Heat Treatments of P295GH Steel Made by Directed Energy Deposition: Metallography and Hardness

Abstract

Directed energy deposition (DED) is an Additive Manufacturing process deposing fused metal powder on a preexisting substrate. This document shows the influence of heat treatment on P295GH deposit made by DED, for hybridization process. The heat treatment must reduce the macroscopic differences between the rolled substrate and the deposited DED material. The experimental plan has been defined around AC3 temperature, according to P295GH existing literature. XRD analysis, hardness measurements and metallographic inspections have been performed on samples before and after heat treatment. XRD analysis and hardness measurements have shown an isotropic material. The as-built microstructure is ferritic and acicular, but coarsens after the heat treatment. The study promotes a heat treatment at 800°C during 3 hours to obtain the best compromise between properties, impact on the substrate and differences with the rolled substrate.