Cantor Colburn LLP
Ultrahigh-strength high-ductility steel sheet having excellent yield strength, and manufacturing method therefor
Provided is an ultrahigh-strength high-ductility steel sheet having excellent yield strength, comprising, by wt %, 0.04-0.18% of C, 2% or less of Si, 4-10% of Mn, 0.05% or less of P (except 0%), 0.02% or less of S (except 0%), 0.5% or less of Al (except 0%), 0.02% or less of N (except 0%) and the balance of Fe and the other inevitable impurities, wherein Si+Mn satisfies 6-10% and the microstructure comprises, by volume fraction, 12% or more of retained austenite and 60% or more of annealed martensite.
POSCO
C C C C C C C B C B C C C C C C C C C C C C
C22C C23C C21D C21D C21D C21D C21D B32B C21D B32B C22C C21D C22C C21D C22C C23C C23C C22C C23C C22C C22C C21D
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Sea-Woong Joo-Hyun Kyoo-Young
Lee Ryu Lee