Effect of Heat Treatment on Microstructure, Mechanical Properties, and Corrosion Performance of 410NiMo Super Martensitic Stainless Steel Cladded on 21CrMoV5-11 by Submerged Arc Welding Process

The effect of heat treatment on microstructure, mechanical properties, and corrosion resistance of 410NiMo super martensitic stainless steel applied by Submerged Arc Welding on 21CrMoV5-11 sublayer has been investigated. The cladded steel was heat treated at different cycles which were; single stage heat treatment (600 degrees C-6 h), double stage heat treatment (700 degrees C-2 h & 600 degrees C-6 h), and austenitizing followed by double stage heat treatment cycles. Results revealed that austenitizing at 1000 degrees C followed by a double stage treatment improved the impact energy (75j) more than other cycles, due to the formation of austenite and dissolution of carbides and delta ferrite, while the lowest hardness was observed for the welded specimens heat-treated at 600 degrees C (318HV). It was further shown that the best corrosion resistance (i(corr) (A/cm(2)) = 1.02E-9 +/- 5E-11 and E-corr(V-vs Calomel) = - 0.132 +/- 0.007) for the cladded steel was obtained by austenitizing the specimen at 1150 degrees C followed by the double stage treatment, due to the complete dissolution of the delta ferrite phase, chromium carbides, and homogeneous chrome distribution in the clad layer.