Zn-Fe めっき層の組成および組織制御による改質に向けたスパッタリング成膜による検証

Translated title of the contribution: Improvement of powdering resistance of Zn-Fe galvannealed coating by controlling of its composition and microstructure: Verification with sputtering method

Aimi Uchiyama, Kohei Kawasaki, Yuji Sutou, Daisuke Ando, Junichi Koike

Research output: Contribution to journalArticlepeer-review

Abstract

Improvement of the powdering resistance of galvannealed (GA) coatings is a key issue in automotive GA steel sheets. To make the relationship between powdering resistance and microstructure of GA layer, sputtering fabrication process was used to prepare Zn-Fe intermetallic films with various composition and microstructure in this study. Zn-Fe films with 1500 nm in thickness were deposited on an iron substrate by RF magnetron sputtering. Г+Г1 two-phase film (17.2~24.4 at.%Fe) was found to show a severe powdering by 3-point bending test, while Г1 (16.2 at.%Fe) or Г (34.3 at.%Fe) single-phase films showed much better powdering resistance. These results indicate that Г/Г1 interfaces boundaries have a low interfacial strength compared to that of Г/iron or Г1/iron interfaces. To improve the low powdering resistance of the Г+Г1 two-phase film, we investigated the effect of grain size refinement by B addition on the powdering resistance. It was found that the grain size refinement by B addition drastically improves the powdering resistance of Г+Г1 two-phase film. The decrease in the fracture toughness of Г+Г1 two-phase film by grain refinement was suggested to cause the improvement of its powdering resistance.

Translated title of the contributionImprovement of powdering resistance of Zn-Fe galvannealed coating by controlling of its composition and microstructure: Verification with sputtering method
Original languageJapanese
Pages (from-to)724-732
Number of pages9
JournalTetsu-To-Hagane/Journal of the Iron and Steel Institute of Japan
Volume105
Issue number7
DOIs
Publication statusPublished - 2019

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Metals and Alloys
  • Materials Chemistry

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