Influence mechanism of heat treatment on corrosion resistance of Te-containing 15-5PH stainless steel
作者
单位
1School of Metallurgical and Ecological Engineering、University of Science and Technology Beijing、Beijing、China 2Key Laboratory for Corrosion and Protection of the Ministry of Education、Institute of Advanced Materials & Technology、University of Science and Technology Beijing、Beijing、China 3National Materials Corrosion and Protection Data Center、University of Science and Technology Beijing、Beijing、China
关键词
收录来源
International Corrosion Congress · 第22届国际腐蚀大会
摘要
In this study, the corrosion resistance mechanism of the Te and heat treatments on martensitic stainless steel (15 -5PH steel) was investigated. Heat treatment affected the dislocation density of the Te -containing 15 -5PH steel and reduced its corrosion tendency. Electrochemical dissolution of the MnS -Te inclusions induced pitting c orrosion. Heat treatment significantly affects the potential difference between the Te-modified inclusions and the steel matrix, consequently influencing the emergence of pitting corrosion. Heat treatment improved the anti-corrosion properties of 15-5PH steel by transforming it from an active state to a passive state. The Mott - Schottky test results show that the passive film always exhibits n -type semiconductor characteristics and that the defect density of the passive film is reduced by the heat treatment. Heat treatment facilitated the enrichment of Cr, Te, and TeO 3 in the passivation film, resulting in its improved stability and corrosion resistance. The formation of an insoluble or slowly dissolved tellurite film through Te anodic oxidation, along with the self-healing properties of TeO3, improved the repassivation capability of the passivation film of the steel.