AHSS are complex, sophisticated materials, with carefully selected chemical compositions and multiphase microstructures resulting from precisely controlled heating and cooling processes. Various strengthening mechanisms are employed to achieve a range of strength, ductility, toughness, and fatigue properties.
The work hardening exponent, or n-value, plays a major role in why these steels are experiencing such a large take-up in the automotive industry. In this video, Dr. Stuart Keeler, Sc.D., Mechanical Metallurgy, developer of the Forming Limit Diagram and Technical Editor of the WorldAutoSteel Advanced High-Strength Steels Application Guidelines, among many career achievements, breaks down the subject of n-values and how it's nature affects advanced steels and their formability. Advanced High-Strength Steels Application Guidelines are available for free download at worldautosteel.org.