压力容器用304不锈钢封头直边段开裂失效分析

摘要

Serial cracks occurred at head when performing hydrostatic test. By using NDE, material analysis and microscope, the macro - surface of the broken head and metallurgical structure, corrosion body were analyzed. The analytical result shows that the major cause of the failure is the stress corrosion due to the combined effect of Cl'and S2- ions and tensile stress in a Cl- containing surrounding. Some proposes was put forward for preventing occurring of failure.%材质为304的不锈钢封头水压试验时直边段出现裂纹,通过无损检测、材质分析、金相检验等检测方法对失效部位裂纹的宏观形貌、显微组织、腐蚀产物等进行分析.结果表明:不锈钢封头暴露在富含氯、硫离子的环境中,在拉应力的共同作用下,发生应力腐蚀开裂,并提出了改进措施.