螺旋缝埋弧焊管管段扩径试验与研究

Experiment and Research on Expansion of HSAW Pipe Body

通过螺旋缝焊管管段扩径试验总结在不同扩径率条件下螺旋缝焊管尺寸及力学性能变化规律,分析认为:扩径试验对焊管的几何尺寸有明显改善;但对管体的冲击性能没有显著影响,管体横向拉伸屈服强度整体呈现上升趋势,在扩径率0.7%时,扩径后母材横向屈服强度上升30 MPa左右,且随着扩径率的增大,屈服强度增幅越大,而抗拉强度的变化较屈服强度的变化更为不明显,因此屈强比呈现整体上升趋势,且绝大部分值均超过标准要求,建议在满足焊管几何尺寸精度和力学性能要求的情况下尽量采用较小的扩径率,以防止扩径率过大带来的不利影响。

The variation regularities of the dimensions and the mechanical properties of the HSAW pipe under different expansion rate conditions are researched by means of the expansion experiment to the pipe body.It is revealed via the experiment that the expansion process obviously improves the geometric dimensions of the HSAW pipe body,whereas has no obvious effect on the impact performance of the pipe body;the transversal tensile yield strength of the pipe body as a whole shows a rising trend,and in case of expansion ratio of 0.7%,and after the expansion,the yiel strength of the base metal rises approximately up to 30 MPa.And long with the increase of the expansion ratio,the yield strength is getting increased.Compared with the change of the yield strength,the change of the tensile strength is further more insignificant,which leads to the rise of the yield ratio as a whole,and most of the values excess the applicable standardspecified requirements.Accordingly it is suggested that for the expansion process,provided that the requirements for the pipe geometric dimension accuracy and the mechanical properties are met,a rather small expansion ratio be used as far as possible so as to prevent the negative effect by excessive big expansion ratio.