• 제목/요약/키워드: 구상 흑연 주철롤

검색결과 3건 처리시간 0.021초

내부경화형 구상흑연주철 롤의 미세조직과 경도에 미치는 열처리의 영향 (Effect of Heat Treatment on the Microstructure and Hardness of Internally Hardened Ductile Cast Iron Roll)

  • 이상묵;김도훈;윤서현
    • 한국산업융합학회 논문집
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    • 제27권1호
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    • pp.1-7
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    • 2024
  • This study was investigated the effect of heat treatment on the microstructure and hardness of internally hardened ductile cast iron roll. The following conclusions were obtained. Some of the graphite was decreased and a bainite was produced by heat treatment. It decreased due to the decomposition of some of the cementite precipitated in the as-cast by heat treatment, but there was no significant change when it reached a certain depth. Hardness increased due to formation of bainite by heat treatment. On the surface, the hardness decreased due to the decrease in the amount of transformation of cementite into bainite, but there was no change beyond a certain depth.

Ductile Cast Iron (DCI) 롤의 마모 특성 고찰 및 마모계수 도출을 위한 실험적 연구 (Experimental Study to Examine Wear Characteristics and Determine the Wear Coefficient of Ductile Cast Iron (DCI) Roll)

  • 변상민
    • Tribology and Lubricants
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    • 제33권3호
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    • pp.98-105
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    • 2017
  • A pin-on-disk test is performed to measure the wear volume of a ductile cast iron (DCI) roll when it wears down using a high carbon steel and two alloy steels at different sliding velocities between the roll and the material (steel). Normal pressure is set as constant and test temperatures are 400, 500 and $600^{\circ}C$. In addition, thermal softening behavior of the DCI roll is examined using a high-temperature micro-hardness tester and the surface hardness variation of the DCI roll is expressed in terms of temperature and heating time. Based on experimental data, a wear coefficient used in Archard's wear model for each material is obtained. The wear volume is clearly observed when the test temperature is $400^{\circ}C$ and sliding velocity varies. However, it is not measured at temperatures of $500^{\circ}C$ and $600^{\circ}C$ even with variations in sliding velocity. From the optical photographs of the pin and disk, the abrasive wear is observed at $400^{\circ}C$ clearly, but no at $500^{\circ}C$ and $600^{\circ}C$. At higher temperatures, the pin surface is not smooth and has many tiny caves distributed on it. It is found that wear volume is dependent on the carbon contents rather than alloy contents. Results also reveal that the variations of wear coefficients are almost linearly proportional to the carbon contents of the material.

내부 경화형 구상흑연주철 롤 동체와 넥의 미세조직과 경도에 미치는 탄소 영향 (Effect of Carbon on the Micro Structure and Hardness of Internally Hardened Ductile Cast Iron Roll)

  • 이상묵;신기항;최병철;남기우
    • 한국산업융합학회 논문집
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    • 제26권1호
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    • pp.79-86
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    • 2023
  • This study was investigated the effect of carbon on the micro-structure and hardness of ductile cast iron roll with internal curing capacity. Spheroidal graphite existed at roll body with rapid cooling, but granular graphite existed at roll neck with slow cooling. The volume fraction of graphite increased at roll body with rapid cooling, That of roll neck with slow cooling decreased, but graphite size increased. The volume fraction of cementite decreased, but volume fraction increased. The cementite size was larger at roll neck than roll body. The hardness was decreased at roll body and roll neck due to volume fraction of cementite. The hardness of roll body was higher than roll neck.