Answer
Jan 24, 2023 - 10:12 AM
Yes, you can MIG weld cast iron with a suitable MIG filler wire & proper procedure.
General repair procedure for joining a crack:
- Prepare a U-groove along the crack, preferably with a gouging stick electrode. If not available, then use a die grinder bit. Using a stone grinder will leave contaminant ceramic traces in the groove.
- Drill a 1/8” to 5/32” hole at both ends of the crack, 3/16” beyond the visible tip of the crack. Use a dye penetrant crack detection kit.
- Employ jigs or fixtures to minimize movement during welding.
Cold welding technique: No preheat, start welding to fill the groove. Only 1 to 2 inches length of straight stringer beads at a time. Check temperature of the welded area between passes. MUST not exceed 160 F. Let the area cool until temperature falls below 160 F before each subsequent pass. Use a crayon temperature indicator. Cool slowly! Hot welding technique (above 350 F) will require the whole part to be preheated & maintained at this minimum temperature throughout the welding process. Chromium Cast Iron & White Chilled cast iron or so-called “Ni-hard” materials are non-weldable. Farm implements or wear parts are examples of these types of cast iron. Recommended filler wire composition: At least 50% Nickel, balance is Iron Shielding gas: 80% Ar / 20% CO2 or closer for thick sections. 98% / Ar 2% CO2 for thin sections.
Contact our sales and service team at support@canadaweldingsupply.ca for further questions or product remomendations.
Cold welding technique: No preheat, start welding to fill the groove. Only 1 to 2 inches length of straight stringer beads at a time. Check temperature of the welded area between passes. MUST not exceed 160 F. Let the area cool until temperature falls below 160 F before each subsequent pass. Use a crayon temperature indicator. Cool slowly! Hot welding technique (above 350 F) will require the whole part to be preheated & maintained at this minimum temperature throughout the welding process. Chromium Cast Iron & White Chilled cast iron or so-called “Ni-hard” materials are non-weldable. Farm implements or wear parts are examples of these types of cast iron. Recommended filler wire composition: At least 50% Nickel, balance is Iron Shielding gas: 80% Ar / 20% CO2 or closer for thick sections. 98% / Ar 2% CO2 for thin sections.
Contact our sales and service team at support@canadaweldingsupply.ca for further questions or product remomendations.
