Characterization of hot deformation of CW602N brass

Alpha brasses (in principle single-phase solid solution alloys containing less than 35% Zn) are usually processed by extrusion, forging or rolling. Although these materials are of widespread use, few detailed studies of the flow behavior of brass at high temperature are available. The hot workability of a CW602N brass (Cu-36.5%Zn-2%Pb) was thus investigated by torsion testing in the temperature range between 550 and 800°C, under equivalent strain rates ranging from 0.01 to 10 s-1. The peak flow stress dependence on temperature and strain rate was described by the well-known Garofalo equation, with a stress exponent close to 4 and Q =220 kJ mol-1. A considerably larger scatter of the experimental data was observed in the high temperature range. The detailed microstructural analysis of the deformed samples by scanning electron microscopy revealed substantial differences among the samples deformed in the low temperature regime and those torsioned at 750 and 800°C. These differences were analyzed and discussed to rationalize the different mechanical responses observed in the two hot-deformation regimes.