed that de-alloying at zero applied stress produces a surface layer that is capable for a brief period of time of inducing intergranular cleavage failure of the normally ductile substrate.
TL;DR: In this paper, a mathematical model relating deformation to electrochemical behaviors of metals in aqueous solution has been developed based upon principles of holographic interferometry for measuring microscopic deformation and of electrochemistry for measuring the corrosion of metals, i.e., anodic dissolution current.
Abstract: A mathematical model relating deformation to electrochemical behaviors of metals in aqueous solution has been developed. The model was established based upon principles of holographic interferometry for measuring microscopic deformation and of electrochemistry for measuring the corrosion of metals, i.e., anodic dissolution current. The model can be used to calculate the stress corrosion of metals under a constant load or displacement in a polarized or unpolarized condition. The current density of metals can be calculated as a function of imposed deformations. The model was used to calculate the stress corrosion behavior of a nickel electrode under a constant load in 1 N H2SO4 solution. The calculation was based on a hypothetical optical arrangement of the holographic interferometry as well as on empirical parameters of Ni electrochemistry in the solution. The study was successful in developing an experimental technique for investigating the influence of deformation on corrosion. The development o...
Patent•
17 Dec 1993
TL;DR: In manufacturing a component from a face-centered cubic alloy is the alloy is cold worked and annealed, and cold working is carried out in several separate steps, each step is the follow-up by the annealing step.
Abstract: In manufacturing a component from a face-centered cubic alloy is the alloy is cold worked and annealed, and cold working is carried out in several separate steps, each step is the follow-up by the annealing step. The resulting product does not exceed 30 microns in particle size, both the organization than twice the strength of not less than 60% "special" mouth precepts, and a random value has a smaller major crystallographic tissue strength. The product has a significantly improved resistance to stress corrosion cracking and reduced material between particles, and has a high isotropic overall.
01 Jan 1993
TL;DR: In this paper, preliminary results of ongoing crack growth studies being performed on an API X-65 line pipe steel in a low-pH cracking environment were reported, and the objectives were to reproduce low pH crack growth.
Abstract: Preliminary results of ongoing crack growth studies being performed on an API X-65 line pipe steel in a low-pH cracking environment were reported. Objectives were to reproduce low-pH crack...
TL;DR: In this article, the effects of hydrogen precharge and stress on anodic dissolution for Type 310 austenitic stainless steel (ASS) have been investigated, and the results showed that both hydrogen and stress would increase the dissolution rate.
Abstract: The effects of hydrogen precharge and stress on anodic dissolution for Type 310 austenitic stainless steel (ASS) have been investigated. An experiment determining the effect of hydrogen on stress corrosion cracking (SCC) was carried out in a boiling 42 pct MgCl2 solution and in a 2.5 mo/L H2SO4 + 1 mol/L HC1 solution. The results showed that both hydrogen and stress would increase the dissolution rate, and the effects of hydrogen and stress on the dissolution rate were synergistic rather than simply additive. Hydrogen lowered the threshold stress and the shortened fracture time of SCC in a boiling MgCl2 solution by a factor of 1/5 and 10, respectively.