SUPER304H锅炉钢管局部腐蚀分析及其防护对策

ANALYSIS OF LOCALIZED CORROSION ON SUPER304H STEEL TUBES USED FOR BOILERS AND PREVENTIVE COUNTERMEASURES THEREOF

对某沿海在建机组锅炉用SUPER304H钢管出现的局部腐蚀进行了宏观形貌、化学成分、金相、扫描电镜及能谱分析结果表明,SUPER304H钢管局部腐蚀的主要原因是由氯离子引起的。对此,建议在SUPER304H钢管海运及存放时,加盖帆布和采用缓蚀剂进行防护。对已产生局部腐蚀的管材进行打磨,并经渗透探伤和壁厚测量检验合格后可正常使用。

The localized corrosion occurred on SUPER304H steel tubes used for boilers of units under construction in coastal areas has been analysed by using macroscopic examination,chemical composition test,metallographic detection,scanning electron microscope,and energy spectrum.Results show that the main cause leading to localized corrosion on SUPER304H steel tubes is due to chlorine ions.For this,it is recommended that the said steel tubes should be covered with canvas during sea transportation and storage,and being protected with corroson inhibitors.The tube materials,which are already being corroded,should be rubbed,and examined through liquid penetration test and wall thickness measurement,after reaching acceptable level of quality,just then they can be normally used.