Analysis of Structural and Phase Transformations in Low-Alloy Steels Based on Dilatometric Studies

Abstract

Actual temperatures of structural and phase transformations Ar₃ and Ar₁ for different chemical compositions of low-alloy pipe steels are determined on the basis of dilatometric studies. Equations are obtained for calculating the temperature of critical points Ar₃ and Ar₁ taking account of the effect of 14 main chemical elements as a result of processing experimental data. It is shown that Ar₃ and Ar₁ temperatures calculated by well-known equations differ (by 10–80°C) considerably from actual temperatures, whereas the relationships proposed increase the precision of critical temperature calculation for low-alloy steels by 10°C at least.