METHOD OF SPRINGS RECOVERY Russian patent published in 2010 - IPC B21F35/00 

FIELD: process engineering.

SUBSTANCE: invention relates to plastic metal working and can be used for recovery of springs at diverse enterprises. Proposed method comprises expansion, heating to (400…600)C°, and cooling in expanded state and tempering. It differs from known method in that the spring is expanded with the pitch exceeding that of finished spring. Then it is thermally treated and shot-blast hardened, or thermally cambered. Now, spring coils are plastically hardened by compressing it at axial load of (10÷300)F₃, where F₃ is spring force at maximum strain.

EFFECT: higher efficiency and quality.

4 cl