高钢级管线钢形变硬化行为及其影响因素分析  

Strain-hardening Behavior of High Grade Linepipe Steel and Its Influence Factors

作　　者：吉玲康 封辉 张继明 徐彤 王海涛 

机构地区：[1]中国石油集团石油管工程技术研究院,陕西西安710077 [2]石油管材及装备材料服役行为与结构安全国家重点实验室,陕西西安710077 [3]西安交通大学材料科学与工程学院,陕西西安710049

出　　处：《西安石油大学学报（自然科学版）》2017年第3期99-104,共6页Journal of Xi’an Shiyou University（Natural Science Edition）

基　　金：中国石油天然气集团公司科技重大专项"第三代大输量天然气管道工程关键技术研究"(编号:2012E-2801)

摘　　要：选取具有单相和双相组织特征的X80、X90直缝管,结合微观因素分析了高钢级管线钢及钢管不同方向的形变硬化行为特征。研究发现贝氏体+铁素体组织的双相钢比单相贝氏体组织的管线钢具有更好的塑性变形能力;此外,与单相组织管线钢管圆屋顶型应力应变曲线不同,双相组织管线钢管的横向应力应变曲线出现了明显的屈服平台,导致二者形变硬化指数变化规律存在差异。双相组织中含有一定比例低位错密度铁素体及制造过程环向应变引起的应变时效是产生该现象的主要原因。The strain hardening behavior of X80 and X90 longitudinal submerged arc welding linepipe with single or dual phase micro- structure in different directions were analyzed. It is found that the pipeline steel with bainite and ferrite dual-phase microstruetnre pos- sesses better plastic deformation ability than the pipeline steel with bainite single-phase microstructure;the stress-strain curve shape of the former in the transverse direction is different from that of the latter, and it has obvious yielding platform, which leads to their differ- ence in the varying law of deformation hardening exponent. This is because there are a certain part of ferrite with low dislocation density in the pipeline steel with dual-phase microstructure and the circumferential strain produced in manufacturing process causes strain ag- ing.

关 键 词：高钢级管线钢 形变硬化 应变时效 位错密度 

分 类 号：TE973[石油与天然气工程—石油机械设备] TG115[金属学及工艺—物理冶金]