Verification of the efficiency coefficient of the welding process by the CMT welding method

In order to obtain results from simulations that are close to reality, it is necessary to correctly set the parameters of the welding process. One of them is the efficiency of the welding process. Currently, new modifications of MIG/MAG methods are being created, which are characterized by lower heat introduced into the material (smaller efficiency coefficient). The efficiency coefficient determined by the European standard EN 1011–1 is no longer accurate enough for simulations. Therefore, it is necessary to accurately determine the efficiency coefficient of the method even for the mentioned modified welding processes. An experiment of calorimetric measurement of the efficiency of the CMT process (cold metal transfer—modification of the MIG/MAG method) was proposed. The specific heat capacity of the base material was accurately measured. Furthermore, a calorimetric measurement of the efficiency of the welding process was carried out on a flat sample (bead-on-plate method) and on a sample with a V-groove to simulate the treatment of welding surfaces. Accurate method efficiency values were determined for different welding current settings and different V-groove depths. The geometric characteristics of the fusion faces in butt welds have a greater influence on the efficiency coefficient than the size of the welding current.