低合金高强度耐磨钢耐磨性与冷弯性能研究材料科学与工程专业论文.docxVIP

AbstractIn Abstract In recent years，the technology of low—alloy high—strength wear-resistant steel has developed rapidly in China．But domestic products still have large gap with foreign products in strength and performance，especially the stability of the finished product． To meet the technical demand of steel enterprise，the NM400 and NM500 wear—resistant steels were studied in this paper．The wear mechanism of erosion wear of NM400 and NM500 wear-resistant steels were investigated。The main causes for cold bending rupture were analyzed．The mechanism of cold bending rupture was discussed．The optimal heat-treatment process for wear-resistant steels were investigated。The microstructure and characteristic of carbide precipitation were analyzed．The results as follows (1)The main causes for cold bending rupture were the internal stress， non-metallic inclusion and non．unifonn microstructure． (2)The precipitated carbide was(Nb，Ti)C when the steel sample was quenched at 900。C and then tempered at 200 oC．This heat treatment was the optimized one for superior mechanical properties (3)The erosion wear mechanism is mainly micro—cutting at small impingement angle for NM400 wear-resistant steels．The erosion wear mechanism is mainly cutting and plastic deformation at small impingement angle for NM500 wear-resistant steels． (4)The erosion wear mechanism is mainly extrusion deformation at high impingement angle for NM400 and NM500 wear-resistant steels Key words：Low—alloy high-strength steels；Cold bending properties；Erosion wear； Microstructure；Non—metallic inclusion II 万方数据 目 目 录 摘 要 I Abstract．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．． ． ．． ．．．．．．．．．．．．．．．．．．．．．．．．．．，，．．．．．．．．．．．．．．．．．．II 目 录 ．．IIl 第一章文献综述 1 1．1前言 一l 1．2耐磨钢概述 ．．1 1．3低合金高强度耐磨钢分类 ．2 1．3．1低合金耐磨铸钢 ～2 1．3．2低合金高强度马氏体耐磨钢 ．3 1．3．3纳米结构双相耐磨钢 一3 1．4耐磨钢的磨损类型 。5 1．4．1冲蚀磨损 5 1．4．2影响气固冲蚀磨损的因素 ．5 1．5耐磨钢冷弯性能的影响因素 ．7 1．6本文研究的内容与目的 ．8 第二章实验材料与方法 9 2．1实验材料 一9 2．2实验方法 一9 2．2．1维氏硬度测试 一9 2．2．2拉伸实验 9 2．2．3冲击实验 ．10 2．2’4冲蚀磨损