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.

The quality of iron castings has a great influence on the performance of mechanical products. For example, the wear resistance and dimensional stability of machine tool castings directly affect the accuracy and maintenance life of the machine tool; the size of the impeller, casing and the internal cavity of the hydraulic parts, the accuracy of the molding line and the surface roughness of various pumps directly affect the pump And the working efficiency of the hydraulic system, energy consumption and the development of cavitation, etc.; the strength and resistance to chilling and heat resistance of internal combustion engine cylinder blocks, cylinder heads, cylinder liners, piston rings, exhaust pipes, etc., directly affect the operation of the engine life.