余热锅炉低碳钢管道泄漏原因及改进建议

摘要

某水泥窑窑头余热锅炉在过热器箱体附近发现多处裂纹,造成管道蒸汽大量泄漏,严重影响发电效率.采用扫描电镜、能谱仪进行分析,综合大量运行参数,判断裂纹形成原因为应力腐蚀.而引起低碳钢应力腐蚀的原因是蒸汽中热碱含量超标.基于应力腐蚀机理,对其余部位也进行了安全性评估,并提出了改进建议.%A lot of cracks were found near the superheater housing of a cement waste heat boiler which caused serious steam leakage in the pipe and affected the generation efficiency.SEM and EDS results combined with the analysis of a large number of operation data indiciate that the cracking was caused by corrosion.The exceeding of hot alkali content in the steam was the main reason causing the stress corrosion of low carbon steel.Based on stress corrosion mechanism,a safety assessment for other parts was made and recommendations for improvement were proposed.