Article ID: ISIJINT-2019-083
Bead-on- plate welding was performed on 20 mm thick cast ductile iron plate in shielded metal arc welding using three different levels (0.05, 0.1, 0.2%) of Ce and one without Ce containing developed coated electrodes after establishing weld procedure as per AWS (D11). As-welded DI weldments were given isothermal heat treatment at two different austempering temperatures (300°C and 350°C) for 1.5 h, 2 h and 2.5 h holding time. Microstructures of as-deposited and austempered weld metals were characterized by OM, SEM, TEM, XRD analysis and microhardness testing. Results show that weld metal containing 0.1% Ce attributed lowest amount of ledeburitic carbide in as-deposited condition and maximum vol.% of retained austenite (46.7%) after austempering heat treatment compare to other two levels of Ce. Since maximum amount of retained austenite is the desirable microstructure after austempering heat treatment, 0.1% Ce is considered as the optimum one in DI weld metal.
