On the Choice of Modern Structural Metal Material for High-Duty Mechanical Systems. Part 2

Abstract

It is shown that when solving the problems of assurance of quality, reliability, competitiveness of high-duty mechanical systems, metal and a complex of its mechanical and service properties are of fundamental importance. Steel cast iron MONICA (Mo–Ni–Cu) (patent BY, no. 15617) exhibits an unconventional and unique ability to lose brittleness (increase viscosity) with increasing strength. In terms of service properties, it is not inferior to alloyed heat-strengthened steels. This makes it possible to recommend it for the manufacture of many and various highly loaded parts and assemblies of modern technology. The article provides several examples of the effective use of MONICA for the manufacture of cast knives for cutting and chopping devices of forage harvesters (Hi-Tech), large-sized gear wheels with a diameter of 500 mm for final drives of agricultural combines (know-how), as well as experimental cast rails for railway transport (Hi-Tech). A complex of laboratory and full-scale tests has convincingly proved that one brand of the new structural material fully provides the required operational reliability of many and different tribo-fatigue systems, the performance of which is determined by many and different criteria (fatigue, wear, friction, crack resistance, etc.) under the action of high repetitive variables and shock-cyclic loads. This determines the unconditional efficiency and competitiveness of critical mechanical systems (tribo-fatigue systems) for modern machines and equipment.

Keywords

• metal
• mechanical and service properties
• limit of strength
• limit of fatigue
• limit of crack resistance
• wear resistance
• stress-strain and limit states
• modification
• microstructure
• monica