Carburizing and Quenching Method for Large Excavator Gears

Abstract

The invention relates to a carburizing and quenching method for a large excavator gear. The method comprises the following steps of temperature rising and averaging, high carburizing, dispersing, temperature lowering and averaging, primary quenching, isothermal spheroidizing, secondary quenching and low-temperature tempering. According to the carburizing and quenching method for the large excavator gear, the carburizing and quenching time can be greatly shortened, a high carburizing speed is obtained, energy consumption is reduced, and production efficiency is improved; and meanwhile, grains can be effectively refined, dispersedly-distributed fine-granular carbide is obtained, the metallographic structure of the surface of the gear is improved, tooth face hardness and abrasive resistance are improved, and the service life of the gear is improved.

Description

technical field [0001] The invention relates to a carburizing and quenching method for large excavator gears, belonging to the technical field of heat treatment. Background technique [0002] Excavators are generally driven by electricity, and are construction machinery that realizes continuous operation through the operation of the motor and the gear power of the reduction box. With the rapid development of my country's infrastructure construction in road transportation, energy and water conservancy, and urban construction, the market demand for large excavators is increasing year by year, and the development prospects are strong. However, the working environment of large excavators is relatively complex, and the internal gears of the reduction box are susceptible to failure due to load impact and mechanical vibration. Therefore, large excavator gears not only carry heavy loads and have strong impact, but also require high safety performance. When used, they require excell...

AI Technical Summary

Problems solved by technology

The carburizing temperature of this method is low, the strong carburizing potential is high, and a large amount of carbon black is easy to deposit in the furnace, which leads to fluctuations in the carbon potential in the furnace and causes great difficulties in controlling the carbon potential.

At the same time, this method takes a long time to carburize and is at the same temperature. Since the carbide-forming elements such as Cr and W in the steel will form stable alloy carbides with carbon, the carbon absorption capacity is strong, and the carbon concentration of the carburized layer increases. , is not conducive to the diffusion of carbon elements, the concentration gradient of the carburized layer becomes steeper, and large block and network carbides are prone to appear, which destroys the continuity of the matrix structure and seriously affects the quality of the carburized layer, making the gear in the subsequent grinding process Grinding cracks are easy to occur during the process, and the gears are prone to fatigue under the action of periodic contact stress, forming pitting and surface peeling

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