Tempered carbon rosettes

Temper carbon rosettes are the graphite precipitates that form during annealing of white cast iron. When welding malleable cast iron, be careful: the heat input can alter this microstructure, affecting the component properties. Keep heat input low and work with short weld segments to avoid unnecessary transformation of the structure. Cool slowly after welding to prevent stresses and cracks. If you're unsure how the base material reacts, rather weld cold and check the result.