Welding material and process for casting defect cold welding repair of high-strength nodular cast iron casting

Abstract

The invention discloses a welding material and process for casting defect cold welding repair of a high-strength nodular cast iron casting. The welding material comprises the following components: 0.100-1.203% of Ni, 12.214-14.338% of Cr, 0.651-0.864% of Si, 0.875-1.323% of Al, less than 0.02% of C, and the balance of Fe. A reasonable cold welding repair process is adopted to repair casting defects (subcutaneous pores and sand holes) of high-strength nodular cast iron. According to the welding repair process, it is guaranteed that the weld joint hardness is larger than that of base metal, the hardness is proper, and the quenching crack tendency of the high-strength nodular iron casting during subsequent quenching treatment is reduced. Meanwhile, the cold welding repair process effectively reduces the number of weld joint hot cracks and air holes, the abrasion resistance of weld joints is equivalent to that of the base metal, the width of a white opening layer is limited within 10 micrometers, and the welding repair requirement of the high-strength nodular iron casting is met. And for multiple casting defects on the surface, welding repair can be continuously carried out after drilling, preheating before welding is not needed, and the production efficiency of cold welding repair of the casting defects of the nodular iron casting is effectively improved.

Description

technical field [0001] The invention relates to the field of welding technology, in particular to a welding material and a welding process for cold welding repair of casting defects of high-strength ductile iron castings. Background technique [0002] High-strength nodular cast iron materials (such as GGG70L, QT600-2, etc.) are often used to make stamping dies for automobile panels, crankshafts and other parts. figure 1 Casting defects such as subcutaneous pores and trachoma are shown. For castings that can be repaired, casting defects need to be repaired before subsequent surface treatment and other processes can be performed. However, the traditional ductile iron casting repair methods commonly used by enterprises, such as arc welding and argon arc welding, have large heat input and low operation accuracy, and are prone to defects such as undercut, pores, cracks, and white structures at the weld. At present, some welding methods with small heat input and high repair prec...

AI Technical Summary

Problems solved by technology

However, the current iron-based welding consumables have high requirements on the welding process, and are prone to brittle phases such as white mouth. Generally, preheating is required, and the welding conditions are poor.

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