Effect of bake-hardening on the strucutre-property relationship of multiphase steels for the automotive industry
RIS ID
29914
Abstract
The effect of a bake-hardening (BH) treatment on the microstructure and mechanical properties has been studied in C-Mn-Si TRansformation Induced Plasticity (TRIP) and Dual Phase (DP) steels after: (i) thermomechanical processing (TMP) and (ii) intercritical annealing (IA). The steels were characterized using X-ray diffraction, transmission electron microscopy (TEM) and three-dimensional atom probe tomography (APT). All steels showed high BH response. However, the DP and TRIP steels after IA/BH showed the appearance of upper and lower yield points, while the stress-strain behavior of the TRIP steel after TMP/BH was still continuous. This was due to the higher volume fraction of bainite and more stable retained austenite in the TMP/BH steel, the formation of plastic deformation zones with high dislocation density around the “as-quenched” martensite and “TRIP” martensite in the IA/BH DP steel and IA/BH TRIP steel, respectively.
Publication Details
Timokhina, I. B., Hodgson, P. D., Ringer, S. P., Zheng, R. K. & Pereloma, E. V. (2009). Effect of bake-hardening on the strucutre-property relationship of multiphase steels for the automotive industry. Steel Research International, 80 (7), 507-514.