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Homogenization heat treatment of GH907 ingot |
WANG Zhi- gang |
(Technical Center, Fushun Special Steel Co., Ltd., Fushun 113001, Liaoning, China) |
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Abstract In order to guide the production practice of alloy GH907, the solid solution law of the interdendritic Laves phase and the diffusion law of Nb element in the GH907 ingot is systematically studied. The homogenization diffusion of alloy GH907 508 mm cast ingot at different temperature and time, which was produced by Fushun Special Steel Co., Ltd., was discussed using the optical microscope and the scanning electron microscope. Studies showed that the best diffusion temperature of Laves phases in GH907 cast ingots was 1 160 ℃, and the Laves phase can be completely eliminated when the diffusion time was more than 10 h. The calculated apparent diffusion coefficients of Nb in GH907 cast ingots was D=0.488 55×10-14 m2/s at 1 160 ℃. The theoretical calculation showed that the residual segregation index of Nb in GH907 cast ingots could reach 0.02 when the heat treatment was at 1 160 ℃ for 56 h.
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Received: 01 February 2018
Published: 02 November 2018
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Corresponding Authors:
Zhi-Gang WANG
E-mail: marvel168@163.com
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