Cold-rolled Multiphase Steel according to DIN EN 10338 and 10346
Cold-rolled multiphase steel is also part of our product portfolio. This area includes DP, TRIP, CP, and MP steels. With certain applications, these steels can achieve weight reduction. The steel grades are sorted according to increasing tensile strength values.
DP Steel “X”
Dual-phase steel has a structure of a ferritic matrix with embedded martensitic or bainitic phases. Forming gives the DP steel an excellent work hardening capacity. This property not only ensures homogeneous forming and excellent deep-drawing ability but also significantly higher values on the finished component than on the starting sheet. This applies in particular to the yield strength.
TRIP Steel “T”
TRIP steels, also known as RA steels (retained austenite), differ due to their microstructure by a very advantageous combination of strength and ductility from other steels. This steel is particularly well suited for the production of structural components. The structure consists of a ferritic matrix with island-shaped embedded hard bainite phases and retained austenite. The transformation of austenite into martensite during forming, TRIP effect or Transformation Induced Plasticity, ensures a very high ductility of the material. This TRIP effect leads to an excellent ratio of strength and ductility.
CP Steel “C”
Complex phase steel is abbreviated as CP and, like TRIP and dual-phase steel, belongs to the group of AHSS steels (Advanced High Strength Steel). It contains martensite and/or bainite in a basic structure of ferrite and/or hardened ferrite. This microstructure favors high yield strength with relatively good elongation. Thus, this steel is particularly well suited for bending and edging.
Surface type according to DIN EN 10338
Surface A:
Defects such as pores, small grooves, small warts, slight scratches and slight discoloration that do not impair the suitability for forming and the adhesion of surface coatings are permitted.
Surface B:
The better side must be free of defects to the extent that the homogeneous appearance of a quality paint or an electrolytically applied coating is not impaired. The other side must at least meet the requirements for surface type A.
Surface finishes according to DIN EN 10338
The surface finish may be particularly smooth, matt or rough; if no further details are given in the order, the surface finish is supplied matt. The four surface finishes mentioned correspond to the center roughness values in the following table and must be tested in accordance with EN 10049.
| Surface finish | Identification | Center roughness value (limit wavelength: 0,80mm) |
|---|---|---|
| Particularly smooth | b | Ra ≤ 0,40 µm |
| Smooth | g | Ra ≤ 0,90 µm |
| Matt | m | 0,6 μm < Ra ≤ 1,9 µm |
| Rough | r | Ra ≤ 1,6 μm |
Zinc finish according to DIN EN 10346
Our zinc coatings are available in various designs that meet the specific requirements and aesthetic wishes of our customers:
Regular spangle (N): This design occurs when the zinc coating solidifies undisturbed. Depending on the galvanizing conditions, either no zinc flowers or zinc crystals with different gloss and size can occur. This variation does not affect the quality of the coating. If a pronounced zinc flower is desired, this should be specifically stated in the request and order.
Small spangle (M): This design is achieved by specifically influencing the solidification process. The surface has smaller zinc flowers, some of which are not visible to the naked eye. This variant is chosen if the regular zinc flower (see above) does not meet the requirements for the surface appearance.
Surface type according to DIN EN 10346
Regular surface (A)
With this surface type, certain irregularities are permitted which do not impair the quality and functionality. These include:
Stretch direction breaks and run-off waves can also occur, as can roll kinks and flow figures. Surface type (A) can be achieved both by cold rolling and without, whereby the choice of process is left to the manufacturer.
Improved surface (B)
With surface type B, it is produced by cold rolling. With this surface quality, the following irregularities are permitted to a small extent:
Bei der Oberflächenart B werden durch Kaltnachwalzen hergestellt. Bei dieser Oberflächenqualität sind in geringem Umfang folgende Unregelmäßigkeiten zulässig:
These features do not affect the functionality and quality of the end product and are a natural part of the cold rolling process.
Best surface (C)
Surface type C is produced by cold rolling. The tested side of this surface is specially suitable for a uniform quality paint finish. The reverse side meets at least the requirements of surface type B, which means that slight irregularities such as stretch direction breaks, dressing imprints and slight scratches are permitted.
Surface treatment and protection
When requesting and ordering our products, you can choose between different surface treatment conditions to meet specific requirements:
Note: The effect of the “oiled” surface protection is highly dependent on the atmospheric and storage conditions. Our products are usually supplied chemically passivated and/or oiled. At the express request of the customer, hot-dip coated products can also be supplied without surface treatment, but the responsibility for this lies with the customer.
Special requirements: If special transport and storage conditions require increased corrosion protection, the customer must inform the manufacturer accordingly when requesting and ordering. If the customer does not want oiled or chemically passivated surfaces, this must also be clearly stated in the request and order.
Ihr Ansprechpartner
Benjamin Schmidt
+49 2841/60041 121
+49 173/4791333
Benjamin.Schmidt@ESB-Group.com