What are Large Diameter Steel Rings Formally Called?

What Are Large Diameter Steel Rings Formally Called

What Are Large Diameter Steel Rings Formally CalledLarge diameter steel rings are formally known in various industries as rolled rings or seamless forged rings. What are rolled rings, you ask? They are donut-shaped rings forged into shape by forming, machining, and grinding to acquire the finished product. The initial material is blank, net-shaped, or a solid wrought block. The end product, or rather the rolled rings, has smooth surfaces, specific dimensions, and tight tolerance with excellent concentricity. The ring equipment is essential in different industries like aircraft, pressure vessel manufacturing, power generation, transmission, oil fields, railroads, automobiles, industrial gas turbines, and other companies in need of custom fabrications.

How is the Ring Rolling Process is Done?

Large-diameter steel ring manufacturers like Cliffe Metal Products, Inc. specialize in casting and forgings hard-to-find specialty metal items and machine parts. The rolled ring open die forging process involves aligning the metal’s grain flow with the die, closing internal porosity present on the metal, and finally producing predictable grain structures and parts with consistent material properties. In addition, the open die forging process ensures the end ring is strong, impact-resistant, homogenous, and can withstand fatigue.

The forging process is performed in stages:

  • Upsetting. At this stage, the process begins with upsetting the metal on flat dies at its plastic deformation temperature.
  • The piercing stage involves force to pierce the hot upset on the metal, leaving a thin web of metal at the bottom.
  • Shearing breaks off the structural grain, removing the thin web, and the result is a complete hole through the metal stack.
  • In the preform stage, the stock is now ready for the ring rolling process.

Some of the materials used in forming the large-diameter steel rings include alloy steel, aluminum alloys, cobalt alloy, nickel alloys, carbon steel, stainless steel, tool steel, and titanium alloy. With the material of choice, the ring rolling process can commence by perforating the metal piece to create a ring shape. Next, the ring shape is subjected to high temperatures for the recrystallization process. From the recrystallization, the ring proceeds to the idler roll and then to the drive roll. During this process, the forging widens the diameter and thickens the ring walls. The final step focuses on achieving the desired size.

Expansion Process/Sizing 

Sizing is an essential part of forming large-diameter steel rings, and you should give your specific dimensions before the forging process. Having the accurate size helps in creating the perfect rolled ring with minimal material waste. In addition, the ring expanders help in achieving the required size and improving the roundness and smoothness of the cylindrical parts. Another added advantage of the expansion process or sizing is improving the material’s microstructure as the workpiece.

The cold expansion helps relieve the internal stress caused by the heat and corrects the distortions, while the hot expansion improves ductility by elongating the grains in the circumference. As a result, most manufacturing companies can accurately size simple alloys like steel, carbon, and aluminum. However, the more complex alloys like titanium prove problematic as they may develop internal shear stress and tensile stress on the boundaries during ring rolling.

SizTech Ring Expansion

SizTech ring expansion involves adding a SizTech expander to the ring production process to prevent the significant internal shear stress at the compressive and the tensile stress on the boundaries when working on more complex metal alloys. The SizTech expander is incorporated during the final planishing phase.

Adding the SizTech expander has two advantages:

  • A faster ring rolling cycle is rolled slightly undersized with more significant reductions reducing the final planishing process. Then the ring is sized to the required specifications on the expander.
  • When the ring diameter increases to the desired diameter on the forging expander, that helps in improving the inner-diameter accuracy and displays the entire cross-section to tensile load. In the long run, this helps in relieving the internal shear stress.

The internal stress caused by heat treatment leads to ring distortion of the metal; however, sizing the ring can correct and improve the distortions. The allowance of the machine resolves this issue at the cost of extra material to avoid the unnecessary loss of material forging; the expander corrects the inner diameter and the outer diameter while eliminating machine allowances.

Advantages of Large-Sized Steel Rings

  • No waste of even a drop of the expensive metal material used.
  • Seamless rings are of superior quality thanks to their circumferential grain flow
  • Lower cost due to elimination of the cost handling layout and production time.

For the best quality, large-diameter steel rings, contact Cliffe Metal Products, Inc. as we supply quality end products and centrifuge castings that are rough-machined or finished-machined to your specifications. ISO-9002 certified manufacturers produce our metal items and machined parts. Since 1979, we have had a reputable reputation for supplying our esteemed customers with hard-to-find specialty metal items. Apart from centrifugal castings, we also provide rolled rings forged up to 8000lbs, custom-made piping components, and open-die forgings up to 25,000 pounds. Call us at (513) 574-7600 or fill out our online form for any inquiries.