The bulk shear stress of a paste that results in a 350 grade maraging steel after a reduction heat treatment was successfully modeled. The maximum solids content was measured using the oil drop test and the reciprocal bulk shear stress test. These techniques were found to be in good agreement. Capillary rheometer experiments on solid-free (fluid phase) and solidcontaining pastes allow the calculation of a relative bulk shear stress under most circumstances. The Dougherty-Krieger equation was then used to calculate the intrinsic viscosity [η] and solve for the bulk shear stress of the unknown paste sample.

Keywords: Extrusion, paste, modeling, Fe2O3