Alloy optimization for reducing delayed fracture sensitivity of 2000 mpa press hardening steel

Hardy Mohrbacher, Takehide Senuma

Research output: Contribution to journalArticle

Abstract

Press hardening steel (PHS) is widely applied in current automotive body design. The trend of using PHS grades with strengths above 1500 MPa raises concerns about sensitivity to hydrogen embrittlement. This study investigates the hydrogen delayed fracture sensitivity of steel alloy 32MnB5 with a 2000 MPa tensile strength and that of several alloy variants involving molybdenum and niobium. It is shown that the delayed cracking resistance can be largely enhanced by using a combination of these alloying elements. The observed improvement appears to mainly originate from the obstruction of hydrogen-induced damage incubation mechanisms by the solutes as well as the precipitates of these alloying elements.

Original languageEnglish
Article number853
Pages (from-to)1-19
Number of pages19
JournalMetals
Volume10
Issue number7
DOIs
Publication statusPublished - Jul 2020

Keywords

  • Austenite grain size
  • Grain boundary cohesion
  • Hydrogen damage mechanisms
  • Precipitation
  • Solute segregation
  • Vacancy complexes

ASJC Scopus subject areas

  • Materials Science(all)

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