A method for producing a motor vehicle component from a 6000 series aluminum alloy including providing a blank made of a 6000 series aluminum alloy, rapid heating of the blank to a temperature between 450 deg. C. and 600 deg. C. at a heating rate of more than 15 K/s in a period of less than 20 seconds, ending the heating process and optionally homogenizing, if a grain size between 20 and 50 μm has been produced, quenching the blank thus tempered, applying a lubricant, preferably at 20 deg. C. to 100 deg. C., forming the cooled blank in a forming tool, wherein the time between completion of the heating process and the start of the forming is less than 30 seconds, and aging.

A hot metal gas forming and quenching system and process thereof are provided. The system includes a hydraulic press, a die assembly, a rapid heating module, and a rapid cooling module. The die assembly includes a progressive die realizing the hot gas bulging and rapid cooling of the workpiece. Through the above system and the process, making pipes with uncoated plates has a lower cost than with coated and plated steel plates, with fewer structural defects and process risks. By using a progressive die, a resistance heating process and hot gas bulging and quenching processes are performed in parallel, and the material is loaded progressively, thereby having a fast pace and a greatly improved efficiency. A heating state of parts is fully protected, oxidation is avoided, and no coating is required. After the workpiece is formed, it can be directly welded to a car body without shot blasting.

A method for manufacturing a trunnion for a constant velocity joint, the trunnion having a plurality of journal units provided outside around a hub unit, the method including a first step of manufacturing the trunnion, a second step of thermally treating a rounded outer circumferential surface of the journal unit, and a third step of thermally treating a connection unit disposed between the journal unit and the hub unit and having a diameter smaller than that of the journal unit.

A continuous hot-dip galvanizing apparatus has a vertical annealing furnace, one or more hearth rolls, a hot-dip galvanizing apparatus, an alloying line, and humidified gas supply ports. When the steel sheet having a Si content of 0.2 mass % or more is conveyed inside the annealing furnace, the humidified gas supply ports positioned in a latter part of the soaking zone supply the humidified gas to the soaking zone and the at least one dry gas supply port supplies the dry gas to the soaking zone. When the steel sheet having a Si content of less than 0.2 mass % is conveyed inside the annealing furnace, the plurality of the humidified gas supply ports do not supply the humidified gas to the soaking zone and the at least one dry gas supply port supplies the dry gas to the soaking zone.

The invention relates to a method for producing a steel composite in which at least two steel sheets that consist of different steel grades are placed against each other, hot rolled together, and then possibly cold rolled and in which after the rolling, the composite material, which is thus produced from at least two layers with different steel compositions, is diffusion annealed, wherein the annealing temperature is set so as to select the chemical potential of the steel materials to correspond to the following equation:
μ.sub.C,material 1>μ.sub.C,material 2,
where material 1 has a lower carbon content than material 2 so that an uphill diffusion of carbon takes place between material 1 and material 2.

An heat treatment apparatus for a vehicle body component includes, a jig base, a lower fixed die fixedly installed on the jig base and supporting the vehicle body component that is press-molded into a predetermined shape, a heating unit installed on the lower fixed die and locally heating the vehicle body component, a plurality of side movable dies that can move reciprocally disposed at both sides of the lower fixed die, installed on the jig base, and selectively combinable with the lower fixed die, a cooling unit installed on each side movable die and cooling a heating portion of the vehicle body component, and an upper movable die that can move reciprocally in the up and down direction correspondingly to the lower fixed die, and configured to clamp the vehicle body component through the lower fixed die and at least one of the side movable dies combined together.

A method for hardening a metal component includes the steps: hating the metal component to a first temperature between 750° C. and 1100° C.; increasing the carbon content in the metal component by applying a carbon donor gas to the metal component at the first temperature; cooling the metal component to a second temperature which is by 40° C. to 100° C. lower than the first temperature; increasing the nitrogen content in the metal component by applying a nitrogen donor gas to the metal component at the second temperature; cooling the metal component to ambient temperature, wherein a sintered component is used as the metal component and, after increasing the nitrogen content in the sintered component and prior to cooling the sintered component to ambient temperature, the sintered component is heated to a third temperature which is by 50° C. to 250° C. higher than the second temperature.

The present disclosure relates to a novel iron-based austenitic alloy for a turbocharger housing and to methods of its preparation.

Provided is a method for producing a galvannealed steel sheet. When the steel sheet passing through the soaking zone is a type of steel containing 0.2 mass % or more of Si, both dry gas and humidified gas are supplied to the soaking zone, where the humidified gas is supplied only from the humidified gas supply port positioned in a latter part of the soaking zone among a plurality of humidified gas supply ports, where the latter part of the soaking zone is determined considering a sheet passing speed V and a target temperature T on the exit side of the soaking zone.

An apparatus for manufacturing a stress relieved length of steel having an oxidised surface layer includes: a heating chamber; a reaction chamber coupled to the heating chamber; and a conveying mechanism conveying the length of steel along a path through the heating chamber and reaction chamber. The heating chamber includes a heating apparatus arranged to heat the length of steel in a heating portion of the path. The apparatus further includes a control means including a sealed unit defined by the heating chamber and the reaction chamber and arranged to control both the temperature of the length of steel and the atmosphere to which the length of steel is exposed in an oxidisation portion of the path within the reaction chamber in which the oxidised surface layer is formed. A method of manufacturing a stress relieved length of steel having an oxidised surface layer is also disclosed.