Stress Corrosion Cracking Of Stainless Steels Research Articles

Detection and imaging of stress-corrosion cracking in stainless steel using the linear elastodynamics gradient imaging technique

Linear Elastodynamics Gradient Imaging Technique (LEGIT) is a nondestructive testing technique recently developed to image cracks on the surface of samples. This technique is based on the interaction of an acoustic wave with a crack and the resulting discontinuity in the acoustic wave field such an interaction generates. LEGIT is used to image stress-corrosion cracks in two samples of 304 stainless steel. The first sample is relatively small (50 × 25 × 1.4 mm3) with two mm-size cracks. For this sample, the acoustic source is glued to the sample. The second sample is much larger (180 × 76 × 25.4 mm3), has a curvature, a weld, and multiple cracks running parallel to and across the weld. The imaging of the cracks for this more complex sample is achieved without contact by partial immersion using an underwater acoustic transducer. Imaging data obtained from LEGIT in the two experiments show excellent agreement with a vibro-thermography.

Austenitic Stainless-Steel Reinforcement for Seawater Sea Sand Concrete: Investigation of Stress Corrosion Cracking

Seawater and sea sand concrete (SWSSC) is a highly attractive alternative to normal concrete (NC) that requires huge amounts of fresh water and river sand. However, reinforcements of stainless steel (instead of mild steel that is used in NC) may be required for SWSSC. This article reports investigation of stress corrosion cracking (SCC) of AISI 316 stainless steel (SS) in simulated SWSSC and NC environments, with and without addition of silica to SWSSC and NC, employing slow strain rate testing (SSRT) at 25 and 60 °C. For the purpose of comparison, SCC of SS was also investigated in simulated seawater (SW) solution. SS showed no SCC at 25 °C in any of the test solutions. Indications of SCC were seen in SW at 60 °C, but no features of SCC in SWSSC and NC at 60 °C, as suggested by scanning electron microscopy (SEM) fractographs. While the absence of SCC in SWSSC and NC is attributed to the highly passivating alkaline condition, its absence in SWSSC also indicates the role of alkalinity to predominate the deleterious role of chloride content of SWSSC. However, the addition of silicate to SWSSC or NC triggers transgranular SCC to SS at 60 °C, as evidenced by the fractography.

Time reversed elastic nonlinearity diagnostic applied to stress corrosion cracking in stainless steel

The Time Reversed Elastic Nonlinearity Diagnostic (TREND) is an inspection technique that enables one to locate damage in a structure using time reversal processing. TREND has been used to detect various types of damage in metals and rocks, but little has been done specific to stress corrosion cracking (SCC) other than the work of Anderson et al. J. Acoust. Soc. Am. 141, EL76–EL81 (2017). SCC in stainless steel, especially around welds, is produced as a result of elevated temperature and saline conditions, and so has different properties from fatigue cracking or delaminations, both of which have been studied with TREND. In current research, welded steel samples exposed to a magnesium chloride bath were created. A number of samples were exposed for successively longer durations in order to study the corrosion damage level versus exposure time. Using TREND, samples were scanned then evaluated for indicators of local cracking at each scan point. Specific changes in spectral characteristics that are indicator...

Inspection of stress corrosion cracking in welded stainless steel pipe using point-focusing electromagnetic-acoustic transducer

Point-focusing electromagnetic-acoustic transducers (PF-EMATs) for shear-vertical (SV) waves were developed for crack inspection of stainless-steel pipes. The transducer has improved defect detectability by accumulating SV waves generated by concentric line sources at a focal point in phase. An optimum frequency for defect detection was found to be 2MHz, with which a crack of 0.5mm depth near a weld was clearly detected. The EMAT exhibited defect detectability comparable to that of a conventional phased-array piezoelectric transducer, indicating that this new EMAT is highly practical for the non-contacting evaluation of stress-corrosion cracking in stainless steels.

Effect of Potential on Stress Corrosion Cracking of 321 Stainless Steel under Marine Environment

Slow strain rate test (SSRT) applied with different potential was adopted to investigate the stress corrosion cracking (SCC) sensibility of stainless steel under marine environment. The fracture morphology of 321 stainless steel SCC specimens were analyzed with the aid of SEM. The strain-stress results showed that 321 stainless steel exhibited less SCC sensitivity when anodic potential or cathodic potential were applied on the specimen, both fracture elongation and fracture time ascended compared with that of corrosion potential. The fractography analysis results also proved this susceptibility clearly.

