Abstract
The effects of cold work and heat treatment on the stress corrosion cracking (SCC) behavior of SUS 304 stainless steel wire were studied in boiling 42%MgCl2 solution under the applied stress of 25kg/mm2.
The SCC susceptibility of the specimen which was subjected to a cold work greatly decreased with lowering the working temperature when the degree of cold work was 7% or above, but has a tendency to increase in the case of a less working or an as-subzero treatment. It seems that the change of such an SCC susceptibility was closely related to the formation of stress-induced martensite. It was found that the intergranular SCC (IGSCC) was observed under the condition of cold work or assubzero treatment which increased SCC susceptibility. The above results suggest that there is a correlation between the SCC mode and the working condition, and the IGSCC was due to the formation of ε-type martensite. In the specimens which were aged at 470 or 530°C for short time after the solution treatment, the SCC susceptibility was increased, and the IGSCC was observed, whereas it was not observed after aging at 600, 700 or 850°C for more than 0.5hr in the solution treated or cold worked specimens.
