V. Warke, M. M. Makhlouf, Worcester Polytecnic Institute, Worcester, MA; R. D. Sisson, Worcester Polytechnic Institute, Worcester, MA; B. L. Ferguson, Z. Li, Deformation Control Technology, Inc., Cleveland, OH

Summary: A major economic benefit of press and sinter P/M technology is net- and near-net shape capability. However, heat treatment of steel components introduces possible distortion due to nonuniform heating and cooling and volumetric changes associated with phase transformations. Unanticipated distortion can eliminate the economic benefit of this production method. Also, heat treatment introduces residual stress into the component which may adversely affect the fatigue resistance of the sintered porous component. This paper reports on work-in-progress at WPI to characterize the phase transformation kinetics of 4600 steel powder in terms of part porosity, and on joint work between WPI and DCT to simulate heat treatment of sintered porous parts using the finite element method. Simulation results will be presented to demonstrate the influence of sintered density gradients on residual stress and distortion for through-hardened porous 4650 steel part.