Abstract: | AbstractThe durability of the springs is limited by plastic deformation, fatigue and fracturing. From this point of view, the use of spring steel with following properties is recommended: high ductility and toughness at operation temperatures from ?40°C to +50°C, good hardenability that provides required mechanical properties even at maximum dimensions. For the manufacturers of springs, the information relating to the heat treatment of specific spring steel is important. This paper describes the influence of heat treatment parameters on tensile strength Rm, yield strength Rp0·2, fracture toughness KIc, impact toughness, Charpy-V as a function of tempering temperature in the range from 350 to 700°C for a specific austenitising temperature. Also the difference between the properties given by the mathematical modelling of heat treatment using the computer software Hardenability and the properties obtained by testing the heat treated samples are presented. |