基于0.8管道设计系数的X80焊管性能研究

介绍了我国管道0.72与0.8设计系数用埋弧焊管技术条件的差异,并对两种设计系数所生产的螺旋埋弧焊管性能进行了对比研究。结果表明,0.8和0.72设计系数用板卷组织均以粒状贝氏体为主,含有不同量的多边形铁素体,其中0.8设计系数板卷头、中、尾3个位置多边形铁素体含量少,晶粒尺寸小,组织更加均匀一致,力学性能差异较小,头、中、尾屈服强度最大差值为14 MPa,比0.72设计系数用卷板减小约50 MPa,同时冲击韧性与0.72设计系数板卷相比提高25%。水压检验结果表明,采用0.8设计系数的焊管在100%屈服强度下进行静水压试验均未发生管体变形和泄露。目前国内冶金制管水平可完全满足0.8设计系数用焊管技术要求。

Study on X80 Welded Pipe Performance Designed by Using 0.8 Coefficient

In this article, it introduced the difference of SAWH pipe technological specifications between 0.72 design coefficient and 0.8 design coefficient, and comparative analysis was carried out for SAWH pipe with two kinds of design coefficient. The result indicated that the structures of plate strip are mainly granular bainite for 0.72 and 0.8 design coefficients, containing different amount of polygonal ferrite. The polygonal ferrite content is less in the head, middle and tail of plate strip with 0.8 design coefficient, small size, and organization is more uniform, the difference of mechanical performance is small. The biggest difference of yield strength in the head, middle and tail of plate strip with 0.8 design coefficient is 14 MPa, it is about 50 MPa lower than that of 0.72 design coefficient, while impact toughness increases by 25%. The hydrostatic test result showed that the welded pipe with 0.8 design coefficient did not appear deformation and leakage when hydrostatic test was conducted under 100% yield strength. At present the pipe processing level can fully meet the technological requirements of welded pipe with 0.8 design coefficient.