After heat treatment
Their extreme hardness after heat treatment makes these grades particularly suitable for applications requiring high wear/abrasion resistance. Their use allows significant weight saving (up to 50% compared with an HSLA grade) in structural and automotive components. The specific advantage of ArcelorMittal quenchable boron steels is their suitability for water quenching, making the process more environmentally friendly (less effluent treatment) than that used for conventional carbon steels. Their hardening performance is excellent with both liquid and gas quenching.
ArcelorMittal offers the following quenchable boron grades: 22MnB5 AM FCE, 30MnB5 AM FCE and 38MnB5 AM FCE. The choice of grade will depend on:
- The required hardness of the finished part
- The abrasion resistance required
- The severity of the forming process envisaged
22MnB5 AM FCE, 30MnB5 AM FCE and 38MnB5 can be hot or cold formed.
In spite of their moderate hardness and mechanical properties, boron grades exhibit remarkably good abrasion resistance in their delivery condition, thanks to their composite microstructure consisting of a hard pearlite phase embedded in ferrite. They are therefore very cost-effective solutions for applications requiring good abrasion resistance.
ArcelorMittal offers a modified version of 30MnB5, for applications such as concrete mixers, in which steel is used untreated: 30MnB5 DRUM AM FCE. Abrasion tests, confirmed by the practical experience of our clients, show a good performance compared with standard structural grades. As a result, parts have a longer lifetime.