通过对10组两种不同宽度的X65管线钢试样进行拉伸对比试验, 分析了试样宽度对管线钢屈强比测试结果的影响及其原因。结果表明: 宽度较大试样测得的屈强比普遍高于宽度较小试样测得的, 其根本原因在于材料内部组织结构的不均匀性; 因此, 应严格执行产品标准要求, 在进行管线钢拉伸测试时统一试样宽度, 使得不同实验室的拉伸测试结果具有可比性。

Through comparing the tensile testing results of 10 groups of specimens of X65 pipeline steel with different width, the influence and reason of specimen width on the yield strength ratio were analyzed. The results show that the yield strength ratios of the wider specimens were generally higher than those of the narrower specimens, and the root cause lied in the interior microstructure nonuniformity of the material. Therefore, when testing the tensile properties of pipeline steel, a unified specimen width should be obeyed strictly according to the product specification, to insure the tensile testing results in different laboratories have comparability.