Transformation behavior of TRIP steels

G. B. Olson*, M. Azrin

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

143 Scopus citations

Abstract

True-stress (σ), true-strain (ε) and volume fraction martensite (f) were measured during both uniform and localized flow as a function of temperature on TRIP steels in both the solution-treated and warm-rolled conditions. The transformation curves (f vs ε) of materials in both conditions have a sigmoidal shape at temperatures above Ms σ (maximum temperature at which transformation is induced by elastic stress) but approach initially linear behavior at temperatures below Ms σ where the flow is controlled by transformation plasticity. The martensite which forms spontaneously on cooling or by stress-assisted transformation below Ms σ exhibits a plate morphology. Additional martensite units produced by strain-induced nucleation at shear-band intersections become important above Ms σ. Comparison of σ-ε and f-ε curves indicate that a "rule of mixtures" relation based on the "static" strengthening effect of the transformation product describes the plastic flow behavior reasonably well above Ms σ, but there is also a dynamic "transformation softening" contribution which becomes dominant below Ms σ due to the operation of transformation plasticity as a deformation mechanism. Temperature sensitivity of the transformation kinetics and associated flow behavior is greatest above Ms σ. Less temperature-sensitive TRIP steels could be obtained by designing alloys to operate with optimum mechanical properties below Ms σ.

Original languageEnglish (US)
Pages (from-to)713-721
Number of pages9
JournalMetallurgical Transactions A
Volume9
Issue number5
DOIs
StatePublished - May 1978

ASJC Scopus subject areas

  • Engineering(all)

Fingerprint

Dive into the research topics of 'Transformation behavior of TRIP steels'. Together they form a unique fingerprint.

Cite this