The Microstructure and Properties of Low Carbon PM 625 Alloy for Marine-Based Application

Abstract:

The low carbon content powder metallurgy (PM) 625 alloy were manufactured by vacuum induction gas atomization (VIGA) and hot isostatically pressing (HIP) for marine-based application such as parts in the subsea Xmas tree. Corrosion experiment was performed in simulated deep seawater and subsea oil & gas service environment. The microstructures and properties of low carbon 625 alloy were comparably investigated with that of the as-cast alloy. The results indicated that the dendritic arm spacing (DAS) of the as-cast 625 alloy is 2 orders of magnitude higher than that of the powders, whereas the HIPed alloys possess a fine equiaxed grain structures without dendritic segregation and an average grain size of 14.5μm. No minor phase has been found beside the γ matrix in the original powders with different particle size. The tensile strength of low carbon PM 625 alloy is 26% higher than that of as-cast 625 alloy. PM 625 alloy possesses an excellent corrosion resistant in simulated deep seawater and oil & gas service environment for 30 days.

• Periodical: Materials Science Forum (Volume 1016)
• Pages: 1747-1752
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.1016.1747
• Online since: January 2021
• Authors: Liang Zheng*, Guo Qing Zhang, Xiu Qing Xu, Zhou Li
• Keywords: 625 Alloy, Corrosion Resistance, Low Carbon Content, Ni-Based Superalloy, Powder Metallurgy, Subsea Xmas Tree, Tensile Properties

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