Impact of Nano sized Aluminum Nitride Second phase Particles on Gamma and Alpha Phase Transformation in Less Carbon added Manganese Steel

Abstract

A scientific investigation has been performed in this research work on the basis of experimental results and ramification to divulge the advancement of second phase particles and its influence on ferrite and austenite phase transformation in less carbon-manganese added steel. Two steels have been engaged in this competition with and without aluminum addition along with nitrogen. To fade out the already present particles, as received steel under investigation was solution heat treated at 1200°C and then both the steel samples were heat treated at 740°C and 800°C for 10, 15, 30, and 60 sec incubation time in the cyanide added liquid bath furnace and were rapidly cooled from elevated temperature at room temperature in ordinary water. Metallography was performed after etching technique in two etchant solutions to dispose the internal microstructural features with advanced Olympus GX51 optical microscope with polarized light. To further enlarge the important microstructure SEM with tungsten filament was used to capture the micrographs. To distinguish the lower critical AC₁ and upper critical AC₃temperature for Both the steels were measured with the help of Dilatometer results were plotted by using Origin data software. It was concluded that aluminum combine with nitrogen stimulate the fine aluminum nitride (AlN) particles and these particles were the major source to hinder the grain boundary mobility and consequently phase transformation of alpha and gamma was interrupted in aluminum added steel and it lowers the critical temperatures. Surprisingly there was no such attitude was observed.