Flange stamping is a manufacturing method that is economically feasible and technological. It is widely used in the production of large-scale batches, characterized by a high production rate of a product of the declared quality, achieved with the use of a minimum amount of forging and pressing equipment: a hot stamping machine for upsetting and final shaping and an edging press for piercing a hole and removing flash.
When hot forging forgings of flanges for pipelines, the highest accuracy of dimensions and shape of forgings is achieved, which makes it possible to exclude subsequent machining of the outer surface of the branch pipe and the adjacent end surface of the flange part of the forging.
The main method for manufacturing flanges is considered to be hot stamping using special presses with a force of up to 4500 kN. After stamping the flanges, the process of drilling and surface treatment of the product follows on special lathes.
The ring blanks plant supplies stamped blanks of flanges in accordance with GOST 33259-2015 and GOST 12821-80 up to DN 500 mm, pressure from PN 1.6 MPa to PN 20.0 MPa from steel grades 20, 09G2S, 13XFA, 15X5M, 12X18H10T and 10X17H13M2T. Flange stamping is performed in open and closed dies, depending on the diameter and weight of the workpieces.
The finished parts are descaled and tested for mechanical properties. If necessary, ultrasonic non-destructive testing or intercrystalline corrosion resistance test can be performed.
