• Proceedings of the KWS Conference
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• 2009.11a
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• pp.7-7
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• 2009

TIG 용접에서는 후판 용접의 경우 용입의 한계 때문에 깊고 넓은 그루브 가공을 하여 다층 용접을 한다. 이 때, 그루브를 채우는 용착금속에 의한 응고 수축과 과대한 입열로 인한 변형이 문제시 되고 있다. 변형을 줄이기 위해서는 용착금속의 양과 입열량을 줄여야 한다. 이러한 문제를 해결하기 위해 그루브의 루트패이스를 두껍게 하고 그루브각을 줄여서 용착량을 줄인다. 이때, 좁은 그루브에서 두꺼운 루트패이스를 완전 용입할 수 있는 용접 프로세스가 필요하다. 비드가 좁고 깊은 용입 특성을 가지는 Plasma welding(PAW) 경우에는 좁은 그루브 속에 토치가 접근하기 어려워 적용하기 어렵다. 따라서 접근성이 용이한 TIG 용접에서 높은 용입형상비를 가지는 용접공정 개발이 필요하다. 선행연구로 높은 용입 형상비를 가지는 Active flux Tungsten Inert Gas(ATIG) 용접이 연구되었다. ATIG의 용입 증가 메커니즘으로는 Marangoni effect, 음이온들로 인한 아크 수축 효과, 절연 플럭스에 의한 아크 수축효과 등으로 알려져 있다. 또한 선행연구에서 ATIG에서 Ar가스에 He 또는 $H_2$ 가스를 첨가하면 용입이 더욱 증가하는 것을 확인하였다. 본 연구에서는 A-TIG에 He 가스를 적용하고 아크길이 0.5mm, 1.0mm, 2.0mm와 전극 선단각 30도, 60도, 90도에 따른 용입 형상비와 변형량을 검토하기 위해 실험을 하였다. 실험 결과는 아크길이가 감소할수록 전극 선단각이 증가할수록 용입 형상비는 증가하였고, 변형량은 감소하였다.

• Proceedings of the KWS Conference
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• 2008.05a
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• pp.35-35
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• 2008

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.70-75
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• 2002

The penetration potential of TIG welding in one single run is limited, though the process itself generates high quality welds with good weld cosmetics. This is one of the main reasons, which has contributed to its development in high duty applications such as those encountered in aeronautical, aerospace, nuclear & power plant applications. For these applications, stainless steels, titanium k nickel based alloys are most often used. As these materials remain very sensible to weld heat input k atmospheric pollution, stringent processing conditions are imposed. For example welding of titanium alloys requires argon shielding of weld zone and for 5 mm thick plates multi-pass runs & filler additions are required. This multi-run operation not only raises the welding cost, but also increases defect risks. In recent years, extensive interest has been raised by the possibility to increase weld penetrations through flux applications & the process is designated ATIG-activated TIG, or FBTIG-flux bounded TIG. The improved welding performance of such flux assisted TIG is related to arc constriction and surface tension effects on weld pool. The research work by authors has lead to the formulation of welding fluxes for stainless steels k titanium alloys with TIG Process. These fluxes are now commercialized & some applications in industry have already been carried out. FBTIG for aluminum has been proposed with silica application for AC mode TIG welding. The paper highlights the fundamentals of flux role in TIG welding and illustrates some industrial applications.

• The Korean Society of Law and Medicine
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• v.11 no.1
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• pp.159-172
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• 2010

Viele medizinische Ma$\ss$snahmen erfordern ein Zusammenwirken verschiedener $\ddot{A}$Arzte. In der arbeitsteiligen Medizin wird deutlich zwischen vertikaler und horizontaler Arbeitsteilung unterschieden. Mit dem Begriff vertikaler Arbeitsteilung geht es darum, ob ein Arzt einem anderen Weisungen erteilen kann oder nicht. Bei der Horizontalen Arbeitsteilung handelt es sich um selbst$\ddot{a}$andig t$\ddot{a}$atige Mediziner, in gleichen oder aneinander sto$\ss$senden Gebieten, bei denen man sich auf die Angaben oder die T$\ddot{a}$atigkeiten des anderen verlassen kann. Die wirkliche arbeitsteilige Medizin wird horizontal geleistet. In der arbeitsteiligen Medizin, insbesondere in der mehr und mehr spezialisierten Medizin, ist ein gewisser Grad des Vertrauens notwendig, schon aus Zeitgr$\ddot{u}$unden. Die Wiederholung aller m$\ddot{o}$oglichen diagnostischen, aber auch pr$\ddot{a}$aoperativen Untersuchungen, w$\ddot{a}$are zeitaufwendig und kostenreich. Es gibt aber auch Verh$\ddot{a}$altnisse, in denen die Kontrolle oder sogar die Wiederholung dieser Tests notwendig ist. Dann ist, insbesondere wenn sie in einer gewissen Zeitfolge t$\ddot{a}$atig werden, die Problematik des Vertrauens und Misstrauens angesprochen. Der Arzt, der von einem anderen Arzt in herk$\ddot{o}$ommlicher Weise Mitteilungen bekommt oder jedenfalls erwarten kann, darf sich grunds$\ddot{a}$atzlich auf den Vertrauensgrundsatz berufen. Das gilt insbesondere, wenn der mitteilende Arzt in einer personell und apparativ $\ddot{u}$uberlegen ausgestatteten Klinik t$\ddot{a}$atig ist. Wenn sich allerdings Zweifel an der Richtigkeit der Mitteilung aufdr$\ddot{a}$angen, etwa zahlreiche Nachl$\ddot{a}$ssigkeiten vorgekommen sind, ist f$\ddot{u}$r Vertauen kein Platz.