With the continuous improvement of automotive gear requirements and the continuous development of automotive gear surface processing engineering technology, the composite treatment of automotive gears with two or more surface strengthening technologies to improve the surface integrity of automotive gears to meet the more stringent use requirements of automotive gears has become an important means in the field of automotive gears, such as QPQ (Queen Polish queen) salt bath composite treatment technology Composite coating technology combining thermal spraying and shot peening, coating and shot peening, etc. QPQ salt bath composite treatment technology is a metal surface modification technology with high corrosion resistance and wear resistance, which is low-temperature salt bath nitrocarburizing and salt bath oxidation.
GM uses this technology to improve the wear resistance of cylinder liner of internal combustion engine. QPQ technology is also used in the camshaft of Volkswagen and the internal gear of the reducer of heavy-duty vehicles of SINOTRUK. The combined Strengthening Technology of thermal spraying and shot peening makes automobile gears have both high bending fatigue resistance and good contact fatigue resistance, and increases the antifriction and lubrication performance of automobile gears.