توصيفگر ها :
ريخته گري , اكسيد-گرافيتي , پرس ايزواستاتيك , رزين فنلي , مكانيزم انسداد , روس افشانك , غوطه ور , كاربيد سيليسيم , باند فسفاتي , ميكروسيليس , سيمان هاي آلومين , پلنيم , سكار80 , نسوزهاي ويژه , تبيولار , هيدراسيون , باند هيدروليكي
چكيده انگليسي :
AbstractContinuous casting is the most important method of producing ingot and slab in the worldand controlling parts of melt flow are Ladle Shroud LS Stopper S and SubmergedNozzle SN which are called Special Refractories The common manufacturing methodfor the production of these parts is mixing of raw materials including alumina graphite andsuitable additions with a phenolic resin or pitch and shaping with Cold Isostatic Pressing CIP followed by firing at above 1000 C in the reducing atmosphere under the coke bedsto develop carbon bond strengths without oxidation of the graphite The second method isusing Hot Isostatic Pressing HIP which employing high presses at above 1000 C byargon gas on steel plates as the molds containing the raw materials and soaking isperformed during shaping The aim of this project was studying the possibility ofproducing Special Refractories by using cold isostatic pressing of castables and replacinghigh temperature firing in reducing atmosphere of coke beds by employing hydraulicbonds of castables This new technology gives economical advantages and feasibility ofproducing these parts in Iran First the composition st ldies were performed for suitablephysical and mechanical properties The best composition at 400bars pressure was found tobe 55 alumina 20 alumina cement 15 graphite 5 micro silica 5 silicon carbideand 6 8 weight percent water above 100 w o raw materials The role of applied pressure onhydration reactions of refractory cement was also studied and the experimental resultsindicated that increasing of pressure increases the kinetic rate of hydration reactionsespecially at earlier stages of hydration The effect of different binders such as cement phosphate phenolic resin and combinations of cement phosphate and cement phenolicresin were studied on strength oxidation resistance and resistance against steel melt Theadvantage of double binders such as cement phenolic resin is that cement providesadequate bond at low temperatures and while weaker during heating up in service time theother bonder supports the structure and keeps the strength almost uniform Studying theproduction possibilities of special refractories by hydraulic bonds and isostatic pressingwithout the need for firing at reducing conditions studying the role of pressure on increasing the kinetic rate of hydration reactions of refractory cements and suggesting theemploying of double bonds are performed for the first time in this research and a newtechnology is presented which is approved by Iron and Steel Institute of Japan ISIJ rj i r 1rn t r 9 fI rII
