Oxy-Acetylene Welding Services: Welding Process for Ferrous Metals

12 May 2020

In joining two or more materials together, industries have utilised the use of welding. Welding is a fabrication process that uses high heat to melt two or more parts together. To cause fusion, the melted materials will be allowed to cool for a specific amount of time. A filler material is then added to the joint for it to cool.

Numerous energy sources can be used for welding, which includes an electric arc, a laser, an electron beam, and an ultrasound. However, one source that can be effectively used for ferrous metals is fuel gases and oxygen. The use of these elements in welding is known as oxy-acetylene welding.

Oxy-Acetylene Welding Features

Oxy-acetylene welding, also known as oxy-fuel welding or gas welding, relies on the combustion of fuel gases or liquid fuels such as gasoline or acetylene and oxygen to weld metals. The use of pure oxygen enables the increase of flame temperature, which allows localised melting of the workpiece material even in a room environment.

In oxy-acetylene welding, the welding tip, which has one hole, is normally mounted on the end of the torch handle. Fuel and gas mixture then pass through it to feed the flame. The flame produced by the combination of the gases melts the metal materials to be joined, which causes them to flow together. The addition of filler metal alloy enables the metal union of the welded material and prevents it from oxidation.

Adjusting the chemical action of the oxy-acetylene flame is done by changing the ratio of the volume of oxygen to acetylene. The flame settings that can be used for oxy-acetylene welding are neutral, oxidising, and carburising. Neutral can be achieved by having equal quantities of oxygen and acetylene. Oxidising flame, on the other hand, is obtained by increasing the oxygen flow rate. Alternatively, a carburising flame is acquired by increasing the acetylene flow in relation to oxygen flow.

Oxy-Acetylene Welding Ferrous Metals

The mixture of oxygen and acetylene enables oxy-acetylene welding to effectively weld ferrous metals. Ferrous metals are metals that contain iron. These metals are generally known to have magnetic properties, great tensile strength, and durability. They, however, contain high carbon content that contributes to their poor resistance to corrosion and rust, except for wrought iron and stainless steel. Some examples of ferrous metals are low-carbon steel, low-alloy steel, cast steel, wrought iron, and stainless steel.

In welding ferrous metals, their carbon content must not be modified to any appreciable degree. Even their atmospheric chemical constituents must not be added or subtracted from the base material without altering the metal properties. However, numerous welding filler wires have constituents that are different from the base material, which is acceptable granted that approved materials are used.

The inclusion of impurities whenever you weld with an oxy-acetylene flame can be minimised by following some precautions. For one, you must maintain a neutral flame for most steels and a slight acetylene increase when welding alloys with high nickel or chromium content. You must also maintain a soft flame and control the puddle. A sufficient flame must also be observed if you want to penetrate and manipulate the metal, protecting your material from the air by the outer envelope of flame.

Oxy-acetylene welding is great for ferrous metals since it can effectively melt them and produce excellent welding quality. High strength steels also utilise this type of welding as it can easily the surface of these metals. For more information about oxy-acetylene welding services, feel free to contact us at Sharp Welding and Crane Hire.