Journal of Materials Research and Technology Journal of Materials Research and Technology
J Mater Res Technol 2017;6:116-22 DOI: 10.1016/j.jmrt.2016.05.004
Original Article
Hot tensile properties and strain hardening behaviour of Super 304HCu stainless steel
M. Vinoth Kumara, V. Balasubramanianb,, , A. Gourav Raoc
a Department of Mechanical Engineering, Hindustan Institute of Technology and Science, Hindustan University,Chennai, India
b Centre for Materials Joining and Research (CEMAJOR), Department of Manufacturing Engineering, Annamalai University, Annamalai Nagar, India
c Naval Materials Research Laboratory (NMRL), Mumbai, India
Received 12 August 2015, Accepted 17 May 2016
Abstract

Super 304HCu austenitic stainless steel containing 2.3–3 (wt.%) of Cu is mainly used in superheaters and reheaters tubing of ultra super critical boilers which operates over 600°C of steam temperature. Tensile tests were carried out on Super 304HCu, using nominal strain rate of 1×10−3s−1, at room temperature, 550°C, 600°C and 650°C. The tensile strength and elongation were found to decrease with increase in test temperature. The stress strain curves were fitted using Hollomon equation to determine the strain hardening exponent value. Differential Crussard–Jaoul (C–J) analysis of the tensile curve is used to determine the variation in strain hardening exponent. Kocks–Mecking (K–M) type plots were used to determine the stages of strain hardening during tensile loading of the specimen. The strain hardening capacity of the Super 304HCu is found to decrease with increase in test temperature.

Keywords
Super 304HCu, High temperature tensile properties, Strain hardening behaviour, K–M plots
J Mater Res Technol 2017;6:116-22 DOI: 10.1016/j.jmrt.2016.05.004