Tribological performance of 410L martensitic stainless steel parts manufactured by Laser directed energy deposition

The processing of AISI 410L martensitic stainless steel (MSS) by laser directed energy deposition (L-DED) for additive manufacturing (AM) of wear-resistant components is an alternative to the high C-content MSS grade, with difficult processability. This work assesses the tribological performance of low C-content 410L MSS additively manufactured by L-DED. Two sets of L-DED parameters were investigated, one targeting Production and high deposition rates, and the other for Resolution and increased geometric freedom. Half of the multilayer samples were subjected to a post heat-treatment route. Samples were evaluated by the dry-sliding linearly reciprocating ball-on-flat tribological test (ASTM G133) in the as-built and heat-treated states. Commercially annealed 410 MSS was the reference material. In the L-DED as-built, microstructures were composed of ferrite with martensite at the grain boundaries. Heat-treatment provides recrystallization, martensite tempering, and hardness decrease. The more refined microstructure of L-DED resolution as-built led to greater hardness and lower wear coefficient in the ASTM G133 test. Wear tracks revealed wider bands of compact tribolayers on its surface, which reduced the action of adhesive and abrasive mechanisms. The other L-DED as-built and heat-treated conditions, and 410 reference material demonstrated a large amount of free debris, indicating lower wear resistance.