Laser cutting high-strength steels and wear plates

Stockholm, Sweden - High-strength steel (HSS) and wear plates offer significant advantages over mild steels. However, when it comes to laser cutting, they behave exactly the same way. Both Hardox and Domex, from SSAB, a global leader in value-added HSS, meet all demands for laser cutting and can be processed with the same cutting parameters as unalloyed steel grades such as S235.

"Contrary to popular belief, a laser beam has the same effect regardless of whether a material is soft or hard," explains Anders Ivarson, a thermal cutting and welding specialist at the SSAB Knowledge Service Center. Since a laser beam is bundled light made up of a certain wavelength, it does not matter whether the light is directed at a hard or a soft steel; the material is heated regardless.”

“For example, the melting temperature of our High Strength Steel Domex 700 is exactly the same as that of S235GR, which includes no alloying elements of any kind. This is why a laser cutting machine with the same parameters can cut Domex 355, 420, or 700 equally well," explains Ivarson.

In contrast to other suppliers, SSAB does not even require to have special laser steel grades. All Hardox and Domex steels can be perfectly laser-cut because of their consistent steel properties, low thickness tolerances, outstanding flatness and surface finish, as well as low alloy and optimized chemical composition. The high steel quality also allows for smaller radii and ensures accurate results when bending.

The experiences of Bystronic, one of the leading manufacturers of laser cutting machines, also confirms this. ”During our in-house exhibition, called Competence Days, we processed Hardox and Domex exclusively and were able to show around 900 visitors from 50 countries that it is possible to cut and bend this material perfectly, even in larger thicknesses. Currently, there is still a certain level of reluctance by our customers to use such high strength material—but without cause," says Mario Duppenthaler, Product Manager, Laser & Automation at Bystronic.

Bystronic's laser cutting systems reliably cut Hardox in thicknesses up to 20 mm with excellent results. Even 25 mm Hardox plates can be laser-cut; however, the results depend to some extent on the contour and the surface of the material.

"We can also laser cut 25 mm Hardox plates very well, without time-consuming post-processing. In doing so, we are opening up many new application areas for our machines," explains Duppenthaler.