• CN：11-2187/TH
  • ISSN：0577-6686
机械工程学报

›› 2011, Vol. 47 ›› Issue (6): 62-68.

• 论文 • 上一篇    下一篇

3Cr17Ni7Mo2SiN不锈钢硫化氢环境下的应力腐蚀开裂

刘智勇;董超芳;李晓刚   

  1. 北京科技大学腐蚀与防护中心;北京科技大学腐蚀与防护教育部重点实验室
  • 发布日期:2011-03-20

Stress Corrosion Cracking of 3Cr17Ni7Mo2SiN Stainless Steel in Sulfide Hydrogen Solutions

LIU Zhiyong;DONG Chaofang;LI Xiaogang   

  1. Corrosion and Protection Center, University of Science and Technology Beijing Key Laboratory of Corrosion and Protection of Ministry of Education, University of Science and Technology Beijing
  • Published:2011-03-20

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摘要： 用U形试样浸泡试验和慢应变速率拉伸试验(Slow strain rate test, SSRT)方法，结合断口形貌的扫描电子显微镜观察，研究3Cr17Ni7Mo2SiN不锈钢在硫化氢介质中的应力腐蚀开裂(Stress corrosion cracking，SCC)行为。研究表明：3Cr17Ni7Mo2SiN不锈钢在2.7pH4.5、H2S质量分数大于0.1%的含Cl–介质中均具有明显的SCC敏感性，SCC萌生的孕育时间随溶液pH的升高或H2S质量分数的降低而增长。在pH较低(pH=2.7)的条件下SCC扩展较快，开始阶段以沿晶形式扩展，然后过渡为穿晶模式；当溶液pH较高(pH=4.5)时，SCC主要以阳极溶解模式扩展、裂尖钝化明显、裂纹扩展速率较慢。夹杂物的存在、氢致开裂(Hydrogen induced cracking，HIC)作用和点蚀均能促进3Cr17Ni7Mo2SiN不锈钢的SCC的发生。

关键词: 不锈钢, 硫化氢, 应力腐蚀开裂

Abstract: Sulfide stress corrosion cracking (SCC) behavior of 3Cr17Ni7Mo2SiN stainless steel (SS) is investigated by using slow strain rate test(SSRT), U-bent specimen immersing test and fractography observation by scanning electronic microscopy(SEM). 3Cr17Ni7Mo2SiN SS is subject to SCC in test solutions containing NaCl (5% in mass) and H2S (no less than 0.1%) within pH range of 2.7 to 4.5. The time to SCC occurrence of 3Cr17Ni7Mo2SiN SS increases with the rising of pH or with the lowering of mass fraction of H2S. SCC under a low pH (pH=2.7) condition grows faster than that under a high pH condition, which initiates in an intergranular mode and then propagates transgranularly, however, in a high pH (pH=4.5) solution, SCC growth is slow with a blunt cracktip due to anodic dissolution mechanism. Inclusions, effects of hydrogen induced cracking (HIC) and corrosion pits will promote the occurrence of SCC.

Key words: Hydrogen sulfide, Stainless steel, Stress corrosion cracking(SCC)

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