In hot rolled process, the yield strength, tensile strength and toughness play major roll in the structural reliability of the hot rolled steel. Hot rolled St60Mn steel rebars are used for the manufacture of steel for use in construction and other industries. Improved yield strength and toughness of the steel used in construction are often desired to avoid fracture failure and promote impact loading. In this study, Response Surface Methodology was used to study the behaviour of the tensile properties and toughness of the hot rolled St60Mn steel when hot rolled at various finish rolling temperatures and rolling strain rates. The Response Surface Methodology (RSM) was used to investigate the individual and interaction effect of finish rolling temperature and rolling strain rate as independent variables on the yield strength, tensile strength and toughness properties of the hot rolled steel. The St60Mn steel was hot rolled at various finish rolling temperature between 915°C-923°C for rolling strain rates of between 5 x 103s-1- 7 x 103s-1.The influence of the finish rolling temperature and rolling strain rates on the yield strength, tensile strength and toughness were investigated by modelling the relationship using cubic order polynomial to develop the response surface plots and their respective contour plots. The RSM proposes models describing the influence of the rolling process parameters on the properties of the hot rolled steel. The model was able to account for the curvature of the response and the interaction of the independent variables in the response surface. There spone surface methodology (RSM) was applied to optimize the rolling process parameters to attain the optimal values of the properties. The optimized values for the yield strength, tensile strength and toughness for the hot rolled St60Mn steel were obtained as 470.13 MPa,701.63 MPa and 0.458042 joules/mm² respectively. The optimization was achieved within the 95% confidence interval
In hot rolled process, the yield strength, tensile strength and toughness play major roll in the structural reliability of the hot rolled steel. Hot rolled St60Mn steel rebars are used for the manufacture of steel for use in construction and other industries. Improved yield strength and toughness of the steel used in construction are often desired to avoid fracture failure and promote impact loading. In this study, Response Surface Methodology was used to study the behaviour of the tensile properties and toughness of the hot rolled St60Mn steel when hot rolled at various finish rolling temperatures and rolling strain rates. The Response Surface Methodology (RSM) was used to investigate the individual and interaction effect of finish rolling temperature and rolling strain rate as independent variables on the yield strength, tensile strength and toughness properties of the hot rolled steel. The St60Mn steel was hot rolled at various finish rolling temperature between 915°C-923°C for rolling strain rates of between 5 x 103s-1- 7 x 103s-1.The influence of the finish rolling temperature and rolling strain rates on the yield strength, tensile strength and toughness were investigated by modelling the relationship using cubic order polynomial to develop the response surface plots and their respective contour plots. The RSM proposes models describing the influence of the rolling process parameters on the properties of the hot rolled steel. The model was able to account for the curvature of the response and the interaction of the independent variables in the response surface. There spone surface methodology (RSM) was applied to optimize the rolling process parameters to attain the optimal values of the properties. The optimized values for the yield strength, tensile strength and toughness for the hot rolled St60Mn steel were obtained as 470.13 MPa,701.63 MPa and 0.458042 joules/mm² respectively. The optimization was achieved within the 95% confidence interval