低温形变马氏体对奥氏体不锈钢腐蚀敏感性影响研究

Influence of Low Temperature Deformed Martensite on Corrosion Susceptibility of Austenitic Stainless Steel

奥氏体不锈钢是低温容器的常用材料,而低温和应变会诱发亚稳态奥氏体不锈钢的马氏体转变,进而改变材料的强度、韧性以及耐腐蚀性能等等,影响低温容器使用的安全性。通过研究奥氏体不锈钢在低温应变中诱导马氏体相变的现象,验证了不同形变马氏体含量对材料耐腐蚀性能的影响。结果表明在相同形变量条件下,温度越低产生的形变马氏体含量越多,并且在奥氏体不锈钢中S30408产生的形变马氏体含量比S32168多。在晶间腐蚀方面,形变马氏体含量变化对S30408和S32168这两种材料晶间腐蚀敏感性的影响不大,但形变马氏体会在一定程度上降低材料的耐腐蚀性能;在应力腐蚀方面,随着形变马氏体含量的增加,应力腐蚀敏感性呈上升趋势。

Austenitic stainless steel is a commonly used material for cryogenic vessels. Low temperature and strain can induce martensitic transformation of metastable austenitic stainless steel, which in turn changes the strength, toughness and corrosion resistance of the material, etc., affecting the safety of cryogenic vessel use. The effect of different deformation martensite content on the corrosion resistance of the material was verified by studying the phenomenon of induced martensite phase transformation in austenitic stainless steels during low-temperature strain. The results show that the temperature lower produces more deformation martensite content under the same deformation variable conditions,and S30408 of austenitic stainless steel produces more deformation martensite content than S32168. In terms of intergranular corrosion, the change of deformation martensite content has little effect on the intergranular corrosion susceptibility of S30408 and S32168, but the deformation martensite will reduce the corrosion resistance of the material to a certain extent. In terms of stress corrosion, stress corrosion susceptibility tends to increase with the increase of deformation martensite content.