Arc welded joint of Zn plated steel sheet

• Main Authors: Nobutoki, Tomokazu, Hosomi, Kazuaki
• Format: Patent
• Language: English
• Published: 10.05.2018
• Subjects: ALLOYS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; CLADDING OR PLATING BY SOLDERING OR WELDING; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; DIFFUSION TREATMENT OF METALLIC MATERIAL; FERROUS OR NON-FERROUS ALLOYS; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; METALLURGY; PERFORMING OPERATIONS; SOLDERING OR UNSOLDERING; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS; WELDING; WORKING BY LASER BEAM

Provided is a welded joint that suppresses occurrences of blow holes in initial parts and final parts in a Zn plated steel sheet and reduces the occupancy ratio for blow holes in the welded part as a whole. The arc welded joint is obtained by the following method of arc-welding Zn-based plated steel sheets, in which a blowhole occupancy over the entirety of the welding length is less than 30W. The method of arc-welding includes: setting an inter-sheet gap within a range of 0.2 to 1.5 mm; a first step of moving the welding means at a first welding speed from a welding start point, and applying a first welding heat input to perform welding; a second step of, after the first step, moving the welding means at a second welding speed, and applying a second welding heat input to perform welding; and a third step of, after the second step, stopping the movement of the welding means, and performing welding for 0.1 to 2 seconds at a position where the welding means is stopped. The first step includes a welding section welded under conditions where the first welding speed is smaller than the second welding speed, and the first welding heat input is larger than the second welding heat input. The third step includes performing welding at a welding current and a welding voltage lower than those used in the second step.