鐵-7.0鋁-23.3錳-1.35碳合金晶界的析出反應

• Main Author: 林家玄
• Other Authors: 趙志燁
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/16907123588463562745

碩士 === 國立屏東科技大學 === 機械工程系所 === 100 === The purposes of the present studies are to investigate the precipitation of grain boundaries on the Fe-7.0Al-23.3Mn-1.35C alloy. The main results are described as following: 1.Being SHT at 1100℃, the microstructure of the alloy a essentially a single austenite phase. In addition, some extremely fine κ-phase carbides could be found within the austenite matrix by the Spinodal decomposition during the quenching. The lattice parameter of the austenite is a=0.369 nm。 2.When aged at 500~700℃ for various times, a phase transition, γ→γ+κ', would occurred within the austenite matrix for coherent precipitation. In the meanwhile, some coarseκ-phase carbides would also be formed on the grain boundaries by heterogeneous nucleation. Increasing the aged time, the coherentκ-phase carbides would grow to the same orientation- relationship matrix (grain), preferentially. And then, some region of γ+ coarse κ phase formed adjacent the grain boundaries. Moreover, prolonged the aged time, some parallel κ-phase carbides were grown to another-side grain by non-coherent precipitation.