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2018
Journal Article
Titel
Hot wire-assisted gas metal arc welding of Ni-based hardfacing
Abstract
For the deposition of Ni-based hardfacings reinforced with fused tungsten carbides (FTCs), a variety of manufacturing processes are industrially applied. Of these processes, plasma transferred arc welding (PTAW) and gas metal arc welding (GMAW) are most widely used. The primary advantages of GMAW are the controlled feeding of the filler material in terms of the flux cored wire, the uncomplicated use on site, and the high mechanical degree. However, GMAW is known to have a negative impact on the metallurgical properties of FTCs for several reasons; for example, FTCs are directly exposed to the high arc temperatures, promoting dissolution mechanisms, and increasing deposition rates are accompanied by a rising heat input. A new GMAW strategy was developed with the objective of separating the material and energy input. The application of an additional hot wire (HW-GMAW) was observed to remove heat from the melt pool. As a result, low dilution rates of ~5% were obtained for deposition rates of ~12 kg/h, approaching PTAW quality. Additionally, the modified process characteristics have an immediate impact on the characteristics of FTCs.