Cold metal transfer (CMT) welding of thin sheet metal products

Abstract

For welding of conventional structural steels semiautomatic technologies (MIG, MAG) are widely used, whereas for welding of Al-alloys and stainless steels the TIG welding method is the most common. The current study concentrates on welding of thin sheet metal products from stainless steel and aluminium by using a novel cold metal transfer (CMT) process. The CMT technology is an alternative to TIG, providing advantages, such as reduction of distortions and increased productivity. This is mainly due to low heat input, achieved by controlled movement of the electrode. In order to realize these advantages, optimization of the CMT welding process is essential. The aim of this study was the optimization of the process using the existing welding equipment (robot, manipulator, etc) and validation ofthe CMT process. The limiting factors for the increase of the productivity are the reduction of quality (increase of porosity, distortions and inacceptable shape of the welding bed). As a result, practical recommendations are given for the implementation ofthe CMT technology for robotic welding.

Analysis of the structure and selected properties of welds obtained by the CMT and MAG method

“…The width of the heat affected zone is significantly greater in MAG joints. In studies [13,14], welds produced by the classical welding method in shielding gases are characterized by higher hardness, compared to welds obtained by the CMT method. What is worth noting in the conducted tests, large grains were separated in the heat affected zone and MAG fillet weld, which were distinguished by greater hardness than the hardness tested in samples obtained by the CMT method.…”

Application of Cold Metal Transition Technology in Automobile Manufacture

“…The CMT technology controls the short-circuit state of the droplet over time, making the droplet short circuit only very small current generation. The mechanical back-pumping movement of the welding wire causes the droplet to fall off normally, compared with ordinary MIG/MAG welding method, CMT technology short-circuit transition without short-circuit bridge explosion, so no splash produced [6][7].…”

CMT Welding of Titanium and Stainless Steel Using CuSi3 Electrode

“…This method has a big potential in the welding industry in the future (Kubíček, 2018;Motloch, 2011). Cold Metal Transfer welding is a modified MIG welding process based on short-circuiting transfer process (Talalaev et al, 2012). From a technological point of view, the CMT method is soldering using an electric arc as a heat source for soldering the solder.…”