Abstract
In current conditions of machine operation, increasing the strength and durability is among the main tasks. In order to maintain the integrity and strength of the tire, the steel cord is required with a high fatigue resistance at the cyclic load. Ensuring the fatigue life is an important issue in the steel cord application. That is why the issue of increasing the fatigue strength is challenging for OJSC “BSW - management company of “BMC” holding”, in this connection research work was carried out on the effect of the quality of steel from which the steel cord is manufactured on fatigue properties. In order to determine the effect of steel purity on the fatigue properties of the steel cord, comparative tests of the cyclic endurance of steel cord samples of various constructions manufactured at OJSC “BSW - management company of “BMC” holding” from wire rod of different manufacturers were carried out. All heats used in the experiment have the same carbon content (0.82-0.83%). The heats of both manufacturers differ significantly in the content of impurities and nitrogen. Contamination of the steel with non-metallic inclusions has been estimated by density and contamination index. The factors of steel cord and wire production (heat treatment, drawing speed, the value of concrete and total reductions) have not been taken into account when analyzing the results. The study of the fatigue properties of the steel cord has been carried out using the Hunter method, in which the sample is subjected to cyclic bending with rotation at various stresses until destruction occurs. Under these conditions, the outer and inner fibers of the sample are alternately subjected to tensile and compressive loads that create stresses in the wire. Results obtained have confirmed the dependence of the fatigue properties of the steel cord on the content of non-ferrous metals and nitrogen in steel.
Keywords
Fatigue, steel, sample, steel cord, cycle, strength, stress, wire rod, rigidity.