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通过低温（－７０℃）拉伸方法，制备出具有不同马氏体（铁磁相）含量的１Ｃｒ１８Ｎｉ９Ｔｉ（ＡＩＳＩ３２１）奥氏体不锈钢试件。采用恒载荷法对双边缺口试样进行应力腐蚀试验，测定了不同马氏体含量的试样在氯化物介质中应力腐蚀破裂（ＳＣＣ）的归一化门槛值。用ＳＥＭ观察断口形貌。结果表明：当铁磁相含量小于５％时，材料的ＳＣＣ敏感性随含量增加而减小；在５～１５％范围内，ＳＣＣ敏感性不断增加；在１５～２４％区域中，材料的ＳＣＣ敏感性迅速下降；超过２４％，ＳＣＣ敏感性又有所上升。
1Cr18Ni9Ti (AISI321) austenitic stainless steel specimens with different martensitic (ferromagnetic) contents were prepared by low temperature (-70 ℃) stretching. The stress-corrosion test of double-notched specimens was carried out by constant load method, and the normalized threshold of stress corrosion cracking (SCC) of specimens with different contents of martensite in chloride medium was determined. Fracture morphology was observed by SEM. The results show that when the content of ferromagnetic phase is less than 5%, the SCC sensitivity of the material decreases with the increase of the content. The SCC sensitivity increases continuously in the range of 5-15%. In the region of 15-24%, the SCC Sensitivity decreased rapidly; more than 24%, SCC sensitivity has increased.