Mainly include appearance quality, internal quality and use quality. Appearance quality refers to the surface roughness, surface defects, dimensional deviation, shape deviation, and weight deviation of the casting; internal quality mainly refers to the chemical composition, physical properties, mechanical properties, metallographic structure of the casting and the holes, cracks, inclusions, and Segregation, etc.; the quality of use refers to the durability of the casting under different conditions, including wear resistance, corrosion resistance, chilling and heat resistance, fatigue, shock absorption and other performance, as well as machinability, weldability and other process properties.
The quality of 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 inner 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 of the internal combustion engine cylinder block, cylinder head, cylinder liner, piston ring, exhaust pipe, etc., directly affect the working life of the engine.