Welding Cast Iron Preheat. If the surrounding cast iron isnt pre-heated and post-heated this high. Cast iron is a metal which is relatively difficult to weld because it contains more than 03 carbon.
CHAPTER II 4 RESULTS AND CONCLUSIONS OF OTHER INVESTIGATORS Recommended Preheat Temperatures. Preheating or cold weld. All cast iron welding requires care.
Preheating is especially important when welding.
Thick materials the rule of thumb on thickness and when to preheat varies by material type. Someone correct me if Im wrong but my understanding is that one of the reasons cast iron cracks after welding it with normal steel electrodes is because some of the carbon in the cast iron which has more carbon than even high-carbon steel dissolves into the weld deposit in effect creating a high-carbon steel weld deposit. The preheating will help them achieve softer weld metal which will have better resistance. Their goal is to preheat the part before it undergoes welding.