Investigation on ECAPed structural steel IS2062 and evaluation of strengthening mechanisms

The structural steel IS2062 was processed by equal channel angular pressing (ECAP) at room temperature with 120 degrees channel angle die. The microstructural properties are evaluated and correlated with the mechanical properties of the ECAP processed material. Every subsequent ECAP passes the strength of the sample was improved and the results are attributed by the SPD process which generated higher dislocation density with refined grains. X-ray diffraction line profile analysis was used to determine the crystallite size, lattice strain and dislocation density. TEM analysis confirmed the dislocation structure in deformed samples. The ECAP processed sample exposed an increase in lattice strain and dislocation density with the number of passes and with a reduced crystallite size. Quantitative contributions of individual strengthening mechanisms for the overall yield strength of ECAP sample was analytically calculated. The results illustrate that the significant contribution comes from dislocation density followed by grain boundary strengthening.