ISSN:1003-8620

CN:42-1243/TF

主管:中信泰富特钢集团股份有限公司

主办:大冶特殊钢有限公司

特殊钢 ›› 2024, Vol. 45 ›› Issue (6): 88-94.DOI: 10.20057/j.1003-8620.2024-00101

• • 上一篇    下一篇

双时效工艺对复合析出强化型超高强度钢的组织与性能的影响

赵佳伟1, 田家龙2, 杨平1, 战东平2, 姜周华2   

  1. (1 中航西安飞机工业集团股份有限公司, 西安710089;2 东北大学冶金学院, 沈阳 110819)
  • 收稿日期:2024-04-20 出版日期:2024-11-30 发布日期:2024-12-01
  • 作者简介:赵佳伟 (1996—),男,硕士,助理工程师
  • 基金资助:
    辽宁省科技计划联合计划项目基金资助(2023 JH2/101700302)

Effect of Dual-aging Process on Microstructure and Properties of Co-precipitation Hardening Ultra-high Strength Steel

Zhao Jiawei1, Tian Jialong2, Yang Ping1, Zhan Dongping2, Jiang Zhouhua2   

  1. (1 Avic Xi’an Aircraft Industry Group Co., Ltd., Xi’an 710089, China;2 School of Metallurgy, Northeastern University, Shenyang 110819, China)
  • Received:2024-04-20 Published:2024-11-30 Online:2024-12-01

摘要: 为了使新开发的Fe-C-Cr-Ni-Mo-Co-Al复合析出强化型超高强度钢实现较好的强韧性匹配,本研究深入探讨了双时效工艺对实验钢组织演化和力学性能的作用机制,确定最优的时效工艺参数,以达到优异的强度与韧性。研究结果表明,正常时效工艺,实验钢具有较高的抗拉强度(1924 MPa),但是屈服强度和韧性较差。双时效工艺(570 ℃×0.5 h+480 ℃×20 h)可以使钢的强度和韧性达到良好的匹配,经优化的双时效工艺后,抗拉强度仅下降42 MPa的情况下,屈服强度提高了224 MPa,冲击功提高了77%,其中,冲击功的误差为±0.5 J。组织表征与理论计算结果表明,析出强化相及逆转变奥氏体的含量对实验钢的强韧性起决定性作用,高温预时效有利于钢中奥氏体和二次硬化析出相的形核长大,逆转变奥氏体的形成有助于提升实验钢的冲击功,但奥氏体含量过高会显著降低钢的强度。当在610 ℃持续时效处理,沉淀相粗化和马氏体组织回复会导致强度和韧性降低。

关键词: 复合析出强化型超高强度钢, 双时效工艺, 强韧性, 动力学计算

Abstract:  In order to achieve better strength and toughness matching for the newly developed Fe-C-Cr-Ni-Mo-Co-Al co-precipitation hardening ultra-high strength steel, this study deeply discussed the mechanism of dual-aging process on the microstructure evolution and mechanical properties of experimental steel, and determined the optimal aging process parameters to achieve excellent strength and toughness. The results show that the experimental steel could achieve higher ultimate tensile strength (1924 MPa) under normal aging treatment, but lower yield strength and toughness. The dual-aging technology (570 ℃×0.5 h+480 ℃×20 h) could achieve superior combination of strength and toughness. After the optimal dual-aging treatment, the yield strength has been increased by 224 MPa and the impact work has been increased by 77% while the ultimate tensile strength was merely decreased by 42 MPa, with an error range of ±0.5 J for the impact toughness.The microstructure characterization and theoretical calculation results show that the content of precipitation-hardening phases and reversed austenite play decisive role in the strength and toughness of the experimental steel. The higher pre-aging temperature is benefit to the nucleation and growth of the reversed austenite and the secondary hardening precipitates in the experimental steel. The formation of reversed austenite is helpful to increase the impact energy of the test steel, but high austenite content would significantly reduce the strength of the steel. When continuously aged at 610 ℃, precipitates coarsening and martensite microstructure recovery would lead to a decrease in strength and toughness.

Key words:  , Co-precipitation Hardening Ultra-high Strength Steel; Dual-aging Process; Strength and Toughness; Dynamic Calculation

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