Study of Truck Spring U-Bolt Properties

Abstract

They presented the studies of the chemical composition, microstructure and the properties of carbon and alloy structural steels, used for spring ladders of a truck, subjected to various heat treatment methods. Improvement and normalization are used as heat treatment. They provided the study results of the chemical composition, microstructure, hardness and cyclic durability in tension of parts made of steels of the following grades: 40, 40X, 30G2 from various manufacturers. The study of the microstructure of the part was carried out on longitudinal microsections cut from the threaded part using an optical microscope via the program - analyzer of the solid SIAMS 800 microstructure fragments. During the study of the microstructure, they evaluated the depth of the decarburized layer, the presence of
nonmetallic inclusions, and the grain size. They provided the results of cyclic tests and fractographic studies of parts. They substantiated the choice of material and the technology of hardening treatment for the ladders of a truck spring. After the study, it was found that it is recommended to use high-quality alloy structural steel 40X for the manufacture
of ladders of a truck spring, normalization is used as a hardening treatment, which significantly reduces the cost of manufacturing part technological process and increases their durability.