Precipitation and decomposition behaviors of carbides in AISI M2 high-speed steel with nitrogen and mischmetal
Autor: | Ting-zhi Ren, Bao-long Liu, Wei-wei Feng, Zhi-qing Lü, Wan-tang Fu |
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Rok vydání: | 2017 |
Předmět: |
010302 applied physics
Materials science Precipitation (chemistry) Metallurgy Metals and Alloys General Engineering chemistry.chemical_element 02 engineering and technology 021001 nanoscience & nanotechnology Microstructure 01 natural sciences Decomposition Nitrogen Carbide Mischmetal chemistry 0103 physical sciences 0210 nano-technology High-speed steel Eutectic system |
Zdroj: | Journal of Central South University. 24:782-788 |
ISSN: | 2227-5223 2095-2899 |
Popis: | The behaviors of the precipitation and decomposition of carbides in AISI M2 high-speed steel modified by nitrogen and mischmetal were investigated using DSC, XRD, SEM and TEM. The as-cast microstructure of the experimental steel consists of dendrites of iron matrix, networks of eutectic carbides and secondary carbides. The average distance between networks is about 34 μm. The carbides mainly include M2C, M(C,N) and M6C, and their relative contents are 58.5%, 30.3% and 11.2%, respectively. The average spacing between the M2C fibers is 1.5 μm. The decomposition of M2C occurs from 897.2 to 1221.5 °C (heating rate of 200 °C/h). Some precipitated carbide particles occur in the M2C matrix after holding for 15 min at 1100 °C. With increasing holding time, the carbide fibers neck down more and more obviously until they are broken down. The spectral peaks of M2C almost disappear after holding for 60 min. The spectral peaks of M6C gradually strengthen with the holding time, and the relative content of M6C increases to 79.8% after holding for 60 min. After holding for 180 min, the carbide fibers disappear, and the decomposition products consist of fine carbide particles (about 300 nm) and short rod-like carbides (about 3.5 μm). |
Databáze: | OpenAIRE |
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