In situ monitoring of corrosion mechanisms and phosphate inhibitor surface deposition during corrosion of zinc–magnesium–aluminium (ZMA) alloys using novel time-lapse microscopy
Author:
Affiliation:
1. College of Engineering
2. Swansea University
3. Swansea SA2 8PP
4. UK
5. Institut de la Corrosion
6. 29200 Brest
7. France
Abstract
In situtime-lapse optical microscopy was used to examine the microstructural corrosion mechanisms in three zinc–magnesium–aluminium (ZMA) alloy coated steels immersed in 1% NaCl pH 7. Preferential corrosion of MgZn2lamellae within the eutectic phases was observed in all the ZMA alloys followed by subsequent dissolution of Zn rich phases. The total extent and rate of corrosion, measured using time-lapse image analysis and scanning vibrating electrode technique (SVET) estimated mass loss, decreased as Mg and Al alloying additions were increased up to a level of 3 wt% Mg and 3.7 wt% Al. This was probably due to the increased presence of MgO and Al2O3at the alloy surface retarding the kinetics of cathodic oxygen reduction. The addition of 1 × 10−2mol dm−3Na3PO4to 1% NaCl pH 7 had a dramatic influence on the corrosion mechanism for a ZMA with passivation of anodic sites through phosphate precipitation observed using time-lapse image analysis. Intriguing rapid precipitation of filamentous phosphate was also observed and it is postulated that these filaments nucleate and grow due to super saturation effects. Polarisation experiments showed that the addition of 1 × 10−2mol dm−3Na3PO4to the 1% NaCl electrolyte promoted an anodic shift of 50 mV in open circuit potential for the ZMA alloy with a reduction in anodic current of 2.5 orders of magnitude suggesting that it was acting primarily as an anodic inhibitor supporting the inferences from the time-lapse investigations. These phosphate additions resulted in a 98% reduction in estimated mass loss as measured by SVET demonstrating the effectiveness of phosphate inhibitors for this alloy system.
Funder
Engineering and Physical Sciences Research Council
Publisher
Royal Society of Chemistry (RSC)
Subject
Physical and Theoretical Chemistry
Link
http://pubs.rsc.org/en/content/articlepdf/2015/FD/C4FD00251B
Reference37 articles.
1. F. Goodwin , Galfan Galvanising Alloy Technology, ILZRO, 2nd edn, 1984
2. The metallurgy of zinc-coated steel
3. Microstructural changes in zinc aluminium alloy galvanising as a function of processing parameters and their influence on corrosion
4. Influence of steel gauge on the microstructure and corrosion performance of zinc alloy coated steels
5. Investigation into the effects of metallic coating thickness on the corrosion properties of Zn–Al alloy galvanising coatings
Cited by 30 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
1. Reflective microscopy for mechanistic insights in corrosion research;Current Opinion in Electrochemistry;2023-06
2. Mechanistic study on the corrosion behaviour of Zinc and Zinc-Calcium alloys designed for enhanced metallic coatings in the presence of chloride and phosphate ions;Corrosion Science;2023-04
3. Current state of electrochemical techniques and corrosion rate analysis for next-generation materials;Current Opinion in Electrochemistry;2022-12
4. Effect of Al and Sn on the microstructure, micro-hardness and corrosion properties of Zn-Al-Mg coatings;Materials Today Communications;2022-12
5. Initial atmospheric corrosion of zinc-aluminum-magnesium coated steel and galvanized steel in regions of extremely cold and industrial climate;Materials Chemistry and Physics;2022-11
1.学者识别学者识别
2.学术分析学术分析
3.人才评估人才评估
"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370
www.globalauthorid.com
TOP
Copyright © 2019-2024 北京同舟云网络信息技术有限公司 京公网安备11010802033243号 京ICP备18003416号-3