Structural performance of stainless steel sections fabricated by laser-welding, hot-rolling and extrusion

Abstract

This paper presents an experimental investigation on the structural performance of austenitic stainless steel columns with open sections fabricated by laser-welding, hot-rolling and extrusion. The aim of the experimental programme was to quantify and compare the effect that different fabrication techniques have on the structural behaviour of the columns. The investigated cross-sections were extruded and laser-welded I-sections with the American designation S5x10, and hot-rolled and laser-welded channel sections with the European designation UAP 120x60x6. All sections were fabricated from austenitic stainless steel grade 1.4307/1.4301 (dual certified). The experimental programme consisted of stub and long column tests, as well as measurements of all the parameters that were considered to have an impact on the structural behaviour of the sections, including: material properties, cross-sectional geometry, residual stresses and global geometric imperfections. The tests showed that although the residual stresses and geometric imperfections of the austenitic stainless steel laser-welded columns are similar to those of the extruded/hot-rolled columns, their structural performance was noticeably better than that of the extruded sections, and equivalent to that of the hot-rolled sections. The experimental data was also used to assess the adequacy of the European column curves for laser-welded and hot-rolled open sections susceptible to flexural buckling about the minor axis. It was found that while for laser-welded I-sections it may be possible to justify a higher buckling curve, more research is needed for channels.