Hot Forging Process and Applications
Hot forging is a metal forming process in which forgeable metal parts are called blanks or workpieces. Such parts are processed to obtain a predetermined shape. Here, procedures such as hammering, upsetting or pressing can be used; in these processes, the workpiece is heated to 75% of its melting temperature. The forging temperature divides the forging process into several categories such as hot forging, cold forging, and warm forging. Most metal parts require hot forging.
What is hot forging?
Hot forging is the most widely used forging process. In the hot forging process, the forging temperature is required to be higher than the metal recrystallization temperature. In short, the temperature at which new grains form in the metal. High temperature or extreme heat is essential for the metal to eliminate strain hardening during deformation.
In the actual situation of industrial manufacturing, friction plays a role in this process. Here, the friction at the die-workpiece interface prevents the diffusion of material near the surface, thereby allowing the center material to expand more effectively. As a result, it forms a barrel shape; this effect is called the barrel effect in metal forging. Barrel rolling is an undesirable phenomenon, and to control it, adequate lubrication can be used.
The hot forging manufacturing process increases the barrel effect and also allows heat to transfer between the molten iron and the cooler die. The metal near the die surface cools faster than the metal in the center portion. The cooler material is less prone to deformation and expands less. Whereas the deformation and expansion of the hotter material also causes the barrel effect.
Advantages of Hot Forging
It provides high strain rates, thus allowing the metal to flow easily. It will achieve recrystallization and recovery processes and require less force.
Applications of Hot Forging
Recrystallization is a process that involves the use of high temperatures. This procedure enhances formability and allows for the adjustment of precise and fine-grained microstructures. Hot forging provides higher strength and durability than any other forming process. In addition, it also enables hot die forging where high workloads place unique demands on the components. These components are known as “safety critical components”. The automotive and aerospace sectors are the most important buyer markets for hot forgings.
Hot Forgings for Automotive Applications
Steel forging is the main process used for automotive forging purposes. Deformed aluminum alloys have helped greatly due to the increase in the demand for lightweight structures, thereby reducing the demand for magnesium. In the automotive industry, many small and medium-sized components are forged under the closed die forging process. This process gives high strength and working performance to most automotive parts. Some of the standard automotive forging products involve engine parts, drive gears, powertrain, chassis, and brake systems.
Hot Forgings in the Aerospace Industry
Fuselage components such as door and wing fittings, ribs, and window frames require forging. Apart from this, engines with turbine blades, thrust cones, discs, control rods, fasteners, and pins require hot forgings. Rotor systems and their components rely on hot forging.
Steel forging is essential in the aerospace sector, which provides high strength and high temperature resistance to the material. In addition, it can also forge nickel-based and titanium alloys and lightweight construction materials.
Other Applications of Hot Forging
Besides automotive and aerospace applications, hot forging also performs well in several other fields. In addition, hot forging also shows its importance and advantages in several other major application areas. Industries such as construction, mechanical engineering, agriculture, defense, steel production, and marine engineering all require hot forging.
