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Advanced protection

ArcelorMittal’s innovative coatings go the extra mile to safeguard automotive applications.

ArcelorMittal Europe – Flat Products is constantly commercialising advanced steel grades for automotive applications to meet the changing needs of the global mobility industry. ArcelorMittal also researches and tests new steel coatings which will protect and extend the life of our automotive offer. Two of the latest automotive coatings released by ArcelorMittal are Jetgal® and Zagnelis®.

Commercial production of Jetgal® began at the end of 2016 and the coating has already been approved by some of the world’s major carmakers. A pure-zinc coating, Jetgal® has the same in-use properties as electrogalvanised coating (EZ) products but leads to significant gains in sustainability as the process uses less energy and water. At the moment, the Jetgal® coating is only produced in Liège, Belgium (Europe).

Vapour deposition creates homogenous surface

The coating is applied to one or both sides of a cold rolled steel substrate using a unique technology known as Jet Vapour Deposition (JVD) as Cecile Pesci, a product developer for automotive coatings and surface treatments with ArcelorMittal Global R&D, explains: “On the JVD line, Jetgal® is applied to the steel substrate in a vacuum. This ensures that hydrogen, which can lead to delayed corrosion fractures, is excluded from the process.”

The JVD line coats the steel strip in a vacuum to ensure no hydrogen is present.


Because it is applied as a vapour, the Jetgal® coating is very homogenous, ensuring excellent corrosion protection. Minor damage such as scratches will self-heal thanks to the sacrificial electrochemical behaviour of zinc when it is in contact with steel.

“A big advantage of Jetgal® is that it can be applied to almost any cold rolled substrate,” notes Cecile Pesci. “It will also work with our future grades including new ultra high strength steels (UHSS) we are developing for the automotive market.”

ArcelorMittal’s JVD line in Liège (Belgium)


Zagnelis® maximises corrosion protection and surface aspect

Zagnelis® Surface and Protect offer improved corrosion protection and stamping behaviour compared to EZ coatings. A double-sided coating, Zagnelis® includes zinc, aluminium, and magnesium to ensure maximum protection. At the moment, the Zagnelis® coatings are only available in Europe. The three Zagnelis® coatings available today include:

  • Zagnelis® Protect: For unexposed parts such as the body-in-white. Available for hot and cold rolled substrates.
  • Zagnelis® Surface: Designed for cold rolled substrates used to form exposed and unexposed parts.
  • Zagnelis® Surface Ultra: Offers the same properties as Zagnelis® Surface but this coating can be supplied with a guaranteed waviness (Wa 0.8, ≤ 0.5 µm at 5% elongation) after stamping.

A sample of Zagnelis® Surface.


A sample of Zagnelis® Surface Ultra – the reflections indicate the low level of waviness that can be achieved after stamping.


Zagnelis® Surface Ultra provides the best aspect after painting, making it ideal for large horizontal parts such as hoods and doors. As well as offering better corrosion protection, Zagnelis® Surface Ultra also performs better in stamping operations thanks to its low friction coefficient.

More info on Jetgal® 

More info on Zagnelis® 

Click here to see ArcelorMittal's complete offer of coatings for automotive steels.

Tested in extreme real-life conditions


 

The combination of zinc, aluminium, and magnesium in the Zagnelis® coating can affect the bonding behaviour of some adhesives. “ArcelorMittal can advise on the best adhesive for your project, but we’re also working with adhesive manufacturers to fine-tune their formulations,” notes Cecile Pesci. “We have also developed an alkaline activation treatment to improve adhesive bonding. This treatment will not change the in-use properties of the steel and is removed automatically during the degreasing step before painting.”

Zagnelis® has undergone extensive corrosion testing over the past five years at ArcelorMittal’s outdoor testing locations around the world. “We’ve also hung Zagnelis® samples under a truck which travels around 150,000 kilometres annually in Sweden,” says Cecile Pesci. “Each year we characterise the samples to measure the rate of metal loss and other corrosion factors. This test simulates real-world conditions and exposes the coating to temperature extremes, de-icing salts, and the general wear and tear a coating must face in real operating conditions. The Zagnelis® Protect samples have already been in place for four years and we are extremely satisfied with its performance."

Samples are hung beneath a truck and driven more than 150,000 km annually as part of ArcelorMittal’s test programme.