Forging is the manufacturing process that involves shaping, deforming, and manipulating the material into desired shapes and configurations through pressing, rolling, hammering, or other compressive forces. These forces used to deform the material are delivered by the die or hammer during the manufacturing process. There is a variety of metal that can be fogged such as stainless steel, carbon steel, brass, copper, or aluminum. Depending on the type of material and requirement of the design of the finished product, forging can be done by hot, warm, or cold methods. Hot forging heats the material at nearly its melting point to reform its shapes, whereas cold forging shapes the material with limited heat or the heat below its melting point. Each type of forging has its own advantages and best uses. Here we will introduce a few common types of forging method and their applications.
We can categorize the forging methods by the temperature used in the process, including Hot forging, Warm forging, and Cold Forging
Hot Forging
The hot forging process involves the use of extreme heat to deform and reshape the material. Depending on the types of material, the temperature applied in the process is higher than their recrystallization temperature. For instance, the temperature used for deforming the steel is usually at around 2,100 degrees Fahrenheit, while only around up to 970 degrees Fahrenheit is required for aluminum alloy. Hot forging is the best choice for deforming the metal that has a high formability ratio. The process uses excessive heat to decrease the yield strength and increases the malleability of the material, makes it easier to form the material into complex geometries.
Cold Forging
Cold forging applies a displacement process that shapes the material at a colder temperature that can be ranging from room temperature to several hundred degrees. The heating temperature should be around 30% less than the material’s recrystallization temperature. There are many processes under cold forging, such as bending, cold drawing, cold heading, extrusion, coining, thread rolling, punching, and many more, to shape the material in a diverse range of shapes. The most common types of materials used in cold forging are standard steel, carbon alloy steel, or soften metal such as aluminum. This process is widely used in producing components with complex or unusual geometries such as the steering, suspension parts, and braking components in the automotive industry.
Compared with the hot forging method, the cold forging method is less expensive, able to shape the product in a tight tolerance dimension, and result in a quality surface finishing that requires little or no finishing work. This method also helps to reduce ductility and is less susceptible to contamination issues. Cold forging is also considered the most eco-friendly method as it reduces the carbon footprint, wastage, and energy usage in production. However, more powerful equipment and stronger tools are required for the cold forging method.
Warm Forging
Warm forging is in between cold forging and hot forging. The temperature applied in the warm forging is above the room temperature that is used in cold forging but not as high as the temperature used in the hot forging. This process is especially for materials that are not suitable for either hot or cold forging. The warm forging method possesses some potential advantages such as reduced press loads, tooling loads, and increase ductility.
The type of forging method can also be categorized according to the arrangement of the die, including open die forging and close die forging.
Open Die Forging
Open die forging is the simplest type of forging method. It uses flat dies or no die that allows the material to be deformed freely when the load is applied in a lateral direction. Open die forging is mostly used hot forging and is suitable for shaping simple shapes that require less dimensional accuracy.
Closed Die Forging
Closed die forging is also called impression die forging. The material is fully constrained in the cavity formed by the lower and upper die halves that have a pre-cut profile of the designed part. It allows the material to be shaped more accurately than open die forging. Closed die forging is suitable for producing more complex shapes and multiple die cavities may require if forging complex geometries. Closed die forging requires a higher interface pressure, strict control of the material volume, and proper die design. This method is considered more expensive as there is a high initial cost to make a closed die and a large production is required to justify its high initial cost.
There are few common types of equipment are used for forging:
Hammer forging
Hammer forging is the most versatile type of forging equipment that uses hammer and anvil to generate load and energy to shape the material. The process involves multiple impact blows on the dies. It is the least expensive method and is commonly used for hot forging.
Press forging
The material is shaped by a continuous squeezing action done by the mechanical press or hydraulic press. The mechanical press is using cranks, cams, and toggle to make reproducible strikes by the hammer. A different stroke position can generate different levels of force. In this case, a mechanical press can perform more stokes per minute than hydraulic press. Hydraulic press is using fluid pressure to generate force. The benefits of hydraulic press are its flexibility and superior capacity. But it is slower, larger, and most costly to operate.
Machine forging
Machine forging is also known as upset forging as it involves the upsetting operation. The machine forging was originally developed for making bolt head, but it is now widely used for producing a variety of shapes such as shafts, gear blanks, rods with flanges. The machine forging includes two parts of die, one is fixed and another is movable. It also includes a corresponding punch that applies pressure in a horizontal direction. A number of strokes are required to obtain the desired shape of the component and it depends on the complexity, material type, and the number of dies. The process can be fully automated and has a high production rate that involve little or no waste.
Forging is a manufacturing process that using equipment and different level of temperature to heat, compress and change the metal or workpiece into a wide variety of shapes and sizes according to our requirements and design of dies. It is widely used in different industries for making hardware, tools, industrial parts. Forged product has higher mechanical properties with stronger creep resistance and fatigue strength. The operation of the forging process is relatively simple and does not require skilled operators. However, the forging process may incur higher initial cost for large forging presses and a secondary finishing may required for some forging methods. The size of the finishing product is also limited by the size of the press. MecHero Malaysia provides forging manufacturing process for a wide range of products, hardware, and industrial tools. You can always contact us at +6011-7000 7687 or email us at my.mechero@gmail.com for an inquiry about the types of forging in Malaysia. As a steel and online hardware store in Malaysia, we also supply a wide range of steel materials, general hardware, or mechanical components. Tell us your requirements now and we can advise you accordingly.
Photo credit: Media from Wix, nord-lock, aida, xconomy, waldunsteel, vimag