Weld Overlay Restoration of Forged DI Pipe Moulds

In this article, the procedure for restoration of forged ductile iron (DI) pipes through the application of weld overlay is discussed. After several trial tests, an optimum composition of the metal cored wire has been found out for overlaying a range of mould materials. Metal-cored wires of 2.4 mm and 3.2 mm diameter have been found to be the suitable sizes for overlaying of small, and large moulds of more than 800 mm respectively. Quite large moulds of 1500 mm and above have been welded successfully using 4.0 mm metal cored wires typically at 650-680A and at a weld deposition rate of over 7.5 kg per hour with heat input up to 2.60 kJ/mm with a control of preheating and reheating temperatures.