Prof.dr.ing. Ion Mitelea, Ing. Claudia Dorohoi

 

Abstract

The calculation of the welding currents and the determination of the discharging pulse shape by the transformer at the stored energy resistance welding require a preliminary knowledge of the discharging circuit parameters, of the welding transformer constructive parameters and of the external circuit parameters. Depending on these parameters, the capacitors discharging trough the welding transformer can have a character aperiodic, periodic amortized or with critical attenuation.
The shape of the discharging pulse and the maximum welding current are very important technological parameters of the resistance welding of the alloys with shape memory effect, because their properties in the weld area must not be altered. These sizes of the process are influenced by the parameters values by which the energy is stored in capacitors, and by the voltage ratio, K of the welding transformer.
The aim of this paper is to analyze the factors influencing the welding current, the determination of the maximum value of the welding current and the current variation in time, in the shape memory Fe-Mn-Si alloys welding.
The materials to be welded were strips, having the thickness of 0.52 to 0.54 mm and the width of 4.58 to 4.75 mm.