Potentiostatic etching method has been suggested as a technique for detection of pre-existing plastic st rain of type 316 stainless steel which is strained at 250°C that is a temperature assumed nuclear reacto r water. After potentiostatic etching (1N HNO3, -600mVSCE, 20min, 35°C), slip lines appear as etched lin es on the surface of specimen, and their density has one-to-one correlation with pre-existing strain. Th is method has a high sensitivity and can detect at least 1% plastic strain. However, it is ...
英字タイトル:
Optimizing electrochemical potential and exposure time for the detection method of plastic strain in austenitic stainless steels by potentiostatic etching

To ensure integrity of structures and components in nuclear power plants, the demand has been increased for establishing nondestructive method for detection of pre-existing plastic strain. In this study, potentiostatic etching method is applied to detect and quantitatively measure plastic strain imposed to austenitic stainless steels by tensile straining. After potentiostatic etching (1N HNO3, -600mVSCE, 20min), twin lines and slip lines appear as etched lines on the surface of specimen because of the...
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Inspection of Plastic Deformation Mechanism in Austenitic Stainless Steel by potentiostatic etching Detection Method

To ensure integrity of structures and components in nuclear power plants, the demand has been increased for establishing nondestructive method for detection of pre-existing plastic strain. In this study, we examined applicability of potentiostatic etching method, which developed in our past paper, for actual austenitic steel components. On etching condition, solution temperature is one of the critical parameter. Thus this method should be conducted at a constant temperature between 30°C -40°C. Using r...
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Applicability of potentiostatic etching method for evaluation of plastic strain in austenitic stainless steel structure

It was reported that nitride layer formed on SUS310S heating tubes in the reactor of melamine production plant showed severe spalling susceptibility. After replacement to SUS304heating tubes, spalling and thinning was suppressed. According to previous studies, a crystal structure of the nitrided layers of SUS310S and SUS304 heating tubes mainly consist of γ’ and α’, respectively. The reason why the SUS304 heating tube showed low spalling susceptibility was considered to be a smaller expansion rate of α...
英字タイトル:
Wastage mechanism of heating tubes made of austenitic stainless steels in a complex environment of nitriding, oxidizing, and carburizing