• 제목/요약/키워드: Nickel brazing

검색결과 17건 처리시간 0.024초

진공 브레이징을 이용한 고온가스냉각로 중간 열교환기 후보재료의 접합성능에 관한 예비시험 (Preliminary Investigation on Joining Performance of Intermediate Heat Exchanger Candidate Materials of Very High Temperature Reactor(VHTR) by Vacuum Brazing)

  • 김경호;김광호;이민구;김흥회;김성욱;김숙환
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2005년도 추계학술발표대회 개요집
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    • pp.195-197
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    • 2005
  • An intermediate heat exchanger(IHX) is a key component in a next-generation VHTR with process heat applications such as hydrogen production and also for an indirect gas turbine system. Therefore, high temperature brazing with nickel-based filler metal(MBF-15) was carried out to study the joining characteristic(microstucture, joining strength) of nickel-based superalloy(Haynes 230) by vacuum brazing. The experimental brazing was carried out at the brazing process, an applied pressure of about 0.74Mpa and the three kinds of brazing temperatures were 1100, 1150, and $1190^{\circ}C$ with holding time 5 minute. It's joining phenomena were analyzed by optical microscopy and scanning electron microscopy with EPMA. The results of microstructure in the centre-line region of a joint brazed with MBF-15 show a typical ternary eutectic of v-nickel, nickel boride and chromium boride.

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Morphologies of Brazed NiO-YSZ/316 Stainless Steel Using B-Ni2 Brazing Filler Alloy in a Solid Oxide Fuel Cell System

  • Lee, Sung-Kyu;Kang, Kyoung-Hoon;Hong, Hyun-Seon;Woo, Sang-Kook
    • 한국분말재료학회지
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    • 제18권5호
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    • pp.430-436
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    • 2011
  • Joining of NiO-YSZ to 316 stainless steel was carried out with B-Ni2 brazing alloy (3 wt% Fe, 4.5 wt% Si, 3.2 wt% B, 7 wt% Cr, Ni-balance, m.p. 971-$999^{\circ}C$) to seal the NiO-YSZ anode/316 stainless steel interconnect structure in a SOFC. In the present research, interfacial (chemical) reactions during brazing at the NiO-YSZ/316 stainless steel interconnect were enhanced by the two processing methods, a) addition of an electroless nickel plate to NiO-YSZ as a coating or b) deposition of titanium layer onto NiO-YSZ by magnetron plasma sputtering method, with process variables and procedures optimized during the pre-processing. Brazing was performed in a cold-wall vacuum furnace at $1080^{\circ}C$. Post-brazing interfacial morphologies between NiO-YSZ and 316 stainless steel were examined by SEM and EDS methods. The results indicate that B-Ni2 brazing filler alloy was fused fully during brazing and continuous interfacial layer formation depended on the method of pre-coating NiO-YSZ. The inter-diffusion of elements was promoted by titanium-deposition: the diffusion reaction thickness of the interfacial area was reduced to less than 5 ${\mu}m$ compared to 100 ${\mu}m$ for electroless nickel-deposited NiO-YSZ cermet.

스테인리스강용 브레이징 합금과 브레이징 공정 (Brazing Filler Metal and Process for Stainless Steel)

  • 홍성철;박상윤;정도현;오주희;이재훈;김원중;정재필
    • Journal of Welding and Joining
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    • 제30권6호
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    • pp.15-20
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    • 2012
  • Brazing technology has been widely used among bonding technologies because it enables to bond various metals, even ceramics, dissimilar metals, and give higher bonding strength, cost down, automation, etc. However, there are many parameters to achieve optimal brazing joint such as brazing alloys, brazing atmospheres, designs and brazing methods, etc. The brazing parameters affect seriously on the characteristic of final brazing products. Stainless steel is broadly used in high temperature applications, chemical industry, heat exchangers, muffler of vehicles, and so on. Accordingly, in this article, brazing alloys, forms of brazing alloys, brazing methods and atmospheres for stainless steel were described.

고온 진공 브레이징을 이용한 초경합금과 스테인리스강의 접합 계면 특성 (Analysis of Bonding Interfaces between Cemented Carbide and Stainless Steel made via Hot Vacuum Brazing)

  • 박동환;현경환;권혁홍
    • 소성∙가공
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    • 제29권6호
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    • pp.307-315
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    • 2020
  • The cemented carbide and stainless steel were bonded using a hot-vacuum brazing method to analyze the bonding interface. Since it is suitable for the hot vacuum brazing, nickel metal was used as a binder among the main components of the cemented carbide, and a new cemented carbide material was developed by adjusting the alloy composition. The paste, which is one of the important factors affecting the hot vacuum brazing bonding, was able to improve brazing adhesion by mixing solder as Ni powder and a binder as an organic compound at an appropriate ratio. Division of the stainless steel yielded a dense brazing result. This study elucidated the interfacial characteristics of wear-resistant parts by bonding stainless steel and cemented carbide via hot vacuum brazing.

