Influence of the HIP process on the properties of A508 steel produced by additive technology

It is generally known that materials produced by additive technology may in some cases have an imperfect internal structure, which limits the use of these materials for the production of critical components. For this reason, it is necessary to perform appropriate post-production processing for these materials. One option is to perform the so-called HIP process (Hot Isostatic Pressing). This process combines thermomechanical processing of the material, as a result of which the material acquires optimal mechanical properties. This paper examines the impact of thermomechanical processing via the HIP method on selected basic mechanical and metallographic aspects of A508 steel produced by additive manufacturing technology. It was found that the HIP process significantly improved the toughness, ductility, and microstructural homogeneity of additively manufactured A508 steel. The frequency of occurrence of macropores (i.e. up to 10 µm in size) was reduced by up to 78% compared to the printed state. The HIP process resulted in a decrease in the static tensile and bending strength values, however, this was compensated by a high increase in the toughness and ductility values of the material. The HIP process resulted in a significant increase in the toughness of A508 steel compared to its as-received condition. This increase is crucial for the use of the material for components in the nuclear industry, as the improvement in toughness directly contributes to the safety of nuclear facilities.