试样形状对高强度感应加热弯管拉伸实验的影响

Influence of sample shape on high-intensity induction heated bend pipe in tensile test

拉伸性能是高钢级管道钢管的重要性能之一。针对高钢级X70和X80感应加热弯管,选取了3种不同规格的试样形状进行拉伸实验,结果表明:试样形状对这两种感应加热弯管的屈服强度、抗拉强度和屈强比均有一定影响。这两种感应加热弯管的横向试样、矩形板状拉伸试样的屈服强度值低于圆棒拉伸试样;X70感应加热弯管的纵向试样、矩形板状拉伸试样的屈服强度值高于圆棒拉伸试样。这两种感应加热弯管不同试样形状的抗拉强度差异不大,横向矩形全壁厚试样的抗拉强度均稍高于圆棒试样。这两种感应加热弯管横向矩形全壁厚试样的屈强比均低于圆棒试样,X70感应加热弯管的纵向矩形全壁厚试样的屈强比则高于圆棒试样。为保障管道钢管的服役安全,建议采用圆棒试样进行实验。

Tensile performance is one of the important characteristics in high-grade pipe steel.Aiming at the high-grade X70 and X80 induction heated bend pipe steel,three shapes with different specifications are chosen to perform tensile test.Results obtained from the test show that different shapes affect the yield strength,tensile strength and yield ratio of the samples.For the transverse sample of X70 and X80 pipe steels,yield strength of the rectangular plant-like tensile sample is less than that of the round-bar tensile sample,but for the X70 longitudinal sample,the result is reversed.The tensile strengths for X70 and X80 pipe steels are almost the same between different sample shapes,the tensile strength of transverse-rectangular full wall thickness samples is just higher than that of columnar sample,and the yield ratio of transverse-rectangular full wall thickness X70 and X80 samples is less than that of columnar sample,and the yield ratio of longitudinal-rectangular full wall thickness X70 sample is higher than that of columnar sample.For the sake of steel pipeline operation safety,it is preferred to use the round bar sample for experiment.