METHOD OF MANUFACTURE OF CYLINDRICAL SPRINGS FROM AUSTENITIC STEEL Russian patent published in 2007 - IPC C21D9/02 C21D6/00 

FIELD: metallurgy; manufacture of cylindrical springs from austenitic steel.

SUBSTANCE: cylindrical spring is manufactured from cold-hardened wire made from austenitic steel at preset diameter, ultimate strength and limit of plasticity. Wire is wound on mandrel at pitch equal to diameter of wire at definite force of tension; wire is fixed in stressed state; after fixing, it is heated to temperature below steel recovery temperature and is subjected to isothermal holding at heat; then, spring is released at room temperature. Diameter of mandrel is found from the following relationship: (D-d)/d·100=ad+b, where D is required inner diameter of spring, mm; d is diameter of mandrel, mm; a(mm^-1) and b are parameters depending on temperature, isothermal holding time, stresses at winding the wire on mandrel and wire diameter. Manufacture of springs of required size and form from low-plasticity steel at retained mechanical properties of wire is possible due to use of stress relaxation effect.

EFFECT: possibility of making springs at preset geometric sizes and mechanical properties.

2 cl, 1 ex