METHOD TO MANUFACTURE MULTILAYER BELLOWS FROM STAINLESS STEEL 12H18N10T Russian patent published in 2011 - IPC B21D15/00 

FIELD: technological processes.

SUBSTANCE: invention relates to metal plastic working and particularly to technology of manufacturing multilayer bellows from stainless steel 12H18N10T. Pipe billets are made of sheets with specified dimensions by a method of electric arc welding in medium of protective gases. The specified billets are assembled into a multilayer packet, which is welded at ends and is thermally treated in a protected medium, and then corrugated. Prior to corrugation the multilayer packet is heated inside and outside to the temperature that provides for preventing generation of deformational γ-α transformation. Thermal treatment of the multilayer packet is carried out at the temperature of 1080-1100°C with soaking at this temperature for 10-12 min, then this multilayer packet is cooled together with the oven to the temperature of 900°C. At the same time from 900°C to 500°C it is cooled by means of blowing with an inert argon gas with a speed of 15°C per minute.

EFFECT: improved efficiency of the method.

3 cl, 1 ex