Evaluation of additive friction stir deposition of AISI 316L for repairing surface material loss in AISI 4340

Additive technologies provide a means for repair of various failure modes associated with material degradation occurring during use in aggressive environments. Possible strategies AISI 4340 steel using 316L deposited by additive friction stir deposition (AFSD) were evaluated under this research metallography, microhardness, and wear mechanical testing. Two geometries investigated: groove-filling surface cladding. The former represents localized grinding to eliminate cracks, while the latter replacement over larger area, example, general corrosion or wear. AFSD exhibited refined microstructure decreased grain size plastic strain, ~ 12% lower strength, 5–12% hardness than as-received feedstock. Wear testing both two-body abrasion erosion particle impingement indicated that resistance cladding was as good as, better than, substrate material; however, there some evidence intergranular compromised due formation carbides sigma phase. In geometries, beneath heat affected zones where appeared have austenized depth 4 mm process, transformed martensite bainite cooling. This report constitutes an initial evaluation novel approach structural components damaged microcracking, wear, corrosion, potentially broad applicability marine, aerospace, heavy duty off-road industries.