BNi-2계 삽입금속에 의한 SUS304 스테인리스강 접합체의 강도와 조직에 미치는 브레이징 온도의 영향 : Ni기 삽입금속에 의한 브레이징 접합성의 기초적 검토(II) (Influence of Brazing Temperature on Strength and Structure of SUS304 Stainless Steel Brazed System with BNi-2 Filler Metal : Fundamental Study on Brazeability with Ni-Based Filler Metal(II))

  • 이용원;김종훈
    • 한국재료학회지
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    • 제17권3호
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    • pp.179-183
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    • 2007
  • A plate heat exchanger (PHE) normally uses vacuum brazing technology for connecting plates and fins. However, the reliability of high temperature brazing, especially with nickel-based filler metals containing boron the formation of brittle intermetallic compounds (IMCs) in brazed joints is of major concern. since they considerably degrade the mechanical properties. This research was examined the vacuum brazing of commercially SUS304 stainless steel with BNi-2 (Ni-Cr-B-Si) filler metal, and discussed to determine the influence of brazing temperatures on the microstructure and mechanical strength of brazed joints. In the metallographic analysis it is observed that considerable large area of Cr-B intermetallic compound phases at the brazing layer and the brazing tensile strength is related to removal of this brittle phase greatly. The mechanical properties of brazing layer could be stabilized through increasing the brazing temperature over $100^{\circ}C$ more than melting temperature of filler metals, and diffusing enough the brittle intermetallic compound formed in the brazing layer to the base metal.

스테인리스강의 브레이징 특성 (Brazing Process of Stainless Steel)

  • 홍성철;박준규;오주희;이재훈;김원중;정재필
    • Journal of Welding and Joining
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    • 제29권6호
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    • pp.40-44
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    • 2011
  • Brazing of a stainless steel was described in this article. Brazing is a joining technology without melting a substrate and joining temperature is higher than $450^{\circ}C$. Brazing can be broadly applicable across industries. In particular, brazing of stainless steel is widely used in aircraft parts, car engines, heat exchangers, etc. due to its excellent strength, corrosion resistance and other suitable characteristics. Characteristics of the stainless steel depend on their classification like austenitic, ferritic and martensitic stainless steels. In addition, there are many processes in brazing and various parameters such as brazing heat source, filler metals, joint design, etc. Therefore, it is necessary to know basic knowledge about brazing to achieve good brazing joint. Accordingly, properties of stainless steel and design of brazing joint and related process were described in this article.

Diffusion Enhancement during Electrically Assisted Brazing of Ferritic Stainless Steel Alloys

  • Luu, Viet Tien;Dinh, Thi Kieu Anh;Das, Hrishikesh;Kim, Ju-Ri;Hong, Sung-Tae;Sung, Hyun-Min;Han, Heung Nam
    • International Journal of Precision Engineering and Manufacturing-Green Technology
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    • 제5권5호
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    • pp.613-621
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    • 2018
  • The electrically assisted brazing of a ferritic stainless steel with nickel-based filler metal is experimentally investigated. During electrically assisted brazing of a lap joint, the temperature of the joint is first rapidly increased to a brazing temperature and held nearly constant for a specific period using a pulsed electric current. Microstructural analysis results strongly suggest that the electric current during electrically assisted brazing enhances diffusion between the filler metal and the ferritic stainless steel, thus inducing significantly thicker diffusion zones compared with induction brazing. The mechanical test results show that the strength of the electrically assisted brazing joint is comparable to or even superior to those of the joint fabricated by induction brazing, while the process time of the electrically assisted brazing is significantly shorter than that of induction brazing.

니켈기 초합금의 접합특성에 미치는 브레이징 공정변수의 영향 (Effect of Brazing Process Variables on joining Characteristics of Ni-based Superalloy)

  • 김경호;김광호;이민구;이호진;김흥회;김숙환
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2006년도 춘계 학술대회 개요집
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    • pp.266-268
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    • 2006
  • The effects of the brazing temperature and homogenizing time for brazed specimens on the joint of Ni-based superalloys such as Haynes 250, Inconel 617 and Hastelloy-X were investigated. The brazing alloy is nickel base MBF 15. The foil had a thickness of $38{\mu}m$, which was used two sheets of that for the all experiments. The experimental brazing was carried out by a brazing process in a vacuum of approximately $2{\times}10^{-5}$ Torr, an applied pressure of about 0.74MPa and the three kinds of brazing temperatures were 1100, 1150, and $1190^{\circ}C$ for a holding time of 5 to 1440 minutes. Microstructural observations were made on the cross-sectional samples by using an optical microscope(OM), scanning electron microscope(SEM), and electron probe X-ray microanalyzer(EPMA). The tensile tests were performed at room temperature with a cross head speed 1.5 mm/min according to ASTM E8M. The results show that excellent joint tensile strengths of as high as 788MPa were obtained when processed at $1190^{\circ}C$ for 5 minutes.

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액체 로켓엔진 연소기 사용 재료의 상온 브레이징부 인장강도 특성 (The Tensile Strength at Room Temperature of Brazing Section for Materials used for Liquid Rocket Engine Combustion Chamber)

  • 정용현;류철성;최민수
    • 한국추진공학회지
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    • 제7권4호
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    • pp.73-79
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    • 2003
  • 재생 냉각형 액체 로켓엔진 제작에 주로 사용되는 합금에 대하여 브레이징 접합 강도 시험 및 파단면 분석을 실시하였다. 브레이징 시 사용되는 용가재(Filler Metal)로 니켈을 주성분으로 하는 BNi-2, BNi-7를 사용하였다. 5종의 합금에 대하여 모두 12개의 시편을 제작하여 인장 강도 시험 및 금속현미경을 통한 접합면 분석을 통해 재료 및 용가재 특성을 분석하였다. 크롬동과 타 합금과의 접합 강도가 크롬/지르코늄동과 타 합금과의 접합 강도보다 높게 나왔다. BNi-2가 BNi-7보다 모재에 대한 젖음성이 보다 더 우수하여 접합면 인장 강도가 BNi-2로 사용한 경우가 BNi-7을 사용한 경우보다 더 높게 나왔다.