Forging is a metalworking process that has been around for thousands of years. The blacksmith in our forefather's village made many of the farming equipment and utensils needed by farmers. He also produced military weapons.
There was only an anvil, hammer, and heat source used for forging, but today it is used in every engineering industry.
A forging article explains what metal forging is, what is the forging process, what are the advantages of forging, what are the uses for forging, and what is the difference between forging and machining.
What is metal forging?
Essentially, metal forging parts involves applying compressive forces to metals to form and shape them by using either a power hammer, a forging press, or a forging machine to exert compressive forces. In metal forging, you are deforming the metal in its plastic state to the desired geometric shape by applying compressive forces. The workpiece can be hot or cold.
Depending on whether a die is used or not (into the open space), the metal flows plastically either into the die cavity or into the open space.
The basic principle of forging is to deform the metal geometrically using plastic deformation.
By forging the metal nearer to the shape of the part, you can reduce the amount of machining while saving material.
When the metal being forged is realigned, it provides added strength to the forging, as opposed to casting and machining. As a result of grain flow in the metal being forged, the forged part is stronger and has a higher strength.
Process of forging
The metal forging process starts with the selection of the metal required for the forging, such as a cast billet or a cast bar. A forging process, the die dimensions, shrinkage allowance, the final part dimensions, etc., can all be taken into account when calculating the weight and size of raw material required per forging. To create your workpiece, the billet needs to be cut to the required size and length.
A workpiece must be heated to its recrystallization temperature before plastic deformation can begin.
The forging process must be selected according to the part. For example, open die forging uses a hot workpiece that is continuously hammered with a forge hammer and manipulated by a smith (operator).
Forging breaks up the coarse grain structure in the cast billet, resulting in recrystallization and formation of finer grains. As a consequence of the applied compressive forces, porosity, shrinkage, and voids in the cast billets are eliminated or minimized, which improves the metal's structural integrity.
As with casting or machining, the metal forging process gives an advantage in the mechanical properties of the part being forged, since any inclusions in the metal are broken up and distributed throughout the part.
Forging enhances the overall mechanical strength of a part by guiding grain flow and shaping it in the desired direction.
By forging, your grain flow will be aligned and you will achieve the best directional strength possible. Heat treatment will improve the strength post-forging.
Forging can be done on metals that are ductile or metals that become ductile after heating, such as alloy steel, carbon steel, tool steel, stainless steel, aluminum, brass, copper, titanium, nickel alloys, etc.
The forging process produces parts with consistent metallurgical quality and with good strength and fatigue properties. Economically, forging is determined by the number and size of forgings that need to be produced. Forging may become more economical if the forging weighs more than machining even if it is a small quantity.
Even though many metals can be forged, ductile metals have better forging ability and better dimensional tolerance. Dimensional accuracy of a forging depends on the forge ability of the metal. It is preferable to forge parts that are fail-proof (failure would be disastrous or costly).
