Effect of Impurities Spacing on Fatigue Strength Coefficient

The influence of impurities present in steel on fatigue strength has been the subject research conducted for many years. Despite a large number studies, there is no unambiguous explanation life steel. interpretation results becomes more complicated as ductility increases. For this reason, most concerns low-ductility hard steels. In addition, studies presented literature mostly concern laboratory conditions, which authors papers have tried (with varying degrees success) to adapt industrial research. There are few resistance factor. coefficient k result zg divided by hardness With its help, it possible determine depending work, an attempt was made impact different sizes and located at distances from each other coefficient. analysis carried out seven heats conditions. Melting electric furnaces with capacity 140 tons. Steel all melts subjected desulfurization. Samples diameter 18 mm were taken. samples hardened austenitizing temperature 880 °C. To diversify microstructure mechanical properties, tempered temperatures 200 600 After heat treatment, rotational bending. Based tests, found that depends size distance between inclusions. A difference specific k-factors noted