The first is the design process of iron castings. When designing, in addition to determining the geometry and size of iron castings according to working conditions and metal material properties, the rationality of design must also be considered from the perspective of casting alloy and casting process characteristics, that is, obvious size effect and solidification, shrinkage, stress and other problems, so as to avoid or reduce the occurrence of defects such as composition segregation, deformation and cracking of iron castings.
Second, there should be a reasonable casting process. That is, according to the structure, weight and size of iron castings, casting alloy characteristics and production conditions, select the appropriate parting surface, modeling and core making method, and reasonably set the casting reinforcement, cold iron, riser and gating system. To ensure high-quality iron castings.
The third is the quality of raw materials for casting. The quality of metal charge, refractory, fuel, flux, modifier, casting sand, molding sand binder, coating and other materials is not up to standard, which will cause defects such as pores, pinholes, slag inclusion and sand sticking, affect the appearance quality and internal quality of iron castings, and scrap iron castings in serious cases. The fourth is process operation. We should formulate reasonable process operation procedures, improve the technical level of workers, and make the process procedures implemented correctly.
In manufacturing, the quality of castings should be controlled and inspected. First of all, we should formulate the process rules and technical conditions for the control and inspection of each specific product from raw materials and auxiliary materials. Each process shall be controlled and inspected in strict accordance with the process code and technical conditions. Finally, the quality of finished castings is inspected. Reasonable testing methods and appropriate testing personnel shall be equipped. Generally, for the appearance quality of professional iron castings, comparative samples can be used to judge the surface roughness of castings; Minor cracks on the surface can be inspected by coloring method and magnetic particle method.