表面裂纹是压力容器中经常出现的一种缺陷形式,为了在容器的检修过程中获得最佳经济效益,必须确定一个合于使用的裂纹容限标准。本文采用COD判据,通过按正交试验设计的小型宽板拉伸试验,应用因子效应函数的正交多项式展开法得出表面裂纹张开位移与裂纹几何尺寸及应力水平之间的函数关系。並通过焊接接头区和母材中同样尺寸裂纹张开行为的比较,对母材试验结果用于焊接接头区的可能性进行了分析,提出了高应变情况下表面裂纹容限的计算公式。 Surface cracks are a frequent form of defects in pressure vessels. To achieve the best cost-effectiveness in vessel inspection, a flaw tolerance standard must be established. In this paper, the COD criterion is adopted. According to the small-width tensile test designed by orthogonal experiment, the relationship between the crack opening displacement and crack geometric dimension and stress level is obtained by orthogonal polynomial expansion method of factor effect function. Through the comparison of the crack opening behavior of the same size in the welded joint region and the base metal, the possibility of using the base metal test results for the welded joint region was analyzed. The formula for calculating the surface crack tolerance under high strain was put forward.