NEOVAC Presents Innovative Vacuum Coating Technology For High-Strength Steels With No Thermal Stress

• No damage to the strip caused by process-induced hydrogen
• Lower resource consumption compared to electrolytic coating processes
• No process-related CO₂ emissions

NEOVAC, a joint venture between SMS group GmbH and SITIZN Group Holding AG, based in Karlstein, Germany, is proud to present a brand new technology for coating steel strip, which was specially developed for high-strength and ultra-high-strength steels. This innovative solution is based on a “cold” process that does not alter the material properties and at the same time ensures maximum coating quality.

Innovative technology
“Our line is a milestone in metal processing,” explains André Herzog, CTO of NEOVAC. “We can now coat high-strength materials that could not previously be coated using conventional means due to their sensitivity to high temperatures, for example. This opens up completely new possibilities for using ultra-high-strength materials with active corrosion protection in the automotive, aerospace, and lightweight construction sectors.”

Eco-friendliness and efficiency go hand in hand
This vacuum coating technology offers both technical and ecological advantages. When using renewable electricity, the coating process is carbon-neutral, thereby contributing significantly to sustainability. Alongside higher energy efficiency levels during coating compared to conventional processes, the consumption of resources is also considerably lower as less material is required for a uniform, even coating.

Functionality and scalability
The 170-ton pilot line installed in Karlstein is a discontinuous vacuum coating line for steel coils. Coils with a maximum weight of up to five tons, an uncoiled length of up to 1000 meters, and a width of up to 650 millimeters are fed into an evacuated chamber after wet cleaning. This is where a three-stage process, consisting of plasma pre-treatment, magnetron-based pre-coating, and a newly developed plasma-enhanced evaporation solution (thermal zinc evaporation via nozzles) is used. From a technical point of view, the zinc is evaporated at temperatures above 600°C, but the precipitation onto the strip takes place during a “cold” process below 200°C and without hydrogen input, thus achieving a targeted growth of layers with defined grain sizes and high adhesive strength, with minimal influence on the microstructure. This technique has already been used to coat a wide range of steel grades. Of particular note here are ultra-high-strength steel strips with tensile strengths of up to 1,500 MPa.

As a result of this success, the innovative system is ready for use in series production, offering customers a scalable solution to meet their individual needs. NEOVAC invites interested companies to order test coatings and to experience the real advantages of this technology first-hand. The line is designed to switch from a coil-to-coil to a continuous production process, thereby achieving even greater efficiency levels.