A spring steel having a superior fatigue life, and a manufacturing method for the same. The chemical components thereof are as follows in weight percentage: C: 0.52-0.62%, Si: 1.20-1.45%, Mn: 0.25-0.75%, Cr: 0.30-0.80%, V: 0.01-0.15%, Nb: 0.001-0.05%, N: 0.001-0.009%, O: 0.0005-0.0040%, P: ≤0.015%, S: ≤0.015%, and Al: ≤0.0045%, with the remainder being Fe and incidental impurities, wherein the following condition is also met 0.02≤(2Nb+V)/(20N+C)≤0.40. The spring steel of the present invention has a microstructure of tempered troostite+tempered sorbite, a prior austenite grain size less than 80 um, a size of alloy nitride and carbide precipitates being 5-60 nm, and a maximum width of single-grain inclusions being less than 30 pm. The spring steel has a handling strength greater than 2020 MPa, superior ductility and toughness (the reduction of area≥40%), and a fatigue life≥800,000 times, thereby meeting application requirements of high-stress springs in industries, such as automobiles, machinery, and the like.

Disclosed are a wire rod and a manufacturing method therefor. The wire rod comprises in percentage by weight: 0.02 to 0.15% of C; 0.05 to 0.3% of Si; 0.5 to 1.2% of Mn; 0.3 to 0.9% of Cr; 0.02% or less of P; 0.02% or less of S; 0.01 to 0.05% of sol. Al; 0.01% or less of N; Fe as the remainder; and unavoidable impurities, wherein the wire rod satisfies following formulas 1 and 2, wherein, when the hardness of the wire rod measured in 1/2d position and in 1/4d position in the diameter direction of the wire rod is Hv,.sub.1/2d(Hv) and Hv,.sub.1/4d(Hv), respectively (here, d is the diameter of the wire).
(Hv,.sub.1/2d+Hv,.sub.1/4d)/2≤150  [Formula 1]
Hv,.sub.1/2d/Hv,.sub.1/4d≤1.2  [Formula 2]

An embodiment of the present invention provides a wire rod and a steel wire which are for springs and have excellent corrosion fatigue resistance properties, and a method for producing same, the wire rod and steel wire containing, in wt %, 0.40-0.70% of C, 1.20-2.30% of Si, 0.20-0.80% of Mn, 0.20-0.80% of Cr, 0.015% or less of P, 0.015% or less of S, and 0.010% or less of N, with the remainder comprising Fe and other unavoidable impurities, along with at least one among 0.01-0.20% of V and 0.01-0.10% of Nb, wherein the V and Nb satisfy relational expression 1 below, the average grain size of prior austenite is no greater than 20 m, and the surface decarburization depth is no greater than 0.1 mm. [Relational expression 1] [V]+[Nb]0.08 (where the V and Nb contents are in wt %)

The present disclosure relates to an alloy wire rod and a preparation method and application thereof. The alloy wire rod is made of a tungsten alloy, and the tungsten alloy contains tungsten and an oxide of cerium. The alloy wire rod has a wire diameter of equal to or less than 100 m; and the alloy wire rod has a tensile strength of greater than 3,800 MPa. The wire diameter of the alloy wire rod is equal to or less than 60 m; the diameter of a push-pull core wire of the alloy wire rod is less than 350 m; the elastic ultimate strength of the alloy wire rod is greater than 2,500 MPa; and the tensile strength of the alloy wire is greater than 4,200 MPa. In the present disclosure, the alloy wire rod having ultra-high strength and good toughness is obtained by doping an oxide of cerium.

The present disclosure relates to a martensitic stainless steel suitable for rock drill steel rods. Furthermore, the present disclosure also relates to the use of the martensitic stainless steel and to products manufactured thereof, especially drill rods.

An inline thermal treatment system for thermally treating a continuous product includes a housing comprising a first opening and second opening respectively configured to allow the continuous product to enter and to exit the housing. The system includes at least one laser coupled to a laser power source and configured to output at least one laser beam that impinges upon and heats the portion of the continuous product.

There is provided a steel cord including a steel wire and a plating layer that covers the steel wire and has Cu, Zn, and Co, wherein Cu and Zn are alloyed and a region covered with Co and a region not covered with Co are mixed on the outermost surface of the plating layer.

A Fe-based shape memory alloy material, containing 25 atom % to 42 atom % of Mn, 9 atom % to 13 atom % of Al, 5 atom % to 12 atom % of Ni, and 5.1 atom % to 15 atom % of Cr, with the balance being Fe and unavoidable impurities; a method of producing the same; and a wire material and sheet material composed of the alloy material.

A wire rod for a 5000 MPa-grade diamond wire and a production method are provided. The wire rod includes the following chemical components: 1.01% to 1.1% of carbon, 0.15% to 0.4% of silicon, 0.3% to 0.6% of manganese, 0.01% to 0.4% of chromium, 0.0005% to 0.002% of boron and/or 0.01% to 0.09% of vanadium; and the balance of iron and impurities. The production method includes vacuum melting, electroslag remelting and/or vacuum consumable melting, grinding after cogging/forging, high-speed wire rolling and cooling, and cogging at 1030 C. to 1060 C. The wire rod, with structural uniformity and tensile strength of more than or equal to 1320 MPa, can be configured to prepare 5000 MPa-grade steel wires with a diameter of 40 m to 46 m.

Method of producing a cold drawn wire from a particle metallurgy steel includes the following steps:-preparation of a bulk of molten metal including in weight %: C 0.03-0.15, Si 0.01-1.2, Mn 0.1-1.5, Cr 15-20, Ni 540, Al 0.5-1.5, optionally max 2 of elements chosen from the group of N, P, S, Cu, Co, W, Mo, Nb, Ti, Zr, Ta, B, Be, Bi, Se, Mg, Ca, Hf, V, and REM, and, using electro slag refining and atomising to provide a metal powder; filling and sealing a capsule with the metal powder; compacting the capsule to provide a full density billet; hot working the billet and finishing by wire rolling; cold drawing the annealed wire with at least 30% area reduction.