An Investigation Into the Influence of Weld Induced Residual Stresses on the Structural Behaviour of Built-Up EN 1.4003 Columns
The presence of longitudinal residual stresses within built-up sections may have a marked effect on their structural behaviour when used as a column [1]. EN 1.4003, also known as 3CR12, is a weldable utility stainless steel developed to provide a superior alternative to coated carbon steels and other alloys which have poor corrosion/abrasion resistance [2]. It is also an economical substitute for conventional stainless steel where environmental conditions do not justify higher alloy content. Hot-rolled structural sections are not readily available in stainless steel and are therefore usually build up by arc and lately laser welding. This paper presents the results of an investigation into the effects of thermally induced residual stresses on the structural behaviour of fabricated EN 1.4003 T-sections. Manual metal arc (MMA) welding and Laser welding are compared as regards to the induced residual stress distribution during fabrication. The residual stresses were measured using the neutron diffraction method. The effect of these measured residual stresses is investigated by incorporation into a non-linear finite element analysis. The buckling strength of a limited number of full scale columns was measured. Conclusions as regards to their effect on the structural integrity of the sections under investigation are made.