The Strength and Crack Propagation in Thermal Fatigue under Multiaxial Thermal Stresses

Abstract

In the present monograph is described a method to predict thermal fatigue resistance of metals under multiaxial thermal stresses, and the multiaxial and uniaxial thermal fatigue tests of low carbon steel and high carbon chromium steel are reported.Two types of specimens were employed to produce multiaxial thermal fatigue; one was a solid cylinder cooled from one end, and the other was a thick walled cylinder cooled from the inner surface. The elasto-plastic thermal stresses in each case were calculated by using the finite element method and the method of successive approximations.It is concluded that the lifetime for crack initiation in multiaxial thermal fatigue can be predicted from the conventional thermal fatigue test results. Attention was focused on the difference in the mode of crack propagation in the two given cases.The results were applied to making estimation of the thermal fatigue strength of the rolls used in the hot strip mills.