The Capacitor Discharge stud welding process is ideal for thin gauge sheet where reverse marking can be minimised or completely eliminated. For CD the sheet surface should be clean and flat and the weld stud must have a precise pip and cone angle on the weld end.
The capacitors store a high voltage charge, which is discharged through the weld zone, generating an intense current flow for a short duration. It stores electrical energy and releases it rapidly during the welding process.
Capacitor Discharge (CD) stud welding, using very short weld times, permits the welding of small-diameter studs to thin, lightweight materials. The weld cycle can be completed in 0.01 seconds on material as thin as 0.5mm. These fast weld times minimize heat buildup, resulting in welds with very little distortion, discoloration, or burning.
One type uses dc power sources similar to those used for shielded metal arc welding. The other type uses a capacitor storage bank to supply the arc power. The arc stud welding processes using these power sources are commonly known as arc stud welding and capacitor discharge stud welding respectively.
It describes three modes of CD stud welding: initial-gap, initial-contact, and drawn-arc welding. The article also discusses the responsibilities of the welding operator. You do not currently have access to this chapter.
Application of the process consists of two steps: Welding heat is developed with an arc between the stud and the plate (work). The two pieces are brought into intimate contact when the proper temperature is reached. 1.