A487-4B铸钢CCT曲线测定及其组织硬度分析  

CCT curve determination,microstructure and hardness analysis of A487-4B cast steel

作　　者：王星 杨志斌 杜凌峙 WANG Xing;YANG Zhibin;DU Lingzhi(School of Material Science and Engineering,Dalian Jiaotong University,Dalian 116028,Liaoning pro.,China)

机构地区：[1]大连交通大学材料科学与工程学院,辽宁大连116028

出　　处：《焊接技术》2023年第11期47-50,I0001,共5页Welding Technology

摘　　要：采用Gleeble 1500D热模拟试验机对A487-4B低合金铸钢进行焊接热模拟试验,绘制其过冷奥氏体连续冷却转变曲线(CCT曲线),研究不同冷却速度对粗晶区相变组织及硬度的影响。结果表明:A487-4B钢的Ac1和Ac3分别为747℃和875℃,Ms为422℃;当冷却速度为0.2,0.5,1,5℃/s时,转变产物主要为铁素体、珠光体和条片状贝氏体;冷却速度为10℃/s时,转变产物为条片状贝氏体和板条马氏体;当冷却速度为20~50℃/s时,转变产物为板条马氏体和针状马氏体。随着冷却速度增加,相变组织中马氏体含量逐渐增加,其显微硬度呈增大的趋势。The Gleeble 1500D thermal simulation test machine was used to carry out welding thermal simulation test on A487-4B low alloy cast steel.The continuous cooling transformation curve(CCT curve)of supercooled austenite was drawn.The effects of different cooling rates on the microstructure and hardness of coarse-grain phase transformation were studied.The results showed that the Ac 1,Ac 3 and Ms of A487-4B were 747℃,875℃ and 422℃.When the cooling rate was 0.2,0.5,1 and 5℃s,the transformation products were mainly ferrite,pearlite and lath bainite.When the cooling rate was 10℃s,the transformation products were lath bainite and lath martensite.When the cooling rate was 20~50℃s,the transformation products were lath martensite and acicular martensite.With the increase of cooling rate,the content of martensite in the phase transition tissue increased and the microhardness showed an increasing trend.

关 键 词：低合金铸钢 焊接热模拟 CCT曲线 组织 硬度 

分 类 号：TG4[金属学及工艺—焊接] TG161