Distortion of steel components in forging companies due to uneven residual stresses is a well-known problem that particularly affects automotive parts such as steering knuckles, pistons and common rail systems. A proven method to counter this problem is to oversize the components, followed by removal of the excess material after heat treatment. Alternatively used ferritic-pearlitic (AFP) steels have less distortion, but have lower strength and toughness and are more difficult to nitride.

The high-quality bainitic steels offer high strength and process reliability for distortion-free and cost-effective forgings or cold forming. A controlled cooling process after forging enables higher mechanical properties without additional heat treatment. Bainitic steels range from low to high carbon content, with the cooling process after forging determining the final microstructure and mechanical properties.

Bainidur® 1300 is a new special steel that enables the cost-efficient production of innovative forged parts. Thanks to specific alloying additions, such as molybdenum, it has a wider "bainite nose" than conventional bainites. This extends the process window during forging and cooling, allowing the workpiece to cool in an uncontrolled manner without the risk of distortion. This is particularly advantageous for large components. The reliable adjustment of the bainitic microstructure enables short process chains and the distortion-free production of strong, ductile lightweight components. Bainidur 1300 offers an average strength of 1200 MPa, which is achieved without additional tempering. In contrast to conventional steels, there are no further heat treatment steps, which saves costs. The optimized properties, such as improved machinability and nitridability, improve process stability and reduce costs. The new steel also exhibits good notched impact strength.

Bainidur® 7980 CN has been specially developed for case hardening and carbonitriding. Bainidur® 7980 CN is a low-alloy steel with a bainitic microstructure at ambient temperature. It is therefore the ideal solution for a wide range of applications in terms of cost-effectiveness, mechanical properties and process stability. Areas of application include, for example, gearboxes specifically for e-mobility with high torque or large gearboxes in wind turbines. The advantages of Bainidur® 7980 CN at a glance:

• Low risk of distortion
• High strength and toughness
• Nickel-free
• Higher through-hardenability than conventional case-hardening steels
• Excellent case-hardening and carbonitriding properties

Bainidur® AM is a special version of Bainidur® 7980 CN and Bainidur® 1300 developed for additive manufacturing. It enables fast and efficient printing of initial samples with the later component properties. Heat and surface treatments can be tested and optimized. Spare parts without existing forging dies can be printed with the same properties as the original. The Bainit structure supports this by enabling easy handling. Advantages of Bainidur® AM: spherical powder with good flow behavior, high processability due to LPBF, almost 100 % bainite structure after printing, high strength and toughness, thermal stability, lower costs than conventional AM materials, mechanical properties after heat treatment at conventional level.

Swissbain-7MnB8 is a micro-alloyed bainitic steel for cold forming without heat treatment for components in the strength class 800 to 1000 MPa. The strength of the component is set via the combination of wire rod strength plus work hardening during drawing and cold forming. Exemplary components are ball studs, screws, threaded and dowel pins and hollow parts without tempering after cold forming.