电站用WB36钢管表面裂纹分析与控制

Analysis and Control of Surface Crack of WB36 Steel Pipe for Power Plant Service

分析Φ610 mm×50 mm规格WB36钢管表面网状裂纹的产生原因,观察该钢管裂纹的宏观形貌、微观组织、扫描电镜分析结果,并进行能谱检验。研究认为钢管裂纹的形成源于坯料裂纹,坯料浇注温度过高造成奥氏体晶粒粗大,加上该坯料化学成分含Cu,凝固过程中Cu的富集是钢管表面网状裂纹形成的主要原因。

Analyzed here in the article are the causes for the surface network-like cracks as staying with the Φ610mm×50 mm WB 36 steel tube,and studied are the results of observation of the macro-morphology and micro structure,the SEM analysis and energy spectrum test of the said cracks.It is regarded via the studies that the cracks of the said steel pipe are originated from the crack of the billet.In case of over high casting temperature,the austenite grain size of the steel is enlarged,and moreover the enrichment of the chemical element Cu as contained in the steel is developed during the solidification process,both of which act as the main causes for the above mentioned network-like surface cracks of the pipe.