As welding classification

welding classification

1. 1 1 28 March 2020 Dr.Abhishek Sharma By Dr. Abhishek Sharma Metal Joining (Welding) KME-403 Unit - IV GL BAJAJ INSTITUTE OF TECHONOLOGY & MANAGEMENT

2. 2 Welding Welding can be defined as a process of joining similar or dissimilar metals by application of heat with or without application of pressure and filler material. 28 March 2020 Dr.Abhishek Sharma

3. 28 March 2020 Dr.Abhishek Sharma 3 Until the end of the 19th century, the only welding process was forge welding . Arc welding and oxyfuel welding were among the first processes to develop during the 1800s, and resistance welding followed soon after. Welding technology advanced quickly during the early 20th century as World War I and World War II drove the demand for reliable and inexpensive joining methods. Following the wars, several modern welding techniques were developed, including manual methods like shielded metal arc welding , now one of the most popular welding methods, as well as semi-automatic and automatic processes such as gas metal arc welding , submerged arc welding and flux-cored arc welding . Developments continued with the invention of laser beam welding and electron beam welding in the latter half of the century. Robot welding is becoming more commonplace in industrial settings today.

4. welding Solid state welding Soldering and brazing Fusion welding Electrical energy Chemical energy Other processes Non consumable electrode Consumable electrode Resistance welding Cold welding Friction welding Diffusion welding Flash welding Ultrasonic welding Explosion welding Gas metal arc welding Shielded metal arc welding Submerged arc welding Flux cored arc welding Electrogas welding Electroslag welding Gas tungsten arc welding Atomic hydrogen welding Plasma arc welding Oxyacetylene welding Oxyfuel gas welding Laser beam welding Thermit welding Electron beam welding Soldering Brazing WELDING CLASSIFICATION

5. 5 Advantages of Welding over other joints: Lighter structures with higher joint strength can be easily and rapidly made. Thus are cheaper. welded joints have higher corrosion resistance. Are fluid tight for tanks and vessels. Can be easily and economically altered. Variety of joints are possible. Disadvantages: Produces waves of longer wavelength than X and γ rays. These are made up of visible light rays, infra red rays and ultraviolet rays. Ultraviolet rays can cause burns to corners and eye retina. Infrared rays have longer wavelength and produce heat when they strike and are absorbed into surface. For protection, welders should wear welding jackets made of leather, denim, boot. 28 March 2020 Dr.Abhishek Sharma

6. 6 Solid Phase or plastic or pressure welding: Clean faces of component are brought into intimate contact to produce a metallic bond with or without application of heat. Here application of pressure is essential to produce the plastic flow. Now a days means to weld dissimilar metals have been found out. Welding gives 100% strength of the joint and is very easy process. Weldability: Is capacity of being welded into inseparable joints having specific properties like definite weld strength, proper structure etc. Weldability is based on criterion like ease of welding and weld quality. Thus welding can be defined as a process of joining similar or dissimilar metals by application of heat with or without application of pressure and addition of filler material. Welding can be categorized in following two wide groups: Fusion or Non Pressure Welding Plastic or Pressure Welding 28 March 2020 Dr.Abhishek Sharma

7. 7 Fusion welding Process of joining two metal pieces by application of heat. Parts to be joined are placed together, heated (often with addition of filler metal), until they melt and solidify on cooling. Following methods could be used to develop heat: Combustion of fuel gas with oxygen. Electric arc. Plasma arc, electron beam, laser beam. Sometimes pressure is also applied with heat to have better joining section. Fillers are used to attain additional strength of the joint. Ways of applying pressure can be hammering, rolling or using dies. In fusion welding metals to be joined are brought to fluid state without application of pressure and joined by filler material. 28 March 2020 Dr.Abhishek Sharma

8. 8 Fusion welding Gas Welding Air Acetylene Oxy Acetylene Oxy Hydrogen Arc Welding Shielded Carbon Arc Unshielded Carbon Arc Metal Arc Welding Gas Metal Arc (MIG) Gas Tungsten Arc (TIG) Atomic Hydrogen Arc Plasma Arc Submerged Arc Flux Cored Arc Electro Slag Others Electron Beam Thermit welding Laser Welding 28 March 2020 Dr.Abhishek Sharma