Metallurgical and Materials Transactions A

, Volume 38, Issue 10, pp 2442–2454

Transmission Electron Microscopy Characterization of the Bake-Hardening Behavior of Transformation-Induced Plasticity and Dual-Phase Steels

Article

DOI: 10.1007/s11661-007-9258-7

Cite this article as:
Timokhina, I., Hodgson, P. & Pereloma, E. Metall and Mat Trans A (2007) 38: 2442. doi:10.1007/s11661-007-9258-7

Abstract

The effect of prestraining (PS) and bake hardening (BH) on the microstructures and mechanical properties has been studied in transformation-induced plasticity (TRIP) and dual-phase (DP) steels after intercritical annealing. The DP steel showed an increase in the yield strength and the appearance of the upper and lower yield points after a single BH treatment as compared with the as-received condition, whereas the mechanical properties of the TRIP steel remained unchanged. This difference appears to be because of the formation of plastic deformation zones with high dislocation density around the “as-quenched” martensite in the DP steel, which allowed carbon to pin these dislocations, which, in turn, increased the yield strength. It was found for both steels that the BH behavior depends on the dislocation rearrangement in ferrite with the formation of cell, microbands, and shear band structures after PS. The strain-induced transformation of retained austenite to martensite in the TRIP steel contributes to the formation of a complex dislocation structure.

Copyright information

© THE MINERALS, METALS & MATERIALS SOCIETY and ASM INTERNATIONAL 2007

Authors and Affiliations

  1. 1.Department of Materials EngineeringMonash UniversityClaytonAustralia
  2. 2.Center for Material and Fiber InnovationDeakin UniversityGeelongAustralia
  3. 3.School of Mechanical, Material and Mechatronics EngineeringUniversity of WollongongWollongongAustralia