Nanocrystallization Mechanisms of Fe52Cr18Mo7B16C4Nb3 Bulk Amorphous Steel

Crystallization kinetics of fe52cr18mo7b16c4nb3 alloy was evaluated using x-ray diffraction, differentialscanning calorimetric (dsc) tests and tem observations in this research work. in effect, crystallization and growthmechanisms were investigated using dsc tests in four different heating rates (10, 20, 30, 40 k/min) and kinetic models(i.e. kissinger- starink, ozawa, and matusita methods). results showed that a two -step crystallization processoccurred in the alloy in which ? - fe and fe3b phases were crystallized respectively in the structure after heattreatment. activation energy for the first step of crystallization i.e., ? - fe was measured to be 421 (kj/mol) and 442(kj/mol) according to both kissinger- starink and ozawa models respectively. further, avrami exponent calculatedfrom dsc curves was 1.6 and a two -dimensional diffusion controlled mechanism with decreasing nucleation rate wasobserved in the alloy. tem observations reveal that crystalline ? – fe phase nucleated in the structure of the alloy inan average size of 10 nm and completely mottled morphology.