不锈钢板焊接件的腐蚀特性研究

Study of Corrosive Characteristics for Welded Parts of Stainless Steel Sheet

本文利用金相、扫描电镜对不锈钢薄板热交换器产生的腐蚀形貌进行了显微组织观察、分析,用能谱仪对其白色带状物和表面附着物进行了成分测定。结果表明:白色带状物是析出的碳化铬(Cr_(23)C_6),它使周围贫铬区被腐蚀。表面附着物是硫化物,它是引起孔蚀的重要因素,导致失效的原因还有应力腐蚀和缝隙腐蚀。

The microstructure for producing corroded morphology on the thermal converter made from stailess steel sheet has been observed and analyzed by examination of metallography and SEM. The Composition on the white strip structure and surface attachment has been measured by EDAX. The results show that the white strip structure is a separated chromic carbide (Cr23C6) , which accelerates corrosion at the poor chromic area around Cr23 C6, meanwhile, the surface attachment is a sulphide, which is a prime factor for cavitation. In addition, the other cause of failure is that stress corrosion and gap corrosion should be taken intofailuses analysis consideration.