Effects of Al content on the high-temperature mechanical properties of Al-TRIP steel

ABSTRACT

As-cast transformation-induced plasticity (TRIP) steels with two different aluminium contents (2.80 and 6.75 wt-%) were subjected to investigate the effect of aluminium content on the tensile strength and hot ductility. As the Al content increases from 2.80 to 6.75 wt-%, the third brittle zone of the steel is shifted from 950–750°C to 800–750°C. The 6.75 wt-% Al-TRIP steel is a typical δ-TRIP steel that contains 44.5 wt-% δ-ferrite compared with no δ-ferrite in the 2.80 wt-% Al-TRIP steel. The solidification behaviour of these two types of TRIP steel was compared by calculating equilibrium phase diagrams. The 6.75 wt-% Al-TRIP steel was found to have better ductility than the 2.80 wt-% Al-TRIP steel below 1100°C.

KEYWORDS:

• TRIP steel
• δ-TRIP steel
• high-temperature mechanical properties
• hot ductility curve
• brittle zones

Acknowledgements

The authors would like to thank Professor C. Bernhard and Dr. P. Presoly of Montanuniversität Leoben for providing access to Thermo-calc software and TCFE9 database.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Heng Cui http://orcid.org/0000-0002-0645-7453

Additional information

Funding

The research was financially supported by the National Natural Science Foundation of China (grant number U1860106) and the China Scholarship Council (grant number 201806465050).