Residual stresses in spray-formed A2 tool steel

The objective of this work was to investigate the fundamental factors that govern the formation and magnitude of residual stresses in A2 tool steel fabricated using spray-forming techniques. To that effect, a finite-element method (FEM) was performed by using a commercial code, ABAQUS, to solve for the temperature and displacement fields. Moreover, the residual stresses in the spray-formed materials were measured using x-ray diffraction to compare the FEM results with experimentation. Two types of substrate material, copper and Rescor™ 780 cer-cast ceramic, were used to investigate the influence of heat conduction on residual stress in the preforms. Relatively good agreement was found between experimentation and theory. The results show that the residual stress varies greatly with the position in deposited preform and that heat-transfer coefficient at the interface of spray-formed material/substrate affects the distribution and magnitude of the residual stresses significantly.