Microstructural Optimization for Multiphase Steels with Improved Formability and Damage Resistance
Multiphase steels typically available in the tensile strength range of 450 MPa to 980 MPa are widely used in today’s car body manufacturing.Their characteristics of high n-value and good elongation (A80) are connoted with good press formability.However,practical experience has shown unexpected failure in forming operations where tight bending,stretch flanging or hole expansion are predominant.The inhomogeneous microstructure of soft ferrite and hard phase constituents in combination with local straining is inherent to these problems.However this forming behavior can be much improved by microstructural refinement and homogenization of the phases as well as modification of hardness contrasts.Modified alloy concepts in combination with adapted processing have been identified as an appropriate approach to achieve this optimization.Niobium and molybdenum are key alloying elements in this approach.The paper explains the fundamentals,demonstrates respective production concepts and presents examples of industrial implementat- ion of such optimized MP steels.
DP steel N-value 3-point bending
Hardy Mohrbacher
NiobelCon bvba,2970 Schilde,Belgium
国际会议
The 2nd International Symposium on Automobile Steel (第二届汽车用钢生产及应用技术国际研讨会)
鞍山
英文
86-89
2013-05-21（万方平台首次上网日期，不代表论文的发表时间）