When standard steels need to have specific characteristics, mills generally use expensive alloying additions and supplementary heat treatment. Steeltec AG, of the Swiss Steel Group, has developed an innovative, alternative technology.

The company developed Extreme Performance Technology (XTP) and found a way to produce an ultrafine grained and tough high-grade steel, which makes the need for additional alloys and special treatment obsolete thanks to a controlled thermomechanical processing phase.

Systematic temperature control and alternative forming processes produce an extremely ultra-fine-grain microstructure with grain sizes of less than 5 µm. Steel produced in this way is noted for improved properties with better dynamic and mechanical characteristics, including:

• Improved tensile strength of up to 2,050 MPa
• Improved dynamic load capacity by at least 10 percent, leading to longer service life and higher operational safety
• Significantly improved properties despite higher tensile strength
• Formability and machinability
• Components can be redimensioned without losing mechanical-technical properties making component design more flexible
• Given the straightness of the bars, lengths of up to 8,000 (-0/+200) mm available with tolerances compliant to DIN EN ISO 286-2 *h11
• No thermal distortion and no need for additional heat treatment 

While XTP-treated steel looks like conventional steel on the outside, its true excellence is hidden beneath the surface: the ultra-fine-grained steel microstructure provides an unprecedented level of material resistance and strength. This creates possibilities and paves the day to versatile designs and unconventional component engineering.

XTP steel withstands even difficult challenges, such as intense vibration, high internal pressure or extreme cold. Even at ultra-low temperatures of -101°C at which conventionally produced steel can become brittle and crack or break, the technically optimized steel grades have a high toughness (notched bar impact work of well over 27 joule in notched bar impact testing). Treatment with XTP technology guarantees the highest resistance to crack propagation.

Ultra-fine grain steel is less brittle than conventional steel

 Xtreme Performance Technology is the future

Thanks to consistent ongoing development of thermomechanical process phases virtually any conventionally produced steel can undergo treatment and be considerably improved. In short, the formula is: heat+ force = ultrafine-grained steel

When subjecting steel to induction heating, the experts of the Swiss Steel Group use austenitization to determine material properties and grain size of the steel microstructure. The steel bar is then immediately cooled to the desired forming temperature and fed into the high-reduction roller unit. 

The steel of the future

Steels suitable for XTP treatment are unalloyed steels, precipitation-hardened ferrite-pearlite steels, Bainitic steels, quenched and tempered steels, tool steels, Austenitic stainless steels, Ferritic stainless steels, and high-speed steels. Steel processing companies stick with the steel grades they are familiar with. Using the same chemical analysis, the properties of Swiss Steel Group steels are significantly optimized from the start thanks to XTP. The processor saves on elaborate, cost-intensive heat treatment. 

XTP-treated steel opens up entirely new possibilities for the following industries and applications: spring manufacturing, hydraulics, connectors and fasteners, refrigeration systems, lifting equipment and lifting gear, cable car and aerial lift systems, wind power, the railway industry, agriculture and forestry, as well as for oil and gas extraction and recovery.