1. Gray cast iron--Use small current and fast welding to reduce the penetration depth and fusion ratio; use short-section welding, intermittent welding, scattered welding, segmented backward welding, and hammer the weld; the welding direction should be first Start welding from the part with high rigidity. can choose Z308, Z408.
2. Ductile iron--Use large current: l=(30-60)D, continuous welding; if necessary, slow cooling after welding can be heat treated: normalizing or annealing. can choose Z408.
3. Malleable cast iron - using a similar process to gray cast iron. can choose Z308.
4. Vermicular graphite cast iron - using a similar process to gray cast iron. can choose Z308.
5. White cast iron - using a process similar to that of nodular cast iron. can choose Z308, Z408.