The tensile test results show that all kinds of microstructures detected in S355JR steel plate have high plasticity. Ferrotitanium bainite microstructure steel has the highest strength and hardness and the lowest plasticity. The microstructure of S355JR steel plate with ferrite-pearlite and solidified carbide ferrite is similar in strength and plasticity.
The S355JR steel plate is widely used in various structures, and its components are often welded together. Therefore, bainite-ferrite microstructure materials are formed in welding materials and heat-affected zone materials.
Long-term use of welding elements in S355JR steel plate, especially at high temperatures, can lead to changes in microstructure and the formation of ferrite steel with solidified carbide. Understanding the mechanical properties and fracture properties of various microstructures of S355JR steel plate is conducive to more accurate analysis of its strength and durability in the process of use.
