CANCELLED - Cyclic Plastic Deformation Behavior of Haynes 282

Haynes 282 is a relatively new alloy for high temperature applications, e.g. both aero and land-based gas turbine engines. Besides good high temperature properties the alloy shows good weldability and fabricability compared to competing alloys. The material in such critical applications are subjected to both mechanical and thermal loads, and hence subjected to thermo-mechanical fatigue. The good weldability of Haynes 282 gives possibilities to fabricate advanced structures with other alloys in the less critical parts. The aim of the work is to study the plastic stress-strain behaviour of the material during thermo-mechanical and isothermal cycling loading. Strain controlled thermo-mechanical fatigue tests were carried out at in-phase and out-of-phase conditions. The temperature ranges from 300°C to 730°C and at strain ranges 1-2 %. Also isothermal test were carried out at the same temperatures and strain ranges. The stress-strain loops were analyzed for the different types of thermal and mechanical cycles in order to identify similarities and differences. A number of parameters were determined from the stress-stain loops, including maximum stress in tension and compression, Bauschinger stress, plastic and elastic strains in tension and compression. There was a clear difference in the shape of the hysteresis loops for the different types of lodgings. The analysis showed differences in the development of cyclic hardening and softening during cycling, and differences in the Bauschinger effect depending on if the test were performed in-phase or out-of-phase. It was also found that the linear part of the hysteresis loops had different sloop when unloading from tensile load or compressive load. This can be attributed to micro-plasticity resulting from the buildup of dislocation structures during the plastic deformation.