Purpose

The purpose of this paper is to investigate, the effects of residual stress and microstructure on the corrosion behaviour of carburised 18CrNiMo7-6 steel in a 3.5% NaCl aqueous solution.

Design/methodology/approach

The electrochemical tests were conducted using an electrochemical workstation with a three-electrode system in a 3.5% NaCl aqueous solution, the residual stress of each working face was measured by a high-speed residual stress analyser, and microstructure of different carburised layers were observed scanning electron microscopy. Finally, the effect of carbon content, microstructure and residual stress on the corrosion behaviour of the steel was discussed.

Findings

The results showed that the residual compressive stress in the carburised layer initially increased and subsequently decreased with increasing depth of the carburised layer, reaching stability in the matrix layer. The electrochemical tests before and after stress reduction showed that the electrochemical impedance and the electrochemical potential increased with the reduction of residual compressive stress.

Originality/value

The residual compressive stress in the carburised layer initially increases and subsequently decreases with increasing carburised layer depth. The electrochemical impedance and the electrochemical potential increased with the reduction of residual compressive stress. The general relationship between electrochemical potential and residual stress was established.

中文翻译：

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残余应力和显微组织对渗碳18CrNiMo7-6钢耐蚀性的影响

目的

本文的目的是研究残余应力和显微组织对渗碳的18CrNiMo7-6钢在3.5％NaCl水溶液中的腐蚀行为的影响。

设计/方法/方法

使用带有三电极系统的电化学工作站在3.5％NaCl水溶液中进行电化学测试，通过高速残余应力分析仪测量每个工作面的残余应力，并扫描不同渗碳层的微观结构电子显微镜。最后，讨论了碳含量，显微组织和残余应力对钢腐蚀行为的影响。

发现

结果表明，渗碳层中的残余压缩应力随着渗碳层深度的增加而先增加然后降低，从而达到基体层的稳定性。应力降低前后的电化学测试表明，随着残余压应力的降低，电化学阻抗和电化学势均增加。

创意/价值

随着渗碳层深度的增加，渗碳层中的残余压应力开始增大，随后减小。电化学阻抗和电化学势随残余压应力的降低而增加。建立了电化学势和残余应力之间的一般关系。