金属热处理 ›› 2023, Vol. 48 ›› Issue (12): 1-6.DOI: 10.13251/j.issn.0254-6051.2023.12.001

• 工艺研究 •    下一篇

组织均匀化处理对Cr-Ni-Mo钢力学性能的影响

史长鑫1,2, 谷国超1,2, 崔树刚1,2, 许文花1,2, 肖桂勇1,2, 吕宇鹏1,2   

  1. 1.山东大学 材料科学与工程学院, 山东 济南 250061;
    2.山东大学 材料液固结构演变与加工教育部重点实验室, 山东 济南 250061
  • 收稿日期:2023-07-13 修回日期:2023-10-12 出版日期:2023-12-25 发布日期:2024-01-29
  • 通讯作者: 吕宇鹏,教授,博士,E-mail:biosdu@sdu.edu.cn
  • 作者简介:史长鑫(1999—),女,博士研究生,主要研究方向为金属材料热处理,E-mail:shi_changxin@163.com。
  • 基金资助:
    国家自然科学基金(52233018);山东省重点研发(重大创新工程)项目(2020CXGC010305,2021ZLGX01)

Effect of microstructure homogenization on mechanical properties of Cr-Ni-Mo steel

Shi Changxin1,2, Gu Guochao1,2, Cui Shugang1,2, Xu Wenhua1,2, Xiao Guiyong1,2, Lü Yupeng1,2   

  1. 1. School of Materials Science and Engineering, Shandong University, Jinan Shandong 250061, China;
    2. Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan Shandong 250061, China
  • Received:2023-07-13 Revised:2023-10-12 Online:2023-12-25 Published:2024-01-29

摘要: 采用阶梯式循环淬火+调质工艺对AISI 4330钢中产生的带状缺陷进行了均匀化处理,并探究均匀化处理过程的组织演变及其对力学性能的影响规律。结果表明,原始带状缺陷试样为铁素体+珠光体组织,带状组织评级为3级,EPMA结果显示存在较为严重的C、Cr、Mo元素偏析。经过多次高温淬火+调质,带状缺陷组织转变为由铁素体和含Cr碳化物以及回火索氏体组成的均匀组织,元素偏析得到一定程度的改善,C元素扩散明显,Cr、Mo元素偏析仍存在,阶梯式循环淬火的多次相变过程使得组织得到明显细化。此外,试验钢的力学性能得到提升,抗拉强度达到1200 MPa以上,硬度达到350 HBW左右,-40 ℃冲击吸收能量达到64.2 J左右,组织细化同时提高了试样的强度及塑韧性,碳化物的大量析出也有利于提高钢的强度。强度和韧性的提升更能满足压裂泵产品使用要求,提高AISI 4330钢使用寿命。

关键词: AISI 4330钢, 带状组织, 均匀化, 组织, 性能

Abstract: Homogenization treatment of AISI 4330 steel with banding defects was carried out through a step-by-step cyclic quenching and tempering heat treatment processes. The microstructure evolution and its effect on mechanical properties was studied during homogenization process. The results show that the original specimen with banded defects consists of ferrite and pearlite, with a banded structure level of 3. The element segregation of C, Cr, and Mo is significantly revealed by means of electron probe micro-analysis (EPMA). After undergoing multiple high-temperature quenching+quenching and tempering cycles, the microstructure transforms into a homogeneous structure consisting of ferrite, carbides containing Cr, and tempered sorbite. The element segregation is improved to a certain extent. Although the diffusion of C element is evident, segregation of Cr and Mo elements still exists. The step-by-step cyclic quenching process leads to lots of phase transformation, resulting in the refinement of microstructure of the steel. Furthermore, the mechanical properties of the steel are enhanced, resulting in tensile strength exceeding 1200 MPa, hardness of about 350 HBW, and impact absorbed energy at -40 ℃ of about 70 J. The refinement of microstructure contributes to the improvement in both strength and toughness of the specimen. Additionally, the large amount of precipitated carbonitride plays a beneficial role in increasing the strength of the steel. The enhanced strength and toughness characteristics fulfill the requirements of fracturing pump products and their service life.

Key words: AISI 4330 steel, band structure, homogenization, microstructure, properties

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