Manufacturing of Bimetallic Materials with Anticorrosive Properties by L-DED and Hot Forging

Additive manufacturing methods make it possible to combine the properties of different alloys within a single component, opening up new possibilities. A particularly interesting application is the improvement of corrosion resistance in high-strength materials that, by themselves, do not provide such protection in aggressive environments.

In this study, a surface layer of corrosion-resistant alloys—AISI 316 and Inconel 718—was applied to 42CrMo4 structural steel cylinders using L-DED (laser cladding). Subsequently, the effect of a common forming process, hot forging, was evaluated. To this end, the components were forged with different degrees of deformation at 850 and 1250 °C. The integrity of the parts, changes in microstructure, and the retention of the coating’s corrosion-resistant properties were then analyzed.

Integrity was assessed through hardness measurements, microstructural analysis, and the detection of surface defects using liquid penetrant testing. Corrosion resistance was evaluated by salt spray tests in accordance with ISO 9227.

This work aims to optimize the production of stainless and high-strength bimetallic components through L-DED combined with hot forging, by determining the optimal temperature and deformation parameters to preserve both structural integrity and corrosion resistance. The resulting bimetallic components show great potential for applications such as fasteners, hand tools, suspension components, and compliance with various standards. As a demonstrator, an M20 bolt manufactured following the optimized process is presented.

Funding: This research was funded by the Department of Economic Development, Sustainability and Environment of the Basque Government, grant number KK-2023/00096 (ReIMAGIN project, ELKARTEK 2023 program).