钢铁结构材料的组织细化

采用组织超细化提高钢铁结构材料的强细性和使用寿命是上个世纪90年代中期以来的发展趋势。介绍了我国973第一批项目之一“新一代钢铁材料重大基础研究”的主要5种超细化方法，适用于不同强度和显微组织的钢类：具有铁素体 珠光体(F P)的碳素或低合金钢，采用强力轧制和形变诱导铁素体相交(DIFT)技术；在薄板坯连铸连轧现代流程下，采用第二相(析出相)的纳米化控制；具有低碳贝氏体或针状铁素体的微合金钢采用形变诱导析出(DIP)和中温相交控制；采用调质处理的合金结构钢，应用新的合金设计思路以提高界面温度，增加氢陷阱和二次硬化路线，快速超细晶热处理的综合技术；发展无碳化物贝／马组织和富碳残奥薄膜以做到中低温回火合结钢的强韧化优良配合。

MICROSTRUCTURAL REFINEMENT OF STRUCTURAL STEELS

Ultra fine microstructure could increase strength, toughness and work life for steel products, this is developing trend since middle of 90 th in last century of the world. In this paper, it has been introduced by fruitable results coming from National Project of "Fundamental Research on New Generation of Iron and Steel Materials in China" that five methods which perform Ultra fine microstructure process: For Ferrite Pearlite (F P) microstructure, the heavy rolling and DIFT technology (Deformation Induced Ferrite Transformation) is applied; In Thin slab casting and rolling (TSCR) process, controlling of nano meter precipitator has been performed;For low carbon bainite steel (LCB) and Acicular Ferrite (A.F) microstructure, the combination of Deformation Induced precipitation (DIP) and controlling at middle temperature phase transformation is used, and developing "Relaxation precipitation controlling" (RPC) technology;For alloy construction steel with quench and high temperature tempering, heat treatment technique with getting Ultra fine prior austenite grain size, increase of hydrogen traps and interface strength are combined;Developing "carbide free bainite / martensite microstructure with retained austenite film" technique is introduced.