Some consistency requirements on hardening-recovery evolution equations for welding: Part 1.

摘要

Welding residual stresses and distortions arise from complex thermomechanical processes driven by the room temperature to melt temperature changes imposed on the metals. These changes also cause many order of magnitude changes in some mechanical properties of the metal in and near the fusion zone, where the principal distortions arise. Thus while stresses are low there at the time of peak temperature, the deformations are large and important. Simulation, to be useful, should treat this zone with a consistent accuracy near the fusion zone and in cooler metal further away. Calculations should also make the maximum possible use of thermophysical property data available for commercially interesting alloys. Heuristic viscoplastic equations of the Armstrong-Frederick type are considered here, and analytical solutions for some nonisothermal processes are employed to restrict the values of hardening-recovery parameters applied to welding processes. Results indicate that use of Ashby and Frost's deformation mechanism maps as templates organizes this analysis, and puts the need for additional data into a clear context for the example of 304L Stainless Steel.