TY JOUR TI EVALUATION OF THE CORRELATION BETWEEN HARDNESS AND STRUCTURE OF ALLOYED CAST IRON WITH FLAKE GRAPHITE, USED FOR MANUFACTURING PISTON RINGS KW grey cast iron KW flake graphite KW hardness KW quantitative metallography KW results KW treatability KW elasticity JO Transport engineering AU Sazonov, V.O. AU Makarenko, K.V. AU Vdovin, A.V. PY 2025 IS 2025 PB Bryansk State Technical University