Influence of alloying elements on the Hall-Petch coefficient in ferritic steel

Setsuo Takaki

Research output: Chapter in Book/Report/Conference proceedingConference contribution

9 Citations (Scopus)

Abstract

Yield strength of ferritic steel increases with grain refinement standing on the Hall-Petch relation. In low carbon ferritic steels, the following relation is established between yield strength σ y and grain size d: σ y [MPa]= 100+600/√d[μm]. The Hall-Petch coefficient of interstitial free steels is substantially small as 0.15MPa·√m but it can be greatly increased by the existence of small amount of solute carbon less than 60ppm. As for the effect of substitutional elements such as Cr and P, some papers reports fairly large influence to the Hall-Petch coefficient of ferritic iron. However, the effect of small amount of carbon is sometime neglected or not cleared on the evaluation of Hall-Petch coefficient in ferritic steels. In order to evaluate the effect of substitutional elements, the research should be performed using interstitial free steels to eliminate the influence of solute carbon and nitrogen. In this paper, Hall-Petch relation was examined in iron, Fe-Cr alloys and Fe-P alloys with 0.02-0.05mass% Ti and the following results were obtained: 1) The Hall-Petch coefficient of interstitial free iron is about 0. 15MPa·√m. 2) Chromium does not give any influence to the Hall-Petch coefficient of ferritic iron, although the friction stress σ 0 is enhanced in proportional to chromium content (Δσ 0 [MPa]=7×(mass%Cr)). 3) Phosphorus does not affect the Hall-Petch coefficient of ferritic iron or reduce it somewhat but increases markedly the friction stress σ 0 (Δσ 0 [MPa]=250×(mass%P) 1/2). 4) Even under the co-existence of carbon with chromium and phosphorus, carbon dominantly works to increase the Hall-Petch coefficient of ferritic steels, but it is changeable due to the interaction between carbon and the other substitutional elements.

Original languageEnglish
Title of host publicationTHERMEC 2011
Pages181-185
Number of pages5
DOIs
Publication statusPublished - Jan 30 2012
Event7th International Conference on Processing and Manufacturing of Advanced Materials, THERMEC'2011 - Quebec City, QC, Canada
Duration: Aug 1 2011Aug 5 2011

Publication series

NameMaterials Science Forum
Volume706-709
ISSN (Print)0255-5476

Other

Other7th International Conference on Processing and Manufacturing of Advanced Materials, THERMEC'2011
CountryCanada
CityQuebec City, QC
Period8/1/118/5/11

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Influence of alloying elements on the Hall-Petch coefficient in ferritic steel'. Together they form a unique fingerprint.

  • Cite this

    Takaki, S. (2012). Influence of alloying elements on the Hall-Petch coefficient in ferritic steel. In THERMEC 2011 (pp. 181-185). (Materials Science Forum; Vol. 706-709). https://doi.org/10.4028/www.scientific.net/MSF.706-709.181