Analysis of heat transfer and material flow in hybrid KPAW-GMAW process based on the novel three dimensional CFD simulation. (February 2020)

• Record Type: Journal Article
• Authors: Wu, Dongsheng; Tashiro, Shinichi; Wu, Ziang; Nomura, Kazufumi; Hua, Xueming; Tanaka, Manabu
• Is Part Of: International journal of heat and mass transfer. Volume 147(2020)
• Publication Date: 2020-02
• Subjects: Hybrid welding -- Heat transfer -- Material flow -- Arc shear stress -- "Pull-Push" flow pattern; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2019.118921
• Languages: English
• ISSNs: 0017-9310

Abstract

Highlights: A novel model considering the complicated interactive phenomena is developed for the hybrid KPAW-GMAW process. The convective patterns and their driven forces in the hybrid KPAW-GMAW process are studied. The "Pull-Push" flow pattern exists on the top surface of the weld pool between the two arcs. Abstract: In this study, a novel electrode-arc-droplet-weld pool model considering the complex interactive phenomena of arc, keyhole and weld pool is developed to investigate heat transfer and material flow in hybrid KPAW-GMAW process, in which the double-ellipse heat source models, arc pressure models, arc shear stress models and electromagnetic force models are adopted. The arc, droplet, keyhole and weld pool are observed by high speed video camera. The temperature of droplet and weld pool are measured by thermal camera. The numerical and experimental results show that: In the KPAW process, two convective eddies exist inside the weld pool. The maximum temperature of the weld pool is firstly increased, then is decreased, and finally becomes stable. In the KPAW-GMAW process, the "Pull-Push" flow pattern helps to transport the molten metals and energy from the region near the GMAW arc to the region near the KPAW arc, resulting in the temperature increase of the molten metals at the top surface of the rear keyhole. The Marangoni force and arc shear stress are proposed to be the dominant driven forces for the "Pull-Push" flow pattern on the top weld pool surface between the two arcs, while the droplet impingement has minor influence on it.