321奥氏体不锈钢单晶应力腐蚀断口的研究

FRACTOGRAPHIC STUDY OF SCC OF 321 AUSTENITIC STAINLESS STEEL SINGLE CRYSTAL

本文观察了321奥氏体不锈钢在沸腾的42％MgCl2溶液中的应力腐蚀行为．结果表明，滑移带的出现与应力腐蚀裂纹的形核和扩展之间存在着内在的联系．应力腐蚀裂纹虽然总是在两个滑移带相交处形核，但并不沿着这两个滑移带扩展．利用SEM观察应力腐蚀断口的结果表明，尽管宏观看来，断口上具有解理特征的河流花样均是沿｛100｝面。

The observation of behavior of SCC of 321 austenitic stainless steel single crystal in boiling 42%MgCl2 showed that there was a relationship between the appearence of slip bands and the initiation or propagation of SCC. Although the stress corrosion cracks often nucleated at the intersection of two slip bands, they propagated along neither of these two slip bands. The SEM observations of the fractography of SCC showed that although the stress corrosion crack with river- markings or fan-patterns nucleated normally along the average macroscopic plane {100}, the detailed observations indicated that the microshear facets were along {111} plane.