Coatings, Vol. 15, Pages 649: Corrosion and Wear Behavior of 17-4PH Stainless Steel Manufactured by Selective Laser Melting and Bulk Material After Solution Treatment

Coatings doi: 10.3390/coatings15060649

Authors:
Bo-Xun Hou
Hung-Hua Sheu
Ming-Yuan Lin
Chun-Ying Lee
Hung-Bin Lee

This study aims to investigate the wear and corrosion–wear behavior of 17-4PH stainless steel specimens, both fabricated via Selective Laser Melting (SLM) and conventional bulk material, after undergoing Solution Treatment (S.T.) in a seawater medium. Microstructural observations indicated that solution treatment contributed to a more uniform distribution of martensitic structures on the sample surface. Moreover, the solution-treated specimens exhibited improved microstructural uniformity and structural stability. SLM specimens exhibit the elimination of fine particles and scanning track traces. Based on the results of dynamic polarization tests, SLM specimens demonstrate superior corrosion resistance. However, in corrosion–wear conditions, the bulk material outperforms the SLM specimens, primarily due to the presence of pores in the latter, which are detrimental under such environments. XPS analysis of the passive film structure indicates that the passive layer is mainly composed of FeO, Cr2O3, and NiO, with the inner layer predominantly consisting of chromium oxide. The Cr2O3 layer, formed by the reaction between chromium and oxygen, significantly enhances the corrosion resistance of the material due to its extremely low chemical reactivity and high stability.

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