中文摘要：

通过在线配分HOP（heating on-line partitioning)技术，使X80管线钢获取了（B+M/A）复相组织和大变形性能。采用力学性能测试、显微组织分析方法研究了预变量和不同温度时效温度条件下（B+M/A）X80管线钢的应变脆化规律，分析了显微组织对其脆化的影响。结果表明，（B+M/A）X80管线钢存在着应变时效现象，随着应变时效温度的升高，试验钢的强度和硬度呈现增加的变化趋势，试样的断后伸长率和均匀伸长率较低。随着时效温度升高，（B+M/A）X80管线钢的屈强比Rt0.5/Rm、形变强化指数n逐渐降低，导致材料大变形能力下降。应变时效脆化的机制是固溶于α-Fe中的C、N原子与位错的交互作用。与普通管线钢相比，（B+M/A）X80经HOP处理后位错恢复和碳、氮化合物沉淀析出有利于改善应变时效性。

英文摘要：

High deformability X80pipeline steel containing bainite and M/A constituent can be obtained through the Heating On-line Partitioning process.Effect of strain aging on tensile properties and microstructure of(B+M/A)X80pipeline steel was researched by means of mechanical property test,microscopic analysis.The results show that the strain aging can induce the embrittlement behavior of(B+M/A)X80pipeline steel.with the aging temperature increasing,the strength and hardness of the experimental steel increases,and the ductility is lower.With the aging temperature increasing,the lower yield ratio and strain hardening index for the experimental steel,resulting in the deformation of(B+M/A)X80pipeline steel decreasing.The strain aging embrittlement mechanism of the experimental steel is the interaction of interstitial and dislocation.The strain aging tendency of(B+M/A)X80pipeline steel is lower than the ordinary X80pipeline steel.The reason is the lower solution of carbon and nitrogen atoms,and the lower dislocation density of the(B+M/A)X80pipeline steel by the partitioning process.