Development of Twin Torch Compound Metal Arc Welding Process to Form for Wide Hardfacing Bead of Wearplate

Cho, Sang-Myung; Kim, Sung-Deok; Hwang, Kyu-Min

Journal of KWJS 2008;26(2):50-54.
Published online June 18, 2008.

내마모판의 광폭 경화육성 용접비드 형성을 위한 트윈토치 CMAW 공정개발

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Development of Twin Torch Compound Metal Arc Welding Process to Form for Wide Hardfacing Bead of Wearplate

Sang-Myung Cho, Sung-Deok Kim, Kyu-Min Hwang

Abstract

The wearplate with Cr-C has been used in condition of severe abrasion. Recently, the demand of wearplate made by hardfacing with Cr-C has increased in the world, but it is lack of supply and expensive due to low productivity. CMAW (Compound Metal Arc Welding) is very useful process of several welding methods to make wearplate.
In this paper, twin torch CMAW to use twin torch at the same time was developed to improve productivity and to ensure quality of wear plate. When the distance between two touches was smaller than 30mm, arc blow was occurred. However when the distance was larger than 35mm, there was no arc blow any more. If the oscillation path of each torch was overlapped together, the melt through at the overlapped zone was occurred due to concentrated heat input in substrate. On the other hand, the turning point of each torch was open more than 5mm, separated bead was generated. Therefore twin torch CMAW which has adequate conditions was able to make wearplate having flatter surface at the bead connection than single torch.

Key Words: Hardfacing, Twin torch welding, Compound metal arc welding, Wearplate, Arc blow, Arc stability, Wide bead formation, Oscillation overlap