• Title/Summary/Keyword: HARDFACING

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The Microstructure For Removing of Beadmark of Hardfacing Wrapping Roll (육성용접된 Wrapping Roll의 비드마크제거를 위한 미세조직)

  • 유국종;백응률
    • Proceedings of the KWS Conference
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    • 2000.10a
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    • pp.216-218
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    • 2000
  • In case of hardfaced wrapping roll, beadmark shape appear at wrapping roll surface due to irregular wear between weld bead. Irregular wear of this is caused by difference of hardness between weld bead. This study aims at investigating which matrix is good for removing of beadmark at wrapping roll surface. So, we make specimen with martensitic matrix and austenitic matrix. The hardfacing alloys were deposited 4 times on a SS41 steel plate using self-shielding flux cored arc welding method. Difference of hardness between weld bead of specimen with matrix of martensite was higher than specimen with matrix of austenite both as-welded and after heat treatment. Therefore, austenitic matrix is better than martensitic matrix for removing of beadmark of wrapping roll surface.

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Characteristics of Hardness of $(Cr,\;Fe)_7C_3$ in the Chromium-Carbide-Type Chromium White Iron Hardfacing Weld Deposits (크롬탄화물형 크롬백철 오버레이 용착금속에서의 $(Cr,\;Fe)_7C_3$의 경도특성)

  • Baek Eung-Ryul
    • Journal of Welding and Joining
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    • v.23 no.2
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    • pp.75-80
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    • 2005
  • The effect of chemical constituents of $(Cr,\;Fe)_7C_3$ carbide phase on its hardness in the chromium-carbide type Cr white iron hardfacing weld deposits has been investigated. In order to examine $(Cr,\;Fe)_7C_3$ carbide phase, a series of filler metals with varying chromium contents was used. The alloys were deposited once or twice on a mild steel plate using the self?shielding flux cored arc welding process. The hardness of $(Cr,\;Fe)_7C_3$ carbide phase was measured by the micro-Vickers hardness test. It was shown that hardness of $(Cr,\;Fe)_7C_3$ carbide phase increased with increasing Cr content in $(Cr,\;Fe)_7C_3$ carbide phase. This behavior of the hardness of $(Cr,\;Fe)_7C_3$ carbide phase was explained by the types of chemical bonds that hold atoms together in $(Cr,\;Fe)_7C_3$ carbide phase.

The Sliding Wear behavior of Fe-Cr-C-Si Alloy in Pressurized Water (Fe-Cr-C-Si 계 경면처리 합금의 고압ㆍ수중 마모거동)

  • Lee, Kwon-yeong;Lee, Min-Woo;Oh, Young-Min;;Kim, Seon-Jin
    • Korean Journal of Materials Research
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    • v.13 no.4
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    • pp.224-227
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    • 2003
  • The sliding wear behavior of a Fe-base hardfacing alloy was investigated in the temperature range of $25∼250^{\circ}C$ under a contact stress of 15 ksi (103 MPa). The wear loss of this Alloy in pressurized water was less than that of NOREM 02. And galling did not occurred at this alloy in all temperature ranges. It was considered that the wear resistance of this Alloy was attributed to the strain-induced phase transformation from austenite to $\alpha$'martensite during sliding wear.

Machining Characteristics and Cutting Force Analysis of Hardfacing Overlay Welding in High Chromium Carbide (고크롬탄화물 하드페이싱 육성용접물의 가공특성과 절삭력 분석)

  • Kim, Min-Ho;Kim, Tae-Young
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.18 no.5
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    • pp.469-476
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    • 2009
  • Hard facing overlay welding in high chromium carbide is a representative way of extending the fatigue life or recompensing damage, because workpiece surface is uniformly overlay-welded by alloy material. In general, grinding process is currently used for finish due to hardness of weld material. The development of tool material, such as PCBN, has made it possible to use turning instead of grinding. There are many advantages of hard Owning, as lower equipment costs, shorter setup time, fewer process steps, higher material removal rate, better surface integrity and the elimination of cutting fluid. In this paper, machining characteristics and cutting performance are examined to investigate turning possibility of overly welding in high chromium carbide.

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Effect of Volume Fraction of Cr Carbide Phase on the Abrasive Wear Behavior of the High Cr White Iron Harcfacing Weld Deposits (고크롬 철계 오버레이용접층의 긁힘마모거동에 미치는 크롬탄화물 양의 영향)

  • 백응률
    • Journal of Welding and Joining
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    • v.16 no.1
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    • pp.125-133
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    • 1998
  • The effect of volume fraction of Cr carbide phase (Cr CVF) on the low stress abrasion resistance in the chromium-carbide-type high Cr white iron hardfacing weld deposits has been investigated. In order to examine Cr CVF, a series of alloys with varying Cr CVF by changing chromium and carbon contents and the ratio of Cr/C were employed. The alloys were deposited once or twice on a mild steel plate using the self-shielding flux cored arc welding process. The low stress abrasion resistance of the alloys against sands was measured by the Dry Sand/Rubber Wheel Abrasion Test (RWAT). It was shown that hardness and abrasion resistance increased with increasing Cr CVF within the whole test range (Cr CVF : 0.23-0.64). Both primary Cr carbide and eutectic Cr carbide were particularly effective in resisting wear due to their high hardness.

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Effect of Vanadium Addition on the Cavitation Erosion Resistance of Fe-Cr-Ni-Si-C Hardfacing Alloy (Fe-Cr-Ni-Si-C계 경면처리 합금의 Cavitaon Erosion 저항성에 미치는 Vanadium 첨가의 영향)

  • 김경오;김준기;장세기;김선진;강성군
    • Journal of the Korean institute of surface engineering
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    • v.31 no.5
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    • pp.297-303
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    • 1998
  • The influences of vanadium addition on the cavitation erosion resistance pf Fe-Cr-Ni-Si-C hardfacing alloy were investigated using a vibratory apparatus up to 30 hrs. It was shown that 1wt.%V additioned alloy improved the resistance to cavitation damage. However, further increase in V content up to 2wt.% reduced the cavitation erosion resistance. It was considered that the addition of V developed the cavitation erosion resistance by reducing the stacking fault energy of Fe-Cr-Ni-Si-C alloy. However, the further increase in V content seemed to reduce the cavitation erosion resistance by increasing the matrix/carbide interfacial area, which was the preferential sites of the cavitation damage.

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