变质处理对高硅铸钢残留奥氏体及力学性能的影响  

Effects of modification on retained austenite and mechanical properties of austempered high silicon cast steel

作　　者：陈祥[1] 

机构地区：[1]清华大学机械工程系,教育部先进成形制造重点实验室,北京100084

出　　处：《材料热处理学报》2011年第3期79-84,共6页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(50974080)

摘　　要：采用X射线衍射对RE/V/Ti复合变质处理后高硅铸钢等温淬火组织中残留奥氏体量及残留奥氏体含碳量进行了测定。采用透射电子显微镜(TEM)和光学显微镜(OM)对高硅铸钢等温淬火热处理后的显微组织以及残留奥氏体分布形态进行了研究。结果表明,等温温度低于385℃时,复合变质处理高硅铸钢中残留奥氏体量及残留奥氏体平均含碳量均低于未变质高硅铸钢;385℃等温处理时,两者的残留奥氏体量及残留奥氏体平均含碳量基本相同。等温淬火高硅铸钢显微组织中残留奥氏体呈两种分布形态:薄膜状及块状。在相同的等温温度下,复合变质处理使残留奥氏体薄膜厚度以及贝氏体铁素体板条厚度、长度均大幅度减小,块状残留奥氏体的量大为减少,有利于高硅铸钢综合力学性能的提高。The volume fraction and carbon content of retained austenite in austempered high silicon（AHS） steel before and after treating with a modifier containing rare earth elements,vanadium and titanium（so called RE/V/Ti modifier） and austempered at different temperatures were investigated by XRD method.The microstructure was characterized by means of transmission electron microscopy（TEM） and optical microscopy（OM）.The results indicate that both of the volume fraction and carbon content of retained austenite in modified steel are less than those of unmodified steel at the same austempering temperatures when the austempering temperature is lower than 385 ℃.While the austempering temperature is higher than 385 ℃,they are basically same in modified and unmodified steels.The retained austenite has two typical morphology,named film shaped and blocky retained austenite.After modification the amount of blocky shaped retained austenite and the length of bainitic ferrite laths decrease,and the distribution of austenite is more homogeneous which is helpful to improve the mechanical properties.

关 键 词：高硅铸钢 等温淬火 残留奥氏体 变质处理 

分 类 号：TG142.13[一般工业技术—材料科学与工程]