A spiral timepiece spring with a two-phase structure, made of a niobium and titanium alloy, and method for manufacturing this spring, including producing a binary alloy containing niobium and titanium, with niobium: the remainder to 100%; titanium between 45.0% and 48.0% by mass of the total, traces of components among O, H, C, Fe, Ta, N, Ni, Si, Cu, Al, of between 0 and 1600 ppm by mass of the total individually, and less than 0.3% by mass combined; applying deformations alternated with heat treatments until a two-phase microstructure is obtained including a solid solution of niobium with -phase titanium and a solid solution of niobium with -phase titanium, the -phase titanium content being greater than 10% by volume, with an elastic limit higher than 1000 MPa, and a modulus of elasticity higher than 60 GPa and less than 80 GPa; wire drawing to obtain wire able to be calendered; calendering or winding.

A spiral timepiece spring with a two-phase structure, made of a niobium and titanium alloy, and method for manufacturing this spring, including producing a binary alloy containing niobium and titanium, with niobium: the remainder to 100%; titanium between 45.0% and 48.0% by mass of the total, traces of components among O, H, C, Fe, Ta, N, Ni, Si, Cu, Al, of between 0 and 1600 ppm by mass of the total individually, and less than 0.3% by mass combined; applying deformations alternated with heat treatments until a two-phase microstructure is obtained including a solid solution of niobium with -phase titanium and a solid solution of niobium with -phase titanium, the -phase titanium content being greater than 10% by volume, with an elastic limit higher than 1000 MPa, and a modulus of elasticity higher than 60 GPa and less than 80 GPa; wire drawing to obtain wire able to be calendered; calendering or winding.

A method for manufacturing a spring is disclosed that comprises: forming the spring from a material; heat treating the spring; performing a first machining step to the ends of the spring; subjecting the spring to a first stress relief heat treatment; performing a second machining step to the ends of the spring; and subjecting the spring to a second stress relief heat treatment step. A spring that is manufactured by this method is also described. This spring may then be used in a pressure relief valve, as well as in other assemblies.

A method for manufacturing a spring is disclosed that comprises: forming the spring from a material; heat treating the spring; performing a first machining step to the ends of the spring; subjecting the spring to a first stress relief heat treatment; performing a second machining step to the ends of the spring; and subjecting the spring to a second stress relief heat treatment step. A spring that is manufactured by this method is also described. This spring may then be used in a pressure relief valve, as well as in other assemblies.

An oil tempered wire includes a steel wire and a lubricant coating disposed around an outer circumference of the steel wire, wherein the lubricant coating includes a lubricant component resin and a binder resin, the lubricant component resin is at least one selected from polyacetals, polyimides, melamine resins, acrylic resins and fluororesins, the deposited mass of the lubricant coating is not less than 1.0 g/m2 and not more than 4.0 g/m2, and the surface roughness Rz of the steel wire is not more than 8.0 m.

An oil tempered wire includes a steel wire and a lubricant coating disposed around an outer circumference of the steel wire, wherein the lubricant coating includes a lubricant component resin and a binder resin, the lubricant component resin is at least one selected from polyacetals, polyimides, melamine resins, acrylic resins and fluororesins, the deposited mass of the lubricant coating is not less than 1.0 g/m2 and not more than 4.0 g/m2, and the surface roughness Rz of the steel wire is not more than 8.0 m.

There is disclosed a softening method for a high-strength Q & P steel hot-rolled coil, comprising: after heating a Q & P steel ingot, subjecting it to rough rolling, finish rolling, laminar cooling and coiling to obtain a hot-rolled coil; after unloading the coil, covering the coil on-line with an insulating enclosure and moving it into a steel coil warehouse along with a transport chain; after a specified period of insulating time, removing the coil from the insulating enclosure, and cooling it to room temperature in air, wherein the coiling is performed at a temperature of 400-600 C.; said covering on-line with an insulating enclosure means each hot-rolled coil is individually covered with an independent, closed insulating enclosure unit within 60 minutes after unloading; the insulating time of the steel coil in the insulating enclosure is 60 minutes. The inventive method replaces the intermediate annealing step in the production process of cold-rolled Q & P steel. The inventive method has low cost and high efficiency, and it is not affected by the surrounding environment.

There is disclosed a softening method for a high-strength Q & P steel hot-rolled coil, comprising: after heating a Q & P steel ingot, subjecting it to rough rolling, finish rolling, laminar cooling and coiling to obtain a hot-rolled coil; after unloading the coil, covering the coil on-line with an insulating enclosure and moving it into a steel coil warehouse along with a transport chain; after a specified period of insulating time, removing the coil from the insulating enclosure, and cooling it to room temperature in air, wherein the coiling is performed at a temperature of 400-600 C.; said covering on-line with an insulating enclosure means each hot-rolled coil is individually covered with an independent, closed insulating enclosure unit within 60 minutes after unloading; the insulating time of the steel coil in the insulating enclosure is 60 minutes. The inventive method replaces the intermediate annealing step in the production process of cold-rolled Q & P steel. The inventive method has low cost and high efficiency, and it is not affected by the surrounding environment.

A high strength spring containing, by mass %, C: 0.40 to 0.50%, Si: 1.00 to 3.00%, Mn: 0.30 to 1.20%, Ni: 0.05 to 0.50%, Cr: 0.35 to 1.50%, Mo: 0.03 to 0.50%, Cu: 0.05 to 0.50%, Al: 0.005 to 0.100%, V: 0.05 to 0.50%, Nb: 0.005 to 0.150%, N: 0.0100 to 0.0200%, P: limited to be less than or equal to 0.015%, S: limited to be less than or equal to 0.010%, and the balance of Fe and inevitable impurities, wherein a Nb-compound including at least one of Nb-carbide, Nb-nitride and Nb-carbonitride is included, and wherein a V-compound including at least one of V-carbide and V-carbonitride that is precipitated around the Nb-compound is included.

A high strength spring containing, by mass %, C: 0.40 to 0.50%, Si: 1.00 to 3.00%, Mn: 0.30 to 1.20%, Ni: 0.05 to 0.50%, Cr: 0.35 to 1.50%, Mo: 0.03 to 0.50%, Cu: 0.05 to 0.50%, Al: 0.005 to 0.100%, V: 0.05 to 0.50%, Nb: 0.005 to 0.150%, N: 0.0100 to 0.0200%, P: limited to be less than or equal to 0.015%, S: limited to be less than or equal to 0.010%, and the balance of Fe and inevitable impurities, wherein a Nb-compound including at least one of Nb-carbide, Nb-nitride and Nb-carbonitride is included, and wherein a V-compound including at least one of V-carbide and V-carbonitride that is precipitated around the Nb-compound is included.