General Info On The Welding Processes
The popular arc welding process requires the usage of a welding power supply in order to create an electric arc connecting the material and the electrode in order to melt the materials when they reach the welding point. During this welding process can be used the direct current and the alternating current, as well as non-consumable and plasma cutter consumables electrodes. The area of the welding should be protected by shielding gas, slag or vapor. The process of arc welding can be of three types, namely manual, semi-automatic and completely automated.
The used power supplies in the welding process include constant current power and constant voltage power. In the process of arc welding, the arc’s length is related to the voltage such as the heat input is connected to the current. The constant current supplies are in general used during the welding processes that are done manually including shielded arc metal welding and tungsten arc welding since they require constant current. The welding methods that require constant voltage power are associated with the automated welding processes such as flux cored arc welding, arc metal welding, and submerged arc welding. In those welding processes the arc length is constant.
During the arc welding process the type of the current also matters. The direct current is used by the gas metal arc welding and the shielded metal arc welding where the electrode can be positively or negatively charged. When the anode is positively charged it has an increased heat concentration. In case the electrode is positively charged, then the weld speed and penetration will be increased. When the electrode is negatively charged this results in shallow welds.
The electrode processes that are non-consumable can use direct and alternating current alike. With the direct current, the electrode that is positively charged results in shallow welds, while the negatively charged electrode results in deeper welds. With the alternating current, the result comes in the form of welds that are of medium penetration. When alternating current is used, the arc should be re-ignited after a zero crossing or special power units that offer square waves should be used.
During the welding process should be used arc welding equipment such as the duty cycle which defines the minutes within a period of 10 minutes during which an arc welder can be used. In other words a welder that is named 80 A with a duty cycle of 60% should rest for 4 to 6 minutes after continuous welding. If the duty cycle limitations are not observed, the chance for the welder to be damaged is very high.