The surface quality of steel castings after welding repair shall meet the following requirements:
① For non machined surfaces, the welding repair surface should be smooth, and the beginning, end, and both sides of the welding repair position should ensure a smooth transition to the base metal of the steel casting;
② The defects to be inspected after welding repair of steel castings shall be in accordance with the ISO 5817:2014 standard. The welding repair position shall be free of defects such as cracks, pores, incomplete fusion, incomplete penetration, incomplete welding, and pits;
③ The depth of weld repair undercut on the non machined surface of important parts shall not exceed 0.5mm, and the depth of other parts shall not exceed 1mm;
④ Within every 100 cm2 of the weld surface, the number of pores with a diameter less than 2 mm and a spacing greater than 6 times the diameter of the pores should not exceed 5;
⑤ The intersection of welds shall be fully fused to ensure good molding. The intersection of welds shall ensure a smooth transition.
When magnetic particle flaw detection is required for steel castings after defect repair welding in accordance with the flaw detection technical requirements, the inspection scope should cover the weld and the range of 100% of the weld repair width on both sides of the weld.
If cracks, lack of fusion, lack of penetration, slag inclusion, and defects beyond the specified limits are found at the position of the steel casting after welding repair, the defects shall be thoroughly removed according to the above requirements and then the welding repair shall be conducted again. The maximum number of welding repairs at the same location shall be two. If the welding repairs at the same location exceed two times, they shall be reviewed before implementation.
After welding and repairing defects in important parts of steel castings, records shall be made or the welder’s steel seal shall be stamped on appropriate parts.