Influence of Heat Treatment on the Microstructures and Mechanical Properties of K465 Superalloy

Abstract:

The microstructures and mechanical properties of superalloy K465 under different heat treatment, including as as-cast, solution treatment and aging, were investigated. The results showed that γ' precipitates in as-cast condition exhibited two kinds of morphologies of fine regular cuboidal shape at dendritic arm and coarse irregular form in interdendritic region. MC carbides decomposed into M₆C carbides partly after 1210°C/4h solution treatment. The high temperature stress-rupture life can be improved obviously with the increasing cooling rate. When cooling rate was lower than 70°C/min, the room temperature tensile elongation increased with cooling rate increasing. When cooling rate was higher than 90°C/min the room temperature tensile elongation decreased with cooling rate increasing. The proper cooling rate of 70oC/min~90oC/min is advantageous for the achievement of excellent comprehensive properties. When aging treatments continued the regularization of γ' resulted in the improvement of stress-rupture life and the reduction of tensile elongation. The mechanical property gap between the solution treatment and aging can be decreased with increasing cooling rate.

• Periodical: Materials Science Forum (Volume 849)
• Pages: 570-579
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.849.570
• Online since: March 2016
• Authors: Qiang Huang*, Jin Xia Song, Qing Li, Wei Peng Ren, Xin Guang Guan, Hao Chen
• Keywords: Heat Treatment, K465 Superalloy, Mechanical Properties, Microstructure

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