Compared with similar products in advanced countries, the quality of truck gears in China lags far behind, with an average service life of only about half, high energy consumption per unit product and low labor productivity. In order to improve the quality of truck gears, in addition to appropriate material selection, we must strictly standardize the heat treatment process, strive for innovation, and widely adopt new technologies, new processes and new equipment.
As mentioned earlier, equipment is the basis of process, and the quality of truck gear heat treatment needs heat treatment equipment to ensure to a great extent. Truck gear heat treatment requires high control accuracy of equipment temperature and carbon potential, uniformity of temperature and atmosphere in the furnace, stirring and circulation of quenching oil. If the control error of temperature and carbon potential is large, and the temperature and atmosphere in the furnace are uneven, the quenching deformation will increase, and the truck gear will be scrapped in serious cases. On average, the technology of heat treatment equipment in China is relatively backward. Most carburizing furnaces cannot carry out automatic control of carbon potential. The carbon concentration on the product surface fluctuates greatly, the process repeatability is poor, the quality of carburized gears is unstable, the production efficiency is low, the energy consumption is high and the cost is high.
Although the application of Chinese gas carburizing dynamic software in carburizing furnace has been successful, there is still a certain gap between the control level and foreign countries. During the period of “85” and “95”, the heat treatment equipment was imported into the large number of automobile enterprises and parts factories. The domestic equipment manufacturers also introduced technology through joint ventures and other channels, which greatly improved the advanced nature of carburizing equipment. At present, various carburizing equipment with controllable atmosphere has been applied in large quantities, and low pressure carburizing, high pressure gas quenching vacuum equipment and plasma carburizing equipment have also entered some manufacturers. Thus, the quality stability of carburizing heat treatment of truck gears in China is greatly improved.