|About this Abstract
||2021 TMS Annual Meeting & Exhibition
||Advanced High Strength Steels V
||Strain Rate Sensitive Martensite Transformation in a Q&P Steel
||Christopher Barret Finfrock, Melissa M Thrun, Trevor J Ballard, John Copley, Benjamin Ellyson, Amy J Clarke, Kester D Clarke
|On-Site Speaker (Planned)
||Christopher Barret Finfrock
Quenching and partitioning (Q&P) steels use the deformation-induced transformation of austenite to martensite (DIMT) to enhance formability and crash performance by increasing the work hardening rate. However, strain state, strain rate, and workpiece temperature can influence DIMT and thus influence the mechanical performance. Competing mechanisms control DIMT across a spectrum of strain rates: at intermediate strain rates (0.1 1/s) , DIMT is restricted by adiabatic heat accumulation and corresponding stabilization of austenite; at dynamic rates (1000 1/s), shear bands (the primary sites for martensite nucleation) form more rapidly and thus accelerate DIMT. This presentation will explore the strain rate sensitivity of DIMT with interrupted formability tests and Hopkinson bar tensile tests with in-situ synchrotron diffraction analysis, along with complementary characterization.