Discontinuous surface cracks during stress corrosion cracking of stainless steel single crystal

Single crystal 321 stainless steel stress corrosion cracking was studied in a 42 wt.% MgCl 2 solution. Cracks propagated macroscopically in the maximum tensile stress plane regardless of the notch orientation with respect to the applied tensile load direction. Some stress corrosion cracks nucleated discontinuously at the intersection of the two slip bands. Most cracks, however, were not related to the slip bands. Cleavage-like fracture was observed, and the river-markings exhibited microshear facets along the {1 1 1} plane. Interaction between the main crack and the discontinuous microcracks increased the calculated stress intensity factor by 17 times and promoted crack coalescence, resulting in mechanical fracture of the ligaments between the cracks.

Some observations on the current status in the understanding of stress-corrosion cracking of stainless steels

Stress-corrosion cracking of austenitic stainless steels continues to be a major cause of concern in all nuclear plant. This paper discusses some of the issues that continue to obscure, rather than illuminate the subject.

Influence of localized deformation on A-286 austenitic stainless steel stress corrosion cracking in PWR primary water

The low cycle fatigue (LCF) behaviour of precipitation-strengthened A-286 austenitic stainless steel was first investigated at room temperature under 0.2% plastic strain control. LCF led to hardening for the first 20 cycles and then to significant softening. LCF-induced dislocation microstructure was characterized using both bright and dark-field imaging techniques in transmission electron microscopy. Cycling softening was correlated with the formation of precipitate-free localized deformation bands. The effect of these precipitate-free localized deformation bands on A-286 stress corrosion cracking (SCC) behaviour in PWR primary water was then examined by means of constant extension rate tensile (CERT) tests at 320 °C and 360 °C. Comparative CERT tests were performed on companion specimens with similar yield stress but pre-fatigued to a few cycles (4–8) or between 125 and 200 cycles. Specimens pre-fatigued to a few cycles with no precipitate-free localized deformation bands exhibited little susceptibility to intergranular SCC (IGSCC). In contrast, the presence of precipitate-free localized deformation bands formed by pre-fatigue to between 125 and 200 cycles strongly promoted IGSCC. The interest of the approach used in this study is to provide insight into the role of localized deformation in irradiation assisted stress corrosion cracking.

Discussion on Factors of Unstable 304 Stainless Steel Stress Corrosion Cracking

Discussion on Factors of Unstable 304 Stainless Steel Stress Corrosion Cracking

Influence of the slip conditions on the stress corrosion cracking microprocesses in FCC materials

Single crystal 321 stainless steel stress corrosion cracking was studied in a 42 wt.% MgCl2 solution. Cracks propagated macroscopically in the maximum tensile stress plane regardless of the notch orientation with respect to the applied tensile load direction. Some stress corrosion cracks nucleated discontinuously at the intersection of the two slip bands. Most cracks, however, were not related to the slip bands. Cleavage-like fracture was observed, and the river-markings exhibited microshear facets along the {1 1 1} plane. Interaction between the main crack and the discontinuous microcracks increased the calculated stress intensity factor by 17 times and promoted crack coalescence, resulting in mechanical fracture of the ligaments between the cracks.

The Use of Stainless Steel and Nickel Alloys To Combat Corrosion In the Brewing, Dairy, Wine and Food Industries

Corrosion problems are described as they affect contamination and general hygiene in the brewing, dairy, wine, confectionery and sugar industries, where stainless steel, because of its bacteriological sterility and ease of cleaning, has become the dominant constructional material.The most suitable grades of stainless steel for specific conditions, preferred surface finishes and methods of cleaning to avoid corrosion are presented.Some examples are given of pitting corrosion of process equipment in the wine industry. Also exemplified is the action successfully taken to overcome problems of stress-corrosion cracking of stainless steel in the confectionery and sugar industries by upgrading to a nickel alloy.

ステンレス鋼の応力腐食割れに及ぼす温度の影響

ステンレス鋼の応力腐食割れに及ぼす温度の影響

Effect of Cold Working on Stress-Corrosion Cracking of Stainless Steel

Effect of Cold Working on Stress-Corrosion Cracking of Stainless Steel

Study of Stainless Steel Stress-Corrosion Cracking By Potential Measurements

Abstract This article describes a method and an apparatus for studies of stress-corrosion cracking. The stress-corrosion cracking of stainless steel in a 40 percent CaCl2 solution has been followed...

オーステナイト・ステンレス鋼の応力腐食亀裂に対するショット・ピーニングの効果について

Assuming that shot-peening leaves compressional stress on metallic surface and may cancel out the harmful tensile stress, the effect of this operation against stress-corrosion cracking of stainless steels was investigated experimentally. A weak peening was practically ineffective, but beyond a degree of peening, stress-corrosion cracking was reduced. A fair success was achieved at the level of peening where “coverage” was 90∼100%, and “archeight” was 0.013∼0.015 A. It is supposed that the uneveness of shot-peened surface may be harmful from the standpoint of general corrosion, but the corrosion resistance of shot-peaned stainless steels did not deteriorate except in corrosive environments which were capable to activate stainless steels.