• 제목/요약/키워드: carbides

검색결과 429건 처리시간 0.027초

선조철강의 탄화물에 따른 수소지연파괴 거동 분석 (Effects of Carbides on Hydrogen-induced Delayed Fracture for the Energy Saving Wire (ESW))

  • 이진범;강남현;박지태;안순태;박영도;조경목
    • 한국소성가공학회:학술대회논문집
    • /
    • 한국소성가공학회 2009년도 추계학술대회 논문집
    • /
    • pp.139-141
    • /
    • 2009
  • This study analyzed the effect of the microstructure and alloying element on hydrogen-induced delayed fracture properties for the Energy Saving Wire (ESW) developed recently. Specimens were produced with a diameter 6.5mm post to the deformation (0, 10, 20 and 30%), followed by injecting the hydrogen. The experimental results by using GAS chromatography showed that the more hydrogen was emitted for high-carbon steel (0.45%C steel and 0.35%C steel) than low-carbon steel(0.2%C-Cr steel and 0.2%C-Cr-Mo steel). And, 0.45%C steel, 0.35%C steel and 0.2%C-Cr-Mo steel exhibited the crack for 30% deformed specimen. The hydrogen emitted was analyzed with the amount, the spheroidization, and the size of the carbides.

  • PDF

방전액의 전도율이 와이어방전가공성에 미치는 영향 (Influence of Electrical Conductivity of Dielectric on Machinability of W-EDM)

  • 김창호;허관도;권택환
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2001년도 춘계학술대회논문집C
    • /
    • pp.64-70
    • /
    • 2001
  • This work deals with the electrical conductivity of dielectric and cobalt percentage on output parameters such as metal removal rate and surface roughness value of sintered carbides cut by wire-electrical discharge machining (W-EDM). To obtain a precise workpiece with good quality, some extra repetitive finish cuts along the rough cutting contour are necessary. Experimental results show that increases of cobalt amount in carbides affects the metal removal rate and worsens the surface quality as a greater quantity of solidified metal deposits on the eroded surface. Lower electrical conductivity of the dielectric results in a higher metal removal rate as the gap between wire electrode and workpiece reduced. Especially, the surface characteristics of rough-cut workpiece and wire electrode were analyzed too. To obtain a good surface equality without cracks, 4 finish-cuts were necessary by reducing the electrical energy and the offset value.

  • PDF

초경합금과 강의 Brazing특성에 미치는 열처리의 영향 (Influence of Heat Treatment on Brazing Characteristics between Cemented Carbides and Steel)

  • 김하영;중촌 만;이상학
    • 대한용접접합학회:학술대회논문집
    • /
    • 대한용접접합학회 2004년도 추계학술발표대회 개요집
    • /
    • pp.43-45
    • /
    • 2004
  • Brazing between cemented carbides and steel for tool investigated by copper alloy brazing filler. Copper alloy filler was high liquidus temperature($990^{\circ}C$), therefor the shank(steel) occurred softening. Because brazing sample was necessary to heat treatment after brazing process. This experiment, influence of austenite time and purge temperature on heat treatment were investigated. As a result, these treatments obtained to high deflective strength In case of austenite time was short and purge temperature was low. Especially, nitride precipitated brazing layers was strongly influenced by the deflective strength.

  • PDF

SEM내 미소절삭에 의한 초경합금재의 칩 생성 기구 (Chip Formation of WC-Co on Micro-cutting in SEM)

  • 허성중;김원일
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2003년도 춘계학술대회 논문집
    • /
    • pp.604-607
    • /
    • 2003
  • This study investigates the micro-cutting of cemented carbides using PCD(polycrystalline diamond) and PCBN(polycrystalline cubic boron nitride) cutting tools are performed with SEM direct observation method. The purpose of this study is to make clear the cutting mechanism of cemented carbides and the fracture of WC particles at the plastic deformation zone in orthogonal micro-cutting. And also to achieve systematic understanding, the effect of machining parameter on chip formation and machined surface was investigated, including cutting speed. depth of cut and various tool rake angle.

  • PDF