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Effect of Primarily Solidified Structure on the Microstructure and the Mechanical Properties of High Cr White Iron

고크롬 백주철의 미세조직과 기계적 특성에 미치는 초기응고 조직의 영향

Jo, Hyun-Wook;Do, Jeong-Hyeon;Jo, Won-Je;Chung, Hyun-Deuk;Lee, Je-Hyun;Jo, Chang-Yong
조현욱;도정현;조원제;정현득;이재현;조창용

  • Received : 2015.10.20
  • Accepted : 2015.12.08
  • Published : 2015.12.31

Abstract

Due to excellent abrasion resistance the high-chrome white irons are widely used in mining and mineral industries. Minor variation of carbon content in 28% chrome white iron resulted in difference in primarily solidified microstructure. Sub-eutectic (hypoeutectic) composition led to formation of primarily solidified dendrites. Formation of primarily solidified dendrites which were supersaturated with carbon and chrome also caused precipitation of fine secondary carbides that are different from relatively large plate type $M_7C_3$ carbides in the eutectic structure. Small portion of primarily solidified dendrite expected to contribute significantly to the improvement of abrasion resistance of the white iron because the dendrites provided mechanical support to carbides. The relative fraction of primary dendrite increased with reduction of carbon content from the eutectic composition. The increased fraction of primary dendrite increased hardness value of the white irons.

Keywords

White iron;Abrasion resistance;Carbide;Sub-eutectic composition

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Acknowledgement

Supported by : 재료연구소