高温金属结构缺陷免予蠕变失效评定的条件

Creep Exemption Criteria for Defective Structures at High Temperature

在有限蠕变变形前提下 ,定义了两个基于结构参考应力的状态参量 :特征温度和特征服役寿命 ;从服役设备合乎使用的角度出发 ,在上述两个参量的基础上建立了高温缺陷免予蠕变失效评定的准则 ,即当工作温度或服役时间小于相应的特征温度和特征服役寿命时不需要进行蠕变分析 ,可以按照常温缺陷评定方法进行评定 ;

Under the conditions of defective structures with limited creep strain, two parameters, that is, characteristic temperature and characteristic service-life, were introduced in terms of the reference stress of structures. From the principle of the fitness for service, a creep exemption criterion for defective structures at high temperature was set up on the basis of the proposed parameters. According to the proposed criterion, the creep failure assessment is then obviated provided that the operation temperature or service time is less than the defined characteristic temperature or characteristic service life, and the assessment techniques of defective structure at ambient temperature such as R6 procedure is suitable in this instance. The safety assessment of a cracked hydrogenation reactor was performed to illustrate the applicability of proposed creep exemption criteria.