金属热处理 ›› 2020, Vol. 45 ›› Issue (2): 134-137.DOI: 10.13251/j.issn.0254-6051.2020.02.026

• 工艺研究 • 上一篇    下一篇

回火工艺对ZG30Mn铸钢组织与力学性能的影响

唐彩1,2, 陈波1,2, 范汇吉1,2   

  1. 1. 江苏徐工工程机械研究院有限公司, 江苏 徐州 221004;
    2. 徐工集团 高端工程机械智能制造国家重点实验室, 江苏 徐州 221004
  • 收稿日期:2019-10-10 出版日期:2020-02-25 发布日期:2020-04-03
  • 作者简介:唐 彩(1988—),女,工程师,硕士,主要从事工程机械零部件耐磨技术及热处理工艺研究,联系电话:0516-87565911,E-mail:tcxcmg@126.com。

Effect of tempering process on microstructure and mechanical properties of ZG30Mn cast steel

Tang Cai1,2, Chen Bo1,2, Fan Huiji1,2   

  1. 1. Jiangsu XCMG Construction Machinery Research Institute Ltd., Xuzhou Jiangsu 221004, China;
    2. State Key Laboratory of Intelligent Manufacturing of Advanced Construction Machinery, Xuzhou Construction Machinery Group, Xuzhou Jiangsu 221004, China
  • Received:2019-10-10 Online:2020-02-25 Published:2020-04-03

摘要:

基于光学显微镜(OM)对不同回火工艺参数下的ZG30Mn铸钢显微组织进行观察分析,同时进行拉伸性能、布氏硬度与冲击性能等力学性能检测。结果表明,经不同回火温度与回火时间处理后,ZG30Mn铸钢显微组织均以不同形态的回火索氏体为主。在相同的保温时间(90 min)下,随着回火温度(580、600、620、640 ℃)的升高,ZG30Mn铸钢的强度与硬度均不断减小,断后伸长率和冲击吸收能量均呈不断增大的趋势。在相同的回火温度(620 ℃)下,随着回火时间(30、60、90、120 min)的增加,ZG30Mn铸钢的强度与硬度均不断减小,但断后伸长率和冲击吸收能量呈现先增后减的变化趋势。回火温度对马氏体向索氏体转变过程起关键作用,温度的升高将影响α-Fe相回复和再结晶的效率,弥散的细小渗碳体逐渐长大并球化,导致强度与硬度降低,断后伸长率和冲击吸收能量增加。而回火保温时间将决定渗碳体的长大程度,随回火时间的增加,渗碳体的聚集长大导致断后伸长率和冲击吸收能量降低。

关键词: 回火工艺, ZG30Mn铸钢, 显微组织, 力学性能

Abstract:

The microstructure of tempered ZG30Mn cast steel under different tempering parameters was observed and analyzed by optical microscopy (OM). The mechanical properties of the steel were also tested, including tensile properties, Brinell hardness and impact properties. The results show that the microstructure of the steel treated by different tempering processes is mainly composed of tempered sorbite. When the holding time is 90 min, with the increase of the tempering temperature (580, 600, 620, 640 ℃), the hardness and strength gradually decrease, and the elongation and impact absorbed energy gradually increase. When the tempering temperature is 620 ℃, with the increase of tempering time(30, 60, 90, 120 min), the hardness and strength of the steel gradually decrease, while the elongation and impact absorbed energy increase first and then decrease. Tempering temperature plays a key role in the transformation process from martensite to sorbite. The increase of tempering temperature will affect the efficiency of recovery and recrystallization of α-Fe phase. The dispersed fine cementite gradually grows up and spheroidizes, resulting in the decrease of hardness and strength, and the increase of elongation and impact absorbed energy. Tempering holding time will determine the growth of cementite. With the increase of tempering time, the aggregation and growth of cementite will lead to the decrease of elongation and impact absorbed energy.

Key words: tempering process, ZG30Mn cast steel, microstructure, mechanical properties

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