期刊
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
卷 528, 期 13-14, 页码 4600-4607出版社
ELSEVIER SCIENCE SA
DOI: 10.1016/j.msea.2011.02.072
关键词
Nickel-based superalloy; Carbon; Strengthening mechanisms; Misfit; Microstructures
类别
资金
- Science and Technology Commission of Shanghai Municipality [09521101404]
Nickel-based superalloy Nimonic 80A with various carbon contents has been developed. Various strengthening mechanisms of carbon were analyzed by optical microscope, X-ray diffraction, scanning electron microscope equipped with energy dispersive spectroscopy and transmission electron microscope. Detailed microstructural analysis revealed that with the increase of carbon content from 0.01% to 0.10%, both the lattice parameters of gamma' and gamma phases decreased, and the misfit delta between the coherent gamma' and gamma phases increased slightly from 0.289% to 0.317% after full heat treatment at 1070 degrees C/8 h, A.C. + 700 degrees C/16 h, A.C. The diameter of spherical gamma' phase decreased from 22.24 nm of 0.01%C alloy to less than 15.76 nm of 0.06%C and 0.10%C alloys. Cr(23)C(6) carbide precipitated at the grain boundary in the alloys with carbon content higher than 0.06%, and when carbon content increased to 0.10%, Cr(23)C(6) carbide had an orientation relationship with the gamma matrix: [00 (1) over bar] Cr(23)C(6) parallel to[00 (1) over bar]gamma matrix and(100)Cr(23)C(6)parallel to (1 0 0) gamma matrix, which can enforce the grain boundary strength. The growth of room temperature tensile strength with the increase of carbon content was primarily due to the coherent strain strengthening and the precipitate strengthening of Cr(23)C(6) carbide. After stress-rupture test at 750 degrees C/310 MPa, the misfit 8 increased from 0.182% to 0.237% with the increase of carbon content, but the values were lower than those after full heat treatment. The precipitate of blocky Cr(23)C(6) in 0.10%C alloy tended to become spherical and dislocation lines were found in the gamma matrix channels between gamma' phases, the combination of the dislocation strengthening and precipitate strengthening of Cr(23)C(6) carbide at grain boundary was beneficial to the stress-rupture properties. (C) 2011 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据