通过X70管线钢板和S690QL高强钢板的室温拉伸试验, 研究了矩形拉伸试样夹持位置对钢材强度测试值的影响。结果表明: 在试验人员、试验机及引伸计、试样、试验方案、试验环境均相同的前提下, 试样夹持在夹头的边缘与夹持在夹头的中间相比, 测得的下屈服强度ReL、上屈服强度ReH和抗拉强度Rm几乎没有变化, 但会造成试样的拉伸应力-应变曲线弹性变形阶段异常, 从而影响对规定塑性延伸强度Rp0.2及规定总延伸强度Rt0.5的测试。

Effect of clamping positions of rectangular tensile specimens on the measurement values of strength was studied through room temperature tensile test to X70 and S690QL steel plate. The results show that under the same condition of tester, machine, material, method and circumstance, when the specimens were clamped on the edge of the chuck or in the middle of the chuck, the measured lower yield strength ReL, higher yield strength ReH and tensile strength Rm are almost the same, but clamping specimens on the edge of the chuck would result in abnormal of elastic deformation stage of the stress-strain curve and affect measurement values of the proof strength plastic extension Rp0.2 and the proof strength total extension Rt0.5.