Arc welding is a type of welding process in engineering that uses an electric arc to generate heat to melt and join metal parts together. The process uses a consumable electrode, which serves as both the filler material and the electrode, to create the electric arc. The arc heats the metal parts, causing them to melt and form a pool of molten metal. As the electrode is consumed, it is automatically fed into the weld pool, supplying the filler material for the weld joint. The molten metal then solidifies, forming a strong bond between the metal parts. Arc welding is widely used in various industries, including construction, fabrication, repair, and maintenance. It is a fast, efficient, and versatile welding process that can be used on a wide range of metal alloys, including steel, aluminum, and stainless steel.
Here are some common viva questions related to arc welding:
- What is arc welding and how does it work?
- Arc welding is a process that uses an electric arc to melt and join metal pieces together. It works by creating an electric arc between the welding electrode and the workpiece, which generates intense heat that melts the metal and allows it to fuse together.
- What are the different types of welding electrodes and how are they chosen?
- There are several types of welding electrodes, including mild steel, stainless steel, cast iron, and aluminum. The choice of electrode depends on the type of metal being welded, the welding position, and the type of joint being made.
- What safety precautions should be taken while arc welding?
- Arc welding can be hazardous, so it is important to take appropriate safety precautions. This includes wearing appropriate protective gear, such as a welding helmet, gloves, and clothing, ensuring proper ventilation, and using the appropriate welding techniques.
- What is the difference between DC and AC welding?
- DC welding uses direct current, while AC welding uses alternating current. DC welding is typically used for welding metals with a higher melting point, while AC welding is used for metals with a lower melting point.
- What is the purpose of preheating before welding and when is it necessary?
- Preheating is the process of heating the metal to a specific temperature before welding. This is necessary for metals that are thicker or have a higher carbon content, as it helps to prevent cracking and other defects in the weld.
- What is the difference between MIG welding and TIG welding?
- MIG welding uses a continuously fed wire as the electrode and a shielding gas to protect the weld from contamination, while TIG welding uses a tungsten electrode and a separate filler metal. TIG welding produces a higher quality weld and is typically used for more precise and delicate welding work, while MIG welding is faster and more efficient for larger and thicker pieces of metal.
