Original Research ARTICLE
Effect of pre-passivation on the corrosion behavior of PH13-8Mo stainless steel in industrial -marine atmospheric environment
- 1University of Science and Technology Beijing, China
- 2Technology Center of Nanjing Iron & Steel Co., LTD, Other, China
The corrosion behavior and mechanism of PH13-8Mo stainless steel with and without nitric acid passivated film were studied through 5 years of outdoor exposure tests in industry-marine atmospheric environments in Qingdao, by means of morphological observation, weight-loss measurement, X-ray photoelectron spectroscopy (XPS) and Scanning Kelvin Probe (SKP). The results showed that the pre-passivation certainly inhibits the corrosion, but exhibits an obvious limitation of protection period for PH13-8Mo stainless steel in industrial-marine atmosphere. Compared with bare PH13-8Mo steel, the number and depth of pitting of pre-passivated steel were reduced, and the average corrosion rate decreased by 14.7%. The reasons of improved corrosion resistance included the higher ratio of Cr/Fe and oxide/hydroxide, and the more positive and homogeneous Kelvin voltage potential for the surface of outdoor exposed pre-passivated steel. Meanwhile, the pre-passivation film on the Cr-depleted regions caused by the Cr-rich precipitated phase was preferentially destructed in the atmosphere with Cl-, which decreased the protection period.
Keywords: PH13-8Mo stainless steel, pre-passivated treatment, Atmosphere corrosion, Pitting, surface potential
Received: 02 Aug 2019;
Accepted: 04 Nov 2019.
Copyright: © 2019 Huang, Liu, Zhao, Zhao, Cheng and Lu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
Prof. Yunhua Huang, University of Science and Technology Beijing, Beijing, China, email@example.com
Prof. Lin Lu, University of Science and Technology Beijing, Beijing, China, firstname.lastname@example.org