Text this: OPTIMIZATION OF TEMPERATURE HARDENING FOR IMPROVING THE HEAT RESISTANCE OF TOOL STEEL 4X5MФ1С IN VARIOUS WORKPIECES Part 1. INFLUENCE OF HEATING TEMPERATURE 1040 °С IN THE OIL HARDENING AND HARDERING ON THE HARDNESS AND STRUCTURE OF FORGINGS AND CASTINGS MADE OF STEEL 4X5MФ1C