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 device and a method for continuous temperature gradient heat treatment of a rod-shaped material are disclosed. The furnace body of the device includes an upper heating zone and a lower heating zone inside, which are independently controlled in temperature by means of an upper heating power supply and a lower heating power supply. Moreover, both the upper heating zone and the lower heating zone are closed heating zones. The closed heat insulation plates could prevent heat loss and ensure precise temperature control of the upper heating zone and the lower heating zone. In the device, a vacuum pumping equipment is included; an annular radiation screen is configured between the upper heating zone and the lower heating zone, and the rod-shaped material is not in contact with the annular radiation screen. The rod-shaped material conducts one-dimensional heat transfer along the axial direction.

This hot-rolled wire rod includes, as a chemical composition, by mass %: C: 0.90% to 1.10%; Si: 0.50% to 0.80%; Mn: 0.10% to 0.70%; Cr: 0.10% to 0.40%; P: 0.020% or less; S: 0.015% or less; N: 0.0060% or less; O: 0.0040% or less; and a remainder consisting of Fe and impurities, in which Formulas (1) and (2) are satisfied by mass %, the structure of the hot-rolled wire rod consists of pearlite in an area ratio of 95.0% or more and a remainder, and TS, which is a tensile strength in unit of MPa, and TS*, which is determined from the C content, the Si content, and the Cr content, satisfy Formula (3),

0.50≤[Si]+[Cr]≤0.90  (1)

0.40≤[Cr]+[Mn]≤0.80  (2)

−50<TS−TS*<50  (3) where the TS* is calculated by Formula (3′),

TS*=1000×[C]+100×[Si]+125×[Cr]+150  (3′).

A predetermined composition is had, when a C content is represented by (C %), in a case of (C %) being not less than 0.35% nor more than 0.65%, a volume fraction of pearlite is 64×(C %)+52% or more, and in a case of (C %) being greater than 0.65% and 0.85% or less, the volume fraction of pearlite is not less than 94% nor more than 100%, and a structure of the other portion is composed of one or two of proeutectoid ferrite and bainite. Further, in a region to a depth of 1.0 mm from a surface, a volume fraction of pearlite block having an aspect ratio of 2.0 or more is not less than 70% nor more than 95%, and a volume fraction of pearlite having an angle between an axial direction and a lamellar direction on a cross section parallel to the axial direction of 40° or less is 60% or more with respect to all pearlite.

Disclosed is a method for manufacturing high-carbon bearing steel, which include: heating a billet at a temperature of about 950 to 1,050° C. for about 70 to 120 minutes, rolling the billet to manufacture a wire rod, winding the wire rod to manufacture a wire rod coil, cooling the wire rod coil, and subsequently heat treating the wire rod coil for spheroidizing and carbonitriding, respectively. The bearing steel may include an amount of about 0.9 to 1.3 wt % of carbon (C), an amount of about 1.1 to 1.6 wt % of silicon (Si), an amount of about 1.0 to 1.5 wt % of manganese (Mn), an amount of about 1.5 to 1.9 wt % of chromium (Cr), an amount of about 0.2 to 0.6 wt % of nickel (Ni), an amount of about 0.1 to 0.3 wt % of molybdenum (Mo), and the balance iron (Fe) based on the total weight thereof.

A method for producing a feedstock wire is produced from a first metal strip and at least one further metal strip by roll forming, wherein in particular the first metal strip and the at least one further metal strip are made of differing metals, preferably of differing meals having differing yield points, wherein a jacket, which in the final shape completely surrounds the at least one further metal strip in the circumferential direction, is formed from the first metal strip in a plurality of passes by roll forming using a plurality of roll stands, and wherein, first, exclusively only the first metal strip is formed to a preliminary shape in a plurality of passes using a first group of roll stands and, thereafter, the first metal strip and the at least one further metal strip are jointly formed to the final shape in a second group of roll stands.

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.

An aluminum alloy having a composition including 0.1% by mass or more and 2.8% by mass or less of Fe; and 0.002% by mass or more and 2% by mass or less of Nd.

A spring steel wire includes a main body made of a steel and having a line shape, and an oxidized layer covering an outer peripheral surface of the main body. The steel constituting the main body contains not less than 0.5 mass % and not more than 0.7 mass % C, not less than 1 mass % and not more than 2.5 mass % Si, not less than 0.2 mass % and not more than 1 mass % Mn, and not less than 0.5 mass % and not more than 2 mass % Cr, with the balance being Fe and unavoidable impurities. The steel constituting the main body has a pearlite structure. The oxidized layer has a thickness of not less than 2 μm and not more than 5 μm. The oxidized layer contains not less than 60 mass % Fe.sub.3O.sub.4.

Disclosed is an iron-manganese alloy including, by weight: 25.0%≤Mn≤32.0%; 7.0%≤Cr≤14.0%; 0≤Ni≤2.5%; 0.05%≤N≤0.30%; 0.1≤Si≤0.5%; and optionally 0.010%≤rare earths≤0.14%. The remainder being iron and residual elements resulting from manufacturing.