等温时间对低碳微合金钢组织和性能的影响  

Effect of isothermal time on microstructure and properties of low carbon micro-alloyed steel

作　　者：孙婷婷[1] 刘朋成 吴忠旺[1] 田方铖 邢磊[1] Sun Tingting;Liu Pengcheng;Wu Zhongwang;Tian Fangcheng;Xing Lei(School of Materials and Metallurgy,Inner Mongolia University of Science and Technology,Baotou Inner Mongolia 014010,China;Technology Center,Inner Mongolia Baotou Steel,Baotou Inner Mongolia 014010,China)

机构地区：[1]内蒙古科技大学材料与冶金学院,内蒙古包头014010 [2]包钢(集团)公司技术中心,内蒙古包头014010

出　　处：《金属热处理》2023年第11期216-220,共5页Heat Treatment of Metals

基　　金：内蒙古自治区科技攻关项目(2020GG0150)

摘　　要：采用金相显微镜、场发射扫描电镜、透射电镜、拉伸试验和X射线衍射仪等,研究了725℃下不同等温时间对低碳微合金钢(0.058%C)组织和性能的影响。结果表明,725℃下等温时间由1800 s增加到86400 s时,板条贝氏体的体积分数减少,铁素体的体积分数增加,等温时间为86400 s的试样中残留奥氏体几乎全部分解。随等温时间的延长,试验钢的抗拉强度降低,屈服强度降低,断后伸长率增加;等温时间为1800 s时可获得具有良好强度-韧性配合的下贝氏体组织。Effect of different isothermal time on microstructure and properties of a low carbon micro-alloyed steel(0.058%C)was studied by means of metallographic microscope,field emission scanning electron microscope,transmission electron microscope,tensile testing and X-ray diffractometer.The results show that when the isothermal time increases from 1800 s to 86400 s at 725℃,the volume fraction of lath bainite decreases while the volume fraction of ferrite increases.Almost all the retained austenite in the specimen under isothermal time of 86400 s decomposes.The tensile strength of the tested steel decreases with the prolongation of isothermal time,the yield strength decreases,while the elongation after fracture increases.When the isothermal time is 1800 s,the lower bainite structure with good match of strength and toughness can be obtained.

关 键 词：低碳微合金钢 等温时间 微观组织 力学性能 

分 类 号：TG151.2[金属学及工艺—热处理]