Effects of thermoviscous flow and mechanical stresses on nitrogen desorption during iron transformation

Abstract

The objective of this paper is a theoretical calculation of the mechanical stresses due to nitrogen pressure in an iron vacancy in the temperature range of 600 to 1100 °C and its effect on the swelling phenomenon associated with the high-temperature viscous flow. The method for quantification is theoretical and based on the analysis of experimental data reported in the literature. Two equations related to the variable were generated: swelling index with time and the stress due to nitrogen pressure. Both the variables are described in increasing ways and correlated significantly at the 99% confidence level. The equations include the value of stresses obtained from previous papers for ferrite (Feα) of 621, 2 Kgf/mm2 and for austenite (Feγ) of 727, 6 Kgf/mm2. The overall effect when opposing these values to the average sample cold compression strength of commercial samples, which varies with the corresponding degree of reduction, the final value of this parameter results in the range of 35.2 and 69.6 Kgf/mm2.