7N01合金の応力腐食割れと粒界腐食

抄録

The effect of aging conditions was investigated metallurgically and electrochemically. Two types of intergranular corrosion are observed in the alloy cold aged at a temperature below 100°C for a short period and in one warm aged at a higher temperature or for a longer period. The former intergranular corrosion occurs due to preferential breakdown of an anodic grain boundary zone. While the latter occurs due to selective dissolution of grain boundary precipitated particles resulting in pit-type intergranular corrosion. SCC in the cold aged alloy is closely related to intergranular corrosion. It occurs by stress-assisted intergranular corrosion. SCC in the warm aged alloy proceeds by the two-step mechanism combining an electrochemical process and a mechanical defor mation process