Forging Processes for Shaping Metal Parts

Forging is an efficient method for shaping metal components using localized compressive forces. The primary forging processes include impression die forging (closed die), open die forging, cold forging, and seamless rolled ring forging. Each method offers unique advantages tailored to different applications.

Impression Die Forging

Also known as closed die forging, this process uses dies that completely enclose the material, allowing it to be molded into the desired shape. It requires higher compressive forces compared to other forging methods to fully fill the die cavities and form the part accurately.

Advantages:

· Minimizes metal waste

· Increases production rates

· Enhances fatigue and impact resistance

· Achieves higher strength-to-weight ratios

Cold Forging

Cold forging shapes parts at room temperature, resulting in components with superior surface finish and tight tolerances. Unlike other forging methods, this process does not apply heat, making it ideal for creating various components such as shafts, hollow parts, and cup-shaped geometries.

Advantages:

· Achieves tight tolerances and smooth surface finishes

· Cost-effective with minimal material waste

· Longer die life compared to heat-based forging

· Increases yield and tensile strength

Material Options for Cold Forging:

· Gold

· Silver

· Copper

· Brass

Open Die Forging

Often called hammersmith forging, open die forging involves shaping metal using direct force. A hammer strikes and deforms the workpiece, which is held between two flat dies that do not enclose it. This method is effective for creating large parts, weighing up to over 200,000 lbs and reaching lengths of up to 80 feet.

Advantages:

· Enhances fatigue resistance

· Promotes continuous grain flow, increasing part longevity

· Increases overall strength with reduced risk of voids

· Produces a finer grain size for improved structural integrity

Seamless Rolled Ring Forging

This process begins by punching a hole in a thick metal disk, which is then rolled and squeezed into a thin ring. Seamless rolled ring forging is suitable for creating rings with diameters from a few inches up to 30 feet. Unlike other forging methods, this process uses curved dies to shape the metal into ring forms.

Advantages:

· Provides superior structural integrity

· Increases strength with controlled directional grain flow

· Eliminates issues such as welding seams, inclusions, and porosity