The Affect Of Microstructure And Properties Adding ZrO_ 2 Nanoparticles On Carbon Steel

Structural steel high performance is currently an important research direction of the material, alloy strengthening and toughening theory suggests that, to avoid the ductility decreases under the premise of substantial increase in intensity is the most effective way to refine the grain size. Grain refinement can bring obvious grain boundary strengthening effect, can keep the plastic without lowering the premise of improving the strength of alloy steel.Fine grain strengthening research mainly concentrated on the deformation and transformation coupling and the study of nano precipitated phase in ultra-fine grain steel in a two direction. The grain refinement methods and effects in the presence of two extremes : one is the industrial application of the method for grain refinement rate is not high ( 10-100 /μm ); the two is the high degree of grain refinement method is not suitable for industrial scale production of steel. From the outside to the steel liquid is added to the second fine particles can refine the microstructure, and improve the comprehensive mechanical properties of steel. This paper studies the molten state in the Q235 steel with different volume fractions of ZrO₂ nanoparticles after hot rolling on the microstructure and mechanical properties of impact. The results show that, by adding 0.3% ZrO₂ nanoparticles rolled tissue, its grain size is 4.50μm, yield strength and tensile strength were 253.25MPa and 369.3MPa. And did not join ZrO₂ nanoparticles Q235 steel grain hot-rolled Organization ( compared with grain size of 24.19μm ), grain refinement of 81.4%, yield strength and tensile strength were increased by 24.75MPa and 60.8MPa. Elongation and contraction rate increases.