The effect of out-of-furnace treatment on the properties of high-grade medium-carbon structural steel

The experimental material consisted of high-grade, medium-carbon, semi-finished structural steel. The production process involved two melting technologies: in a 140-ton basic arc furnace with desulphurisation and argon refining variants, and in a 100-ton oxygen converter. Following heat treatment, rolled samples with a diameter of 10 mm were subjected to fatigue tests. Heat treatment involved quenching from a temperature of 1153 K and tempering at a temperature of 473, 673 and 783 K. Fatigue tests were performed with the use of a rotary bending machine at a frequency of 6000 cpm. The results were processed and presented in graphic form.