热处理工艺对X70管线钢组织和力学性能的影响  

Effects of Heat Treatment Process on Microstructure and Mechanical Properties of X70 Pipeline Steel

作　　者：李龙 章传国 LI Long;ZHANG Chuanguo(Technology Center of Steel Pipe,Center Research Institute of Baosteel,Shanghai 201900,China)

机构地区：[1]宝钢中央研究院钢管技术中心,上海201900

出　　处：《热加工工艺》2025年第4期64-68,共5页Hot Working Technology

基　　金：国家重点研发计划项目(2018YFC0310304)。

摘　　要：采用650~800℃保温后空冷和水冷两种工艺路线对X70管线钢进行热处理,并利用OM、SEM等表征手段分析了热处理工艺对X70组织和性能的影响。结果表明:热处理温度达到700℃时进入两相区,室温组织由铁素体和少量MA岛构成。随着热处理温度的升高,组织中MA岛含量增加,水冷工艺相比于空冷工艺在室温下保留了更高比例的MA岛;热处理后X70的塑性呈现上升趋势,但屈服强度随着热处理温度的升高逐渐降低,当温度超过700℃时,屈服强度不再满足X70钢级的要求。X70 pipeline steel was air-cooled or water-cooled at room temperature after heat treatment at 650-800℃,and the effects of heat treatment on the microstructure and properties of X70 were analyzed by OM and SEM.The results show that when the heat treatment temperature reaches 700℃,the microstructure is composed of ferrite and a small amount of MA islands.As the temperature increases,the content of MA islands in the microstructure increases,and the water cooling process retains a higher proportion of MA islands than air cooling process at room temperature.After heat treatment,the plasticity of X70 pipeline steel shows an upward trend,but the strength decreases gradually with the increase of heat treatment temperature.When the temperature exceeds 700℃,the yield strength can no longer meet the requirements of X70 steel grade.

关 键 词：X70管线钢 热处理 显微组织 力学性能 

分 类 号：TG161[金属学及工艺—热处理]