• Journal of Welding and Joining
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• 제19권5호
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• pp.486-491
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• 2001

The effect of S content in welding wires on spattering characteristics and droplet transfer phenomena was studied. In MAG welding using 80%Ar-$20%CO_2$ shielding gas, spattering characteristics and droplet transfer phenomena were varied with S content of wire. Sulfur addition in wire reduced surface tension of droplet and weld pool, and made arc more stable in MAG welding. With increasing S content, the spattering ratio and the ratio of large size spatter ($d{\geq}1.0mm$) were reduced in short circuit transfer mode. In spray transfer mode, spattering ratio, however was increased when sulfur was added more than 0.020wt.% because surface tension of droplets and weld pool was reduced too much even though arc stability was improved.

• Journal of Welding and Joining
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• 제17권3호
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• pp.36-43
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• 1999

The effect of Si content in welding wires on spattering characteristics and droplet transfer phenomena was studied. In MAG welding using 80% Ar-20% $CO_2$ shielding gas, spattering characteristics and droplet transfer phenomena were varied with Si content of wire. With increasing Si content, the spattering ratio and the ratio of large size spatter $(d\geq1.0mm)$ were increased. The increase of Si content in molten metal made surface tension increase due to reduction of oxygen content, which resulted from deoxidizing action of silicon. The increase of surface tension resulted in unstable transfer phenomena and arc instability in both short circuit and spray region. With changing Si content of wire, spattering characteristics and droplet transfer phenomena was directly influenced by the variation of surface tension, compared with the effect of arc stability.

• 대한조선학회논문집
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• 제35권4호
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• pp.65-75
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• 1998

GMA 용접 중 100% $CO_2$ 가스를 사용하는 $CO_2$ 용접은 경제적이고 고능률적이라는 점 때문에 많이 사용되고 있다. $CO_2$ 용접의 아크현상과 스패터 발생량은 용접용 와이어의 화학성분, 실드가스, 용접조건 등에 영향을 받는다. 특히 용접조건은 용적이행 모드를 결정하기 때문에 스패터 발생량에 커다란 영향을 미친다. 본 연구는 $CO_2$ 용접 재료 중 두 type의 FCW(titania계, semi-metal계)를 이용하여 용접조건을 변화시켜 아크현상과 스패터 발생량을 파악하여 용접부의 품질 평가와 용접조건 설정에 기여코져 한다. 본 연구를 통해, 다음과 같은 결론을 얻을 수 있다. 1) 저전류 영역(140A)의 FCW 모두 22V까지는 전형적이 단락이행이 나타났고, 스패터 발생량의 증가와 저전류 스패터 입도를 대립화하였다. 2) 대전류 영역(320A)의 전형적인 globular이행에서 titania계 FCW가 semi-metal계 FCW보다 아크 안정성이 양호하였다.

• Journal of Welding and Joining
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• 제14권5호
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• pp.106-112
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• 1996

The effects of Ti addition in welding wire on the spatter generation and the droplet transfer phenomena were investigated. With increasing Ti content the spattering rate was decreased but the ratio of large size spatter (D $\geq$ 1. 0mm) was increased in both short circuit and globular transfer mode of $CO_2$welding. In short circuit transfer region, the arcing time was increased and the droplet transfer frequency was decreased with increasing Ti content In globular transfer region, the transition current and voltage to globular transfer was lowered and the welding condition region for stable globular transfer was widened with increasing Ti content.