摘要
利用扫描电镜分析3Cr低合金管线钢高频电阻焊接头微观组织,采用高温高压反应釜和电化学阻抗测试技术对焊接接头的CO2腐蚀行为进行研究.3Cr低合金钢高频电阻焊焊缝和母材的化学成分一致,组织均为铁素体+珠光体,且焊缝组织更加细小、均匀.失重试验结果表明,焊接接头的腐蚀速率比母材小0.28 mm/年.电化学阻抗测试结果表明,浸泡时间48和168 h后,焊缝表面腐蚀膜电阻均大于母材,焊缝腐蚀膜对基体的保护性均好于母材.这是由于焊缝组织分布均匀细小,表面腐蚀膜均比母材均匀和致密.浸泡48 h时焊缝表面为双层膜结构,母材为单层膜;浸泡168 h时焊缝和母材表面均为单层膜结构.
The microstructure of 3Cr low alloy pipeline steel welded joint was analyzed by scanning electronmicroscope( SEM). CO2 corrosion behavior of 3Cr low alloy pipeline steel welded joint was studied with high temperature and high pressure autoclave and electrochemical impedance test technology. The weld metal and the base matal of 3Cr low alloy pipeline steel have the same chemical compositions,and consist of ferrite and pearlite. The microstructure of the weld metal is finer and betterdistributed. Weight loss test results show that the corrosion rate of weldrf joint less than that of base metal by 0. 28 mm / year.Electrochemical impedance test results show that the resistance of the weld surface corrosion film is greater than that base metal after soaking for 48 h and 168 h,and the protection to the base metal by weld corrosion product is better than that by the base metal,which caused by the weld microstructure are even and small,the surface corrosion film is compact and uniform than that of the base metal surface.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2015年第7期83-87,117,共5页
Transactions of The China Welding Institution
