Outros eventos

Título

A ULTRAHIGH STRENGTH MEDIUM MN STEEL MANUFACTURED BY WARM ROLLING PROCESS

Autoria

Hu, Bin; Luo, HaiWen

DOI

10.5151/9785-9785-32217

Downloads

Baixar Artigo 137 Downloads

Resumo

 

A ultra-high strength medium Mn steel with good ductility was designed and manufactured via the combination of warm rolling and V alloying, which produced not only the extensive precipitation of fine VC particles in both ferrite and austenite but also the bimodal size distribution of retained austenite (RA) grains. A substantial increase of yield strength up to 650 MPa was achieved due to the addition of V without deteriorating ductility. The coarse RA grains firstly transformed to martensite during yielding at the much higher stress threshold, followed by a significant work hardening due to dislocations multiplication, twinning-induced-plasticity (TWIP) and transformation-induced-plasticity (TRIP) in the ultrafine RA grains. The best combination of strength and ductility included 1.5 GPa ultimate tensile strength and 28% total elongation. This was achieved due to the sustainable TRIP and TWIP effects in the later straining stage resulting from the ultrafine austenite grains, the latter were reversely transformed from the recrystallized ferrite grains.

Palavras-chave

Medium Mn steels; Vanadium carbides; Transformation induced plasticity, Twinning induced plasticity