低碳含硼钢方坯表面淬火工艺及组织演变  

Surface quenching process and microstructure evolution of low carbon boron-containing steel billet

作　　者：张梦远 龙木军[1] 左小坦 钱亮 张亚兵 黄雁 陈登福[1] ZHANG Meng-yuan;LONG Mu-jun;ZUO Xiao-tan;QIAN Liang;ZHANG Ya-bing;HUANG Yan;CHEN Deng-fu(College of Materials Science and Engineering,Chongqing University,Chongqing 400030,China;Steelmaking Department,Wuhu Xinxing Ductile Iron Pipes Co Ltd,Wuhu 241002,China;Engineering Department,CCTEC Engineering Co Ltd,Wuhan 430073,China)

机构地区：[1]重庆大学材料科学与工程学院,重庆400030 [2]芜湖新兴铸管有限责任公司炼钢部,安徽芜湖241002 [3]中冶南方连铸技术工程有限责任公司,湖北武汉430073

出　　处：《材料热处理学报》2021年第12期93-101,共9页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(51874060)。

摘　　要：利用建立的淬火-自回火过程传热模型开展了铸坯表面淬火试验研究,分析了淬火后铸坯表层组织的演变规律以及相应组织的形成条件。结果表明:表面淬火可以有效消除铸坯表层组织中的膜状铁素体,形成一定的淬透深度。在40~60 s的淬火时间内,淬透深度从8 mm提高到10 mm;在60~100 s的淬火时间内,淬透深度基本保持在10 mm左右。在显微组织分析的基础上,结合铸坯表层区域传热分析,给出了低碳含硼钢的两种在线表面淬火工艺方案,其预期表层组织分别为贝氏体(弱冷方案)与回火索氏体(强冷方案)。对于弱冷方案,淬透深度为4~5 mm;对于强冷方案,淬透深度可达到10 mm左右。Based on the established heat transfer model of quenching and self-tempering process,the surface quenching test of billet was carried out,and the surface microstructure evolution of the billet after quenching and the formation conditions of corresponding microstructure were analyzed.The results show that surface quenching can effectively eliminate the membranous ferrite in the surface microstructure of the billet and form a certain hardening depth.In the quenching time of 40-60 s,the hardening depth increases from 8 mm to 10 mm,and can be maintained at about 10 mm when the quenching time is in the range of 60-100 s.On the basis of microstructure analysis and heat transfer analysis of the billet surface area,two on-line surface quenching process schemes of low carbon boron-containing steel are given,and the expected surface microstructure is bainite(weak cooling scheme)and tempered sorbite(strong cooling scheme).For the weak cooling scheme,the hardening depth is 4-5 mm,and for the strong cooling scheme,the hardening depth can reach about 10 mm.

关 键 词：表面淬火 膜状铁素体 传热 淬透深度 

分 类 号：TG142.3[一般工业技术—材料科学与工程]