Precision casting products

Quality inspection results of precision castings:

Qualified products of precision casting products refer to casting precision parts that meet the relevant standards or technical conditions for delivery and acceptance; repaired products refer to the appearance and internal quality, which do not fully meet the standards and acceptance conditions, but they are allowed to be repaired. Castings that can meet the standards and technical requirements for delivery acceptance of castings; Scrap refers to castings that are unqualified in appearance and internal quality and are not allowed to be repaired or fail to meet the standards and technical requirements of casting delivery acceptance. Waste products are divided into two types: internal waste and external waste. Internal waste refers to the waste castings found in the foundry or foundry; the external waste refers to the waste found after the delivery of the casting, which causes more economic losses than internal waste.

Due to a variety of factors, defects such as pores, pinholes, slag inclusions, cracks, and pits often appear. Commonly used repair equipment is argon arc welding machine, resistance welding machine, cold welding machine and so on. For casting defects that do not require high quality and appearance, they can be repaired by welding machines with high heat and speed such as argon arc welding machines. However, in the field of defect repair of precision castings, due to the large heat impact of argon welding, the repair will cause deformation of the casting, decrease in hardness, blisters, partial annealing, cracking, pinholes, abrasion, scratches, undercuts, or insufficient bonding force and internal resistance. Secondary defects such as stress damage.

The cold welding machine just overcomes the above shortcomings. Its advantages are mainly in the small heat-affected area, no preheating of the casting, cold welding repair at room temperature, so there is no deformation, undercut and residual stress, no local annealing, and no change to the metal of the casting Organizational status. Therefore, the cold welder is suitable for the repair of surface defects of precision castings. The repair range of cold welding is the process of repeated melting and accumulation of weld repair points of Φ1.5-Φ1.2mm. In the process of large-area defect repair, the repair efficiency is a factor restricting its wide application.