鐵-9鋁-28錳-1.3碳-5鉻合金相變化

Abstract

Reently, the application of the Fe-Al-Mn-C alloys were focused on the product of the Golf Head. Essentially, these Golf-Heads could posses some excellent properties. However, the manufacture processes would be occurred some problems. The purposes of the studies wre to investigate the phase transformation and mechanic properties of the Fe-9Al-28Mn-1.3C-5Cr alloy. Based on the present study, some main results are described as followings: When the alloy being SHT at 1080℃, the microstructure was a austenite phase within som extremely fine κ-phase carbides. During aged at 450-750 ℃ for a short time, some fine κ-phase carbides precipitated within the austenitic matrix. Prolonged the aged time, some phase transition sequences were found on the grain boundaries. When aged at temperature of the 550 ℃-650 ℃ for various times, the phase transition sequences was found to be γ→DO3 + Cr7C3 +β- Mn. Increasing the aged temperature to 750 ℃, the phase transition sequences was found to be γ→DO3 + Cr7C3 . In addition, the precipitqates of the Cr7C3 could be found in the specimen being at 1050 ℃. The alloy being SHT at 1080℃, the Ultimate tensile strength, Yield strength, elongation and hardness were in the range of the 780~850 MPa、620~670 MPa、55~90 % and HRc 16-28, respectively. According to the coherent precipitate of the κ-phase carbides, the Ultimate tensile strength of the alloy would increase to 1150 MPa with the elongation in the range of 40~45 %. In addition, the elongation would decrease dramaticall. When the alloy aged at the 550 ℃/16 H, 600 ℃/4 H, 650 ℃/2 H, or 700 ℃/1 H, the alloy would be entirely embrittlement.