Non-metallic inclusions in 17-4PH stainless steel parts produced by selective laser melting

Corrosion of Additively Manufactured Stainless Steels—Process, Structure, Performance: A Review

“…Such inclusions are morphologically similar to those found in welds, albeit considerably smaller due to the high cooling rates of AM, Table 2. 20,[74][75][76][77][78][79] Atom probe and electron microscopy studies have identified these inclusions as primarily oxides in austenitic SLM and DED SS without evidence of discrete MnSrich inclusions in as-built components. 2,20,80 These oxides are prevalent in AM microstructures in part due to the typically elevated oxygen content of as-built material originating from the feedstock and build chamber atmosphere (see Powder Feedstock, section 4).…”

Pitting corrosion of 17-4PH stainless steel manufactured by laser beam melting

“…Mechanical behaviour and especially the crack initiation are associated to pores and un-melted cavities, which reduce the elongation to failure and fatigue life time. Oxide inclusions specifically generated by the LBM process in presence of oxygen could initiate and propagate cracks when mechanical stress is applied, and this impacts negatively the toughness and SCC properties [26][27][28].…”

Competing mechanisms of particle fracture, decohesion and slip-driven fatigue crack nucleation in a PM nickel superalloy

“…Subject to cyclic loading regimes, commercial disc alloys with inclusions are known to nucleate cracks at a higher rate indicating that inclusions are detrimental to fatigue life [4]. While in this study we focus on fatigue crack nucleation within turbine disc alloys, fracture at non-metallic inclusions also remains a problem in other alloys; AM steels [5,6], SMA NiTi alloys [7], Steels [8] and Al alloys [9] are all known to contain inclusions and are relevant to fatigue.…”