AcaSal®700 StronSal: Hot-rolled high-strength TM steel with hot-dipped zinc coating

01.03.2017 | Salzgitter Flachstahl GmbH

The development of AcaSal regarding an increased corrosion protection was achieved by the combination of AcaSal®700 and StronSal®. This formed an optimized product of AcaSal®700.

The steel grade AcaSal®700 with StronSal® is a high-strength steel based on thermomechanically rolled strip with a hot-dip zinc-magnesium coating. It features a very high yield strength and tensile strength, with sufficiently high expansion for cold forming processes. These products are suitable for cold bending, folding, cold flanging or cold bordering without crack formation.

Photo of the acacia
The Acacia

The new brand from Salzgitter Flachstahl is named after the acacia, whose wood displays enormous resistance. The wood is furthermore not only hard and robust, it is also very elastic and very suitable for processing. AcaSal®, the new steel from Salzgitter Flachstahl, also offers these characteristics.

The characteristic of StronSal® (+ZM) lies in the significantly improved corrosion resistance thanks to the addition of magnesium and aluminium. Compared to normal zinc coatings, this special coating provides better processing properties and a lower abrasion during processing. The coating consists of a zinc alloy with contingents of magnesium and aluminium from 1 to 2 mass percentage. The rest contains of zinc (see picture 2).

Schematic structure of zinc coating
Picture 1: Schematic structure of zinc coating
Schematic structure of zinc-magnesium coating
Picture 2: Schematic structure of zinc-magnesium coating

Salzgitter Flachstahl is currently manufacturing AcaSal®700 in thicknesses from 2.0 to 2.5 mm and in widths from 900 to 1300 mm. The thickness of the zinc coating is in the range of 100 g/m² to 275 g/m².

The AcaSal®700 microstructure typically consists of bainite. Occasionally there can be minimum content of other phases (e.g., martensite, ferrite) (Figure 3 and 4).

Microstructure after hot-dip zinc coating
Picture 3: Microstructure after hot-dip zinc coating: Bainite with slight martensite content
Laser joint microstructure
Picture 4: Laser joint microstructure: Completely welded through

Typical applications to utilize the high strength potential combined with weight savings in the component are vehicle construction, longitudinal beams and cross-members in trucks and trailers, safety parts in cars (crash tubes), and rail car construction.

Delivery is based on the provisions of DIN EN 10149-2 in combination with the DIN EN 10051 dimensioning standard (hot-rolled strip basis). Test unit for hot-rolled material is the coil. We generally promise  50 % of table 4 of DIN EN 10051. Tighter thickness tolerances and special agreements are available on request.

Your customer representatives from Sales and Technical Customer Services are available to answer any questions you may have.