Technological Research For Remanufacture Of The Surface Damage Of Vehicle’s Drive Axle Housing

Drive axle housing is an important component of vehicle chassis driving system and a basic part to install the final drive assembly, differential, half shaft, wheel hub and suspension. There will be different failure forms appearing on the surfaces of the axle housing under various alternative stresses after long terms of using, such as wear, cracks, thread damage and so on. The working performance of the axle has a direct impact on the car stability and security, and also relates to the life and property safety of the occupants.Taking the vehicle’s drive axle housing as studying objects, the major damage forms of the drive axle housing are analyzed in the dissertation. Choosing three common damage forms as examples, which include axle body surface wear and tiny crack, axle tube surface abrasion and corrosion wear and axle tube shaft thread damage, the remanufacturing process technology for drive axle housing has been studied by adopting welding, electro-brush plating and electro-spark coating method respectively. The main works are reflected in the following three aspects:(1) Choosing H13CrMoA and ER50-6soldering wires, utilizing the technology of sub-melt laser instantaneous, the welding layers with different thicknesses are covered on surface of the drive axle housing shells. The stress distribution of the welding specimens is measured by the magnetic memory testing device and the characteristics of the section are analyzed by SEM. The hardness is tested and the nondestructive tests are made by osmosis, magnetic powder and X-ray testing devices.(2) Using different parameters of electro-brush plating process, the repairing coatings are prepared on the surface of40Mn steel half shaft bushing. Under different process conditions, the coating adhesive force, deposition rate and coating hardness of the steel half shaft bushing are studied. The EDS and XRD of the coating under different process conditions are tested and the coating surface morphologies are observed as well.(3) The threads of the axle tube are remanufactured by two methods, one is turning the threads by lathe after surface welding, the other is coating the threads with electro-sparks. The advantages and disadvantages of repairing threads by lathe after surface welding are analyzed. Nondestructive tests are made by osmosis, magnetic powder and magnetic memory testing devices. The reliability of the remanufactured threads are verified by screw matching experiment.Through experiments, the most suitable remanufacturing methods and technological parameters have been found, for the above three failure forms, such as surface wear and tiny crack of vehicle’s drive axle housing, half shaft surface wear and tiny crack and half shaft thread damage. It provides technical references for the remanufacture of the vehicle’s drive axle housing surface.