The thermal and rolling treatment of forged rolled rings sometimes leads to the creation of residual stresses, causing dimensional distortion in the results. However, there are tons of corrective measures employed by forging industries to address this concern. Ongoing studies are seeking to base newly-found corrective measures on the laws of physics.
How does Dimensional Distortion Happen?
Ring Rolling Process
First, the rings and other metal components are rounded and cut to how much it weighs. It is then processed to reach the intended integrity, directional grain, and other specifications. It is then punched and pierced to create a ring.
After that, it is placed on the ring mill to be rolled. The idler roll applies pressure against the drive roll and slowly the ring diameters are increased. Continued pressure is applied, and this reduces the wall thickness.
The axial rolls control the height as it is being rolled and this is repeated until the proper size and specifications are reached.
Distortion is Not the Only Problem
Once the metal components have been rolled at a certain forging temperature, most of them are heat treated. Due to this method, some parts of the components become ovular and distorted.
This occurs more often in huge metals with outer-diameter to wall-thickness proportions. More so, distortion is the only concern resulting from this method. Despite furnishing results that meet dimensional tolerances, residual stresses may still happen even after the product has been shipped to the customer.
The reason is that succeeding machining processes conducted by customers or other metal-production companies may cause extra distortion and deformation to the product.
Preventive Measures Must be Employed
In light of the intricacy of the issue, various ring-rolling companies approach it with only corrective measures while disregarding the essential preventive measures. There are companies which manufacture the metal components with great tolerances so it can be earlier manufactured to its final dimension and preventing any possible distortion.
Others employ corrective ring distortion measures through expansion and compression processing, partially relieving the components of residual stresses.
Looking for Forged Rolled Rings with Minimal Distortion?
To produce rings and other metal parts with minimal distortion, it’s important that the ring-rolling company employ both corrective and preventive measures, if possible. Contact Ferralloy Inc. to get your quality rolled rings!