Hot-dip galvanized dual-phase steel products now available up to a thickness of 2.5 millimeters in greater widths

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The hot-dip galvanizing line 2

The hot-dip galvanized dual-phase steels feature among the highlights of our product portfolio. High strength in connection with excellent formability are the hallmark of this material, enabling complex geometries, as required in reinforcing beams, for example. The body components impress with their high energy absorption in the event of an accident, thereby providing superior passenger protection. These product properties can also be used to reduce material thickness, thereby achieving optimal component weight.
Dual phase steels gain these desirable properties thanks to the two structural constituents ferrite and martensite that are set by way of a specific heating and cooling rate in the annealing furnace of the hot-dip galvanizing line (FV2).
There are only a few European steel manufacturers capable of producing the HCT600XD steel grade in thicknesses exceeding 2.00 mm and widths beyond 1610 mm. At Salzgitter Flachstahl to date, these dimensions were too wide for the horizontal hot-dip galvanizing line (FV1) and too thick for the vertical hot-dip galvanizing operations (FV2).
The desired larger cross section reduces process speed in connection with the identical maximum annealing capacity of the furnace. Consequently, the chemical composition had to be optimally adapted to the possible annealing conditions.
From the plant engineering standpoint the production of these demanded dimensions presented particular challenges. Extended settings of the directional aggregate as well as the welding machinery were tested and implemented in the run up phase. The drives and driving gear at the skin pass rolling mill were reinforced, in order to ensure stable running characteristics. Particular attention was focused on the shears at the outlet of the line, as these had been originally dimensioned for strip thicknesses of up to 2.00 mm.

The dimensional range of Salzgitter Flachstahl products now includes thicknesses of up to 2.5 mm with widths over 1610 mm, and is available to customers with immediate effect.