Welding is broadly classified into two types: I. Plastic Welding: In this case the two pieces of metals to be joined are heated to plastic state and welding is completed by forcing them. In this case no filler material is added. II. Fusion Welding: In this case the two pieces of metal are heated and brought to molten state and [...]
In this article we will discuss about:- 1. Principle of Welding of Steel 2. Standard Welding Processes of Steel 3. Defects 4. Inspection 5. Welding Positions 6. General Considerations 7. Economy 8. Advantages and Disadvantages. Principle of Welding of Steel: Welding is a process of connecting metal parts by fusion. Arc welding and oxy-acetylene welding are the two usual methods [...]
Most important application of computer in welding is for the setting of welding parameters. Computer is used to control the welding process with regard to both static and dynamic characteristics. A computerised welding process controller is designed to handle the various phenomena occurring during the welding process, viz., the start-up sequence, continuous welding-including parameter setting, and the termination sequence. Start [...]
In oxyacetylene welding, the two gases used for producing flame are oxygen and acetylene. Oxygen is used to support and intensify combustion. It is generally prepared in factories by liquefying air and then separating it into its component parts by rectification. From factories, it can be obtained under high pressure in cylinders which are fitted with pressure regulators to get [...]
The following points highlight the equipments used for oxyacetylene welding. The equipments are: 1. Welding Torch 2. Pressure Regulator 3. Hose and Fittings 4. Cylinders 5. Goggles 6. Spark Lighter 7. Apron 8. Gloves 9. Welding Rods 10. Fluxes. Equipment # 1. Welding Torch: It is a tool for mixing the two gases in the desired volumes and burning the [...]
The following points highlight the five main types of resistance welding. The types are: 1. Spot Welding 2. Projection Welding 3. Seam Welding 4. Butt Welding 5. Percussion Welding. Type # 1. Spot Welding: This is probably the simplest form of resistance welding and best suited for ordinary sheet steel. For obtaining good welds having strength, and to avoid the [...]
The following points highlight the main thirty one methods of welding used in industries. The methods are: 1. Plastic Welding 2. Fusion Welding 3. Solid-Phase Welding 4. Cold Welding 5. Forge Welding 6. Pressure Welding 7. Flash Welding 8. Resistance Welding 9. Gas Welding 10. Oxyhydrogen Welding 11. Air-Acetylene Welding 12. Pressure Gas Welding 13. Atomic Hydrogen Welding and Few [...]
In this article we will discuss about:- 1. Meaning of Arc Welding 2. Shielded-Arc Welding 3. Shielded Metal Arc Welding (SMAW) 4. Precautions to be Taken in Arc Welding 5. Arc Energy 6. Starting an Arc 7. Arc Stability 8. Puddle Control for Fusion Welding 9. Welding Adjustments to Correct the Bead 10. Good Arc by Proper Length Adjustment. Meaning [...]
The current and voltage requirements during arc welding process vary considerably. In arc welding, short circuits keep on taking place frequently. For example, whenever the operator touches the electrode to the work in order to strike an arc, short circuit is created. Similarly when the molten globules of weld metal cross the arc, electric short circuits (around 20 nos. per [...]
In this article we will discuss about:- 1. Introduction to Electrodes 2. Ingredients of Electrodes 3. Electrode Covering/Coating 4. Classification 5. Factors to be Considered in Selection 6. Disadvantages 7. Electrode Efficiency. Introduction to Electrodes: Bare, fluxed and heavy coated electrodes are types of metal electrodes most commonly used. Bare electrodes have limited applications as during the welding operation, they [...]