Hot deformation map and its application of GH4706 alloy

Abstract

The hot deformation behaviors of GH4706 alloy were investigated using compression tests in a deformation temperature range from 900°C to 1200°C with a strain rate range of 0.001–1 s⁻¹. Hot processing maps were developed on the basis of the dynamic material model and compression data. A three-dimensional distribution of power dissipation parameter (η) with strain rate and temperature reveals that η decreases in sensitivity with an increase in strain rate and a decrease in temperature. Microstructure studies show that the grain size of GH4706 alloy increases when η is larger than 0.32, and the microstructure exhibits local deformation when η is smaller than 0.23. The hot processing map at the strain of 0.7 exposes a domain peak at η=0.32 for the temperature between 940°C and 970°C with the strain rate from 0.015 s⁻¹ to 0.003 s⁻¹, and these are the optimum parameters for hot working.

Keywords

superalloys / nickel alloys / deformation / microstructure / dynamic recrystallization

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