金属热处理 ›› 2020, Vol. 45 ›› Issue (11): 197-200.DOI: 10.13251/j.issn.0254-6051.2020.11.037

• 工艺研究 • 上一篇    下一篇

G20CrNi2MoA钢的回火特性及在柴油机针阀体上的应用

杨欢1, 冉启燕1, 范希杰1, 杨静1, 刘悦1, 商荣凯1,2   

  1. 1.重庆红江机械有限责任公司, 重庆 402162;
    2.船舶与海洋工程动力系统国家工程实验室, 重庆 402162
  • 收稿日期:2020-04-15 出版日期:2020-11-25 发布日期:2020-12-29
  • 作者简介:杨 欢(1993—),女,工程师,主要研究方向为材料强化、失效及保护,E-mail:1904347510@qq.com
  • 基金资助:
    工信部“高技术船舶科研计划—船用低速机工程(一期)”(工信部联装函[2017]21号)

Tempering characteristics of G20CrNi2MoA steel and its application in needle valve body for diesel engine

Yang Huan1, Ran Qiyan1, Fan Xijie1, Yang Jing1, Liu Yue1, Shang Rongkai1,2   

  1. 1. Chongqing Hongjiang Machinery Co., Ltd., Chongqing 402162, China;
    2. National Engineering Laboratory for Marine Power System, Chongqing 402162, China
  • Received:2020-04-15 Online:2020-11-25 Published:2020-12-29

摘要: 研究了由G20CrNi2MoA渗碳轴承钢制作的柴油机渗碳针阀体的回火特性。对该材料的化学成分、力学性能及显微组织进行了详细的检测,并研究制定了最佳的热处理工艺。在180~250 ℃不同温度下对针阀体试样进行回火处理,通过光学显微镜对针阀体座面及心部组织进行了分析,XRD检测了端面残奥含量,并用显微维氏硬度计对座面渗层及心部进行了硬度分析。结果表明,当回火温度为230 ℃时,G20CrNi2MoA钢针阀体的座面硬度可达740 HV(61.8 HRC),端面残奥体积分数为0.25%,能保证针阀体在230 ℃左右温度下具有良好的耐磨性和组织、尺寸的稳定性。试制出的针阀体寿命较长,能满足柴油机对针阀体的使用要求。

关键词: 柴油机, G20CrNi2MoA钢, 针阀体, 回火特性

Abstract: Tempering characteristics of carburized needle valve body for diesel engine made of G20CrNi2MoA carburizing bearing steel was studied. The chemical composition, mechanical properties and microstructure were tested in detail. The preferable heat treatment process was optimized. The needle valve body specimens were tempered at different temperatures between 180 ℃ and 250 ℃. The microstructure of the pyramidal face and core was analyzed by metallographic microscope, the residual austenite content of the end surface was detected by XRD, and the hardness of the pyramidal face and core was analyzed by means of microhardness tester. The results show that the pyramidal face hardness of G20CrNi2MoA needle nozzle can reach 740 HV(61.8 HRC) when tempered at 230 ℃, and the volume fraction of residual austenite in end surface is 0.25%, it can ensure the needle nozzle has a good wear resistance and stability of structure and size at the operating temperature of 230 ℃. The needle nozzle has a long service life and can meet the requirements of the diesel engine.

Key words: diesel engine, G20CrNi2MoA steel, needle nozzle, tempering characteristics

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