| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a surface treated duplex stainless steel capable of improving corrosion resistance of the duplex stainless steel and preventing, evading or delaying corrosion damages in a mildly acidic to mildly alkaline aqueous solution environment (pH 5.0-9.0) containing chloride ions, and a method of manufacturing the same. <P>SOLUTION: The surface treated duplex stainless steel has uneven with a projection 4 formed by an austenitic phase 1 on the surface of the duplex stainless steel, wherein the depth of a recess 3 between the austenitic phases is≥10μm, and a coating film 8 containing zinc dust is present in the recess 3. Further, the surface of the austenitic phase is coated with the coating film 8 containing the zinc dust. The surface treated duplex stainless steel is manufactured by immersing the duplex stainless steel in a solution whose chloride ion concentration is 1-5%, sulphuric acid concentration is 20-40%, and temperature is 40-60°C, for 30 to 60 minutes, to preferentially dissolve a ferrite phase, then washing and drying it, and coating or spraying the coating containing the zinc dust. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
