含缺陷压力管道的应力腐蚀断裂及其安全评定

STRESS CORROSION CRACKING AND ITS SAFETY ASSESSMENT FOR PIPING WITH DEFECTS

在严重的腐蚀介质中,压力管道等含缺陷构件常常易于发生应力腐蚀脆性断裂.本文分析了应力腐蚀环境下临界应力强度因子KISCC的含义,给出了含缺陷构件的应力腐蚀失效判据为KI≤KISCC.在实际工程中,由于临界应力强度因子门槛值KISCC均通过实验方法来获取,给评定过程带来了一定困难且不便于推广应用.为此,本文推荐了一种简要的KISCC工程计算方法。结果表明:工程计算方法所得计算结果与实验测定结果有较好的吻合,可用于压力管道等含缺陷构件的安全评定.

Stress corrosion fractures often occurred in piping with defects in corrosive medium. The meaning of the critical stress intensity factor （KISCC） in of stress corrosion cracking was discussed and the failure criteria of stress corrosion cracking,KI≤KISCC was also given. However the value of the factor KISCC was acquired by experimental tests, so it was inconvenient and has not been widely used in engineering practice. Therefore a simple numeric formula of KISCC was suggested in this paper. The results showed that the suggested values KISCC were in excellent correspondence with the experiment values and would be used in the assessment of structures with defects like piping.