Characterization of microstructure and residual stress in a 3D H13 tool steel component produced by additive manufacturing

H13 tool steel was deposited using the additive manufacturing technique Direct Metal Deposition to produce a part having a wedge geometry. The wedge was characterized both in terms of microstructure and residual stress. It was found that phase transformations were significantly influencing the microstructure, which was then linked to the residual stress distribution as seen in Fig. 8. The residual stress distribution was found to be opposite to that reported in the literature. This was attributed to the low temperature martensitic phase transformation of the H13 tool steel and the subsequent tempering of the microstructure with an increasing number of layers of deposited material. The high hardness and compressive residual stress of the top 4 mm of the wedge are ideal in die casting and forging dies, as it will resist thermal fatigue. It also has a hardness higher than that produced by typical heat treatment processes.