Journal of Lanzhou University of Technology ›› 2021, Vol. 47 ›› Issue (3): 10-14.

• Materials Science and Engineering • Previous Articles     Next Articles

Characterization of Fe-Cr alloy powder prepared by close-coupled vacuum induction melting gas atomization

YIN Yan1, DONG Kai-ji1, LI Zhi-heng2, BO Yao1, LU Chao3, ZHANG Rui-hua3,4   

  1. 1. State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou Univ. of Tech., Lanzhou 730050, China;
    2. School of Mechanical Engineering, Xinjiang University, Urumqi 830047, China;
    3. Central Iron and Steel Research Institute, Beijing 100081, China;
    4. Yangjiang Hardware Knife Cut Industrial Technology Research Institute, Yangjiang 529533, China
  • Received:2021-01-26 Online:2021-06-28 Published:2021-07-19

Abstract: Fe-Cr alloy powders were prepared by close-coupled vacuum induction melting gas atomization and shifted through different mesh sizes to obtain powders with four particle size segments of 0-25 μm、25-53 μm、53-105 μm and 105-150 μm. Oxygen and nitrogen analyzer, carbon and sulfur analyzer and inductively coupled plasma emission spectrometer were used to analyze the chemical composition of powder before and after atomization, and the change of oxygen content in all particle size segments and each particle size segment. SEM and laser particle size analyzer were used to observe the surface morphology and microstructure of powder and determine the particle size. The results showed that the chemical composition of Fe-Cr metal powder prepared by close-coupled vacuum induction melting gas atomization can be precisely controlled, and the oxygen content in full-size section was 0.024wt.%. The cooling rate increased exponentially with the decrease of powder particle size. With the increase of powder particle size segment, the surface structure mainly developed from cellular and columnar crystals to dendritic crystals. The oxygen content in each grain size segment decreased with the increase of grain size. The formation of hollow powder was mainly related to bag crushing mechanism and grain solidification shrinkage difference.

Key words: gas atomization, oxygen content, surface microstructure, hollow powder

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