Microstructure, Mechanical Properties and Formability of a Duplex Steel

05 Aug 2011

Radhakanta Rana, Jenny Loiseaux, Chris Lahaye; Tata Steel RD&T IJmuiden Technology Centre, The Netherlands

A duplex steel with 26Mn-9.7Al-0.47C (wt.%) was investigated for its suitability as an automotive material. The material was processed in the laboratory following standard processing route for steel sheets. It is found that this duplex steel achieves promising mechanical properties at about 22–28 vol.% of ferrite in the microstructure. Control of ferrite volume fraction by optimising annealing temperature appears to be key to monitor the mechanical properties. A tendency of the alloying elements Mn, C and Al to be partitioned in austenite/ferrite bands is observed irrespective of the annealing temperature. The formability (stretchability, bendability and hole expansion coefficient) of the material is better/comparable than conventional automotive steels with similar strength levels.

Paper presented at Thermec 2011, Quebec, Canada, August 1-5, 2011 and published in Materials Science Forum, Vols. 706 - 709,  2012, pp. 2273-2279