The durability of parts of internal combustion engines under thermal stress loading

Abstract

The paper analyzes the structural material-cast iron for diesel engines, from which the cylinder head covers are made. The main defect of these complex metal-intensive parts are heat-resistant cracks. The analysis of chemical composition of cast irons of various manufacturers is made. As a result of the conducted researches chemical compositions of the pig-irons having the greatest heat-fatigue durability are defined. It is established that to increase their strength and durability in operation, it is necessary to change the percentage of basic chemical elements (C, Si, Mn) in cast iron to use rare earth metals (Y, Ce, La). Specific recommendations are given on the choice of the chemical composition of cast iron for cylinder heads and covers, providing an increase in their fatigue strength and durability during operation. The best combination of mechanical and thermal fatigue strength was shown by samples containing carbon C-4.0%, silicon Si-2.0%, manganese Mn-0.18%, yttrium Y-0.1%, and copper Cu-0.8% with sulfur s – 0.008% and phosphorus P – 0.1%.