金属热处理 ›› 2020, Vol. 45 ›› Issue (12): 160-168.DOI: 10.13251/j.issn.0254-6051.2020.12.032

• 组织与性能 • 上一篇    下一篇

新型纳米强化马奥复相钢的应力腐蚀行为

付航1,2, 梁小凯2, 孙新军2, 黄涛2   

  1. 1.河北科技大学 材料科学与工程学院, 河北 石家庄 050018;
    2.钢铁研究总院 工程用钢研究所, 北京 100081
  • 收稿日期:2020-05-19 出版日期:2020-12-25 发布日期:2021-01-14
  • 通讯作者: 梁小凯,博士,E-mail:83852546@qq.com
  • 作者简介:付 航(1996—),男,硕士研究生,主要研究方向为工程能源与石化用钢,E-mail:fh626983712@126.com。
  • 基金资助:
    国家重点研发计划(2017YFB0305100)

Stress corrosion behavior of novel nano-reinforced M&A dual-phase steel

Fu Hang1,2, Liang Xiaokai2, Sun Xinjun2, Huang Tao2   

  1. 1. School of Materials Science and Engineering, Hebei University of Science and Technology, Shijiazhuang Hebei 050018, China;
    2. Institute of Engineering Steel, Central Iron and Steel Research Institute, Beijing 100081, China
  • Received:2020-05-19 Online:2020-12-25 Published:2021-01-14

摘要: 采用慢应变速率拉伸以及WOL试样应力腐蚀试验研究一种含有逆转变奥氏体和纳米尺度多种析出相的新型纳米强化马奥复相钢在3.5%NaCl溶液的应力腐蚀行为。通过扫描电镜(SEM)、透射电镜(TEM)以及物理化学相分析观察了马奥复相钢的微观组织并解释了其应力腐蚀机理。结果表明,该马奥复相钢应力腐蚀敏感性较低,裂纹扩展速率较慢,抵抗裂纹能力强,抗应力腐蚀能力优异;Cl-会促进马奥复相钢应力腐蚀开裂的发生,使得与在空气中的拉伸试验结果相比,在3.5%NaCl溶液中的抗应力腐蚀性能有一定损失;由于具有亚稳态逆转变奥氏体使得马奥复相钢具有好的塑韧性,并且弱化了应力集中,阻碍裂纹扩展;位错群共平面性较差,不容易产生腐蚀的敏感通道;碳化物以及Cu纳米第二相析出在600 ℃高温回火后,在提高了材料强度的同时,也可改善钢对应力腐蚀的敏感性。

关键词: 慢应变速率拉伸, WOL试样应力腐蚀, 应力腐蚀, 逆转变奥氏体, 碳化物, Cu析出

Abstract: Stress corrosion behavior of a novel M&A dual-phase steel in 3.5%NaCl solution was studied by using slow strain rate tension and WOL specimen stress corrosion experiments. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and physicochemical phase analysis were used to observe the microstructure of the M&A dual-phase steel, and the anti-stress corrosion mechanism was explained. The results show that the M&A dual-phase steel has a low stress corrosion sensitivity, strong crack resistance and excellent stress corrosion resistance. In addition, Cl- can promote stress corrosion behavior of M&A dual-phase steel, resulting in a certain loss of stress corrosion performance in 3.5%NaCl solution compared with tensile test results in air.The metastable reversed austenite makes M&A dual-phase steel have good ductility and toughness, which weakens stress concentration and hinders crack growth. The common plane of dislocation group is poor, and it is not easy to produce corrosion sensitive channel. The secondary phase of carbide and Cu nanometer is precipitated at 600 ℃ after tempering, which greatly improves the strength of materials and the stability of stress corrosion of steel.

Key words: slow strain rate tension, stress corrosion of WOL specimen, stress corrosion, reversed austenite, carbide, Cu precipitate

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