Influence of Nickel on Aluminide Coating and Cyclic Oxidation of 321 AISI Stainless Steel

Two different types of aluminide coatings on cyclic austenitic stainless steel 321 AISI, were investigated. One is based on predeposition of nickel by electrodeposition followed by aluminization using a pack cementation technique (double step- coating), while the other coating is based on codeposition of nickel and aluminium powder simultansly using a pack cementation (single step- coating).
The coating microstructure and intermetallic compound of the coating layers, as well as, coating thickness were identified using metallugraphy and X-ray analysis
The cyclic Oxidation test of the coating at elevated temperature reveals the formation of stable and protective scale -Al2O3 along the exposure time.