Reasons for Atmosphere Corrosion of 304 Stainless Steel

The reasons for atmosphere corrosion of 304 stainless steel were investigated by analyzing the microstructure,the grade of non-metallic inclusion,the micrograph,the chemical composition and composing of rust samples.And the spray salt testing was used to evaluate the corrosion resistance of the samples.The results showed that the corrosion potential could be reduced by the non-metallic inclusions,further more,the steels were pickled partially,the acid was not removed clearly,which would cause corrosion in the steel.The corrosion depth was only 30 μm,it could be prevented by grinding the rust layer.