A method for producing a steel strip containing, in addition to iron as the main component and unavoidable impurities, one or more of the following oxygen-affine elements in wt. %: Al: more than 0.02, Cr: more than 0.1, Mn: more than 1.3 or Si: more than 0.1, where the surface of the steel strip is cleaned, oxidation-treated and annealed. The treated and annealed steel strip is subsequently coated with a hot-dip coat. In order to be less cost-intensive and to achieve uniform, reproducible adhesion conditions for the coat, the steel strip is oxidation-treated prior to the annealing at temperatures below 200° C., where on the surface of the steel strip, with the formation of oxides with iron from the steel strip, an oxide layer is formed, which contains iron oxide and is reduction-treated during the course of the annealing under a reducing atmosphere to achieve a surface consisting substantially of metallic iron.

The invention relates to a temperature-control device for partially cooling a component, wherein the component is blown on with a fluid in the region to be cooled by means of a nozzle. The nozzle comprises a connecting tube which is connected to a fluid reservoir in a fluid-conducting manner and which is connected to a plurality of nozzle tubes in a fluid-conducting manner.

Provided is an ultra-high-strength reinforcing bar and a method for manufacturing the same are disclosed. In an exemplary embodiment, the ultra-high-strength reinforcing bar includes an amount of 0.10 to 0.45 wt % carbon (C), an amount of 0.5 to 1.0 wt % silicon (Si), an amount of 0.40 to 1.80 wt % manganese (Mn), an amount of 0.10 to 1.0 wt % chromium (Cr), an amount greater than 0 and less than or equal to 0.2 wt % vanadium (V), an amount greater than 0 and less than or equal to 0.4 wt % copper (Cu), an amount greater than 0 and less than or equal to 0.5 wt % molybdenum (Mo), an amount of 0.015 to 0.070 wt % aluminum (Al), an amount greater than 0 and less than or equal to 0.25 wt % nickel (Ni), an amount greater than 0 and less than or equal to 0.1 wt % tin (Sn), an amount greater than 0 and less than or equal to 0.05 wt % phosphorus (P), an amount greater than 0 and less than or equal to 0.03 wt % sulfur (S), an amount of 0.005 to 0.02 wt % nitrogen (N), and the remainder being iron (Fe) and other inevitable impurities.

A valve spring which has an excellent fatigue limit is provided. A chemical composition of the valve spring according to the present embodiment contains, in mass %, C: 0.50 to 0.80%, Si: 1.20 to less than 2.50%, Mn: 0.25 to 1.00%, P: 0.020% or less. S: 0.020% or less: Cr: 0.40 to 1.90%, V: 0.05 to 0.60%, Ca: 0.0001 to 0.0050%, and N: 0.0100% or less, with the balance being Fe and impurities. In the valve spring, a number density of V-based precipitates having a maximum diameter ranging from 2 to 10 nm is 5000 to 80000 pieces/μm.sup.3, and a numerical proportion of Ca sulfides with respect to a total number of oxide-based inclusions and sulfide-based inclusions is 0.20% or less.

A steel wire which has excellent cold coiling workability, and which has an excellent fatigue limit when made into a spring is provided. A chemical composition of the steel wire according to the present, embodiment containing, in mass %, C: 0.50 to 0.80%, Si: 1.20 to less than 2.50%, Mn: 0.25 to 1.00%, P: 0.020% or less, S: 0.020% or less, Cr: 0.40 to 1.90%, V: 0.05 to 0.60%, and N: 0.0100% or less, with the balance being Fe and impurities. In the steel wire, a number density of V-based precipitates having a maximum diameter ranging from 2 to 10 nm is 5000 to 80000 pieces/μm.sup.3.

A damper spring which has an excellent fatigue limit is provided. A chemical composition of the damper spring according to the present embodiment contains in mass %, C: 0.50 to 0.80%, Si: 1.20 to less than 2.50%, Mn: 0.25 to 1.00%, P: 0.020% or less, S: 0.020% or less, Cr: 0.40 to 1.90%, V: 0.05 to 0.60%, and N: 0.0100% or less, with the balance being Fe and impurities. In the damper spring, a number density of V-based precipitates having a maximum diameter ranging from 2 to 10 nm is 5000 to 80000 pieces/m3.

Cooling device (1) for cooling a wire (100), comprising a first chamber (2) and a second cooling chamber (4) through which the wire (100) passes. The device also comprises cooling liquid driving means (16) for driving the cooling liquid from the first chamber (2) to the second chamber (4) through at least one coding liquid inlet (12). Through the driving means (16) and the cooling liquid inlet (12), a jet of coding liquid is projected on the wire path at a mean speed of at least 0.6 m/s, and at a distance between 6 and 13 times the diameter of the wire (100). Cooling is performed in an inert gas atmosphere inside the second chamber (4). The invention also relates to a corresponding installation and a corresponding wire cooling method.

The present disclosure relates to a steel wire rod enabling the omission of softening heat treatment and a method of manufacturing same. An embodiment of the present disclosure provides a steel wire rod enabling the omission of softening heat treatment and a method of manufacturing same, the steel wire rod comprising, in weight %, 0.2-0.45% of C, 0.02-0.4% of Si, 0.3-1.5% of Mn, 0.01-1.5% of Cr, 0.02-0.05% of Al, 0.01-0.5% of Mo, 0.01% or less of N, and the balance Fe and other unavoidable impurities, wherein the microstructure of the steel wire rod is a composite structure of proeutectoid ferrite+perlite as a main phase; the steel wire rod contains 10 area % or less (including 0%) of at least one of bainite or martensite; and the average colony size of the perlite is 5 μm or less.

A manufacturing process of a high-strength aluminum alloy wire/strip includes the following steps: A. subjecting an alloy to smelting and spray forming to obtain a high-strength Al—Zn—Mg—Cu aluminum alloy blank; B. subjecting the blank to semi-solid upset forging to form an ingot; C. subjecting the ingot to hot extrusion and then to vacuum annealing to form a coiled material; D. subjecting the coiled material to hot continuous rolling to obtain a wire blank; and E. subjecting the wire blank to solution heat treatment, multiple stretching treatments, annealing, and multiple continuous stretching treatments to obtain the high-strength aluminum alloy wire/strip. The high-strength aluminum alloy wire/strip has the characteristics of fine and compact grains, uniform structure, clear grain boundaries, no precipitates, and no layered structure affecting the stretching performance.

A process for manufacturing compact coils of ultra-fine grained, martensite-free steel bars, the process comprising the following stages:

a) rolling a steel billet by means of a roughing rolling mill producing a steel bar;

b) performing at least one first cooling stage so that the steel bar has a surface temperature higher than the martensite start temperature, and performing at least one first equalization stage in air;

c) rolling the steel bar by means of at least one intermediate rolling mill;

d) performing at least one second cooling stage always maintaining the surface temperature higher than the martensite start temperature, and performing at least one second equalization stage in air;

e) rolling the steel bar by means of a finishing rolling mill in a non-recrystallization temperature range, maintaining the whole cross-section of the steel bar within said non-recrystallization temperature range, and with a total reduction between 25 and 50% with respect to the cross-section of the steel bar at the entry of the finishing rolling mill, in order to obtain an ultra-fine-grained austenitic matrix;

f) winding the steel bar in a compact coil, by means at least one spooling device, so that the ultra-fine-grained austenitic matrix transforms in a mixture of ferrite and pearlite.

After the winding operation is completed, the compact coil can be transferred to a storage area through a transferring device, for example a walking beam, where a natural or forced or retarded cooling is applied to the coil.