Tractor parts track shoes are the largest number of easily worn parts on tractors and bulldozers. Its working conditions are relatively poor. It often has to be in the open air and in direct contact with soil and gravel, and withstand certain stress effects such as impact, tension, extrusion and bending. For a long time, the research on improving the service life of track shoes has been one of the important topics at home and abroad. In recent years, the following work has been done to improve the performance of track shoes:
- Change the structure of track shoe and thicken the size of easily worn parts. In some special cases, sealing lubrication device is also used to improve its service performance;
- Adopt a variety of manufacturing processes. For example, rolling tractor parts track shoes instead of casting track shoes, surface alloying, insert sleeve, etc;
- Select economical and durable new track shoe materials and corresponding heat treatment process.
At present, the research focus on improving the service life of track shoe is still on the selection and application of track shoe materials. The purpose of the research is to obtain a higher service life of track shoes on the one hand, on the other hand, using high manganese steel as track material has high smelting requirements and needs to consume a large amount of high-quality ferromanganese. Under the service conditions of tractor parts track shoes, high manganese steel is not easy to obtain sufficient work hardening, so it is not an ideal track shoe material. It is hoped to obtain an economic and durable substitute material with a service life equivalent to that of high manganese steel.
Most of the past research work evaluated the wear resistance of tractor parts track shoes directly through field experiments. Various test tractor parts track shoes and high manganese steel tractor parts track shoes are installed on the same vehicle for test comparison. This direct loading test is affected by many factors such as test conditions, production characteristics of each plant, measurement and statistical errors. The test cycle is long, the test parameters are difficult to control, and the results are scattered, so it is difficult to draw a more accurate conclusion.
Therefore, it is necessary to use the corresponding laboratory wear test to make up for the deficiency of field test. At the same time, in order to reasonably select wear-resistant materials, we must essentially understand the damage characteristics of track shoes and guide the selection direction and way of wear-resistant materials. In recent years, the team of ZHY casting senior engineers has focused on the indoor wear test of track materials, the micro analysis of wear surface of tractor parts and track shoes, and the damage mechanism. The tractor parts and track shoes tested are from the main manufacturers of tractors and track shoes in China, and the selected materials are representative.