Mechanical properties anisotropy of cold rolled and solution annealed Ni–20Cr–8Fe alloy

Abstract

Present work describes a correlation amongst texture, in-plane anisotropy in tensile properties and yield locus in Ni–20Cr–8Fe alloy. The alloy exhibits high and moderate values of in-plane anisotropy and anisotropy index, respectively. This has been attributed to the presence of moderate overall intensity of texture as well as partially recrystallized microstructure. The tensile properties evaluated in five sample directions, namely the 0° (longitudinal or L), 22.5°, 45°, 67.5° and 90° (transverse or T) to the rolling direction, display two slopes in true plastic stress–strain curve and follow a Ludwigson relation. At low strains, sample displays the presence of annealing twins and less strain localization (1.5–3.5° boundaries) while the formation of deformation twins and high strain localization are observed in high strained region. The 67.5° orientation sample shows relatively low ductility and low work hardening exponent. This has been explained using Kock–Mecking–Estrin analysis based on higher degree of dynamic recovery/glide softening and fluctuations in work hardening rate during stage II.