金属热处理 ›› 2021, Vol. 46 ›› Issue (5): 71-74.DOI: 10.13251/j.issn.0254-6051.2021.05.011

• 组织与性能 • 上一篇    下一篇

残留/逆转变奥氏体对改善高强度不锈钢-196 ℃超低温冲击性能的影响

邱旭扬帆, 杨卓越, 丁雅莉   

  1. 钢铁研究总院 特殊钢研究所, 北京 100081
  • 收稿日期:2021-02-25 出版日期:2021-05-25 发布日期:2021-07-21
  • 通讯作者: 杨卓越,教授级高工,博士,E-mail:Yangzhuoyue@nercast.com
  • 作者简介:邱旭扬帆(1995—),男,硕士研究生,主要研究方向为超低温用高强不锈钢韧化工艺,E-mail:18401669210@163.com。

Effect of retained/reversed austenite on improving -196 ℃ cryogenic impact property of high strength stainless steel

Qiu Xuyangfan, Yang Zhuoyue, Ding Yali   

  1. Institute for Special Steels, Central Iron and Steel Research Institute, Beijing 100081, China
  • Received:2021-02-25 Online:2021-05-25 Published:2021-07-21

摘要: 采用力学性能测试、SEM和XRD等手段研究了淬火+低温回火处理的0Cr16Ni6高强度不锈钢和过时效处理的00Cr11Ni11MoTi马氏体时效不锈钢,并分析了残留/逆转变奥氏体对试验钢超低温缺口抗拉强度和冲击性能的影响。结果表明,在两种试验钢室温强韧性相近的情况下,0Cr16Ni6钢在超低温下(-196 ℃)的缺口抗拉强度和冲击性能显著优于00Cr11Ni11MoTi钢。根据冲击试样远离断口和断口附近马氏体/奥氏体衍射峰的相对强度分别定量计算的残留/逆转变奥氏体含量,发现在裂纹形成和扩展过程中0Cr16Ni6钢有接近90%的残留奥氏体通过应变诱发相变生成马氏体,显著改善了超低温韧性;而过时效00Cr11Ni11MoTi钢形成的逆转变奥氏体具有较高的稳定性,难以发生应变诱发马氏体相变,改善超低温韧性作用程度有限。

关键词: 0Cr16Ni6高强度不锈钢, 00Cr11Ni11MoTi马氏体时效不锈钢, 残留奥氏体, 逆转变奥氏体, 超低温韧性

Abstract: High strength stainless steel 0Cr16Ni6 treated by quenching+low temperature tempering, and maraging stainless steel 00Cr11Ni11MoTi treated by over aging were studied by means of mechanical properties tests, SEM and XRD, and the effects of retained/reversed austenite in the tested steels on -196 ℃ cryogenic notched tensile strength and impact property were analyzed. The results show that, with the nearly same strength and toughness of the tested steels at room temperature, the notch tensile strength and impact property of the 0Cr16Ni6 steel are significantly higher than that of the 00Cr11Ni11MoTi steel at -196 ℃. According to the residual/reversed austenite contents quantitatively calculated based on the relative intensities of the martensite and austenite diffraction peaks far from the fracture and near the fracture, it is found that nearly 90% retained austenite in the 0Cr16Ni6 steel transforms into strain-induced martensite during the formation and propagation of cracks, which improves cryogenic impact property remarkably. But the reversed austenite formed by over-aging of the 00Cr11Ni11MoTi steel has higher stability, which is not suitable for strain-induced martensite transformation to occur, so the improvement of -196 ℃ cryogenic toughness is limited.

Key words: high strength stainless steel 0Cr16Ni6, maraging stainless steel 00Cr11Ni11MoTi, retained austenite, reversed austenite, cryogenic toughness

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