EH47止裂钢过冷奥氏体等温相变行为  

Isothermal transformation behavior of super-cooled austenite of EH47 crack-arresting steel

作　　者：胡文莉 侯娅丽[1] 邹宗晏 赵金华 黄志权[1,2] 马立峰[1,2] HU Wen-li;HOU Ya-li;ZOU Zong-yan;ZHAO Jin-hua;HUANG Zhi-quan;MA Li-feng(School of Mechanical Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China;Heavy Machinery Engineering Research Center of the Ministry of Education,Taiyuan University of Science and Technology,Taiyuan 030024,China;Shanxi North Jindong Chemical Industry Co Ltd,Yangquan 045000,China)

机构地区：[1]太原科技大学机械工程学院,山西太原030024 [2]太原科技大学重型机械教育部工程研究中心,山西太原030024 [3]山西北方晋东化工有限公司,山西阳泉045000

出　　处：《材料热处理学报》2024年第10期117-124,共8页Transactions of Materials and Heat Treatment

基　　金：太原科技大学博士科研启动基金(20232023);国家自然科学基金青年基金项目(52304409)。

摘　　要：采用高分辨热膨胀相变仪研究了EH47止裂钢过冷奥氏体等温冷却条件下的相变行为,利用扫描电镜(SEM)对试验钢在不同相变条件下的微观组织特征进行表征,基于获得的膨胀量曲线变化规律及微观组织特征,讨论了试验钢在不同等温相变条件下过冷奥氏体的演变规律。结果表明:在40℃/s冷却速率下,试验钢的相变开始温度为628~636℃;当等温相变温度介于630~570℃时,试验钢过冷奥氏体在等温转变过程中出现相变不完全现象;当等温温度为600和570℃时,试验钢的相变产物为由针状铁素体(AF)、贝氏体铁素体(BF)、粒状贝氏体(GB)及马氏体(M)组成的复相组织;当等温温度为540、510和480℃时,试验钢相变产物为由AF、贝氏体(B)及GB组成的复相组织,M消失。对于试验用EH47止裂钢而言,为了获得由AF、BF及GB构成的复相组织,需保证等温温度介于540~480℃,等温时间不少于10 min,以避免相变产物中出现M等组织。The phase transformation behavior of super-cooled austenite of EH47 crack-arresting steel during isothermal transformation was studied using a high-resolution thermal expansion transformation instrument.The microstructure characteristics of the experimental steel under different phase transformation conditions were characterized using scanning electron microscopy(SEM).Based on the obtained expansion curve and microstructure characteristics,the evolution of super-cooled austenite in the experimental steel under different isothermal transformation conditions was discussed.The results show that at a cooling rate of 40℃/s,the starting temperature of phase transformation in the experimental steel is 628-636℃.When the isothermal transformation temperature is between 630-570℃,the super�cooled austenite in the experimental steel exhibits transformation stasis phenomenon during the isothermal transformation.When the isothermal temperatures are 600 and 570℃,the phase transformation products of the experimental steel are a multiphase structure composed of acicular ferrite(AF),bainite ferrite(BF),granular bainite(GB)and martensite(M).When the isothermal temperatures are 540℃,510℃and 480℃,the phase transformation products of the experimental steel are a multiphase structure composed of AF,bainite(B)and GB,and M disappears.For the experimental EH47 crack-arresting steel,in order to obtain a multiphase structure composed of AF,BF and GB,it is necessary to ensure that the isothermal temperature is between 540-480℃and the isothermal time is not less than 10 min to avoid the appearance of M and other structures in the phase transformation products.

关 键 词：EH47止裂钢 等温相变 过冷奥氏体 

分 类 号：TG142.3[一般工业技术—材料科学与工程]