The controlled cooling of previously heated and substantially straight steel wires of diameter more than 3.5 mm to a predetermined temperature including the steps: guiding the wires along individual paths through first coolant bath having bath liquid of water and a stabilizing additive, the bath liquid and the wires create a steam film around each wire along individual paths; directing an impinging liquid immersed inside first coolant bath towards the wires over a length along individual paths to cool down the wires, the impinging liquid decreases the thickness of the steam film or destabilizes the steam film, increasing speed of cooling over the length along individual paths; guiding the wires along individual paths out of the first coolant bath to be cooled down in air; after the further cooling, guiding the wires along individual paths through second coolant bath.

Iron-based alloys and articles in strips, sheets, workpieces and the like are converted into high strength steel with a minimum of cost, time and effort, including producing dual phase materials. This is achievable by extremely rapid micro-treating of low, medium, and high carbon iron-based alloys and articles by rapid heating and rapid cooling at least a portion of the alloy/article. This heating step involves nearly immediately heating the iron-based alloy to a selected temperature above its austenite conversion temperature. Then, the alloy is immediately quenched, also at an extremely fast rate, on at least a portion of the iron-based alloy in a quenching unit adjacent the heating unit. This procedure forms high strength alloy in a desired area, depending upon where the treatment was performed.

Iron-based alloys and articles in strips, sheets, workpieces and the like are converted into high strength steel with a minimum of cost, time and effort, including producing dual phase materials. This is achievable by extremely rapid micro-treating of low, medium, and high carbon iron-based alloys and articles by rapid heating and rapid cooling at least a portion of the alloy/article. This heating step involves nearly immediately heating the iron-based alloy to a selected temperature above its austenite conversion temperature. Then, the alloy is immediately quenched, also at an extremely fast rate, on at least a portion of the iron-based alloy in a quenching unit adjacent the heating unit. This procedure forms high strength alloy in a desired area, depending upon where the treatment was performed.

A batch furnace for annealing material, in particular a single chamber furnace or single coil furnace, with a furnace housing. The batch furnace has a closable charging opening, a receiving chamber for receiving furnace material, and a device for convective heat transfer onto the furnace material by a heat transfer medium. The batch furnace includes at least one fan, which is arranged in the furnace housing, at least one heating device for the heat transfer medium and/or at least one inlet for an externally heated heat transfer medium, wherein the heating device and/or the inlet is arranged directly in front of the intake side or directly behind the pressure side of the fan or circumferentially in an annular gap between the fan and the furnace housing, and a receiving chamber for the furnace material, which is arranged on the pressure side of the fan.

A batch furnace for annealing material, in particular a single chamber furnace or single coil furnace, with a furnace housing. The batch furnace has a closable charging opening, a receiving chamber for receiving furnace material, and a device for convective heat transfer onto the furnace material by a heat transfer medium. The batch furnace includes at least one fan, which is arranged in the furnace housing, at least one heating device for the heat transfer medium and/or at least one inlet for an externally heated heat transfer medium, wherein the heating device and/or the inlet is arranged directly in front of the intake side or directly behind the pressure side of the fan or circumferentially in an annular gap between the fan and the furnace housing, and a receiving chamber for the furnace material, which is arranged on the pressure side of the fan.

An equipment for the continuous hot dip-coating of a metal strip including an annealing furnace, a tank containing a liquid metal bath, a snout connecting the annealing furnace and the tank, through which the metal strip runs in a protective atmosphere and the lower part of the snout, the snout tip, is at least partly immersed in the liquid metal bath in order to define with the surface of the bath, and inside this snout, a liquid seal and a separate overflow attached/hold to the snout through fixings, the overflow including at least one tray, placed in the vicinity of the strip when entering the liquid metal bath and encompassed by the liquid seal.

An equipment for the continuous hot dip-coating of a metal strip including an annealing furnace, a tank containing a liquid metal bath, a snout connecting the annealing furnace and the tank, through which the metal strip runs in a protective atmosphere and the lower part of the snout, the snout tip, is at least partly immersed in the liquid metal bath in order to define with the surface of the bath, and inside this snout, a liquid seal and a separate overflow attached/hold to the snout through fixings, the overflow including at least one tray, placed in the vicinity of the strip when entering the liquid metal bath and encompassed by the liquid seal.

Iron-based alloys and articles in strips, sheets, workpieces and the like are converted into high strength steel with a minimum of cost, time and effort, including producing dual phase materials. This is achievable by extremely rapid micro-treating of low, medium, and high carbon iron-based alloys and articles by rapid heating and rapid cooling at least a portion of the alloy/article. This heating step involves nearly immediately heating the iron-based alloy to a selected temperature above its austenite conversion temperature. Then, the alloy is immediately quenched, also at an extremely fast rate, on at least a portion of the iron-based alloy in a quenching unit adjacent the heating unit. This procedure forms high strength alloy in a desired area, depending upon where the treatment was performed.

Iron-based alloys and articles in strips, sheets, workpieces and the like are converted into high strength steel with a minimum of cost, time and effort, including producing dual phase materials. This is achievable by extremely rapid micro-treating of low, medium, and high carbon iron-based alloys and articles by rapid heating and rapid cooling at least a portion of the alloy/article. This heating step involves nearly immediately heating the iron-based alloy to a selected temperature above its austenite conversion temperature. Then, the alloy is immediately quenched, also at an extremely fast rate, on at least a portion of the iron-based alloy in a quenching unit adjacent the heating unit. This procedure forms high strength alloy in a desired area, depending upon where the treatment was performed.

A bolt of the present invention has a composition comprising: 0.50 mass % or greater and 0.65 mass % or less of carbon (C), 1.5 mass % or greater and 2.5 mass % or less of silicon (Si), 1.0 mass % or greater and 2.0 mass % or less of chromium (Cr), 0.2 mass % or greater and 1.0 mass % or less of manganese (Mn), 1.5 mass % or greater and 5.0 mass % or less of molybdenum (Mo), wherein a total amount of phosphorous (P) and sulfur (S) as impurities is 0.03 mass % or less, the remaining is iron (Fe), and the bolt comprises an iron based oxide film with a film thickness of 3 m or greater and 20 m or less on the surface thereof. The bolt has excellent delayed fracture resistance and reliably provides a fastening axial force.