Description Of Stud Welder; Short-Cycle Drawn Arc Technology - Soyer BMK-12 W Operating Instructions Manual

2 Description of stud welder

2.1

Short-cycle drawn arc technology

Illustration 1:Short-cycle drawn arc technology
The BMK-12 W SOYER stud welder runs according to the principle of short-cycle
drawn arc stud welding. For detailed information, please refer to the following
regulations:
• DIN EN ISO 14555, "Arc welding of metallic materials"
• DVS Information Sheet 0902, "Drawn arc welding"
When welding, the stud is positioned on the workpiece. The preweld current is ignited
and the stud is lifted off the workpiece. The subsequent ignition of the main current
creates a molten pool between stud and workpiece. The stud immerses in the liquid
molten pool and the material solidifies.
This method allows manual, semi-automatic and fully automatic inseparable welding
of threaded stud fasteners, pins, balls, T-bolts, tapped studs, insulating pins, special
studs and many other fasteners made of steel, CrNi steel, heat-and acid-resisting
steel with the workpieces. Conditionally it is also possible to weld nickel and titanium
depending on the respective requirements. Standard studs for drawn arc and
capacitor discharge welding in compliance with DIN EN ISO 13918 can be welded
without requiring any auxiliary aids. The application of shielding gas or ceramic
ferrules is recommended for studs with a diameter of more than 6 mm to prevent pore
formation and to optimise the formation of bulges.
The standard BMK-12 W stud welder is suitable for operation with shielding gas and
ceramic ferrules. A d.c. power supply provides the welding current. The weld duration
can be selected. Owing to the low penetration depth of about 0.4 mm, the short-cycle
drawn arc method can be applied from a sheet thickness of 0.6 mm on. It guarantees
particularly safe, uniform and reproducible stud welded joints without high
requirements to setting accuracy and stud tip quality. Application is especially
recommended for workpieces with difficult surface characteristics, e.g. oil, grease, zinc
and other galvanic treatments as well as rolling scale, filling materials, forging scale,
oxide films, etc. The ratio of minimum sheet thickness and stud diameter amounts to
1:8.
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BMK-12 W