Heat up the defect area which needs to be welded up to around 150℃ before welding.
Clean the defect area thoroughly before welding. Eliminate sand, oxide skin by angle grinder till metal luster shows up.
Choose welding wire which meets the casting material. Adopt suitable welding process such as carbon dioxide arc welding, argon arc welding or cold welding process according to casting material to weld up carefully and responsibly each defect area.
Adopt low current, in turn, symmetrical and intermittent welding solution to weld up each defect. Do not make any welding part over heated or form a significant temperature difference (hand touch feeling not too hot), so as not to result in welding stress. After welding for a while ( a certain length of 50mm or one pass ), knock the welding area with electric hammer right away to eliminate the welding stress in time.
Crack or suspected crack should be tested to confirm after grinding the defect area. Then clean out the crack by angle grinder. Test again to make sure the crack area cleaned out thoroughly before starting to weld.
Crack welding: Use short welding seam to guarantee the welding strength. Welding along the V type opening of the crack area using wide welding seam is absolutely forbidden.
Grind the surface after welding, test the welding quality until it meets requests. If necessary, test again to confirm.
Pay attention to heat reservation after welding. Welding operation location should not be at the place with a draught.
Heat treat the casting after welding to eliminate stress.
The Key Point And Requirement For The Process Of Welding
- Jun 06, 2017 -