冷轧搪瓷钢搪烧后氧化铁皮剥落原因分析

Causes analysis of oxide scale spallation of cold-rolled enamel steel

潮湿环境下服役的热水器内胆,其外层致密附着的氧化铁皮能对钢基体起到保护作用,而外层氧化铁皮的不连续性剥落,易引起局部腐蚀,降低整个内胆使用寿命。对热水器内胆外层氧化铁皮进行分析,结果表明造成内胆外层氧化铁皮剥落的原因是搪瓷钢热轧原料卷表层粗晶遗传,导致冷轧搪瓷钢板表层粗晶,局部存在的表层粗晶在潮湿大气环境下高温搪烧,其氧化铁皮结构中,较疏松的FeO层较厚,在冷却过程中,应力作用发生裂纹扩展,造成氧化铁皮剥落。

The iron oxide densely adhered on the outer layer of the water heater tank used in damp environment can protect the steel substrate,and the discontinuous spallation of the outer oxide scale can easily cause the local corrosion and reduce the service life of the whole tank.The outer oxide scale of the water heater tank were analyzed.And the results showed that the inheritance of coarse on the surface of hot-rolled enamel steel plate resulted in the coarse on the cold-rolled enamel steel substrate surface.And when the local surface coarse burned at high temperature in moist atmosphere environment,in the oxide structure,the relatively loose FeO layer was thicker.And in the process of cooling,the crack growth on the stress caused the oxide scale spallation.