材料期刊网

A NiCrAlYSi coating was deposited by arc ion plating on a cobalt-base super-alloy K40S to improve its hot corrosion resistance at 1173 K in air. The K40S suffered from accelerated corrosion and formed non-protective scale with poor adherence when its surface was beneath Na(2)SO(4) and Na(2)SO(4) containing 25 wt.% NaCl salt deposits. After the K40S was coated with NiCrAlYSi coating, a protective alpha-Al(2)O(3) scale was formed on the coating. Although the NiCrAlYSi coating changed into NiCoCrAlYSi during corrosion processes, it still possessed good corrosion resistance. In addition, the corrosion mechanisms were discussed on a basis of basic fluxing model. (C) 2011 Elsevier Ltd. All rights reserved.