Esferoidização em aço SAE AISI 52100: esferoidização cíclica para redução de tempos

Abstract

The industries relentlessly search for process optimization, aiming at greater profitability, quality and competitiveness in the market. The premise is basically the same: do more with less. When we talk about high carbon steel, these can be too hard to be conveniently machined or plastically deformed. To make this type of material more workable, these steels can be heat treated or annealed to develop the structure of the spheroidite, which has greater ductility, less hardness and is easily machined or deformed. However, conventional spheronization heat treatments are lengthy. This work aims to find a way to accelerate the spheronization process in SAE 52100 steel, seeking an alternative approach to the conventional proposal. Test specimens (CP) made of SAE 52100 steel were subjected to a cyclic spheroidization process, at temperatures above and below the eutectoid temperature (727°C) for 3 and 6 cycles. The material was then characterized for hardness, with hardness of 86.5 HRB after 3 cycles and 88.5 HRB after 6 cycles. As for tensile strength, it was obtained 626.45 MPa and 638.60 MPa after 3 and 6 cycles, respectively, and the microstructure was characterized by optical microscopy. Conventional spheroidization treatment was applied, which took about 16 hours and 21 minutes, while the treatment of 3 cycles lasted 1 hour and 13 minutes, while the spheroidization treatment for 6 cycles lasted 2 hours and 16 minutes, and with this presented a reduction in the treatment time of 92.56% applying 3 cycles and 86.13% in relation to 6 cycles.