Modeling the correlation between yield strength, chemical composition and ultimate tensile strength of X70 pipeline steels by means of gene expression programming

In the present work, the ultimate tensile strength of steel made using thermomechanically controlled processing has been modeled by means of gene expression programming. To build the model, training and testing using experimental results from 104 specimens were conducted. The data used as inputs in gene expression programming models are arranged in a format of six parameters that cover the carbon equivalent, based upon the International Institute of Welding equation and the chemical portion of the Ito-Bessyo equation, the sum of the Nb, V, and Ti, the sum of the Nb and V, the sum of the Cr, Mo, Ni, and Cu contents and yield strength. The training and testing results in gene expression programming models have shown a strong potential for correlating the ultimate tensile strength to yield strength and chemical composition of X70 pipeline steels.