History of Forge Welding
Forge welding is by far the most ancient known welding method, which has been practised for centuries. It is believed that it started with the discovery of metals (copper and bronze etc.) in the Bronze Age. It is one of the simplest methods of joining metals and has been traditionally used since ancient times. At that time, only one method of joining metals was known, in which the metals were heated to high temperatures in furnaces and then joined by hammering.
Forge welding is a solid-state welding process, in which two pieces of metal are joined by heating them at high temperatures and then pressing/hammering them together.
In this process, metal parts are heated in a forge furnace with fuel such as coal, coke, or charcoal. The parts to be joined are heated until the metal joining surface becomes soft. When this condition is reached, the two parts are quickly superimposed with each other and the weld is made with pressure or a hammer.
Forge welding is a process of joining metals by heating them beyond a certain threshold and forcing them together with enough pressure to cause deformation of the weld surfaces, creating a metallic bond between the atoms of the metals.Wikipediahttps://en.wikipedia.org/wiki/Forge_welding
Types of forge welding
- The pieces are heated in a fire by the blacksmith. He takes them back at the appropriate time and joins them by striking them with a hammer.
- Water-Gas Welding finds application in the manufacturing of pipes, containers, etc. The edges of the plate (to be converted into a pipe) are heated by a water gas flame (consisting of hydrogen, carbon monoxide, and nitrogen) and, as soon as they have attained a suitable temperature, placed under a hammer or by pressure rollers, for welding together.
In this method, the metal parts are heated in a forge furnace in which fuel such as coal, coke, or charcoal is used. The part of metals is heated to over 1000 degrees centigrade until they are plastic.
Application of pressure
The force of the hammer or pressure in forge welding depends on the size and mass of the metal parts to be joined.
Use of flux
In this process, a flux (usually sand or borax is sprinkled on the joining surfaces) to remove foreign substances such as oxides and dirt, etc. ). The flux spreads over the metal, prevents oxidation by keeping air out, lowers the melting point, and liquefies it so that it can be pulled out of the weld when the metal is hammered.
Modernization of Forge Welding
With the invention of modern welding processes like electric welding and gas welding methods during the Industrial Revolution, manual forge-welding has been largely replaced, although automatic forge-welding is a common manufacturing process.
Uses and applications
• It is used to join individual pieces of metal to form more important and specific metal products, such as making chains, swords, railroad rods, gates, grills, and many more. It is also used in making cookware and agricultural equipment.
• It is also used to make pipes from plates( by rotating plates).
• In addition, forming cylindrical forms by forge welding and longitudinal junctions by the forge, etc.
The working method of forge welding
The forge welding process is basically accomplished in four steps.
• First, the connecting ends are put into a forge furnace for heating and heated to a fully plastic state.
• After completely heated, it is removed and flux is sprayed on it, usually, borax is used as the flux which acts as a low-temperature, glass shield that prevents oxidation of the metal prevents.
• After the flux is used, the metal is put back in the forge furnace. It is heated back to a bright yellow state.
• When it is bright yellow, the metal piece is removed from the forge furnace to be joined and pressurized with the help of a power hammer or hydraulic press, thus completing the welding process.
Metals to be joined and their thickness
• Wrought iron and low carbon content steel with less percentage of carbon(approx 0.2%) can be satisfactorily welded.
• Metals with a thickness of about 30 mm can be joined.
Advantages and Limitations of Forge Welding
Although forge welding is a traditional and simple joining process and welding is performed at a low cost without the use of expensive equipment, there are some limitations to this welding process, such as it is possible to join only small equipment with the forging method.
Mass production is not possible by the method and or a slow welding process
Even after being an ancient practice, forge welding is used today in both its traditional and modern forms, which has been proved in many places to be a less expensive or simpler process than any welding process, that is why forge welding is still popular today.