AHSS: A Study of the Effects of Microstructure on the Mechanical Properties and Failure Mechanisms of Advanced High Strength Steels

Carnegie Mellon University, Pittsburgh PA

Investigators

Abstract

Broadly speaking this work will focus on the effects of microstructure on the mechanical properties and formability of steels having ultimate tensile strengths of 1200 MPa and higher. Microstructurally, there are two main components to the work, In the first, PIs will evaluate the effects of microstructure on the mechanical behavior and formability of complex microstructures consisting of 0%, 25% or 50 % ferrite combined with 100%, 75% or 50% of either Martensite or Bainite. At each ferrite level the Martensite and Bainite will have similar strength levels. In all of these structures PIs can vary the amount and mechanical stability of the retained austenite. Thus PIs will address the effects of the amount of ferrite, of retained austenite characteristics and of a Bainitic structure as opposed to a Martensitic structure on work hardening behavior, ductility, toughness and formability. In the second, they will examine the effects of the resistance of inclusions to void nucleation on formability. In the broader impact, accomplishing the above will provide useful information on how to achieve high formability in high strength sheet steels which would be of benefit to those actually involved in the production and use of such materials.