Study On A New Kind Of Composite Impurity Agent Used In Making Clean Steel

Steel is base material, it created a modern civilization. A sufficient number of high-quality steel is all the necessary conditions to realize industrialization. Clean steel in recent years is the fastest development, application is extensive, most vibrant steel varieties of one. Clean steel are in low carbon steel or ultra-low carbon steel foundation with the physical and chemical methods add impurity removal agent, The steel the impurity element S, O, N, P, H reduced, and with controlled rolling process of controlled cooling combination, to achieve the high strength and high toughness, thus make steel the comprehensive performance can be improved. How to remove the steel within the inclusion improve its performance, is the key problem facing clean steel.This topic research in a low-carbon steel adding self study design of complex element impurity removal agent. First of all, according to the metallurgical physical chemistry reaction mechanism design complex element impurity removal agent the component and proportion, the determination of reasonable melting process system, analyzing main impurity element S, O, N the removal, and carry out relevant thermodynamic calculation. Then in vacuum induction furnace is melting, in ultra-low carbon steel smelting process to join the removal agent. Component analysis results show that the S content low carbon steel can be reduced to 10×10-6, O content can be reduced to 19×10-6, N content can be reduced to 13×10-6, to achieve the desired objectives.Determine a laboratory methods will impurity removal agent to join in liquid steel. By adopting a controlled rolling controlled cooling process in lab smelting steel by austenitic a.v., for rolling. In subsequent cooling process, deformation austenitic change, Its steel organization by massive ferrite and granular bainite composition.The tensile fracture morphology of experimental steel's characteristic is nest fracture toughness, not added a composite impurity removal agent to join composite impurities removal agent low-carbon steel is concerned, as steelmaking refining agent AD-20-powder (removal agent contains) content decrease, corresponding yield strength, tensile strength and reduce first increases. Steel refining agent AD-20-powder content is 1%, S elements significantly higher than other removal efficiency, the yield strength, tensile strength to achieve maximum, tensile strength for 685MPa, yield strength reached 560 MPa. Although elongation and impact toughness decrease, but steel comprehensive mechanics performance to achieve the best, precipitation strengthening and fine-grain strengthening plays a main reinforcement.