双相X80管线钢塑性变形和损伤机制  

Plastic deformation and damage mechanism of duplex X80 pipeline steel

作　　者：张洋[1] 王葛[1] 吕正芳 范利锋[2] 秦淑琪 ZHANG Yang;WANG Ge;L Zheng-fang;FAN Li-feng;QIN Shu-qi(National Engineering Research Center for Equipment and Technology of Cold Strip Rolling,Yanshan University,Qinhuangdao 066004,China;Transportation Institute,Inner Mongolia University,Hohhot 010000,China)

机构地区：[1]燕山大学、国家冷轧板带装备及工艺工程技术研究中心,河北秦皇岛066004 [2]内蒙古大学交通学院,内蒙古呼和浩特010000

出　　处：《塑性工程学报》2023年第4期127-136,共10页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(51761030,52161022);内蒙古自然科学基金资助项目(2019MS05081);内蒙古大学自治区级大学生创新创业训练计划(202010126070);内蒙古自治区高等学校“青年英才支持项目”(NJYT23045)。

摘　　要：针对油气管线在高压、大变形等运行工况下极易产生局部屈曲、失稳和延性断裂等与塑性损伤相关的失效行为,为了揭示管线钢塑性损伤行为的微观机制,以双相结构(贝氏体+多边形铁素体)X80管线钢为研究对象,采用有限元方法研究了双相X80管线钢微观塑性损伤演化规律。通过电子背向散射衍射技术分析了塑性损伤过程中的微观结构演化机制。结果表明,应变主要由铁素体承担,应力主要由贝氏体承担,在拉伸变形作用下,易在两相界面处发生位错堆积,导致应力集中,形成孔洞。随着应变的增加,孔洞逐渐地向铁素体内部扩展、聚集直至贯通;铁素体晶粒的主要变形机制是晶粒内部滑移系统的滑移和晶格的转动,造成了微孔洞的形成。In view of the failure behaviors related to plastic damage,such as local buckling,instability and ductile fracture,which are easy to occur in oil and gas pipeline steel under high pressure,large deformation and other operating conditions,to reveal the microscopic mechanism of plastic damage behavior of pipeline steel,the(bainite+polygonal ferrite)X80 pipeline with duplex structure steel was taken as the research object.The microscopic plastic damage evolution laws of duplex X80 pipeline steel were studied by finite element method.The microstructure evolution mechanism during plastic damage process was analyzed by electron back-scattered diffraction(EBSD)technique.The results show that the strain is mainly borne by ferrite,and the stress is mainly borne by bainite.Under the action of tensile deformation,the dislocation accumulation is easy to occur at the two-phase interface,resulting in stress concentration and the formation of voids.With the increase of strain,the voids gradually expand into the interior of ferrite and accumulate until penetrating.The main deformation mechanism of ferrite grains is the slip of slip system in grains and the rotation of the lattice,which results in the formation of microvoid.

关 键 词：双相X80管线钢 代表体元法 塑性损伤 EBSD 

分 类 号：TG142.1[一般工业技术—材料科学与工程]