等温淬火Mn-Cr白口铸铁的研制

Development of Austempered Mn-Cr White Cast Iron

阐述了等温淬火白口铸铁中主要元素的作用及选择原则。研究了锰、铬元素对力学性能的影响以及等温淬火温度对力学性能和抗磨性能的影响 ,并与铸态合金白口铸铁、高铬铸铁及高锰钢的抗磨性进行比较。结果表明 ,选取适量的碳、硅元素 ,并加入适量的锰和少量铬以及微量的铋有利于铸态下获得全白口 ,等温淬火后得到无碳化物贝氏体加奥氏体复相基体组织。在优选化学成分的基础上 ,于 32 5℃等温淬火 2h可获得硬度和韧性均较高的奥氏体和贝氏体组织 ,且耐磨性能良好 ,是一种有希望的廉价耐磨新材料。

The function and selecting principle of major elements of austempered white cast iron are introduced.The effects of Mn,Cr element and the effects of austempering temperature on mechanical properties and abrasive wear resistance of alloyed white cast iron are studied.The abrasive wear resistance of the alloyed white cast iron austempered at different temperature was compared with that of the as-cast alloyed white cast iron,high chromium cast iron and high manganese steel.The results showed that the as-cast white cast iron and multi-phases structure of free-carbide bainite and austenite after austempering are obtained by correctly selecting carbon and silicon content,adding proper manganese content and a small mount of chromium as well as a trace bismuth.Manganese can be used to improve the hardenability and to reduce productive cost.Based on optimum chemical compositions,the austenitic-bainitic alloyed white cast iron by austempering at 325℃ for 2h,with higher hardness and toughness and better abrasive wear resistance can be obtained.This white cast iron is a new economical and promising wear resistant material.