Influence of grain size distribution on the Hall-Petch relationship of welded structural steel

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:592

Article

Lehto, Pauli¹  Remes, Heikki¹  Saukkonen, Tapio²  Hanninen, Hannu²  Romanoff, Jani¹ 

[1] Aalto Univ, Sch Engn, Dept Appl Mech, FIN-00076 Aalto, Finland

[2] Aalto Univ, Sch Engn, Dept Engn Design & Prod, FIN-00076 Aalto, Finland

关键词: Grain size;    Hall-Petch relationship;    Hardness;    Strength;    Steel;    Welding;   

DOI  :  10.1016/j.msea.2013.10.094

来源: Elsevier

【 摘 要 】

The strength of polycrystalline metals increases with a decrease in grain size according to the Hall-Petch relationship. However, heterogeneous microstructures deviate from this relationship depending on the distribution of grain sizes. This paper introduces a rule of mixtures based approach for determining the characteristic length of the microstructure for heterogeneous weld metal. The proposed grain size parameter, the volume-weighted average grain size, is measured experimentally for nine structural steel weld metals and two base materials. The weld metals are found to have a large variety of grain size distributions that are noticeably broader than those of the base material due to differences in phase contents. The results show that the volume-weighted average grain size is able to capture the influence of grain size distribution on the strength of welded structural steel. Based on the experimental results, a modified Hall-Petch relationship is formulated for the strength prediction of heterogeneous microstructures. The modified relationship is also found to be applicable to data from the literature. (C) 2013 Elsevier B.V. All rights reserved.

【 授权许可】

Free