Microstructure and Room Temperature Mechanical Properties of a New Corrosion-Resistant Alloy GH945 for Oil and Gas Applications

Abstract:

The microstructure and mechanical properties of a new corrosion-resistant alloy GH945 with high strength for oil and gas production were studied in this paper. The results showed that the main precipitations of GH945 alloy after solution heat treatment and two-stage age hardening treatment were γ′ and γ′′ phase, MC-type carbide, σ phase and M₂₃C₆-type carbide. The increase of primary aging temperature not only promoted the precipitation of σ phase and film of continuous M₂₃C₆ carbide on the grain boundary, but also led to the coarsening of γ′ and γ′′ phase, which resulted in the decrease of yield strength and impact toughness. Alloy with high Nb content had high strength but low impact toughness. The following heat treatment was preferably used to obtain the combination of high strength and excellent ductility and toughness for GH945 alloy: 1010 °C/70 min, WQ+ 735 °C/9 h + FC to 615 °C/18 h, AC.

• Periodical: Materials Science Forum (Volume 849)
• Pages: 609-617
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.849.609
• Online since: March 2016
• Authors: Zhao Xia Shi, Xiao Feng Yan, Chun Hua Duan
• Keywords: Corrosion-Resistant Alloy GH945, Gas Applications, Mechanical Properties, Microstructure, Oil Applications

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