A656Grade80 steel plate is mainly suitable for manufacturing automobile girders, brackets, crane jibs, etc. The thickness of A656Grade80 steel plate is not more than 20mm, and the main features require high strength level.
1. Control of conventional elements
C. The increase of SiMn content is beneficial to the strength of the steel plate, so it is controlled according to the middle limit, and the content of impurity elements P and S is reduced as much as possible to ensure the metallurgical quality.
2. Control microalloying elements No, V, N, Mo The Mechanism of Microalloying Elements Improving the Strength and Toughness of Steel
2.1 Solid solution strengthening All alloying elements dissolved in ferrite can increase its hardness, tensile strength and yield strength. SiMn has the largest solid solution strengthening effect, followed by NiNb, V, etc., but in low-alloy high-strength steel , its strengthening effect is small.
2.2 Precipitation strengthening Nb, V, Ti form fine carbonitrides in the steel to prevent grain growth, inhibit recrystallization and enrich nucleation during deformation in the X non-recrystallized region, and at the same time have a strong precipitation strengthening effect, NbC, TiC, and VN are three basic compounds in low-carbon microalloyed steels, which have similar crystal structures and dissolve each other.
