晶界工程处理对316和316L奥氏体不锈钢耐晶间腐蚀性能的影响

Effect of Grain Boundary Engineering Treatment on Intergranular Corrosion Resistance of 316 and 316L Austenitic Stainless Steels

对316与316L奥氏体不锈钢进行晶界工程处理:拉伸至5%的变形量,在1100℃分别保温45和60 min后水淬。将未经过和经过晶界工程处理的316和316L钢进行650℃×5 h敏化处理,随后进行耐晶间腐蚀试验。结果表明:经过晶界工程处理的两种不锈钢低Σ重合位置点阵(CSL,Σ≤29)晶界比例提高到了75%以上(Palumbo-Aust标准),并形成了由大尺寸“互有Σ3n取向关系的晶粒团簇”组成的显微组织。此外,与未经晶界工程处理的钢相比,经晶界工程处理的316和316L钢均显示出了更好的耐晶间腐蚀性能,且316L钢比316钢具有更好的耐晶间腐蚀性能。

316 and 316L austenitic stainless steels were grain boundary engineering treated by tension-deforming to 5%,followed by soaking at 1100℃for 45 and 60 min respectively,and then quenching in water.The 316 and 316L steels not subjected to and subjected to grain boundary engineering treating were sensitized at 650℃for 5 h,and then tested for intergranular corrosion.The results showed that proportion of lowΣcoincidence site lattice(CSL,Σ≤29)boundary in the two steels subjected to grain boundary engineering treating was increased to more than 75%(according to Palumbo-Aust criterion),and their microstructure consisted of large-size grain-cluster which contained large quantity of interconnectedΣ3n GBs.Furthermore,the 316 and 316L steels subjected to grain boundary engineering treating were superior to ones not subjected to grain boundary engineering treating in intergranular corrosion resistance,and the 316L steel exhibited better intergranular corrosion resistance as compared to the 316 steel.