MICROSTRUCTURAL EVOLUTION AND RECRYSTALLIZATION ANNEALING EVALUATION OF EN 1.4105 FERRITIC STAINLESS STEELS

The microstructure evolution of cold-drawn ferritic stainless steel round bars, EN 1.4105, recrystallized under annealing heat treatment with different conditions, is investigated in this research study. To this end, the chemical composition alongside with reduction rate of ferritic stainless steel (FSS) round bars are interrelated with each other for analysis of this study. EBSD characterization after the isothermal recrystallization annealing stage arises from an actual multi-step cold wire drawing process headed for a bar drawing industrial case study is carried out. The heat treatment process has implemented at three different set ratio soaking temperatures of 0.65, 0.68, and 0.71 between the temperatures of heat treatment and melting point under seven various soaking time. The objectives are to evaluate the grain growth and recrystallization fractions before and after the heat treatment. The results represent that the recrystallization fraction is much higher and prompt for higher reduction rate of 35.9%, while also the formation of new grains is engendered much quicker showing fully recrystallized after 128 min heat treatment under the 0.65 set ratio temperature. This is while for 19.4% reduction rate under the same condition, after 108 min, only 80% has been recrystallized. However, for the specimens of the current study, the bars with higher reduction rate had already illustrated around 2% of recrystallization in unheated condition by further characterization.