Mo含量对高等级管线钢相变行为及组织和性能的影响  

Effects of Mo content on phase transformation behavior,microstructure and mechanical properties of high grade pipeline steel

作　　者：段贺 单以银[1] 杨柯[1] 史显波[1] 严伟[1] 任毅 Duan He;Shan Yiyin;Yang Ke;Shi Xianbo;Yan Wei;Ren Yi(Institute of Metal Research,Chinese Academy of Science,Shenyang Liaoning 110016,China;School of Materials Science and Engineering,University of Science and Technology of China,Shenyang Liaoning 230000,China;State Key Laboratory of Metal Materials and Application for Marine Equipment,Anshan Liaoning 114009,China)

机构地区：[1]中国科学院金属研究所,辽宁沈阳110016 [2]中国科学技术大学材料科学与工程学院,辽宁沈阳230000 [3]海洋装备用金属材料及其应用国家重点实验室,辽宁鞍山114009

出　　处：《金属热处理》2021年第5期1-8,共8页Heat Treatment of Metals

基　　金：国家重点研发计划(2017YFB0304901)。

摘　　要：通过调整一种高强韧管线钢中的Mo含量,研究Mo含量对动态相变规律的影响。在相同热机械控制轧制(TMCP)工艺下,比较Mo含量为0.2%和0.3%的两种钢的强度和韧性的差异,通过光学显微镜、EBSD、TEM等手段研究两种钢的复杂针状铁素体组织,并对组织和性能间的关系进行分析。结果表明:提高Mo含量有利于组织细化和针状铁素体的形成,动态CCT曲线向右下方移动;在相同轧制工艺条件下,0.3%Mo钢具有更高的强度,Mo含量的增加有助于提高沉淀强化和细晶强化的作用,同时增加了贝氏体铁素体(BF)的体积分数和MA岛的尺寸及数密度,并进一步提高了强度;两种钢在大角度晶界比例相同时,0.3%Mo钢的冲击性能较差,MA岛的尺寸和数密度及形状的不规则程度是影响冲击性能的主要因素。By adjusting the Mo content in a high-strength pipeline steel,the effect of Mo content on dynamic phase transformation was studied.Under the same TMCP condition,the strength and toughness of the steels with 0.2% Mo and 0.3% Mo were studied comparatively,and two different complex acicular ferrite(AF)microstructures were analyzed by optical microscope,EBSD,TEM and other means.The relationship between the microstructures and the mechanical properties was investigated.The results show that the increasce of Mo content is beneficial to refinement of the microstructure and formation of the acicular ferrite,and move the dynamic CCT curves to the lower right.Under the same rolling conditions,the strength of the steel with 0.3% Mo is higher,the increase of Mo content helps to improve the effects of precipitation strengthening and fine grain strengthening,at the same time,the volume fraction of bainitic ferrite(BF),the size and number density of MA islands are increased,and the strength is further increased.In the case of the same proportion of high angle grain boundaries,the impact property of the steel with 0.3 %Mo is worse,the size and number density of MA islands as well as their degree of irregularity are the main factors to affect the impact property.

关 键 词：管线钢 MO 动态CCT曲线 显微组织 贝氏体铁素体 

分 类 号：TG142.1[一般工业技术—材料科学与工程]