Per: Maycoln depianti Conci (Ifes), DANY MICHELL ANDRADE CENTENo (IPT), HÉLIO GOLDENSTEIN (usp), rene ramos de oliveira (ipen), Paula Fernanda da Silva Farina (unicamp)
Abstract:
Parameters are used to estimate relationships between time and temperature that produce similar effects in tempering. This study proposes to analyze different tempering conditions of AISI D2 tool steel, quenched at 1040 ºC, and the possibility of reproducing the secondary hardening peak obtained in conventional tempering, which occurs at around 500 ºC. Increasing the tempering temperature to 600 ºC, the Hollomon-Jaffe parameter suggests treatment in minutes, and for 700 ºC, in seconds. Results from dilatometry, X-ray diffraction, microscopy, hardness measurement, and residual stress analysis show that at 700 ºC over-tempering, carbide precipitation results in hardness similar to annealing, with a microstructure analogous to recrystallization. Microstructural changes alter residual stresses, maintaining hardness in tempering up to 600 ºC, limiting the Hollomon-Jaffe parameter's predictions in reproducing secondary hardness in tempered AISI D2 steel.