Name: crawler joint
Casting quality has a great influence on the performance of mechanical products. For example, the wear resistance and dimensional stability of mining machinery castings directly affect the accuracy and maintenance life of machine tools; The size, accuracy and surface roughness of impellers, shells and internal cavities of hydraulic parts of various pumps directly affect the working efficiency, energy consumption and cavitation development of pumps and hydraulic systems; The strength and heat shock resistance of castings such as cylinder block, cylinder head, cylinder liner, piston ring and exhaust pipe of internal combustion engine directly affect the working life of the engine.
There are many factors affecting the quality of castings. One is the design process of castings. During the design, in addition to determining the geometry and size of the casting according to the working conditions and the properties of metal materials, the rationality of the design must also be considered from the perspective of casting alloy and casting process characteristics, that is, obvious size effect, solidification, shrinkage, stress and other problems, so as to avoid or reduce the occurrence of defects such as component segregation, deformation and cracking of the casting. Second, there should be a reasonable casting process. That is, according to the structure, weight and size of the casting, the characteristics of the casting alloy and the production conditions, the appropriate parting surface, molding and core making method are selected, and the casting ribs, cold iron, riser and gating system are reasonably set. So as to ensure high quality castings. The third is the quality of raw materials for casting. The substandard quality of metal charge, refractory, fuel, flux, modifier, casting sand, molding sand binder, coating and other materials will cause defects such as porosity, pinhole, slag inclusion and sand sticking in the casting, which will affect the appearance and internal quality of the casting. In serious cases, the casting will be scrapped. The fourth is process operation. It is necessary to formulate reasonable process operation procedures, improve the technical level of workers, and ensure the correct implementation of the process procedures.