金属热处理 ›› 2023, Vol. 48 ›› Issue (11): 55-61.DOI: 10.13251/j.issn.0254-6051.2023.11.009

• 材料研究 • 上一篇    下一篇

Ni元素对新型热作模具钢热疲劳性能的影响

程曦1,2, 顾鹏程1, 曾艳1, 吴晓春1   

  1. 1.上海大学 材料科学与工程学院 省部共建高品质特殊钢冶炼与制备国家重点实验室, 上海 200444;
    2.上海航天信息研究所, 上海 201109
  • 收稿日期:2023-06-06 修回日期:2023-09-28 出版日期:2023-11-25 发布日期:2023-12-27
  • 通讯作者: 吴晓春,教授,博士生导师,E-mail:wuxiaochun@shu.edu.cn
  • 作者简介:程 曦(1999—),女,硕士研究生,主要研究方向为热作模具钢,E-mail:cx07300618@shu.edu.cn。
  • 基金资助:
    上海大学省部共建高品质特殊钢冶金与制备国家重点实验室与上海市钢铁冶金新技术开发应用重点实验室开放课题(SKLASS 2022-Z12);上海市科学技术委员会基金(19DZ2270200)

Effect of nickel on thermal fatigue properties of novel hot working die steel

Cheng Xi1,2, Gu Pengcheng1, Zeng Yan1, Wu Xiaochun1   

  1. 1. State Key Laboratory of Advanced Special Steel, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China;
    2. Shanghai Institute of Aerospace Information, Shanghai 201109, China
  • Received:2023-06-06 Revised:2023-09-28 Online:2023-11-25 Published:2023-12-27

摘要: 采用Uddeholm自约束热疲劳试验方法对SDDVA钢以及新型热作模具钢SDYZ1钢进行热疲劳试验,对比分析了材料热疲劳后表面形貌、截面裂纹、微观组织以及硬度变化,探讨了镍元素对材料冷热疲劳性能的影响。结果表明,与SDDVA钢相比,SDYZ1钢裂纹数量明显较少,深度较浅,高温表面软化程度更小,这主要是由于Ni元素聚集在晶界以及碳化物附近,对碳化物长大有钉扎作用,并且SDYZ1钢具有更高的高温强度,从而可以抵抗裂纹扩展。SDYZ1钢在热疲劳过程中析出尺寸较小的碳化物,碳化物聚集在晶界处可以有效阻碍晶粒长大,从而提高材料的抗疲劳性能。通过透射观察分析,SDYZ1钢热疲劳后粗化碳化物颗粒主要形态为不规则球状、细长杆状,主要存在类型为M23C6以及M6C,且SDYZ1钢碳化物尺寸整体比SDDVA钢的细小。

关键词: 热作模具钢, 镍元素, 热疲劳裂纹, 显微硬度, 碳化物

Abstract: Thermal fatigue test of SDDVA steel and a novel hot work die steel SDYZ1 was carried out by Uddeholm self-constrained thermal fatigue test method. The surface morphology, cross-section crack, microstructure and hardness of the materials after thermal fatigue were compared and analyzed. The effect of nickel element on the cold and thermal fatigue properties of the material was discussed. The results show that compared with the SDDVA steel, the number of cracks in the SDYZ1 steel is obviously less, the depth is shallower, and the degree of high temperature surface softening is smaller. This is mainly due to the fact that Ni element accumulates near grain boundaries and carbides, which has a pinning effect on carbide growth, and the SDYZ1 steel has higher high temperature strength, which can resist crack propagation. The SDYZ1 steel precipitates carbides with smaller size during thermal fatigue, and the accumulation of carbides at grain boundaries can effectively hinder grain growth, thereby improving the fatigue resistance of the material. Through transmission observation and analysis, the main forms of coarse carbide particles after thermal fatigue of the SDYZ1 steel are irregular spherical and slender rods, and the main types are M23C6 and M6C, and the size of carbides in the SDYZ1 steel is smaller than that in the SDDVA steel.

Key words: hot work die steel, nickel element, thermal fatigue cracks, microhardness, carbides

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