Repairing cracks in cast steel, which electrode should I use?
NiCi is a 99% Ni coated electrode, designed to weld higher carbon cast steel components, (AWS A5.15, ENi-CI) it contains high carbon content. It expands as the weld deposit freezes and causes expansion of the weld metal. This balances contraction stresses and offsets cracking tendency by lowering residual stress.
Welding Tips & Techniques
It helps to preheat the component in order to slow down the cooling rate and minimise brittle Martensite forming in the heat affected zone. Usually 200-300C would be applied if convenient. It helps if the cracked area is cleaned as well as can be achieved to minimise weld contamination.