Must parts be preheated before hardfacing?
As a rule, you should bring all parts at least to room temperature. You can select higher preheat and interpass temperatures based on the base metal chemistry and hardfacing product you’re using. Manganese and some stainless steels and similar hardfacing products require no preheating, and welding temperatures should be kept as low as possible. Other steels usually require proper preheat and interpass temperatures. You should consult the manufacturer for the best combination to prevent cracking and spalling.
