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论文类型：期刊论文

发表时间：2017-02-01

发表刊物：INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY

收录刊物：SCIE、EI、Scopus

卷号：88

期号：9-12

页面范围：2717-2725

ISSN号：0268-3768

关键字：Narrow-gap; Welding; Weld bead formation; Indirect arc; Sidewall fusion

摘要：Narrow-gap triple-wire gas indirect arc (TW-GIA) welding is a novel process. Previous studies have reported the process and explained how the wire arrangement affects the arc behavior and the metal transfer which correspondingly affect the sidewall fusion. In this paper, effects of process parameters on sidewall fusion, weld bead formation, microstructure, and hardness are studied, to reveal more characteristics of the narrow-gap TW-GIA. Results show that welding currents affect the sidewall penetration more significantly than groove gap and welding speed. In addition, sidewall penetration increases with larger welding currents. The heat affected zone (HAZ) width decreases with lower welding current, wider groove gap, or higher welding speed. With all the parameters, weld beads produced by narrow-gap TW-GIA present convex surfaces, which can lead to serious incomplete fusion at the weld root for the next weld layer. To solve this problem, addition of a gas tungsten arc (GTA) behind the TW-GIA is proposed. An additional benefit is that the arc pressure and extra heat input of the GTA obtain weld beads with concave surfaces.