Optimisation of precipitation hardening for 15-5 PH martensitic stainless steel produced by wire arc directed energy deposition

Abstract

This paper discusses directed energy deposition of 15-5 PH, which was successfully tailored with precipitation hardening (PH) to achieve the desired properties. Parametric analysis of solution annealing and aging at various time and temperature combinations was performed. Material characterisation was done in the as-deposited, solution annealed, and PH states. Investigations included microscopy, SEM/EDS, fractography, hardness, tensile, and impact toughness test. The as-deposited microstructure was composed of martensite laths along with delta ferrite. Optimisation of solution annealing was mandatory to achieve homogeneous austenite, which allowed PH. PH resulted in similar properties compared to conventionally produced steel. Peak aging resulted in 450 HV10 and an Rm of 1350 MPa, while the over-aged condition resulted in an impact toughness of over 77 J/cm 2 .

Effect of Microstructure Modifications on Stress Corrosion Endurance of 15-5 PH Stainless Steel Formed by Wire Laser Additive Manufacturing (WLAM)

“…According to Brauer [45], Niobium Carbo-Nitrides (Nb(CN)) can be formed in various stoichiometries, depending on the ratio between the three composing elements. Ščetinec et al [46] also confirm that the presence of Nb(CN) in 15-5 PH stainless steel produced through the DED process is of a similar size (about 20 nm) to that obtained in this study. Altogether, it is believed that the minor amount of Niobium Carbo-Nitride phase that was found in the WLAM alloy post-heat treatment has an insignificant effect on the properties.…”

Recent progress in process, structure, properties, and performance in additive manufacturing

“…The special issue contains contributions on the major variants of AM including laser DED [6,9,18,24], gas metal arc DED [7,[10][11][12][13][14]16,19,[21][22][23], laser PBF [8], cold spray [17], laser-arc hybrid manufacturing [20], and fused deposition modelling [15]. Chaurasia et al [22] presented a novel approach to real-time monitoring of melt pool cross-sectional asymmetry during laser PBF using a two-color thermal camera.…”

“…Ščetinec et al [18] studied the microstructure and mechanical properties of 15-5 PH steel parts made by laser DED using optical microscopy, SEM/EDS, fractography, hardness, tensile, and impact toughness tests. The as-deposited microstructure was found to be composed of martensite laths along with delta ferrite.…”

“…The articles in the special issue cover a wide variety of alloys including Ti alloy [6][7][8][9], steels [11,13,14,18], Ni alloys [9,16,19], and Al alloys [10,12,23]. In addition, several new materials are discussed that were specially designed for AM.…”

“…This special issue includes all aforementioned trends of progress through 19 original research articles [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. The editors of STWJ invited active researchers from the AM and welding communities to contribute to this special issue.…”