Research On The Laser Cladding Remanufacturing Process Of Automobile Crankshaft

With the car ownership increasing rapidly, the update rate of car is higher,resulting in more end-of life vehicles, but the Elv recovery is lower. The life of partscan be extended if they can be fixed with the remanufacturing technology, and ourcountry can get great economic benefit.Working in hot and high pressure, the crankshaft was easily run out of wear,corrosion and even may break. The influence on microstructure and hardness ofcladding layer were studied with different laser processing parameters, researching onthe technics of laser cladding alloy powder on the40Cr steel surface, Al2O3powderand Y2O3powder so that the best processing parameters can be chosen. Then thesurface quality and microstructure and hardness of fixed sample were studied. Themain contents as follows:(1) The influence of different parameters：on the premise of the voltage is380Vand the pulse width is2.0ms and the frequency is10Hz, the hardness increases and thegrain size was refined within a certain range. With little ranges of defocusing amount,the influence of it was not obvious. The best processing parameters were that thevoltage is380V and the pulse width is2.0ms and the frequency is10Hz and scanningspeed is120mm/min and distance is30mm.(2) The hardness increased with adding Al2O3powder. The microstructure wasrefined and grain equally distributed.(3) Because adding the Y2O3powder, the fine-grain strengthening and alloyingmade segregation of impurities decreased. The crystal boundary was strengthened andpurified so that the hardness increased.(4) The surface quality of sample was good and it had no indication. Themetallurgical combination had formed so that its performance was good. The hardnessof cladding layer was higher than matrix material’s. And the tissue was uniform andclose.