高速重ねシーム溶接の接合部形成現象の基礎的研究(第3報)

電極間抵抗および電極と被溶接材との接触面の通電領域について

抄録

Voltage across electrodes and current flow area of the contact part between a electrode and a plate are measured to elucidate the current distribution in the plate. The results obtained are as follows.
(1) Voltage across electrodes increases with increased welding current. The increment of the voltage becomes large as welding speed increases.
(2) Resistance across electrodes R_e decreases with increased welding current and electrode force. R_e at the current value corresponding to commencement of nugget formation is almost same in any welding speed but R_e at the same nugget penetration increases as welding speed increases.
(3) Both length between start to center of electrodes and it to end of the current flow area are smarller than that of contact area between the electrode and the plate.
(4) The current flow length L_s of the contact part between the electrode and the plate increases with increased welding current and electrode force. The increment of L_s at same welding speed decreases as plate thickness decreases:
(5) Average current density δ_s of the contact part between the electrode and the plate is nearly same regardless of welding curernt for plate thickness above 1.2 mm but of δ_s, 0.5 mm in thickness increases slightly as welding current increases. δ_s increases with increased welding speed.