HIP Process of a Valve Body to Near-Net-Shape using Grade 91 Powder
Toyohito Shiokawa, Hiroshi Urakawa, Mitsuo Okuwaki, Yuto Nagamachidownload PDF
Abstract. Materials used for steam piping of power plants are exposed to high temperatures and high pressures over long periods of time. As a consequence, forged Grade 91 alloy steel is commonly chosen to meet these demands. However, complicated structures such as a valve body are often machined from large forged blocks resulting in long machining time and the material weight being heavy. Therefore, by manufacturing a valve body with near net technology, both the time and material weight can be reduced. This paper will present 1) a survey of the dimensions of a valve body HIPed to a near net shape, 2) an investigation of the mechanical properties of Grade 91 powder, 3) a comparison of the structure of a HIPed product and a forged product, 4) The machining time and material weight of a near net shaped (NNS) product by HIP compared to a forged product. This paper will illustrate that the NNS product was able to reduce the machining time by 30% and the material weight by 40% less than when machining from a forged product.
Near-Net-Shape, Grade 91, HIP
Published online 2/11/2019, 7 pages
Copyright © 2019 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA
Citation: Toyohito Shiokawa, Hiroshi Urakawa, Mitsuo Okuwaki, Yuto Nagamachi, HIP Process of a Valve Body to Near-Net-Shape using Grade 91 Powder, Materials Research Proceedings, Vol. 10, pp 58-64, 2019
The article was published as article 8 of the book Hot Isostatic Pressing
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 T. Shiokawa, Y. Yamamoto, S. Hirayama and Y. Nagamachi “Comparison of experimental and FEM simulations of densification during HIP processing of powder into a cylindrical component” Proceedings of International Conference on HIP, 2011, pp. 225-230.