The effects of different heat treatments on the fatigue strength of tool steels

Various heat treatments are applied to improve the mechanical properties of steels depending on intended use. In this study, variation fatigue strength H13 hot work tool steel with treatment in a GS 550 bath was investigated. It investigated by applying four different as first preheating, second hardening and hardening. Each batch samples subjected rotating bending test at room temperature after treatment. The untreated determined 470 MPa. hardened untempered (Group 1) increased 610 2), which were annealed for two hours 550ºC hardening, measured 630 3) found be 720 MPa third treatment, annealing 610ºC hours. 4), fourth tempered then 635ºC 710 has been observed that all positively affect steel. While resulted strength, highest obtained double (550 °C hours) initial preheating quenching.