What are the golden rules of welding?

Many distinct factors influence the strength of welds and the material around them, including the welding method, the amount and concentration of energy input, the weldability of the base material, filler material, and flux material, the design of the joint, and the interactions between all these factors. For example, the factor of welding position influences weld quality, that welding codes & specifications may require testing—both welding procedures and welders—using specified welding positions: 1G (flat), 2G (horizontal), 3G (vertical), 4G (overhead), 5G (horizontal fixed pipe), or 6G (inclined fixed pipe). To test the quality of a weld, either destructive or nondestructive testing methods are commonly used to verify that welds are free of defects, have acceptable levels of residual stresses and distortion, and have acceptable heat-affected zone (HAZ) properties. Types of welding defects include cracks, distortion, gas inclusions (porosity), non-metallic inclusions, lack of fusion, incomplete penetration, lamellar tearing, and undercutting.

Covalent bonding is when one of the component atoms loses one to more electrons. The electrons are then gained by the other atom, creating an electron cloud that is shared with the whole molecule. Both covalent and inionic bonding are characterised by brittleness because of their constrained locations. Metallic bonding refers to a type or covalent bonding where the constituent atoms do not mix with each other to form a chemical link. A number of positive ions can be formed when an atom loses an electron. These electrons will be shared by the Lattice. This makes the electron cluster mobile because the electrons and ions are free to move. It is responsible for metals' high thermal conductivity and electrical conductivity.

Gas metal arc weld (GMAW), also known under the names metal inert gas, MIG welding, or semi-automatic welding, uses a continuous wire feed to serve as an electrode. An inert or semi inert gas mixture protects the weld from contamination. GMAW has a faster welding speed than SMAW, because the electrode is continuously fed. Similar equipment is used in flux-cored (FCAW), which uses a wire with a steel electro and a fill of powder material. Although cored wire is more costly than the standard wire and can cause fumes, slag and/or smoke, it also allows for higher welding speeds and greater metal penetration. Gas tungsten (GTAW) welding or tungsten Inert Gas (TIG), is an manual welding process that uses non-consumable electrodes, an inert/semi-inert mixture of gases, and a separate, filler material. This method is great for welding thin materials. Although it produces a stable and high-quality arc, it requires extensive operator skill and cannot be done at very low speeds.

Explosion welding, which is another common process involves the joining and pushing materials together under very high pressure. Although the impact only produces a very small amount heat, the energy produced plasticises the materials. The process is often used for welding dissimilar materials. This includes bonding aluminum and carbon steels in ship hulls and stainless or titanium to steel in petrochemical Pressure vessels. As spot welding does, seam welding uses two electrodes that apply pressure and current in order to join metal sheet. However, instead of using pointed electrodes to join metal sheets, seam welding uses wheel-shaped electrodes that move along the workpiece and often feed it. This allows you to make long continuous welded. Although it was once used in the manufacture and sale of beverage containers, the use of this process is much less common. Other resistance welding methods are flash welding and projection welding.