The key components of the internal combustion engine of transportation machinery such as automobiles, ships, and locomotive power are subjected to high temperature wear, high temperature corrosion and other working conditions. The parts of automobile internal combustion engine using thermal spraying technology include: crankshaft, engine block, valve sealing surface, synchronizing 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 thickness of the coating can be determined according to the wear amount of the crankshaft. The bonding strength of spraying 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. High-power high-speed locomotive crankshaft
Base material: 38CrMoal, crankshaft diameter is 185mm, speed is 1500r/min, and the surface nitrogen layer is removed before spray repair. Using active arc spraying, TAFA9000 arc spraying equipment, spraying 75ni/al composite wire bonding coating, 60ECr steel wire surface working layer. The bonding strength of the coating can be increased to 30MPa, and the porosity is less than or equal to 8%. It has been proved by practical application that the coating is intact in one overhaul cycle.
3. Locomotive dryer
The inner 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 not only be used for the repair of waste cylinder liners, but also for the pre-protection and strengthening coating of new cylinder liners.
4. Synchronous ring, piston ring
Synchronous rings and piston rings are made of wire flame-sprayed metal Mo coating, and a spray coating production line has been established in China.
5. Valve sealing surface, valve seat
The valve sealing surface and valve seat are coated with Co-Cr-W high-temperature wear-resistant and corrosion-resistant coating by plasma spray welding or laser melting. The use of plasma spray welding technology on the valve sealing surface of ships, locomotives and automobiles has been officially listed as an indispensable process technology for pre-strengthening of new products.
