Weld procedural effect on the performance of iron based hardfacing deposits on cast iron substrate

Two commercial and four formulated iron based high Cr high C type hardfacing electrodes were deposited on gray cast iron plate (ASTM grade 2500) using various welding procedures such as preheat and without preheat, single and double hardfacing layer as well as buffer or without buffer layer. The effect of welding procedural variation upon the cracking sensitivity and performance of interface between substrate cast iron and deposited layers were studied. Since there is no standard method for evaluating the performance of such interface, shear strength values at their interfaces have been considered and compared among different weld deposits made with different procedures. The results show that crack length per unit area of the deposits is affected by the welding procedure and Cr/C ratio of the hardfacing electrodes used. Though high nickel buffer electrodes attributed highest bond strength, low hydrogen type electrodes could also be used at comparable bond strength with better cost effectiveness.