overview
Cast track shoes are widely used in construction machinery, mining machinery, excavators, bulldozers, etc. They are key components of construction machinery equipment, directly related to the safety and reliability of vehicle operation. With the development of large-scale and heavy-duty construction machinery equipment in China, the operating conditions of track shoes have undergone significant changes, and the working conditions have become more severe. The track shoes come into direct contact with sand, soil, rock, coal, and minerals during use and operation, and are subjected to severe abrasive wear, strong transverse tensile stress, and longitudinal shear force, resulting in a large amount of wear and consumption. Therefore, research on high-strength and high toughness track shoe cast steel materials is necessary. The application of rare earth as an alloy additive in steel is becoming increasingly widespread. Adding rare earth elements to steel can purify the molten steel, improve the morphology and distribution of non-metallic inclusions, enhance the microstructure of steel, refine grain size, improve the impact toughness of steel, and improve low-temperature performance. Adding rare earth elements to alloy cast steel and carbon cast steel, utilizing their unique physical and chemical properties, has a very good effect on improving the mechanical properties of castings, especially the low-temperature impact toughness index of materials.
High strength track shoe cast steel parts require increasing strength while ensuring plasticity and toughness, preventing early brittle cracks and fractures, improving safety and reliability, and extending service life.
In order to ensure that the mechanical properties of the castings, especially the castings themselves, meet the requirements of product technical standards, a preliminary heat treatment process has been added to the track plate cast steel parts, that is, a normalizing process has been added. The technical conditions have special requirements for the mechanical properties of the casting body. After heat treatment, the cast steel parts of the track plate in the experimental furnace were sampled and tested for mechanical properties. The mechanical properties of the castings after heat treatment met the technical requirements of the product.
Conclusion
(1) I have a basic understanding of the reaction, existence mechanism, and role of rare earth elements in low-alloy cast steel, which can provide practical experience data for the research and application of materials.
(2) Applying rare earth elements to engineering machinery steel castings, utilizing the purification, modification, and alloying effects of rare earth elements, EL steel for engineering machinery track plates has been developed; On the basis of ensuring the plasticity of steel castings, the strength will be greatly improved to meet the demand for high strength and high toughness steel castings for the development of large-scale and heavy-duty engineering machinery and equipment, as well as the needs of national infrastructure and the “the Belt and Road” great project.
(3) Through the research of rare earth modification technology, the unique physical and chemical properties of rare earth elements can be utilized to adjust the alloy components and their contents reasonably, which can minimize production costs and maximize benefits while ensuring the quality of casting products.