规定总延伸强度Rt0.5是管线钢最重要的力学性能指标之一, 也是保证管道工程安全运行必不可少的技术参数。通过对X70管线钢不同取样方向及不同压平程度试样的拉伸试验结果进行对比, 分析了制样因素对X70管线钢Rt0.5测定结果的影响。结果表明: 取样方向为纵向时, 测得的Rt0.5最大,在产品供货协议中必须注明取样方向; 拉伸试样不完全压平会造成Rt0.5测定结果波动,为了获得真实准确的Rt0.5,制样人员必须保证试样在拉伸试验前被严格压平。

The proof total extension strength Rt0.5 is one of the most important mechanical properties of pipeline steels, and it is also necessary to ensure the safe operation of pipelines. Through comparing the tensile test results of X70 pipeline steel samples with different sampling direction and flattening degree, the effects of sample preparation factors on Rt0.5 test results were analyzed. The results show that the measured Rt0.5 of longitudinal direction samples was largest, so sampling direction must be indicated in the product supply agreement. The incomplete flattening of tensile samples would cause Rt0.5 test results fluctuation. In order to guarantee the accuracy of Rt0.5 test results, the tensile samples must be flattened completely before test.