Corrosion Properties of Powder Bed Fusion Additively Manufactured 17-4 PH Stainless Steel

The Role of Microstructure and Surface Finish on the Corrosion of Selective Laser Melted 304L

“…Similar trends of the effects of porosity have been observed for other SLM SS in chloride solutions. 3 However, the SLM 304L pitting potential, even with porous regions tested, was still substantially higher than that measured for the wrought by more than 100 mV.…”

“…3,4 However, there is still a need for further investigation in order to develop a full understanding of the microstructural and morphological characteristics inherent to AM materials due to the unique processing conditions and their relative contributions to the materials' corrosion behavior. Ideally, a ranking of the deleterious or advantageous properties formed in AM materials with respect to corrosion should be established.…”

“…[5][6][7] Porosity, formed by entrapped gas or lack of fusion of powder particles in the SLM build, can also reduce both the mechanical properties of the SS and the corrosion resistance again by acting as a local crevice former in chloride solutions. 3,[8][9][10][11][12][13] In conventional wrought 304L, inclusions, such as MnS or oxides, have been observed to reduce localized corrosion resistance by acting as sites for pit initiation, and could also pose an issue for SLM materials. [14][15][16][17][18][19] Regarding SLM materials, one study showed that a reduction in the size and distribution of MnS particles in 316L resultant from SLM processing actually enhanced its corrosion resistance relative to conventional wrought material.…”

Corrosion of Additively Manufactured Alloys: A Review

“…61,64,[73][74][75][76][77][78][79][80][81][82][83][84][85] Several researchers have, often with little to no experimental support, reported that porosity may significantly impact the pitting characteristics of alloys produced by AM. 61,[73][74][75][76][77] However, a mechanistic description of how pores (particularly unconnected pores) may assist in pit initiation/propagation is yet to be clarified. Similarly, solute segregation driven by the formation of cellular structures has also been proposed to be detrimental toward pitting of alloys manufactured by AM.…”

“…The effect of porosity was investigated by several researchers in the context of corrosion. 61,[73][74][75][76][77] Porosity has been reported to be a preferential pit initiation site if the porosity was >1%. 78…”