The Effect of TMT on the Fatigue Property of Domestic Rail Steel
강계명Kae Myung Kang, 송진태Jin Tae Song
Abstract
The effect of thermomechanical treatment(TMT) on the fatigue and wear properties of a rail steel was examined. The sample was austenitized at 1090℃ and then transformed to pearlitic structure by holding at 700℃ for 17 hr. Samples were then cold rolled to the thickness of 25 ㎜. These samples were heated at 760℃ for 5 to 50 sec. The reduction of pearlitic interlamellar spacing and refinement of the austenite gram size were achieved by the TMT. The sample heated at 760℃ for 10 sec after cold rolling showed better fatigue strength and wear resistance than both the sample without cold rolling and the one with only cold rolling treatment. The fatigue cracks tend to orient them selves parallel to pearlite lamellars. This could be explained by Miller-Smith model. The higher fatigue srtrngth the sample has, the higher wear resistance it has.