Low‐cycle fatigue of X 2 NiCoMo 18 12 and X 10 NiCrAITi 32 20

Abstract

The low‐cycle fatigue and short crack‐growth behaviour of an ultra‐high strength maraging steel and a high‐nickel austenitic steel have been studied. The tests were performed in a laboratory environment at room temperature in push‐pull cycles with constant strain amplitudes of 0.25 to 2 %. Short crack‐growth investigations were performed using bending specimens loaded by a resonance bending machine. Crack growth was measured using the replica method. The cyclic and tension stress strain behaviour has been compared. Fatigue tests were interpreted according to the recommended practice of ASTM‐E 606‐80. First microcracks were observed after 10 to 70 % of the fatigue life.