Casting quality mainly includes the appearance quality, the internal quality and the working quality.
Appearance quality refers to the surface roughness, surface defects, dimensional deviations, shape deviations and weight deviations.
Internal quality refers to the chemical composition, physical properties , mechanical properties,metallographic structures of castings and the holes, cracks, inclusions and segregation existing in the castings.
Working quality refers to the working durability of the castings under different conditions, including wear resistance and corrosion resistance. It has many properties, such as heat shock, fatigue, shock absorption, machinability and weldability.
The casting quality has great influence on the performance of mechanical products. For example, the wear resistance and dimensional stability of the machine tool castings directly affect the precision of the machine tool. The size of the impeller, the shell and the inner cavity of the hydraulic parts,the accuracy of the shape line and the surface roughness directly affect the working efficiency of the pump and the hydraulic system, the energy consumption and the development of the cavitation; the cylinder, cylinder head, cylinder sleeve, piston ring, exhaust pipe and other castings of the internal combustion engine strength and heat shock resistance directly affect the working life of the engine.