Development of water-repellent stainless steel (sus 316l) surface by stepwise anodizing technique

Abstract

The present disclosure relates to a technology for developing a water-repellent stainless steel (SUS 316L) surface for improving a corrosion inhibition (corrosion resistance) efficiency. According to the method for forming a hydrophobic and corrosion resistant oxide film on a stainless steel surface according to the present disclosure, uniform porous oxide film may be formed without a pre-patterning process for forming uniform porous oxide films of the related art to achieve excellent hydrophobicity and corrosion resistance, thereby being applied to medical devices, marine transportation vehicles, land transportation vehicles, air transportation vehicles, water and sewage pipes, water and sewage filters, and the like, including stainless steel and also be useful as a machine learning database for developing stainless steel surface treatment technology.

What is claimed is: 
     
         1 . A method for forming a hydrophobic and corrosion resistant oxide film on a stainless steel surface, comprising:
 washing and drying the stainless steel surface (Step 1);   anodizing at an applied voltage of 80 to 100 V for 2.5 to 3.5 hours to form an anodized film on the stainless steel surface (Step 2);   immersing the anodized stainless steel of Step 2 into 0.05 to 1.0 M a phosphoric acid solution to widen pores (Step 3);   conducting plasma treatment to remove organic residues and making the anodized film surface hydrophilic (Step 4); and   coating with a self-assembled monolayer (SAM) coatable hydrophobic coating agent (Step 5).   
     
     
         2 . The method of  claim 1 , wherein the stainless steel is SUS 316 or SUS 316L. 
     
     
         3 . The method of  claim 1 , wherein during the anodizing of Step 2, a mixture of NH 4 F, water, and ethylene glycol is used as an electrolyte. 
     
     
         4 . The method of  claim 1 , wherein the anodizing of Step 2 is performed at an applied voltage of 85 to 95 V for 2.8 to 3.2 hours. 
     
     
         5 . The method of  claim 4 , wherein the anodizing of Step 2 is performed at an applied voltage of 88 to 92 V for 2.9 to 3.1 hours. 
     
     
         6 . The method of  claim 1 , wherein the SAM coatable hydrophobic coating agent is any one selected from the group consisting of 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS), trichloroctylsilane (OTS), and octadecyltrichlorosilane (ODTS). 
     
     
         7 . The method of  claim 1 , wherein the anodized film with a contact angle of 160° or larger is formed on the stainless steel surface. 
     
     
         8 . The method of  claim 1 , wherein the anodized film with a corrosion inhibition efficiency of 90% or higher is formed on the stainless steel surface. 
     
     
         9 . A stainless steel in which a hydrophobic anodized film manufactured by the method of  claim 1  is formed. 
     
     
         10 . A stainless steel in which a corrosion resistant anodized film manufactured by the method of  claim 1  is formed. 
     
     
         11 . A medical device including a stainless steel manufactured by the method of  claim 1 . 
     
     
         12 . A transportation vehicle including a stainless steel manufactured by the method of  claim 1 . 
     
     
         13 . The transportation vehicle of  claim 12 , wherein the transportation vehicle is a marine transportation vehicle, a land transportation vehicle, or an air transportation vehicle. 
     
     
         14 . A water and sewage pipe including the stainless steel manufactured by the method of  claim 1 . 
     
     
         15 . A water and sewage filter including the stainless steel manufactured by the method of  claim 1 .