Precipitation kinetics and mechanical behavior in a solution treated and aged dual phase stainless steel

The precipitation kinetics and the mechanical behavior in a solution treated and aged dual phase stainless steel (DSS) are investigated. X-ray diffraction, transmission and scanning electron microscopy techniques are used to characterize the microstructure and to identify its constituents. The precipitation kinetics analysis shows that the ferrite to sigma phase transformation follows the modified Johnson Mehl Avrami (JMA) model containing an impingement parameter c that is adjusted to 0.3. Activation energies calculation leads to conclude that interface reaction is the main mechanism that controls the sigma phase formation. Detailed analysis of the extent of the different tensile deformation domains reveals the significant contribution of both sigma phase particles and dislocation accumulation to the strain hardening of the material. (C) 2014 Elsevier B.V. All rights reserved.