Welding is a process of joining two pieces of material into a piece of materials. This can be done in two ways, either the material is initially made as a liquid and solidify together or joining them by providing a lot of pressure and sometimes by heat. Melting type of welding is called fusion welding and heat and pressure type welding is called solid-state welding
- Metal Inert Gas Welding
It is also called as Gas Metal Arc Welding/ Wire welding. In this thin wire acts as an electrode. This wire is constantly fed through a spool mounted on a gun through a flexible tool and out of the nozzle on the welding gun. The wire is fed continuously when the trigger on the weld is pulled accordingly. Simultaneously an arc is generated between the weld torch and specimen. The arc thus generated will melt the electrode and workpiece above the melting point. When heated these metals mix together and solidify to join the workpiece into a single piece. It is a consumable electrode process. Shield gas with a mixture of Argon and carbon dioxide is fed through the welding lead nozzle to protect the weld from environmental condition.
- Tungsten Inert Gas Welding
It is also called as gas tungsten arc welding/heliarc welding. It uses a tungsten electrode; tungsten has an extremely high melting point i.e. when we TIG weld the electrode gets hot but it will not melt. So, it is called a non-consumable welding process. Tungsten electrode is Held in a TIG Torch. Electrode slips into the collet and the collet tightens up in a collet body. The end cap is used to adjust the length of the electrode. In TIG the base metal gets melted by the heat generated due to the arc between the electrode and workpiece. We can control the level of heat using a foot peddle or with a thumb wheel on the torch.
- Stick Welding
It’s an electric arc welding process which consists of a rod-shaped metal electrode covered with a flux material. Stick welding is also called as shielded metal arc welding/manual metal arc welding. During welding, an electric current is passed through the metal electrode, due to this current an arc is produced between the electrode and base metal. This arc melts both base metal and the metal in the rod. The flux material on the electrode is melted into the molten pool and mixes with the workpiece. So, it is a consumable electrode process. During welding, this flux covering melts and produces some shielding gases to stabilize the arc and protect the weld from environmental condition. It must be removed when the weld is cooled.
- Flux core welding (FCW)
It is also a type of arc welding process. It uses a tubular wire electrode with a flux filled in a core. Its arrangement is somewhat like MIG welding. During welding, an electric arc is formed between the wire electrode and the workpiece. In FCW always add filler metal to the base metal during welding.
Two type
- Self-shielded FCAW- S– Flux completely protect the molten weld from oxygen and nitrogen.
- Gas shielded FCAW- G– Gas shielding equipment containing argon and carbon dioxide is used.