The effect of high temperature austenitization on the mechanical properties such as hardness, tensile strength, reduction of area, Charpy impact energy, fracture toughness and on the hydrogen embrittlement has been studied.
With increasing austenitizing temperature from 870 to 1220℃, hardness and tensile strength were not changed, reduction of area decreased continuously from 45 to 10%, Charpy impact energy tested at room temperature showed a maximum at 1000℃, fracture toughness increased continuously from 45 to 90 ksi-in$\frac{1}{2}$ and hydrogen embrittlement susceptibility showed a minimum at 1000℃ and a maximum at 1170℃. The result were discussed with grain size and microsegregation effects induced by austenitizing treatments.
