Modern structural and operating materials in development of road-building machines

Abstract

BACKGROUND: The analysis of modern state of using structural and operating materials in development of road building machines is given in the article. AIMS: To highlight the most important tendencies in obtaining modern structural and operating materials in development of road building machines. METHODS: The study subject is modern structural and operating materials in development of road building machines. The novelty of the study lies in highlighting main modern tendencies of modification and technological features of modern structural and operating materials for road building machines with enhanced mechanical strength characteristics. The materials of the study include main scientific and practical information on ways of using structural and operating materials in development of road building machines. The study methods include classification and integration of the information on the topic of modern structural and operating materials in development of road building machines. RESULTS: It is found that the key difference between steel types for structural and operating materials as a part of development of units, mechanisms and parts of road building machines is parameters of corrosion resistance, which is defined by qualitative and quantitative chemical composition directly. Among the main issues of modern industry development, improvement of cost-performance ratio of road building machines, their mechanisms and engineering parts by means of reducing specific metal content and increasing operational reliability and durability is outlined. CONCLUSIONS: It is shown that, opposed to majority of low-alloyed structural steel types, change of austenite in steel types, micro-alloyed with vanadium and niobium and with strength class in the range from S350 to S490, with constant cooing according to the thermal cycle of welding performs mainly in bainitic range. As a result of structural changes, taking place in steel and influenced by thermal cycles of welding, the static strength indicators of the metal in zones of thermal impact of welding joints increase, whereas the indicators of plastic properties reduce. Sufficient reduce of impact viscosity of the metal in zones of thermal impact of welding joints of micro-alloyed structural steel types is observed at w6/5 5C/s. With increasing of cooling speed, the impact viscosity of the metal in zones of thermal impact rapidly increases and it may achieve the level of the main metal in some steel types.