Disclosed is a continuous thermal treatment line for a steel strip. The strip passes through consecutive thermal treatment chambers, is quickly cooled in at least one of the chambers by spraying liquid onto the strip, or by spraying a fluid made up of gas and liquid or spraying a combination of gas and liquid forming a mist. After quick cooling, a protective metal layer is deposited on the strip by dip coating. The cooling fluid strips iron oxides or other alloy elements contained in the steel to be treated, minimizing oxidation and reducing the oxides on the strip. Spray pressure and distance are chosen to facilitate the stripping property and the mechanical action of the sprayed fluid, reducing the layer of oxides on the strip. The temperature of the strip at the end of the cooling step is the temperature necessary for carrying out the desired treatment cycle.

Systems and methods of quenching a metal substrate include cooling a top surface and a bottom surface of the metal substrate until a strip temperature is cooled to an intermediate temperature. Cooling of the top surface of the metal substrate is discontinued when the strip temperature reaches the intermediate temperature, and cooling of the bottom surface of the metal substrate continues until the metal substrate reaches a target temperature, where the target temperature is less than the intermediate temperature.

Provided is a steel comprising the following chemical composition in percentage by mass: 0.150-0.250% of C, 0.10-0.50% of Si, 0.60-1.50% of Mn, 0.30-1.20% of Cr, 0.20-0.80% of Mo, 2.00-4.00% of Ni, 0-0.10% of Nb, 0.0010-0.0050% of B, 0-0.12% of V, 0.003-0.06% of Ti, 0.01-0.08% of Al, the balance being Fe and unavoidable impurities. Also provided is a steel bar and a manufacturing method thereof. The steel bar is made from the above steel. The manufacturing method comprises the steps of smelting and casting, heating, forging or rolling, quenching, and tempering.

Methods for forming carbon-based lubricious and/or wear-protective films in situ on the surface of steel alloys are provided. The methods use chromium-containing steel alloys, molybdenum-containing steel alloys, and steel alloys that contain both copper and nickel. When such alloys are subjected to a rubbing motion in the presence of a hydrocarbon fluid, the chromium, molybdenum, copper, and nickel in the steel alloy catalyzes the formation of solid carbon-containing films that reduce the friction, wear, or both of the contacting surfaces.

Methods for forming carbon-based lubricious and/or wear-protective films in situ on the surface of steel alloys are provided. The methods use chromium-containing steel alloys, molybdenum-containing steel alloys, and steel alloys that contain both copper and nickel. When such alloys are subjected to a rubbing motion in the presence of a hydrocarbon fluid, the chromium, molybdenum, copper, and nickel in the steel alloy catalyzes the formation of solid carbon-containing films that reduce the friction, wear, or both of the contacting surfaces.

A system includes a vehicle and at least one rail dividing a field into an unprocessed material field and a processed material field. The vehicle is supported upon at least one rail and (a) at least one primary material-containing bay configured for receiving the quantity of unprocessed material, and (b) a secondary material-containing bay configured for receiving a portion of one or more of a first portion of processed material and a partially processed material from the at least one primary material containing bay. The vehicle is configured for movement upon the at least one rail for transporting one or more of the first portion of processed material and a partially processed material from the at least one primary material containing bay to the secondary material containing bay.

A system includes a vehicle and at least one rail dividing a field into an unprocessed material field and a processed material field. The vehicle is supported upon at least one rail and (a) at least one primary material-containing bay configured for receiving the quantity of unprocessed material, and (b) a secondary material-containing bay configured for receiving a portion of one or more of a first portion of processed material and a partially processed material from the at least one primary material containing bay. The vehicle is configured for movement upon the at least one rail for transporting one or more of the first portion of processed material and a partially processed material from the at least one primary material containing bay to the secondary material containing bay.

Disclosed are implementations for heat treatment of steel components. In one or more first regions of a steel component, a predominantly austenitic structure can be adjusted, from which, by way of quenching, a mainly martensitic structure is educible. In one or more second regions of the steel component, there is a mainly bainitic structure, wherein the metal component is initially heated in a first furnace to a temperature above the Ac3 temperature. Subsequently, the steel component is transferred into a treatment station, wherein the steel component can cool down during the transfer. In the treatment station, the one or more second regions of the steel component are cooled down to a cooling stop temperatures ϑ.sub.2 during a treatment period. Subsequently, said metal component is transferred to a second furnace, wherein the temperature of the one or more second regions increases again to a temperature below the Ac3 temperature.

The railway axle according to this disclosure has a pair of fitting portions and which each include a fitting portion hardened layer and a base metal portion, and a center parallel portion which includes a center parallel portion hardened layer and the base metal portion. The base metal portion has the chemical composition described in the description. In a region having the Vickers hardness of 480 HV or more in the center parallel portion hardened layer, a dislocation density p obtained based on a CoKα characteristic X-ray diffraction result is 2.5×10.sup.16 m.sup.−2 or less, a half-value width B of the (211) diffraction plane is 1.34 degrees or less, and the dislocation density p and the half-value width B of the (211) plane obtained by X-ray diffraction satisfy Formula (1).

(−4.8×10.sup.16×B+8.5×10.sup.16)/ρ≥1.00  (1)

Cooling section for a steel strip continuous annealing or galvanizing line arranged to handle a metal strip (1), said section comprising at least one area (2) for dry cooling set up to project gas on said steel strip and at least one wet cooling area (5) set up to project a liquid or a mixture of gas and liquid on said steel strip.