工艺制度对X70抗大变形管线钢组织性能的影响  

Effects of Process on Microstructure and Mechanical Properties of X70 for Strain-based Design Line Pipe Steel

作　　者：冉旭[1] 蔡庆伍[1] 焦多田[1] 武会宾[1] 

机构地区：[1]北京科技大学高效轧制国家工程研究中心,北京100083

出　　处：《热加工工艺》2009年第2期38-41,15,共5页Hot Working Technology

摘　　要：利用扫描电镜、透射电镜与背散射电子衍射技术,研究了工艺制度对X70抗大变形管线钢组织、性能的影响。结果表明,随开始冷却温度的降低,先共析铁素体含量逐渐增加,贝氏体组织含量逐渐降低,钢板抗大变形性能参数提高,当开始冷却温度在700℃左右时,铁素体组织均匀地分布于基体中,铁素体晶界处位错纠结形成较明显的胞状结构,细化了铁素体晶粒,钢板具有最佳的综合力学性能,屈服强度为560MPa,抗拉强度为710MPa,伸长率为23.5%,n值为0.10,屈强比为0.78,均匀伸长率达到18.1%。EBSD研究表明,铁素体和贝氏体两相以取向大于15°的大角度晶界相结合,贝氏体中出现的大量亚结构以小角度晶界相结合,这些小角度晶界的存在可以大大提高材料的形变能力。The effects of process on microstructure and mechanical properties of X70 for strain-based design line pipe steel were studied by the analysis of SEM, TEM, EBSD. The results show that the content of pro-eutectoid ferrite increases, the content of bainite reduces and the parameters of high deformability increases with the decrease of the start cooling temperature. When the start cooling temperature is about 700 ℃, pro-eutectoid ferrite is equably dispersed in the matrix, the dislocation at ferrite grain boun...

关 键 词：抗大变形 铁素体 显微组织 位错 

分 类 号：TG142.1[一般工业技术—材料科学与工程]