Optimizing weathering steel tie rod production for sustainable greenhouse structures

Abstract The current paper is based on a case study conducted at an industrial facility in Egypt, which is responsible for processing greenhouse structures. Steel tie rods play a vital role, as they prevent the truss frames from spreading outwards. Irrigation and plant transpiration generate water vapor that condenses on truss parts, accelerating corrosion and degrading the mechanical performance of the truss system. To enhance durability under these conditions, the study investigates the use of weathering steel, a copper-alloyed structural steel known for its long-term corrosion resistance. Furthermore, the study investigates the flanging process used to create tie rod ends, where uneven flange thickness and non-homogeneous deformation have been observed due to deformation in the unstable region of the hot-working map. The process was conducted using a 14-ton press at 700 °C with a strain rate of 0.4 s⁻¹. It was found that a steel composition containing 0.37% Cu with phosphorus provides optimal resistance to weathering and humid conditions. The processing map revealed stable deformation regions between 1000 and 800 °C, with an optimal hot-working window at 850 °C and a strain rate of 0.03 s⁻¹. The integration of weathering-steel alloying with optimized processing parameters significantly improves durability, stability, and sustainability.