High-pressure intake pipe after coarse grinding

　　The key components of internal combustion engines of vehicles, ships, locomotive power and other transportation machinery are subject to high temperature wear, high temperature corrosion and other working conditions. The parts of the automobile internal combustion engine using thermal spraying technology include: crankshaft, engine block, valve sealing surface, synchronous ring, piston, piston ring, fuel injector, sensor, synchronous generator cover, etc.

　　1. Crankshaft

　　Arc spraying (high-speed arc spraying) Cr13 or carbon steel series coating materials. The coating thickness can be determined according to the wear amount of the crankshaft. The bonding strength of the coating is greater than or equal to 25Mpa, and the porosity can reach 10%. Due to the existence of voids, it has the effect of oil storage, and increases lubrication, which can significantly improve the service life of the coating.

　　2. Crankshaft of high-power high-speed locomotive

　　Base material: 38CrMoal, crankshaft diameter 185mm, rotating speed 1500r/min, remove the surface nitrogen layer before spraying repair. Active arc spraying, TAFA9000 arc spraying equipment, 75ni/al composite wire bonding coating and 60ECr steel wire surface working layer are applied. The bonding strength of the coating can be increased to 30 MPa, and the void ratio is less than or equal to 8%. It has been proved by practical application that the coating is intact in an overhaul cycle.

　　3. Locomotive drying cylinder

　　The internal surface of the locomotive cylinder liner is sprayed with NiCr-Cr3Cr2 by high-speed flame spraying technology. The coating has good high-temperature wear resistance, which can be used not only for the repair of old cylinder liners, but also for the pre-protection and strengthening coating of new cylinder liner manufacturing.

　　4. Synchronizing ring, piston ring

　　The synchronous ring and piston ring are sprayed with metal Mo coating by wire flame, and the spraying coating production line has been established in China.

　　5. Valve sealing surface and valve seat

　　The valve sealing surface and valve seat adopt plasma spray welding or laser cladding Co-Cr-W high-temperature wear-resistant and corrosion-resistant coating, which is completely metallurgically combined with the base material and has good high-temperature gas abrasion resistance. The plasma spray welding technology for the valve sealing surfaces of ships, locomotives and automobiles has been officially listed as an essential technology for the pre-strengthening of new product manufacturing.