深冷处理工艺对M2高速钢显微组织与性能的影响  

Influence of Deep Cryogenic Treatment Process on Microstructure and Properties of M2 High Speed Steel

作　　者：胡海波 朱丽慧[1] 涂有旺 段元满 吴晓春[1] 顾炳福 HU Haibo;ZHU Lihui;TU Youwang;DUAN Yuanman;WU Xiaochun;GU Bingfu(School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China;Jiangsu Fuda Special Steel Co.,Ltd.,Yangzhong 212200,Jiangsu,China)

机构地区：[1]上海大学材料科学与工程学院,上海200444 [2]江苏省福达特种钢有限公司,江苏扬中212200

出　　处：《材料导报》2023年第9期167-172,共6页Materials Reports

基　　金：国家重点研发计划(2016YFB0300403);镇江“金山英才”计划,江苏省高层次创新创业人才引进计划。

摘　　要：对M2高速钢进行不同时间或循环三次的深冷处理,然后测量深冷处理前后试样的硬度、冲击韧性以及高温摩擦磨损性能,结合X射线物相分析、扫描和透射电子显微分析技术研究深冷处理工艺对M2高速钢硬度、红硬性、冲击韧性、高温耐磨性和组织的影响及机理。结果表明:深冷处理后,残余奥氏体含量降低,一次共晶碳化物分解,二次碳化物弥散析出,并且孪晶马氏体细化。因此,深冷处理后M2高速钢的室温硬度、红硬性、冲击韧性和高温耐磨性均得到提高。延长深冷时间和循环深冷处理均利于提升M2高速钢的性能。循环三次深冷后M2高速钢的显微组织的改善和性能的提升最明显。较未深冷试样,循环三次深冷后试样残余奥氏体含量降低50%,大尺寸一次碳化物数量减少75.2%,二次碳化物析出增加约296%,室温硬度提高2.27%,红硬性提高2.7%,冲击韧性提高15.6%,高温相对耐磨性提高140%。与一次长时间深冷相比,循环深冷处理在提升性能和降低成本方面更有优势。The M2 high speed steel was cryogenically treated for different time or repeated for three cycles,and the influence and mechanism of deep cryogenic treatment on the hardness,red hardness,impact toughness,wear resistance at high temperature and microstructure of M2 high speed steel were studied by measuring hardness,impact toughness and high-temperature friction and wear property combined with X-ray phase analysis,scanning electron microscopic analysis and transmission electron microscopic analysis.The results showed that after deep cryogenic treatment,the amount of retained austenite reduced,the primary eutectic carbides decomposed,the secondary carbides precipitated dispersedly,and the twin martensite was thinned in M2 high speed steel.Therefore,the hardness,red hardness,impact toughness and high temperature wear resistance improved.The prolonging of deep cryogenic time and cyclic cryogenic treatment were beneficial to improving the properties.The microstructure and properties of M2 steel were improved most significantly after deep cryogenic treatment for three times.Compared with the specimen without deep cryogenic treatment,the specimen after deep cryogenic treatment for three times led to 50% reduction in retained auste-nite,75.2% reduction in large-sized primary carbides and 296% increase in secondary carbides.Consequently,after deep cryogenic treatment for three times,the room temperature hardness increased 2.27%,red hardness increased 2.7%,impact toughness increased 15.6%,and relative wear resistance at high temperature increased 140%.Hence cyclic deep cryogenic treatment is more beneficial for property improvement and cost reduction compared with the long-time deep cryogenic treatment.

关 键 词：M2高速钢 深冷处理 显微组织 力学性能 耐磨性 

分 类 号：TG430.40[金属学及工艺—焊接]