The Study Of The Tissue Feature Of The Rare Earth Oxide Passivated Magnesium Powder And Its Ignition Proof And Desulphurization Performance

In the present dissertation, a new type of rare earth oxide passivated magnesium powders as desuifurizer in molten iron was prepared by the combinative method of physics and chemistry(labeled as P-C sample). It was tested and analyzed compared to two present passivated magnesium powders(one was prepared by physical method, labeled as P sample; another one was prepared by chemical method, labeled as C sample).The ignition-proof time, burning point and surface topography as well as the composition and structure of the surface layers of the three kinds of passivated magnesium powders were determined by means of TG/DTA,SEM,XRD,EDS line scan and AES.The mechanical properties of the surface layer of the passivated magnesium were studied by nanoindentation method and tensile test to simulate that of the new passivated magnesium powder. The feasibility of desulphurization by passivated magnesium powder in molten iron is expounded through calculation in thermodynamics and dynamics in this article and the industrialized desulphurization trial of the rare earth oxide passivated magnesium was processed in the Bao-steel Co.Ltd. The main results after...