奥氏体晶粒细化对特厚EH47止裂钢组织性能的影响  

Effect of Austenite Grain Refinement on Microstructure and Properties of Ultra‑Heavy EH47 Crack Arrest Steel

作　　者：张九鑫 任潇健 金东正 田勇[1] ZHANG Jiu-xin;REN Xiao-jian;JIN Dong-zheng;TIAN Yong(State Key Laboratory of Rolling and Automation,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学轧制技术及连轧自动化国家重点实验室,辽宁沈阳110819

出　　处：《东北大学学报（自然科学版）》2024年第5期643-651,共9页Journal of Northeastern University(Natural Science)

基　　金：辽宁省“兴辽英才”计划项目(XLYC2007036)。

摘　　要：常规工艺下特厚船舶用钢奥氏体晶粒细化的程度受限,导致极小尺寸奥氏体晶粒对钢板组织性能的影响尚不明确.利用二次奥氏体化法和热机械控制工艺,研究了细化奥氏体晶粒对特厚EH47止裂钢的显微组织演化及力学性能的影响.结果表明:试轧钢的加热温度从890℃升高至1050℃时,原奥氏体晶粒尺寸从14μm增加至28μm;铁素体含量的降低导致大角度晶界数量比例由57.4%降低至40.5%;马氏体/奥氏体(martenite/austenite,M/A)岛体积分数从2.0%增加至6.5%;钢板的屈服强度从440 MPa提高到488 MPa.890℃轧制钢板的单位体积有效晶界面积为269.0 mm-1,是其显微组织细化、均匀化,并在-100℃时具有241J的冲击功的重要原因.The degree of austenite grain refinement in steel for ultra‐heavy ships is limited by conventional processes,resulting in the effect of very small‑size austenite grains on the organization and properties of the steel plate being unclear.The effect of austenite grain refinement on the microstructure evolution and mechanical properties of ultra‐heavy EH47 crack arrest steel was investigated by using the secondary austenitization method and thermo mechanical control process.The results showed that the prior‐austenite grain size increased from 14μm to 28μm,with the reheating temperature of the test rolled steels rising from 890℃to 1050℃;the decrease of ferrite content reduced the proportion of large angle grain boundary from 57.4%to 40.5%;the volume fraction of martenite/austenite(M/A)islands increased from 2.0%to 6.5%;the yield strength of the steels increased from 440 MPa to 488 MPa.The effective interfacial area per unit volume of 890℃rolled steel was 269.0 mm-1,which was the key reason for its microstructure refinement,homogenization,and 241 J impact energy at-100℃.

关 键 词：EH47止裂钢 原奥氏体晶粒 显微组织 M/A岛 冲击功 

分 类 号：TG142.1[一般工业技术—材料科学与工程]