Forge welding is a welding process of heating two or more pieces metal and then hammering them together. The process has been used since ancient times, being one of the simplest methods of joining metals. Forge welding is versatile, being able to join a host of similar and dissimilar metals. With the invention of electrical and gas welding methods during the Industrial Revolution
Forge welding between similar materials is caused by solid-state diffusion. This results in a weld that only consists of the materials without any fillers or bridging materials.
Forge welding between dissimilar materials is caused by the formation of a lower melting temperature eutectic between the materials. Due to this the weld is often stronger than the individual metals.
This ancient form of welding was one of the first methods used to join metals by heating two or more pieces metal and then hammering them together. Initially used on wrought iron and steel, but is now used to join a wide array of similar and dissimilar metals. forge welding has taken the back seat with the invention of electical and gas welding methods during the Industrial Revolution.
A simple flux can be made from borax, sometimes with the addition of iron filings. Since the welding temperature is above the forging temperature, typically 50-90% of the melting temperature care must be taken to avoid 'burning' the metal, which is overheating to the point that it gives off sparks from rapid oxidation. For example Steel welds at a lower temperature than iron. The metal may take on a glossy, or wet, appearance at the welding temperature. One of the most famous applications of forge welding is in the production of Japanese katana blades. During the process a billet of steel is repeatedly drawn out, folded back and welded upon itself. The katana, kris, and other Damascus steel products are fine examples of pattern welded objects.
One of the most famous applications of forge welding is in the production of pattern-welded blades. During the process a billet of steel is repeatedly drawn out, folded back and welded upon itself. Another lesser known application was the manufacture of shotgun barrels. Metal wire was spooled onto a mandrel, and then forged into a barrel that was thin, uniform, and strong. Often such objects are acid etched to expose the underlying pattern of metal which is unique to each item and adds to their aesthetic appeal.
