低铬粉末冶金烧结硬化钢的显微组织及力学性能  

Microstructure and mechanical properties of powder metallurgy sinter hardening steels with low Cr content

作　　者：杨洁 刘乐 黄晓琳 YANG Jie;LIU Le;HUANG Xiaolin(Höganäs China Co.,Ltd.,Shanghai 201799,China)

机构地区：[1]赫格纳斯(中国)有限公司,上海201799

出　　处：《粉末冶金技术》2023年第4期345-349,355,共6页Powder Metallurgy Technology

摘　　要：烧结硬化作为一种经济有效的高强度粉末冶金零件生产工艺,可以通过控制烧结后冷却速度影响显微组织(马氏体含量),从而改善材料的最终性能。本文介绍了一种新开发的低Cr预合金烧结硬化材料Astaloy^(TM)CrA,研究其在不同烧结温度和冷却速度下的力学性能和显微组织,并与常见的粉末冶金烧结硬化钢Distaloy?DH进行对比。研究表明,在压制密度为7.0 g·cm^(-3)并添加同等含量碳的条件下,添加质量分数2%Ni的Astaloy^(TM)CrA混粉淬透性更高,获得比其他两种材料更高的马氏体含量及表观硬度。Astaloy^(TM)CrA在1250℃烧结、冷却速度为3℃·s^(-1)时,硬度最高达到HRC 38;在1250℃烧结,冷却速度为1℃·s^(-1)时,强度和韧性最佳。Sinter hardening is an established cost-effective process to produce high strength powder metallurgy parts by controlling the cooling speed to affect the sintered microstructure(martensite content)to improve the final performance.A newly developed pre-alloy sinter hardening steels with low Cr content(Astaloy^(TM)CrA)was introduced in this paper,the mechanical properties and microstructure under the different sintering temperature and cooling rate were investigated,and the common powder metallurgy sinter hardening material(Distaloy®DH)was referenced for the comparison.In the results,under the pressing density of 7.0 g·cm^(−3)at the same carbon level,the Astaloy^(TM)CrA added with 2%nickel(mass fraction)has the highest hardenability which can obtain the highest martensite content and the macro hardness compared to the other materials.Astaloy^(TM)CrA sintered at 1250℃and followed with the cooling rate of 3℃·s^(-1)can achieve the hardness of HRC 38,which can obtain the optimum strength and toughness by sintered at the same temperature and followed with the lower cooling rate of 1℃·s^(-1).

关 键 词：粉末冶金 烧结硬化 微观组织 力学性能 

分 类 号：TF121[冶金工程—粉末冶金]