The invention provides a production method for stabilizers which produces with high productivity in a compact production line, without tempering. The production method for stabilizers of the invention includes: forming a steel bar material containing at least C: 0.15 wt % to 0.39 wt %, Mn, B and Fe into a product shape by bending; and quenching the bent steel bar material in a medium having a heat transfer coefficient higher than or close to that of water.

A steel wire for high-strength bolts is used for a non heat-treatment bolt with an excellent cold forgeability for which quenching and tempering steps have been omitted after bolt formation, and which has a tensile strength of 1200 MPa or more and an excellent delayed fracture resistance. The steel wire includes C, Si, Mn, P, S, Cr, Al, N, and B, at least one selected from the group consisting of Ti, V, and Nb with the balance consisting of iron and inevitable impurities. The steel wire has a microstructure wherein ferrite and perlite have a total area rate of 98% or more, perlite lamellar spacing is 250 nm or less, and an area rate of the perlite is more than 40%, and 80% or less. The steel wire has a tensile strength of 1300 MPa or less.

A canted coil spring includes a core wire 10 formed of steel having a pearlite structure; and a copper plating layer 20 formed of copper or a copper alloy and covering an outer circumferential surface 11 of the core wire 10. The steel contains 0.5 mass % or more and 1.0 mass % or less carbon, 0.1 mass % or more and 2.5 mass % or less silicon, and 0.3 mass % or more and 0.9 mass % or less manganese, with the balance being iron and inevitable impurities. The copper plating layer 20 has a crystallite size of 220±50 Å.

A steel reinforcing bar contains 0.06 wt % to 0.11 wt % carbon, more than 0 and not more than 0.25 wt % silicon, 0.8 wt % or more and less than 2.0 wt % manganese, more than 0 and not more than 0.01 wt % phosphorus, more than 0 and not more than 0.01 wt % sulfur, 0.01 to 0.03 wt % aluminum, 0.50 to 1.00 wt % nickel, 0.027 to 0.125 wt % molybdenum, more than 0 and not more than 0.25 wt % chromium, more than 0 and not more than 0.28 wt % copper, more than 0 and not more than 0.01 wt % nitrogen, and the remainder being iron and unavoidable impurities. The reinforcing bar has a surface layer and a core. The surface layer has a hardened layer of tempered martensite, and the core has a mixed structure of bainite, ferrite and pearlite.

A process for smelting steel for ultrafine carborundum sawing wires, comprising: 1) in a vacuum induction furnace, using pure iron and low-phosphorus pig iron as raw materials to be melted into molten steel under the protection of argon; vacuumizing and smelting, and degassing; using silicon iron as a deoxidizer to adjust components of the molten steel; and casting a circular ingot in vacuum; 2) cleaning the surface of the circular ingot to produce an electrode bar; 3) remelting and smelting the electrode bar as raw material to a cylindrical electroslag ingot in an electroslag furnace, wherein the electroslag protecting slag comprises: CaF.sub.2: 45-55%, Al.sub.2O.sub.3: 15-25%, SiO.sub.2: 20-25%, Na.sub.2O: 2-4%, and K.sub.2O: 1-2%; 4) forging the electroslag ingot to a square billet; and 5) rolling the forged billet to a steel wire rod, and the steel wire rod comprising [C]: 0.92-1.1%, [Si]: 0.3-0.4%, [Mn]: 0.5-0.8%, [Al]<0.0008%, [N]<0.005%, [S]<0.01%, and [P]<0.015%.

In a rolled steel bar or rolled wire rod for a cold-forged component having a predetermined chemical composition, Y1 represented by Y1=[Mn]×[Cr] and Y2 represented by Y2=0.134×(D/25.4−(0.50×√[C]))/(0.50×√[C]) satisfy Y1>Y2, the tensile strength is 750 MPa or less, an internal structure is a ferrite-pearlite structure, and the ferrite fraction in the internal structure is 40% or greater.

AMOUNT IS 0.30%

In a rolled steel bar or rolled wire rod for a cold-forged component having a predetermined chemical composition, Y1 represented by Y1=[Mn]×[Cr] and Y2 represented by Y2=0.134×(D/25.4−(0.50×√[C]))/(0.50×√[C]) satisfy Y1>Y2, the tensile strength is 750 MPa or less, an internal structure is a ferrite-pearlite structure, and the ferrite fraction in the internal structure is 40% or greater.

AMOUNT IS 0.30%

Provided is a wire rod having enhanced strength and impact toughness. The wire rod includes, by wt %, carbon (C): 0.05% to 0.15%, silicon (Si): 0.2% or less, manganese (Mn): more than 3.5% to 5.0% or less, chromium (Cr): 0.5% to 2.0%, phosphorus (P): 0.020% or less, sulfur (S):0.020% or less, aluminum (Al): 0.010% to 0.050%, iron (Fe) as a residual component, and inevitable impurities. The microstructure of the wire rod includes martensite in an area fraction of 95% or more, and retained austenite (y) as a residual component.

Provided is a wire rod having enhanced strength and impact toughness. The wire rod includes, by wt %, carbon (C): 0.05% to 0.15%, silicon (Si): 0.2% or less, manganese (Mn): more than 3.5% to 5.0% or less, chromium (Cr): 0.5% to 2.0%, phosphorus (P): 0.020% or less, sulfur (S):0.020% or less, aluminum (Al): 0.010% to 0.050%, iron (Fe) as a residual component, and inevitable impurities. The microstructure of the wire rod includes martensite in an area fraction of 95% or more, and retained austenite (y) as a residual component.

The invention relates to a duplex stainless steel having austenitic-ferritic microstructure of 35-65% by volume, preferably 40-60% by volume of ferrite and having good weldability, good corrosion resistance and good hot workability. The steel contains 0.005-0.04% by weight carbon, 0.2-0.7% by weight silicon, 2.5-5% by weight manganese, 23-27% by weight chromium, 2.5-5% by weight nickel, 0.5-2.5% by weight molybdenum, 0.2-0.35% by weight nitrogen, 0.1-1.0% by weight copper, optionally less than 1% by weight tungsten, less than 0.0030% by weight one or more elements of the group containing boron and calcium, less than 0.1% by weight cerium, less than 0.04% by weight aluminium, less than 0.010% by weight sulphur and the rest iron with incidental impurities.