What is Cold Forging?
Also called cold forming, cold forging is a process that takes place near room temperature, rather than at higher temperatures like warm and hot forging. It’s done by placing the workpiece in-between two dies, and pounding the dies until the metal assumes their shape.
Advantages of Cold Forging
Because this process takes place without heating the metal beforehand, it provides many advantages and is often used in the automotive industry. For example, it’s often more economical than other processes, as the final product doesn’t require much finishing if any at all. There’s also little to no excess material left afterward, as the net weight of the original metal is about the same as the weight of the finished product. In addition to having no excess material, the dies used in cold forging last longer than in hotter processes, meaning fewer replacements.
Another advantage is that although the ductility of the metal decreases during the cold forging process, the metal sees a great increase in both yield and tensile strength. Because it’s not heated, the grain of the metal retains its size and changes direction to match the change in the shape of the piece itself, resulting in this increased strength.
How is it Different From Hot Forging?
Unlike cold forging that starts at or near room temperature, hot forging happens when metal is heated above its recrystallization temperature. This is usually an extremely high temperature, for example, steel is heated to 1150°C or 2202 °F, and copper alloys to 700-800°C or 1300-1470°F, which equals about 75% of the melting temperature. These high temperatures are necessary to keep the metal from strain hardening during the forging process. At these temperatures, the metal is in a plastic-like state, still technically a solid, but much more malleable.
Hot forging is usually done through a process called stamping, which means the heated metal is put into a press, and then squeezed in between a die and a tool.
Advantages of Hot Forging
Because the forging process occurs at high temperatures, the plastic metal is ductile and easily molded. Intricate shapes and designs can be created during hot forging, unlike cold forging where this can be extremely difficult. If you’re looking to manufacture customized metal pieces, hot forging is the best option because of its malleable state before hardening. This method is ideal for creating 3-D and complex shapes.
Unlike cold forging, which sometimes requires the extra step of heating the outside of the metal afterward to give it the right properties, the surface of the metal that has been forged through high temperatures is ideal for most types of finishing work.
Hot forging is also ideal for metals with a high formability ratio, because the integrity of the metal isn’t compromised by the high heat. These metals can be easily shaped without seeing any defects in the metal, making them both strong and ductile.
ABOUT KEVA
Keva Casting is a professional casting company that focuses on Construction, Machinery, Automobile, Hardware, Pipeline and many other industries.
We provide top quality products with the best service based on our complete production chain including our own mold design, advanced production techniques, and full management of the supply chain. Keva Casting has two factories located in Zhucheng, China's Shandong province.
We use "shell molding", which is a new technique that has been developed in recent years.This new technique has simplified production procedures and reduced air pollution compared with traditional sand casting and investment casting. Shell making and core making are faster to ensure production in enormous quantities. The dimensions and surface finishing are satisfactory for all kinds of industrial requirements. Besides supplying our own formwork & scaffolding systems, our casting products also supply OEM services in various industries.