Selection and usage techniques of casting defect repair agents

Casting workpieces often have defects such as pores, sand holes, shrinkage cavities, and cracks, which can significantly increase production costs if scrapped directly. Casting defect repair agents have become a commonly used material for casting repair due to their easy operation, high bonding strength, and strong adaptability. Reasonable selection and standardized use can effectively restore the structural strength and sealing of castings, ensuring the normal use of workpieces.

1、 Key points for scientific selection of repair agents

The selection must strictly match the casting material and operating conditions. Cast iron, cast steel, and aluminum alloy castings require the use of corresponding specialized repair agents and cannot be used interchangeably. Ordinary mechanical castings at room temperature and pressure can be repaired with universal repair agents, which have a higher cost-effectiveness; High temperature resistant and pressure bearing components such as engine cylinder blocks and pump bodies require the use of high temperature resistant and high-strength industrial repair agents to prevent later detachment and leakage. For fine pores, choose a delicate repair agent, while for large defects and cracks, choose a high-strength wear-resistant type to ensure that the performance meets the standards after repair.

2、 Pre treatment techniques before construction

Surface treatment is the key to successful repair. Firstly, thoroughly clean the oil stains, rust, oxide scales, and impurities at the defect location. They can be sanded, sandblasted, or wiped with cleaning agents to ensure that the base surface is dry and clean. For deep pores and cracks, it is necessary to enlarge holes and slots, remove internal impurities, increase the bonding contact area, avoid internal hollowing and weak bonding, and prevent false repair phenomena.

3、 Standardize allocation and construction methods

Most repair agents are two-component materials that need to be strictly mixed uniformly according to standard proportions to avoid incomplete curing and insufficient strength caused by uneven proportioning. After mixing, quickly apply and fill the gaps, compact and fill the defects, and smooth the surface for finishing. The temperature of the construction environment should be controlled within a suitable range. In low-temperature environments, the workpiece can be preheated appropriately to accelerate curing, while in high-temperature environments, rapid drying should be avoided to affect the bonding effect.

4、 Curing and post treatment

After the repair is completed, it needs to be left to fully cure, and it is strictly prohibited to be subjected to force or water before curing. After complete solidification, the surface is polished and polished to restore the size and flatness of the workpiece. After repairing pressure and high temperature resistant workpieces, water pressure and air tightness tests need to be conducted to confirm that there are no leakage or detachment issues. Standardizing selection and construction can significantly improve the quality of casting defect repair and extend the service life of castings.