Prediction of steady state dilution in multipass hardfacing overlays deposited by self shielded flux cored arc welding

Abstract

A method of predicting the steady state dilution of multipass hardfacing overlays deposited via self shielded flux cored arc welding is described. A new variable is defined and used to describe the steady state dilution of multipass overlays. A mathematical model for dilution is presented in terms of this variable. Eight multipass overlays were deposited, using different combinations of welding parameters in each instance. The steady state dilutions for these overlays were measured and compared with those predicted by the model for dilution. It is found that, with an empirical correction, it is possible to predict the dilution of multipass hardfacing overlays over a wide range of welding conditions. This predictive capability establishes a relationship between welding process variables and the steady state composition, and hence the microstructure, of high chromium white iron weld overlays. Microstructure–wear relationships can then be applied to complete the link between welding parameters and the wear performance of the overlay.