Study of stress-strain state of the roller conveyor

Numerous studies have established that the damage to the lower surface of hot-rolled strips is mainly due to their friction against rollers of mill rollers. In this case, the probability of scoring, scrapes and other mechanical damage increases otherwise severe wear on the surface of the rollers, improper installation and jamming. This also applies fully to the pulling and forming rollers of the coilers. A prerequisite for preventing damage to the surface of hotrolled strips is also the maintenance of a high level technical condition of the mill equipment, which includes inspections of wiring armature bars, roller conveyor rollers and other units for each transshipment, timely replacement and repair of individual parts and assemblies

Development of hot rolling technology using the method of physical modeling

These days, ensuring the high quality of thin products (0,6 – 2,0 mm) is the most promising direction for the development of hot-rolled strip production. Hot-rolled strips can be used in place of a more expensive cold-rolled strip. The effect of cooling modes on quality of hot-rolled metal was observed heating at different temperature, the degree of deformation was observed after cooling by water-air mixture. It was observed that the micro hardness of the samples decreases and the amount of structurally free ferrite increases by decreasing the cooling time and increasing the temperature

Theoretical background of the restoring of the crankshaft necks by ferromagnetic materials welding

When developing the technological process of cast iron crankshaft restoring, it is necessary to obtain a martensitic structure in the pad weld in order to ensure the wear resistance needed. To form the martensitic structure the cooling rate after padding must be at least 80 - 90 0°C / s. The helical surface welding does not lead to such a result, so in our research we use the welding according to the width of the shaft neck. We also examined the heat release from the pad weld and its cooling rate. For its implementation, the necessary calculations were made according to a compiled program in the QBASIC language. On the basis of these provisions, the theoretic background is proposed for the possibility of the wide-ringed welding of crankshaft necks, which ensures a minimal change in the structure and geometry of the crankshafts

Development of A TECHNOLOGY of Gas-flame Application of Powders to Increase Wear Resistance and Adhesion Strength

Every year, the world economy suffers enormous losses due to wear and corrosion of machine parts and equipment. With targeted preventive protection against wear and tear, these losses can be avoided. Along with the coating of new parts, this includes the restoration of worn parts. An effective method is the surfacing of materials with high performance properties. The quality of hardened parts depends on the properties of deposited material, so hardening material or alloy is selected taking into account the working environment of the part and the coating method. Today there are many self-fluxing surfacing powder alloys based on nickel, copper and others, obtained by different methods. The paper discusses the process of studying the gas-flame application of powders to increase wear resistance and adhesion strength. Experimental studies have been carried out to determine the optimal composition of the CrB2 master alloy introduced into the composition of the GP-Ir40 surfacing alloy. It has been found that to obtain the hardness of the deposited metal in the range of 450–600 HV, it is necessary to introduce CrB2 into the coating composition, within 10 % of the total mass. Thus, the strength of the alloy is increased by more than 54.41 HV. Tests for corrosion resistance in aggressive environments of hydrogen sulfide H2S, sulfuric acid H2SO4 were carried out. The wear resistance of ground pumps was evaluated, and the service life of wear-resistant ground pump parts made of the IChH28N2 alloy was determined. The new developed self-fluxing surfacing powder material based on iron with a hardening additive will be used to restore machine and equipment parts operating under conditions of abrasive wear, corrosion and elevated temperatures or corrosive environment

Study of stress-strain state of the roller conveyor

Numerous studies have established that the damage to the lower surface of hot-rolled strips is mainly due to their friction against rollers of mill rollers. In this case, the probability of scoring, scrapes and other mechanical damage increases otherwise severe wear on the surface of the rollers, improper installation and jamming. This also applies fully to the pulling and forming rollers of the coilers. A prerequisite for preventing damage to the surface of hotrolled strips is also the maintenance of a high level technical condition of the mill equipment, which includes inspections of wiring armature bars, roller conveyor rollers and other units for each transshipment, timely replacement and repair of individual parts and assemblies