Plastic strain characteristics of butt-welded ultra-high strength steel (UHSS)

Mohsen Amraei, Tuomas Skriko, Timo Björk, Xiao Ling Zhao

Research output: Journal article publicationJournal articleAcademic researchpeer-review

55 Citations (Scopus)

Abstract

This paper investigates the mechanical properties of direct quenched (DQ) ultra-high strength steel (UHSS) joints in butt-welded configuration. Experimental and numerical investigation of the monotonic behavior of heat-treated and welded UHSS is undertaken. The tensile tests in the study investigate the effects of three different parameters on the plastic strain capacity of UHSS, namely: size of the heat affected zone (HAZ), matching between the filler material and the BM, and welding and post welding treatments such as TIG-dressing and high frequency mechanical impact (HMFI) treatment. Laser welding with a narrow HAZ was also performed without filler material and with zero air gap. A digital image correlation technique was utilized to monitor the plastic behavior of the specimens under tensile loading. The results indicate that the strain capacity of the joint is highly sensitive to heat input (HI); even a small HAZ leads to a considerable drop in the strain capacity. A strong constraint at the boundaries of the HAZ with the surrounding material generates a hydrostatic stress component, and thus an increase in both the ductility and strength of the joint can be expected.

Original languageEnglish
Pages (from-to)227-241
Number of pages15
JournalThin-Walled Structures
Volume109
DOIs
Publication statusPublished - 1 Dec 2016
Externally publishedYes

Keywords

  • Heat input
  • Heat-affected zone (HAZ)
  • Plastic strain
  • Post-welding treatment
  • Ultra-high strength steel

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Building and Construction
  • Mechanical Engineering

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