Work-hardening in Inconel X-750: Study of Stage II

The effect of the precipitate structure on plastic behavior during the Stage II of Work Hardening in Nickel-base superalloy Inconel X-750 has been studied. Tensile tests were carried out at room temperature. The measures were analyzed by the application of the generalized stress components superposition rule sigma = sigma(f) + sigma(ss) + (sigma(gamma)(q) + sigma(d)(q))(1/q) for combining the stress components due to: lattice friction sigma(f), solid solution sigma(ss), gamma'-precipitates sigma(gamma) and dislocation-dislocation interaction sigma(d), with q as an adjustable parameter. By using this criterion, the stress component associated with the dislocation density was determined. The results an discussed in the framework of "one parameter" models by means of sigma(d)(d sigma(d)/d epsilon) vs sigma(d) graphs, the structural evolution during Stage II has been characterized along the transition from shearable to unshearable gamma'-precipitates. (C) 1998 Acta Metallurgica Inc.