Think zinc. voestalpine is a pioneer and solution leader in the hot forming of galvanized press-hardening steels.
Hot forming and cathodic zinc protection are compatible!
Zinc coatings as a means of corrosion protection have been a conventional state-of-the-art technology for many years. Cathodic corrosion protection is achieved by the zinc coating "sacrificing" itself in favor of high-strength steel. The sacrificial protection of zinc coatings can prevent components from sustaining damage by corrosion throughout their entire service life. This also applies to cut edges or scratches in the coating down to the steel substrate.
However, a zinc coating on press hardening steels (phs) for hot forming seemed impossible for a long time. This is because zinc liquefies at 420 °C and evaporates at temperatures above 900 °C. Additionally, zinc weakens during hot forming as a result of the formation of microcracks on the steel surface.
The voestalpine pioneering spirit makes indirect hot forming possible
In 2002, voestalpine implemented a research and development team with the first basic hot forming tests on galvanized steel strip. Only two years later, the combination of material and manufacturing processes was used to produce a component made of galvanized hot-formed material (B pillar). The key to success was the selection of the right coating (composition and thickness of the zinc material), the precise selection and control of time and temperature characteristics and the prevention of elongation during hot forming and form hardening. This was when the serial production of press-hardening parts made of galvanized steel strip became a reality. The indirect hot forming has been a great success since 2008 (phs-ultraform®) in serial production.
Direct hot forming as a world first in light-weight automotive design
The automotive industry also wanted excellent zinc protection for direct hot forming because it is highly economical, especially in smaller quantities. voestalpine was successful in mastering this challenge as well. Today, phs-directform® is a world novelty that directly hot-forms hot-dip galvanized steel strip into corrosion-resistant light-weight components for the automotive industry.
Comprehensive know-how as a success factor for the automotive industry
The foundation for the innovative power in voestalpine phs technology is comprehensive expertise bundled into one group of companies. As a group of technological companies, voestalpine networks the development, production and processing of steel. The know-how of material developers provided by the experts in the Steel Division is combined with the process know-how of the forming specialists in the Metal Forming Division.
The advantages of voestalpine phs technology
- Excellent cathodic corrosion protection based on a zinc coating
- Exceptional formability
- Excellent crash performance (ductility)
- Strengths ranging from 1,200 to 2,000 MPa
- Wide variety of solutions for individual component requirements
- Economical manufacturing
Safety and environmental compatibility
The light-weight automotive solutions with phs-ultraform® and phs-directform® from voestalpine reduce fuel consumption and thus reduce CO2 emissions and increase the service life of the component and enhance passenger safety. Special technologies in steel strip production increase the ductility of the hardened steel component and thus improve crash performance. Expressed in the factor of bending angle, which was determined in a three-point bending test and a measure for bending deformation, this value has been increased by 10 to 30 %. The steelmaking plant in Linz is one of the most modern and environmentally compatible in the world. When steel finally reaches the end of its lifecycle after many years of service as a reliable component, it can be recycled without losing any of its high-quality properties. 100% of all steel can be recycled..
Why zinc does not evaporate
The remote effect of corrosion-resisting zinc
The secret of the bending angle
No chance for microcracks