X80与X100级管线钢屈服强度R_(t 0.5)与R_(p 0.2)的差异性研究

Study on Difference Between Yield Strength R_(t 0.5) and R_(p 0.2) for X80 and X100 Pipelines Steel

对钢级为X80和X100的两种管线钢的拉伸性能进行了试验研究分析,结果显示X80级管线钢纵向和横向屈服强度的Rt 0.5与Rp 0.2的值重合,而X100级管线钢的Rp 0.2对应的总应变比0.5%要高。通过对应力-应变曲线分析可知,这是因为X100级管线钢拉伸曲线弹性阶段的延伸,使曲线的屈服部分和其后的均匀延伸部分上升造成的。因此,在进行级别高于X80的管线钢拉伸试验时,建议使用Rp 0.2的值作为材料的屈服强度,或使用与Rp 0.2相对应的总应变强度作为屈服强度。

This present paper discussed the tension properties of X80 and X100 pipeline steel.In case of X80 grade,stress at 0.5% total strain and 0.2% offset strain agrees each other.For X100,higher total strain must be employed to measure the same stress as 0.2% offset strain.Having researched strain-stress curve,flexibility stage is extension that cause the difference of stress at 0.5% total strain and 0.2% offset strain for X100 pipeline steel.In terms of yield strength of pipes,it is proposed that yield strength should adopt 0.2% offset strain or the total strain corresponding value of to 0.2% offset strain.