Effect of heat treatment on microstructure and tensile property of 420 martensitic stainless steel produced by binder jetting additive manufacturing

Binder jetting additive manufacturing of 420 martensitic stainless steel is attractive due to its low-cost and high efficiency, however, the as-sintered parts do not typically provide the desired properties. Here, a heat treatment route was designed to improve its mechanical properties. The heat treatment increased the ultimate tensile strength (UTS) from 657 MPa to 1032 MPa compared to the as-sintered state, while the elongation to fracture decreased from 6.9% to 5%. The increase in martensite fraction as a result of martensitic transformation is responsible for the enhanced UTS of the heat-treated sample.