Forging rolled ring

The process of rolled ring forging is used in the manufacture of seamless rings. A hollow cylindrical billet is rotated between a mandrel and pressure roll to reduce its thickness and increase its diameter. 

B 247 Aluminum and Aluminum-Alloy Die Forgings, Hand Forgings, and Rolled Ring Forgings... 

The core shroud separates the upward flow of coolant through the reactor core from the downward recirculation flow. The core shroud is an assembly of cylinders fabricated from rolled and welded stainless steel plate material, which encompasses the reactor core as shown in Figure 2-15. For the replaced core shrouds of Japanese BWRs and the ABWR core shrouds, a forged ring material is used to decrease the weld lines. Typical core shroud weld locations are shown in Figure 2-15. Shell sections are normally solution heat treated, cold formed and joined with longitudinal and circumferential welds. The steam separator/shroud... 

Roll forging reduction of section thickness of a doughnut-shaped preform to increase its diameter. Similar to ring rolling (see 3.2), but uses impact forces from hammers. 

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