Constitutive model for nickel alloy 690 (Inconel 690) at various strain rates and temperatures

Mechanical behavior of nickel alloy 690 (NY690) is characterized from 25 degrees C to 1100 degrees C and for a strain rate ranging from 10(-4) to 5 x 10(-3) s(-1). The effects of chromium carbides and grain size (50-150 mu m) on the tensile properties of NY690, were studied at 25 degrees C and 750 degrees C. Chromium carbides have negligible influence on the yield stress and on the strain hardening whereas the grain size slightly decreases the yield stress and the hardening rate at room temperature. The grain size has little influence on the strain-hardening but increases the steady-state stress. The dislocation density is the major microstructural parameter governing the mechanical behavior of the alloy for the studied experimental conditions. The Kocks-Mecking-Estrin formalism is adapted to a wide range of temperature and strain rate to predict the mechanical behavior. (C) 2015 Elsevier Ltd. All rights reserved.