Electric butt welding of thick metal cable, esp. aluminium wire - which is welded, upset, and then cold rolled and annealed to make strong joints

摘要

Both ends of two wires or profiles are pressed together to make a butt joint, which is then hot upset (I) to increase its dia. Cold working is then used to reduce the butt joint to the required size. After cold working, the upset zone is pref. subjected to a recrystallisation-anneal (II). Upsetting (I) is pref. undertaken at min. 450 deg.C to increase the cross-section by 40%, esp. inside an insulating tube. Cold working of the upset joint is pref. achieved via rolling; and anneal (II) is pref. at min. 400 deg.C. The welds are extremely reliable, both electrically and mechanically, so they are very suitable for protective circuits or earth wires.