Free-cutting Ni-base heat-resistant alloy

US6752883B2 · kind B2 · utility

Assignees

• Kiyohito Ishida · JP
• Dokuritsu Gyousei Houjin Sangyo Gijutsu Sougo Kenkyusho · JP
• Daido Tokushuko Kabushiki Kaisha · JP
• Tohoku Tokushuko Kabushiki Kaisha

Inventors

• Kiyohito Ishida · Sendai, JP
• Katsunari Oikawa · Murata, JP
• Shigeki Ueta · Nagoya, JP
• Toshiharu Noda · Tajimi, JP
• Takashi Ebata · Murata, JP

Key dates

• Filing date: May 31, 2002
• Grant date: Jun 22, 2004
• Expiry date: Aug 1, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C22C19/058
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A free-cutting Ni-base heat-resistant alloy excellent in the high-temperature strength and corrosion resistance was proposed. The alloy contains Ni as a major component, 0.01 to 0.3 wt % of C and 14 to 35 wt % of Cr, and further contains at least one element selected from Ti, Zr and Hf in a total amount of 0.1 to 6 wt %, and S in an amount of 0.015 to 0.5 wt %. The alloy has dispersed in the matrix thereof a machinability improving compound phase, where such phase contains any one of Ti, Zr and Hf as a major constituent of the metal elements, essentially contains C and either S or Se as a binding component for such metal elements. The alloy also satisfies the relations of WTi+0.53WZr+0.27WHf>2WC+0.75WS and WC>0.37WS, where WTi represents Ti content (wt %), WZr represents Zr content (wt %), WHf represents Hf content (wt %), WC represents C content (wt %) and WS represents S content (wt %). This successfully suppresses the amount of free S residing in the alloy, which results in an improved machinability while preventing the hot workability from being degraded.