Forging

Forging is a metal shaping technique using compressive localized forces. commonly performed with the help of forging presses or hammering tools powered by either electricity, hydraulics or compressed air. Some of the common materials used for forging are carbon steel, alloy steel, micro alloy steel, stainless steel, aluminum, and titanium. 

Different Types of Forging and Their Advantages 

Forging gives its product unbroken grain flow, elimination of defects, inclusions, and porosity. Forging is relatively low costs associated with moderate and long production runs. Once the forging tools have been created, products can be manufactured at relatively high speeds with minimal downtime. 

There are two main types of forging — hot and cold.

Hot Forging 

In Hot forging metal is heated above its recrystallization temperature. The average forging temperature necessary for hot forging of different metals is: 

• Up to 1150°C for Steel
• 360 to 520°C for Al-Alloys
• 700 to 800°C for Cu-Alloys

The main benefit of hot forging is the decrease in energy required to form the metal properly because excessive heat decreases yield strength and improves ductility. Hot forged products also benefit from the elimination of chemical inconsistencies. 

Cold Forging 

Cold forging typically refers to forging a metal at room temperature or any temperature below recrystallization. Steel high in carbon can not be cold forged. Cold forging gives better dimensional control, product uniformity, surface finish, and contamination than Hot Forging. Some of the Cold forging processes are bending, extrusion, cold drawing and cold heading. Cold forging requires more powerful equipment and often needs intermediate anneals. 

Forging Process Categories 

Draw forming decreases the width of the product and increases length. 

Upset forging increases the width of the products and decreases length. 

Compression forming provides forging flow in multiple or customized directions. 

These three categories entail many different specific types of forging: 

Open Die Forging Process 

Flat dies with no precut profiles are used. The open design allows the metal to flow everywhere except where it touches the die. It is useful for short-run art smithing or for shaping ingots prior to secondary shaping measures. 

Closed Die Forging Process 

Closed die forging or impression die forging uses molds. These molds are attached to an anvil while a hammer forces molten metal to flow into the cavities of the die. Multiple strikes and/or die cavities are often used when forging complex geometries.

High initial tooling costs hence not favorable for low volume but cost-effective where higher volume produced. Produces higher strength products in comparison to other forging processes. Common applications of closed die forging include the production of automobile components and hardware tools. 

Press Forging 

The metal sits on a stationary die while a compression die applies continuous pressure, achieving the desired shape. Simultaneously deform the entire product, as opposed to a localized section. Applications of press forging are numerous, as there are relatively no limits to the size of product that can be created. Press forging can be hot or cold forged.  

Roll Forging Process 

Roll forging is the process of increasing rods or wires in length. The manufacturer places heated metal bars between two cylindrical rolls, which rotate and apply progressive pressure to shape the metal. Benefits of roll forging include the elimination of flashing and a superior grain structure. 

Top Forging companies in India

FORGING INDUSTRY ASSOCIATION, USA – ABOUT FORGING