电焊机2024，Vol.54Issue(10)：77-85,9.DOI:10.7512/j.issn.1001-2303.2024.10.09
海洋环境下E690低合金高强钢MAG焊接接头热影响区耐腐蚀性能研究
Study on the Corrosion Resistance of Heat-Affected Zone of E690 Low-Alloy High-Strength Steel MAG Welded Joints in Marine Environment
摘要
Abstract
With the development of marine oil exploitation technology,the corrosion resistance of high-strength steel welded joints has become a critical issue.This paper aims to study the corrosion behavior of the heat-affected zone(HAZ)of E690 low-alloy high-strength steel MAG welded joints in a simulated marine environment,and to analyze the corrosion mecha-nism.The study uses a 3.5%NaCl solution as the corrosive medium for immersion tests.Techniques such as optical micros-copy,scanning electron microscopy,and energy-dispersive X-ray spectroscopy are employed to observe and analyze the mi-crostructure,mechanical properties,corrosion morphology,and corrosion product composition in different regions of the HAZ.The results indicate that the corrosion degree of different regions in the HAZ decreases in the order of overheated zone(GRHAZ)＞normalized zone(CHAZ)＞mixed grain zone(CGHAZ).The GRHAZ has the least amount of corrosion products,which are evenly distributed,and no large-area corrosion occurs.The corrosion products are primarily composed of two compounds,Fe3O4 and Fe2O3,with a structure characterized by nodular and columnar shapes.The CHAZ and CGHAZ have relatively more corrosion products,which are unevenly distributed,and localized areas of enhanced corrosion are observed in the CHAZ.When designing welded joints,the corrosion sensitivity of the HAZ should be fully considered,and appropriate protective measures should be taken to ensure the safety and reliability of offshore platforms.With the devel-opment of marine oil exploitation technology,the corrosion resistance of high-strength steel welded joints has become a criti-cal issue.This paper aims to study the corrosion behavior of the heat-affected zone(HAZ)of E690 low-alloy high-strength steel MAG welded joints in a simulated marine environment,and to analyze the corrosion mechanism.The study uses a 3.5%NaCl solution as the corrosive medium for immersion tests.Techniques such as optical microscopy,scanning electron microscopy,and energy-dispersive X-ray spectroscopy are employed to observe and analyze the microstructure,mechanical properties,corrosion morphology,and corrosion product composition in different regions of the HAZ.The results indicate that the corrosion degree of different regions in the HAZ decreases in the order of overheated zone(GRHAZ)＞normalized zone(CHAZ)＞mixed grain zone(CGHAZ).The GRHAZ has the least amount of corrosion products,which are evenly dis-tributed,and no large-area corrosion occurs.The corrosion products are primarily composed of two compounds,Fe3O4 and Fe2O3,with a structure characterized by nodular and columnar shapes.The CHAZ and CGHAZ have relatively more corro-sion products,which are unevenly distributed,and localized areas of enhanced corrosion are observed in the CHAZ.When designing welded joints,the corrosion sensitivity of the HAZ should be fully considered,and appropriate protective mea-sures should be taken to ensure the safety and reliability of offshore platforms.关键词
E690低合金高强钢/MAG焊/显微组织/耐蚀性能/腐蚀产物Key words
E690 low-alloy high-strength steel/MAG welding/microstructure/corrosion resistance/corrosion products分类
矿业与冶金引用本文复制引用
张丽萍,苟毅,罗晓东,王刚,李明忠,尹立孟..海洋环境下E690低合金高强钢MAG焊接接头热影响区耐腐蚀性能研究[J].电焊机,2024,54(10):77-85,9.基金项目
重庆市自然科学基金创新发展联合基金重点项目(KJZD-M20240150) （KJZD-M20240150）
重庆市自然科学基金创新发展联合基金项目(CSTB2023NSCQ-LZX0002) （CSTB2023NSCQ-LZX0002）
