不同钢种真实应力屈强比与工程应力屈强比的测试与对比

Testing and Comparison of True Yield Ratio and Engineering Yield Ratio of Different Steels

对五种试验钢进行了拉伸试验,得到了工程应力屈强比、真实应力屈强比和静力韧度实测值,根据静力韧度计算公式计算得到了五种钢颈缩前后吸收的能量和静力韧度,并与实测值进行了对比。结果表明:各试验钢的真实应力屈强比比工程应力屈强比小约0.13,静力韧度的实测数据和公式计算的结果一致;对高钢级管线钢,在静力韧度足够的前提下,用真实应力屈强比做为安全性指标比用工程应力屈强比更客观,更具实际意义。

The tension tests of five experimental steels were conducted,and then the engineering yield ratio,true yield ratio and static toughness were obtained.The deformation energies of the five steels before and after necking and the static toughness were also calculated by the mathematical expression of static toughness.The calculated static toughness was compared with the experimental value.The results show that the values of true yield ratios were about 13% lower than those of engineering yield ratios.The experimental values of static toughness coincided well with the calculated values.Based on the sufficient static toughness,the true yield ratio was more objective and more meaningful than the engineering yield ratio as a safety index for high strength pipeline steels.