On the same wavelength

ArcelorMittal can offer OEMs a range of steel coatings which improve the appearance, corrosion resistance, and processing performance of its steels. In the automotive sector, ArcelorMittal’s coatings are used by leading brands to optimise the appearance of their vehicles. The low waviness properties of Ultragal^® ensures that the vehicle part has an almost mirror finish after stamping. This makes it ideal for large vehicle parts such as the bonnets, roofs, and body panels of premium models.

Ultragal^® is a pure-zinc coating which was first introduced more than 15 years ago. ArcelorMittal controls the processing parameters of the coating to optimise the aspect of the final part. The aspect is influenced by the roughness, waviness, and form of the steel surface.

ŠKODA AUTO was closely involved in the early industrial trials of Ultragal^® notes Ing. Lubomír Roleček, Manager of Skoda’s Technical Service Press Shop and Body Shop:

The ideal level of waviness can be measured – and guaranteed. “The automotive industry has recently created a new norm to measure waviness,” says Cécile Pesci, coating products development manager at ArcelorMittal Global R&D. “Known as the VDA norm, it measures a small spectrum of the reflected light. For the optimum mirror finish we are aiming for a value of Wsa1-5 at 5-percent elongation. ArcelorMittal can guarantee that Ultragal^® can meet this standard.”

The new VDA norm replaces the Wa0.8 standard which was originally developed by ArcelorMittal and widely adopted by the automotive industry. Under the Wa0.8 standard, the coating should have a waviness of 0.42 µm after stamping with 3.5-percent elongation. This is equivalent to the new VDA Wsa1-5 norm. Note: Wsa1-5 is the arithmetic mean of the absolute ordinate values within wavelength range between 1 mm and 5 mm, based on standard SEP1941 describing Wsa(1-5) measurement.

In addition to Ultragal^®, ArcelorMittal offers a complete range of hot dip galvanised coatings which are suitable for automotive applications manufactured using cold stamped steels. These include:

• Extragal^®: The high level of corrosion protection offered by Extragal^® makes it suitable for use on both exposed and non-exposed parts. The coating results in a high level of surface quality which enables OEMs to achieve an excellent finish on exposed parts.
  Although Extragal^® does not come with a waviness guarantee, ArcelorMittal aims to achieve a level of 0.40 at 5-percent elongation according to the Wsa1-5 standard. Around 95-percent of the Extragal^® ArcelorMittal produces is at this level.
• Zagnelis^® Surface offers a level of corrosion protection that exceeds traditional zinc-based coatings. It is also compatible with OEM processes such as drawing and welding.
  Zagnelis^® Surface has a lower friction coefficient than traditional zinc coatings. It is compatible with the VDA239-100 standard and suitable for use on both exposed and non-exposed parts.

ArcelorMittal’s premium hot dipped galvanised coatings for cold stamped steels

ArcelorMittal’s range of coatings for various car parts

ArcelorMittal can deliver Ultragal^® to carmakers from various lines in Europe, and North and South America. Worldwide deliveries are also available on request.