Metal spraying manufacturers teach you how to repair crankshafts with metal spraying process

       How to Repair Crankshaft with Metal Spray Process:



Metal spraying can be divided into gas spraying, electric spraying and plasma arc spraying. The following describes the wire electrospraying process commonly used in production:



First: wash. Use gasoline or 4% alkaline water to clean the crankshaft, especially pay attention to the dirty oil in the crankshaft oil circuit, otherwise it will reduce the spray quality.

The second step is surface treatment. Before spraying, turn or grind the journal to eliminate wear marks and uneven grinding, so that the coating thickness is uniform and not less than 0.5mm; after processing, use low-voltage AC transformer power supply, electrodes and nickel plates, crankshaft as another electrode, use The sparks generated when the two electrodes are in contact make the surface of the nickel particles (or blisters) melt the T part, in order to improve the bonding strength of the spray coating

The surface nickel plate should be sprayed in time after treatment, and the interval should not be too long, otherwise the bonding strength will be reduced due to oxidation or falling on dust.



The surface nickel plate should be sprayed in time after treatment, and the interval should not be too long, otherwise the bonding strength will be reduced due to oxidation or falling on dust.



The third step is the two oil holes. Plug the oil hole with a carbon stick or chalk (be careful not to use powder)



Brush dust or toner on the journal surface).



The fourth step is to select the spraying process parameters. Compressed air pressure is 0.49^-0.588MPa; 1 pack pressure is 30-36V; current is 80-15 oa; injection distance is 150-200mm; crankshaft speed is 10-15r/min; steel wire diameter is 1.6^-1.8mm; The speed is 5mm/min.



In step 5, spray. At the beginning of spraying, the spraying distance can be shortened appropriately until the temperature of the journal rises to 70^-30C, and then spray at the specified distance. If the arc breaks during the spraying process, the spray gun should be moved immediately, otherwise the coating will be cold broken. Each diary should be sprayed once in a row. Otherwise delamination will occur.



The sixth step is the processing of crankshaft after spraying. After spraying, according to the size of the machining allowance, the method of turning first and then grinding can be used to select the appropriate abrasive tool and cutting amount; after Z, the crankshaft is immersed in 100-120C: oil for 3 hours for oil immersion treatment to improve the shaft preheating. wear resistance.