When purchasing hubs and spindles, product integrity is critical,
since it is often what makes or breaks a part in the field.
Machined castings or hot rolled machined bars often have poor
structural integrity or inclusions that lead to problems with
cracking and part failure. As shown in the cases below, forging
has proved to be a successful solution to these problems.
Product/Application:
Previous Processing Problems:
Hub for air compressor
Material:
Stainless Steel
The previous process involved casting, followed by intricate machining.
Critical surface quality requirements were not met with the casting.
After extensive machining, part rejections arose due to porosity, extending lead times and incurring additional rework or replacement costs.
Forging as the Solution:
Forging has successfully replaced casting, providing outstanding strength, soundness and structural integrity properties.
Surface quality standards were met through combining the forging process with controlled material selection.
Product/Application:
Previous Processing Problems:
Coupling hub for high pressure cylinder requiring strength and property uniformity
Material:
Alloy Steel
Hub Size:
4-1/4" O.D. X 4-1/4" Long,
Stepped Down to 1-3/4" O.D.
X 5" Long
The former process involved sawing and machining a hot rolled bar to shape.
The longitudinal grain flow caused cracking, which led to field failures.
Abuse in the field was causing more wear than expected, resulting in breakage and the need for stronger parts.
Forging as the Solution:
A customized, triaxial forging process provided the solution.
Triaxial forging produces a special isotropic grain flow, which was required to meet the design specifications.
Controlling the grain flow has increased part strength and minimized field failures.
Product/Application:
Previous Processing Problems:
Gearbox pinion
Material:
Alloy Steel
Previously the pinion was manufactured from a hot rolled bar machined to size.
Cleanliness was critical,
but often-times unacceptable inclusions were
found on the machined surface, causing rejections.
The inclusions often
were not found until after finish machining,
resulting in excessive time and costs spent
repairing the parts.
Forging as the Solution:
The machined hot rolled bar has been replaced by a forged spindle using 37% less material.
Material cleanliness is optimized by controlling melt practices and teaming processes.
Material rejections due to inclusions have been eliminated.
A copy of Successful Cases of Forged Hubs and Spindles is available in pdf format. To view pdfs, you will need Acrobat Reader. Download a free copy if needed.
