How to minimize defects in casting production
During the production process of castings, defects such as pores, pinholes, slag inclusions, cracks, pits, etc. often occur due to various factors.
At this time, in order to ensure that the casting can meet the usage standards and reduce losses and waste, defects are often repaired. The commonly used repair equipment is argon arc welding machine, resistance welding machine, cold welding machine, etc. For casting defects with low quality and appearance requirements, welding machines with high heat generation and fast speed such as argon arc welding machines can be used to repair them.
However, in the field of defect repair for precision castings, due to the significant impact of argon welding heat, secondary defects such as deformation, hardness reduction, sand holes, local annealing, cracking, pinholes, wear, scratches, undercuts, insufficient bonding force, and internal stress damage can occur during repair. The cold welding machine just overcomes the above disadvantages. Its advantages are mainly shown in the small heat affected area, no preheating required for the casting parts, and cold welding repair at room temperature, so there is no deformation, undercut and residual stress, no local annealing, and no change in the metal structure of the casting parts.
Therefore, cold welding machines are suitable for repairing surface defects in precision castings. The scope of cold welding repair is Φ 1.5- Φ The process of repeated melting and accumulation of 1.2mm welding repair points is the only factor that restricts its widespread application in the process of repairing large area defects.
For major defects, it is recommended to combine traditional welding repair processes with casting defect repair machines. When choosing a cold welding machine, it is also necessary to choose equipment that has advantages such as simple operation, high welding repair efficiency, high post weld strength, post weld shot blasting cleaning, and mechanical processing that does not fall off. Choosing such a cold welding machine, after welding, repairing, and polishing, no repair marks can be seen at all.