The Influence of the Substitution of Si by Al on the Properties of Cold Rolled C-Mn-Si TRIP Steels
The effect of the substitution of silicon by aluminium on the mechanical properties and the microstructure of cold rolled C-Mn-Si TRIP steels was investigated for different continuous annealing cycles. <br>The mechanical properties were evaluated using tensile testing. It was seen that the Al alloyed steel had very good mechanical properties with an improved formability compared to the conventional C-Mn-Si TRIP steel. The strain hardening behaviour was studied in detail. All the investigated specimens showed a very high <I>n</I> value but their strain dependence was different. For the conventional C-Mn-Si TRIP steel the maximum <I>n</I> value was reached at low strain, while the Al substituted TRIP steel showed a gradual increase of the <I>n</I> value. The latter effect resulted in a larger uniform elongation for the C-Mn-Al-Si TRIP steel.<br> Investigation of the microstructure using color etching and scanning electron microscopy revealed that the Al alloyed steel composition contained a larger amount of bainite with a finer structure than the C-Mn-Si TRIP steel. Furthermore, XRD measurements showed that the Al substitution resulted in a larger volume fraction of retained austenite.
- ISIJ international
ISIJ international 39(8), 813-822, 1999-08-15
The Iron and Steel Institute of Japan