奥氏体不锈钢锥形锻件酸洗开裂原因

摘要

酸洗后奥氏体不锈钢锥形锻件局部出现数条沿圆周方向的裂纹.为找到开裂原因,研究了锻件制造过程,分析了不同位置的化学成分、拉伸性能、非金属夹杂物、显微组织、微观形貌及微区成分.结果表明:奥氏体不锈钢锥形锻件中存在含马氏体的异常组织,这些组织在酸洗过程中发生腐蚀,从而形成了沿圆周方向的条带状裂纹;建议加强冶炼过程中的质量管控及制造过程中的显微组织检验,防止马氏体出现,采取上述措施后再未出现过该类裂纹.%Several circumferential cracks were observed on the localized tapered forgings of austenitic stainless steel after pickling.To find the reason for cracking,the forging process was investigated,and the chemical composition, tensile properties, non-metallic inclusions, microstructure, micromorphology and micro-area composition at different positions were analyzed.The results show that an abnormal structure containing martensite existed in the tapered forgings of austenitic stainless steel.The abnormal structure was corroded during the pickling process,leading to the formation of the circumferential crack belts.The measures,such as strengthening quality control during melting process and performing microstructure examination during manufacturing process,were proposed to prevent the formation of martensite.No pickling cracks appeared after taking these measures.