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
张九鑫 1任潇健 1金东正 1田勇1
作者信息
- 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
- 折叠
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1 050℃时,原奥氏体晶粒尺寸从14 μm增加至28 μm;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241 J的冲击功的重要原因.
Abstract
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 14 μm to 28 μm,with the reheating temperature of the test rolled steels rising from 890℃to 1 050℃;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Key words
EH47 crack arrest steel/prior-austenite grain/microstructure/M/A islands/impact energy引用本文复制引用
基金项目
辽宁省"兴辽英才"计划项目(XLYC2007036)
出版年
2024
NETL
NSTL
万方数据