Low cycle fatigue behaviour of HAYNES 230 alloy

HAYNES (R) 230 (R) alloy is a commercial solid-solution strengthened Ni-base superalloy that has found wide spread use in the hot sections of gas turbines. Recently, the alloy has been considered for other applications, e. g. in concentrated solar power plants. One common key performance criterion for all these applications is the ability of the material to withstand large numbers of thermal cycles due to start-ups, operatings, and shut-downs. Such thermal cycles may trigger low-cycle fatigue (LCF) due to differential thermal expansion and contraction. This paper reports isothermal LCF performance data of 230 alloy standard mill-annealed plate product for a wide range of temperatures 427-982 degrees C and strain ranges (up to 1.5%), relevant to many of the aforementioned applications. Low-cycle fatigue lives are analysed in terms of the contributions of cyclic elastic and plastic strain components to fatigue damage. The fit parameters are discussed in the context of the alloy's tensile properties.