SciELO - Scientific Electronic Library Online

 
vol.7 issue2Comparison of the compressive strength of impregnated and nonimpregnated eucalyptus subjected to two different pressures and impregnation timesMechanical behavior of silver alloys used as cast post and core in maxillary incisors author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Materials Research

Print version ISSN 1516-1439

Abstract

OLIVEIRA, Mauro Aparecido Ferreira de; JORGE JR, Alberto Moreira  and  BALANCIN, Oscar. Influence of deformation on the kinetics of phase transformation in a forging steel during warm working. Mat. Res. [online]. 2004, vol.7, n.2, pp. 247-253. ISSN 1516-1439.  http://dx.doi.org/10.1590/S1516-14392004000200006.

Dilatometric techniques were used to determine the start and finish transformation heating temperatures for a carbon steel (0.30% C - 1.5% Mn). The mechanical behavior of the steel was measured by torsion testing in the temperature range of 700 to 820 °C with holding times ranging from 1 to 30 min. The flow stress curves presented different shapes and stress levels. These differences were attributed to the ferrite and pearlite, ferrite and austenite, and austenite strained structures. When ferrite and pearlite were deformed together, the flow stress presented a hump with little straining; when the austenitic structure was deformed the shape of the flow stress curve was typical of materials having low stacking fault energy. The microstructural evolution observed by optical and scanning electron microscopy revealed that the evolution of the phase transformation was dependent on the testing temperatures, holding times and amount of straining. Comparisons were made on the kinetics of phase transformation with and without the application of plastic deformation, and evidence of strain-induced dynamic transformation was investigated.

Keywords : warm working; pearlite austenite transformation; flow stress curves.

        · text in English     · pdf in English