If there is sand hole on the surface of the cast iron floor plate, according to the regulations, if the size of the hole does not exceed 0.5 mm, normal use will not be affected. If the sand hole is large, the cast iron workbench will be repaired during processing.

cast iron floor plate

The following is the repair method of sand holes on cast iron floor plate:

1. Repair with putty and epoxy resin: some defects do not affect the use and appearance, so there is no need to repair. The defects of holes found on the parts that are not important to the casting but have decorative significance can be repaired by making putty according to the color of the casting.

The following putty ratios are available (the content of the components is expressed in mass fraction): (1) Iron powder 75, water glass 20 and cement 5. (2) Brine sand (magnesium oxide) 2.5, water 3, iron powder 81, sulfur 11, acetic acid 2.5. (3) Cast iron shavings 80, magnesium oxide powder 15-20, use a full magnesium chloride solution to adjust into a mass.

The shortcomings of the non-machined surface and non-azimuth guide rails of the cast iron workbench castings, as well as the oil leakage shortcomings of the oil pool and the fuel tank, can be patched with epoxy resin adhesive (also called caster glue). Epoxy resin adhesive is made of epoxy resin as the main raw material plus plasticizer, reinforcing agent, toner and curing agent. When sticking, clean the defective parts of the casting platform first, and then pour the sticking agent. The sticking agent should be 1~2mm higher than the casting, and then use an infrared lamp to bake for 2~3hours until it is solidified.

2. Electric welding: The shortcomings of steel castings are repaired by electric welding, and there is usually no preheating before welding. Castings are prone to cracks and white holes because of poor weldability. Repair is divided into cold welding and hot welding. The cold welding technique is simple, the castings are not preheated before welding, and they should be used for welding repair castings without processing their appearance. If the cast iron platform castings need to be machined after welding repairs, nickel-based alloy electrodes can be used. The strength, hardness and color of the weld repaired by using cast iron electrodes should be the same as the casting body. It can be machined after repairing, but it is easy to crack after repairing. For the shortcomings of the working surface of the cast iron workbench castings or the places subject to dynamic load, high-silicon cast iron electrodes should be used for hot welding. Preheat the casting to 500~700 degrees Celsius before welding repair. After welding repair, heat preservation and slow cooling are required. Castings are not easy to crack and can be machined.

3. Gas welding: The cast iron workbench uses the heat generated by the mixed combustion of combustible gas (acetylene, propane, hydrogen, etc.) and oxygen to weld the body metal of the casting and the welding metal (electrode, welding wire, welding powder). An integrated welding repair method, the most commonly used in production is the oxygen-acetylene flame welding repair method.

4. Impregnation repair: impregnation is to infiltrate the gelatinous infiltrant into the pores of the casting, and then solidify the infiltrant to connect with the inner wall of the pore of the casting to achieve the purpose of plugging.