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Indexed by:期刊论文

Date of Publication:2017-02-01

Journal:INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY

Included Journals:SCIE、EI、Scopus

Volume:88

Issue:9-12

Page Number:2717-2725

ISSN No.:0268-3768

Key Words:Narrow-gap; Welding; Weld bead formation; Indirect arc; Sidewall fusion

Abstract: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.