Articles cast from molten iron are collectively referred to as iron castings. Due to various factors, defects such as pores, pinholes, slag inclusions, cracks, and pits often appear.

The processing of large and small iron castings includes appearance quality, internal quality and use quality. Appearance quality refers to the surface roughness, surface defects, size deviation, shape deviation, and weight deviation of the casting; mainly refers to the casting, metallographic structure, and the holes, cracks, inclusions, segregation, etc. existing in the casting; the use quality refers to the cast iron Work durability under different conditions, including wear resistance, corrosion resistance, shock resistance to cold and heat, fatigue, shock absorption and other performance, as well as process performance such as machinability and weldability.

Due to a variety of factors, iron castings often have defects such as pores, pinholes, slag inclusions, cracks, and pits. Commonly used repair equipment is argon arc welding machine, resistance welding machine, cold welding machine, etc. For casting defects that do not require high quality and appearance, they can be repaired with a welding machine with large heat generation and high speed such as an argon arc welding machine.