Surface treatment method of austenitic stainless steel with excellent sulfuric acid corrosion resistance

摘要

The present invention relates to a method for surface treatment of austenitic stainless steel, which significantly improves corrosion resistance to sulfuric acid of Mo-added austenitic stainless steel, which is used as a material for chemical facilities such as sulfuric acid vessels. In order to concentrate more than 2.5% by weight of Cu on the surface of stainless steel, austenitic stainless steel containing 0.75% by weight or less of Cu is adjusted to 0.05 to 0.15 ppm of chlorine remaining in the solution after pickling. It is characterized by immersing in a NaClO solution at room temperature for 30 minutes to 24 hours.;According to the present invention, the sulfuric acid vessel can be prepared by concentrating Cu to 2.5% or more on the surface of stainless steel to which 0.75 wt% or less of Cu is added, thereby exhibiting excellent corrosion resistance to sulfuric acid without degrading the properties of the base metal. It can be effectively used as a material for chemical equipment.