The State-of-the-Knowledge on Medium Mn Steel
Medium Mn steel is a multi-phase material with an ultra-fine grained microstructure,which appears to have a clear potential for use in lightweight automobile body-in-white construction.When suitably processed,the material can exhibit an ultra-high strength (UTS > 1 Gpa) and a high degree of plasticity (Uniform elongation ≈ 20 %).These properties are due to the activation of plasticity-enhancing mechanisms,i.e.the TWIP effect and/or the TRIP effect,in the ultra-fine grained (Grain size <500 nm) meta-stable austenite phase.The complex microstructuremechanical properties relationships of medium Mn steels are reviewed,and a number of important issues,which have up to now not received much attention,are discussed.These issues include the formation of the characteristic ultra-fine microstructure of intercritically annealed medium Mn,the poorly defined stability requirements for the austenite,and the occurrence of dynamic strain aging.These issues are illustrated for an intercritically annealed Fe-0.3%C-6%Mn-3%Al-1.5%Si medium Mn steel.
medium Mn steel mechanical properties microstructure evolution
DE COOMAN B. C.
Materials Design Laboratory, Graduate Institute of Ferrous Technology, Pohang University of Science and Technology, Pohang, 790-784, South Korea
国际会议
成都
英文
35-41
2016-11-16（万方平台首次上网日期，不代表论文的发表时间）