Steeltec AG says the ultra-fine-grained steel microstructure it has created provides an unprecedented level of material resistance and strength. PHOTO courtesy Steeltec AG.
When standard steels need to have specific characteristics, expensive alloying additions and supplementary heat treatment are generally used. Steeltec AG, a company of the Swiss Steel Group, says it has developed alternative technology for this very reason.
The company says it has found a way to produce an ultra-fine-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, according to Steeltec, 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
Labelled Extreme Performance Technology (XTP)-treated steel, the company says that while this new steel looks like conventional steel on the outside, its enhancement 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,” the company says in a release. It adds that 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.
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. We solve quality problems with XTP technology.
XTP-treated steel opens up entirely new possibilities for the following industries and applications Steeltec says: 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.