Microstructural evolution of a dual hardening steel during heat treatment

Research output: Contribution to journalArticleResearchpeer-review

Authors

  • Maximilian Staudacher
  • Miloslav Ognianov
  • Christoph Turk
  • Harald Leitner

Organisational units

External Organisational units

  • voestalpine BÖHLER Edelstahl GmbH & Co KG
  • Böhler Edelstahl GmbH & Co KG

Abstract

Dual hardening steels combine precipitation of both secondary hardening carbides and intermetallic phases in a martensitic matrix. Due to this combination, the carbon content necessary to achieve high hardness levels can be reduced, resulting in a decreased amount of large and embrittling carbides. In this study, the influence of different heat treatments on microstructure evolution and secondary hardness is investigated. Different metallographic preparation methods were tested in order to visualize the microstructure. Carbides were characterized using spot-pattern electron backscatter diffraction. For light optical investigations, preparation with V2A-pickle lead to the best results. Preparation with colloidal silica suspension achieved the best results for investigations by scanning electron microscopy and for carbide characterization using electron backscatter diffraction. It was found that a homogenization treatment prior to austenitization was unable to increase the amount of dissolved carbides, and thus had no effect on secondary hardness. By increasing the austenitization temperature, the amount of carbides and secondary hardness could be increased significantly.

Details

Original languageEnglish
Pages (from-to)48-56
Number of pages9
JournalMicron
Volume120.2019
Issue numberMay
DOIs
Publication statusPublished - 10 Feb 2019