Effect Of Adding Different Treatment Methods Nano ZrO₂Particles On The Structure And Performance Of Casting And Hot-rolled Carbon Steel Grain

High strength, high toughness and high plasticity of steel material is the idealmaterial. Improve the strength and toughness of steel and plastic is the best way to refine the grain[1]. Fine grains must be demanded in steel were fine and dispersion precipitates or the secondphase of the controlled rolling process of controlled cooling joint implementation. Deposition orthe existence of the second phase has the effect of two aspects, on the one hand, precipitationstrengthening, improve the strength of materials. On the other hand is pinning grain boundary toprevent grain growth, refine the grain size[2].Small dispersion of precipitated phase in steel or second relatively steel group performancehas a positive impact. The dispersion of tiny particles in casting process can have the effect ofnucleation agents, grain refining casting organization, if these particles exist in the grain boundarycan also play the role of pinning grain boundary. When casting austenite grain size is small, hotrolled austenite will be more fine to end can form ultrafine ferrite. Or the second phase in theprocess of rolling, finer particles have the effect of fine grains, internal or external precipitationmethod adding method can make for two phase particle in steel, external adding method is easierto control the distribution of second phase particles, number, size[3]. Based on improving theperformance of the steel has a positive effect, so by adding the method to add two phase particle insteel has become a subject worth exploring.Plus ultrafine particles in molten steel on molten steel composition and accuracy is not high,and the handle is easy to control, to refine casting organization and crystal grain size and variousmechanical properties after hot rolling all have positive effects. This article summarizes thecurrent and the research on the method of second phase particles in steel, use a variety of way toadd to add ZrO2nanoparticles to the Q345steel liquid, ZrO2nanoparticles are analyzedtheoretically in the movement behavior of liquid steel, ZrO2nanoparticles of heterogeneousnuclear capability, nano ZrO2particles in the liquid steel in thermodynamic stability. Throughmetallographic analysis, scanning electron microscopy (sem) analysis, XRD analysis experimenttechnology, research in different mass fraction of ZrO2nanoparticles of Q345steel casting and theinfluence of the grain size, structure, performance, and its refinement mechanism are discussed.The experimental results show that the liquid steel solidification, ZrO2nanoparticles hadobviously refine as-cast organization effect; In the process of rolling ZrO2nanoparticles also havethe effect of refining grain; ZrO2nanoparticles after dealing with the surface modification effecton the performance of the steel is better than not after surface modification treatment of ZrO2nanoparticles.