【摘要】 采用一种新的HOP(Heat on-line partitioning)技术使X80管线钢得到了(B+M/A)复相组织。与普通X80管线钢相比,(B+M/A)X80管线钢在满足强度要求的基础上,有更优良的变形能力,其屈强比为0.80,均匀伸长率为10.3%,形变强化指数为0.14,满足了大变形管线钢的技术要求,适合应用于地震带、冻土等大位移的油气管线服役环境。显微组织分析表明,在(B+M/A)X80管线钢中,回火态贝氏体和细微化M/A间的复合作用,赋予材料高的强、塑特性。其中贝氏体基体中碳化物的析出和马氏体的形成,保证了材料具有较高的强度。贝氏体基体回火软化、位错恢复和薄片状或块状残留奥氏体的形成,使得材料具有良好的塑性变形能力。更多还原

【Abstract】 X80 pipeline steel containing bainite and M / A constituent was obtained by a novel HOP( heat on-line partitioning) technology.Compared with traditional X80 pipeline steel,the( B + M / A) X80 pipeline steel has a similar strength and higher plasticity with the yield ratio of 0. 80,uniform elongation of 10. 3% and strain hardening exponent of 0. 14,which meets the technical requirements of high deformability linepipe and is suitable for the environmentally severe regions such as permafrost and seismic regions. Microstructural analysis indicates that the synergistic effect of the tempered bainite and fine M / A component endow experimental steel with higher strengthplasticity. Moreover,the precipitation of carbides and the formation of martensite lead to high strength of experimental steel. The excellent plasticity of experimental steel results from the tempered softening of bainite,the recovery of the dislocation and the formation of thin sheetlike or block-like retained austenite.更多还原