There are many factors affecting the quality of castings, the first is the casting design process. Design, in addition to working conditions and metal material properties to determine the casting geometry, size size, but also from the casting alloy and casting process characteristics of the point of view to consider the reasonableness of the design, i.e., the obvious size effect and solidification, shrinkage, stress and other issues, in order to avoid or reduce the casting of the composition of the segregation, deformation, cracking and other defects occurring. Secondly, there should be a reasonable casting process. That is, according to the casting structure, weight and size, casting alloy characteristics and production conditions, select the appropriate parting surface and modelling, core making methods, reasonable setting of casting tendons, cold iron, risers and pouring systems. To ensure that we get high quality castings. The third is the quality of raw materials for casting. Metal charge, refractory materials, fuels, fluxes, densifiers, and casting sand, sand binder, paint and other materials of substandard quality, the casting will produce porosity, pinhole, slag, sticky sand and other defects, affecting the appearance of the casting quality and internal quality, and in serious cases, the casting will make the casting scrapped. The fourth is the process operation, to develop a reasonable process operating procedures, improve the technical level of workers, so that the process regulations are correctly implemented.
Casting production, to control the quality of castings and inspection, whether cast iron gear, cast iron gate valve or cast iron check valve. first of all, we must formulate from raw materials, auxiliary materials to each specific product control and inspection of the process code and technical conditions. Each process is strictly controlled and inspected according to the process code and technical conditions. Finally, the quality inspection of finished castings should be equipped with reasonable testing methods and suitable testing personnel.