Response surface methodology to predict the mechanical properties of hot-rolled sheets

¹ Department of Mechanical Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran
e-mail: Mohsen.ayaz@yahoo.com
² Department of Materials Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran

Received: 15 November 2012
Accepted: 8 November 2013

Abstract

The goal of this study is to empirically investigate the major hot rolling process parameters affecting the yield strength, ultimate tensile strength and strain-hardening exponent of Nb-microalloyed steel sheets. The parameters considered were the roughing, finishing and coiling temperatures. Three levels for each parameter were used to develop a model relating the process parameters to mechanical properties. By applying the response surface methodology, analysis of variance was done to determine the mathematical models related to each response. The results indicated that decreasing the coiling and finishing temperatures significantly influenced the mechanical properties. Also, the models predicted that the maximum yield strength, ultimate tensile strength and strain-hardening exponent are simultaneously obtained under the following conditions: roughing temperature = 1097 °C, finishing temperature = 837 °C and coiling temperature = 580 °C. The predicted values were close to the experimental values, indicating the suitability of the models.