- We will not recommend CD (Capacitor Discharge) welding method for Ships of Oil rigs. Mainly because that welding time for CD is 0,003 sec and in the heat input is vey low. In practice CD welding only will burn 0,1-0,3 mm into the steel. Typical the pins will only “sit” on the black surface - Oxide scale forms during hot metal rolling. The pins will easy drop of again. CD welding (220 Volt) we can recommend for Air channels and thin clean plates. This method can not burn through a surface with oxide.
- We can recommend DA (Drawn Arc) welding (DT410 or similar) method for ships and oil rigs. Mainly because DA welding will burn through the black surface – Oxide- How deep the pins will burn into the steel you can adjust by the welding time? Here the pins will never drop of.
More Information’s about welding method described below here:
220 Volt Equipment – CD Capacitor Discharge
Capacitor Discharge (CD) stud welding is an extremely efficient method of welding fasteners to a wide variety of metals like mild steel, stainless steel, aluminium, brass, copper, titanium, etc. The process utilizes a powerful bank of capacitors to store energy at a specific voltage determined by stud size and material. When a weld is initiated, this energy is "discharged" through a special "ignition tip" at the base of the stud, creating an instantaneous arc which melts both the base of the stud and the adjoining surface on the workpiece. At the same time, the welding gun forces the stud into the workpiece, resulting in a permanent bond as the molten material solidifies……..all in 0.003 seconds!
380 Volt (440-460 Voltage) Equipment – DA Drawn Arc.
Drawn-arc stud welding is an extremely efficient method of attaching fasteners primarily to mild steel and stainless steel by utilizing a constant-current DC power supply, typically a 3-phase transformer-rectifier, equipped with integral controls to operate a special drawn-arc stud welding gun. When a weld is initiated, current begins to flow through the stud while the weld gun simultaneously lifts the stud to "draw an arc", which melts the base of the stud and adjoining surface on the workpiece. Upon completion of the weld time, the gun plunges the stud back to the workpiece, resulting in a permanent bond as the molten material solidifies…….all in less than one second.
In general, the drawn-arc process is capable of welding a broad range of stud diameters (up thru 1-¼" or 32 mm) and to almost any material thickness above 0.040" (1 mm). To accommodate such a broad range, the process is actually split into two categories: Standard Drawn-Arc and Short-Cycle.
Standard drawn-arc is used with studs ¼" (6 mm) diameter and larger, and base material thicknesses at least 1/3 the stud diameter. This process requires the use of flux-loaded studs and ceramic ferrules, included with the studs, to contain the molten material during the weld and form a fillet around the stud base