The influence of grain size and precipitation and a boron addition on the hot ductility of a high Al, V containing TWIP steels

The hot ductility of V containing high Al, TWIP steels was determined at a 1000 degrees C, when no dynamic recrystallisation occurred, and precipitation was too coarse to influence ductility. A change in grain size from similar to 1250 to 500 mu m caused the reduction of the area to increase by similar to 25%, intimating that the improvement in ductility on adding boron is due to its segregation to the boundaries causing grain refinement on solidification. Fine VC precipitation was mainly responsible for deteriorating ductility. In these steels, the ductility of un-recrystallised austenite decreases gradually with increasing temperature from 700 degrees C to 1000 degrees C and this in combination with fine precipitation can markedly change the shape of the hot ductility curve from ductility decreasing to increasing with temperature.

Automated summary

The hot ductility of TWIP steels containing high Al and V was studied at 1000°C, showing that adding boron can improve ductility by segregating to boundaries and causing grain refinement. Fine VC precipitation has a negative impact on ductility, and the ductility of un-recrystallised austenite gradually decreases with temperature from 700°C to 1000°C.