1994

Marquis, Gary

Fatigue threshold behaviour of a high strength structural steel has been investigated. The test material was RAEX 460 steel produced by Rautaruukki Oy at the Raahe steelworks. For comparison RAEX 460 with 7% cold work and FE 52 steel were also tested. Threshold testing included endurance limit testing of smooth cylindrical specimens and crack growth threshold testing of compact tension C(T) type specimens. Testing was performed at different stress ratios and test frequencies. The material showed a very high endurance limit and a low crack growth threshold which was not greatly influenced by stress ratio. A few strain controlled tests showed cyclic softening of the material even at low total strain amplitude and long fatigue lives. Figures illustrating the use of this steel in design are also given and discussed.