The Research And Application Of The High-speed Steel Rroller For Bar Rolling Mill In The Chongqing Iron And Steel Company

This paper analysed the influence of the microstructures and property about alloying agent in high speed steels in detail. A type of high speed steel roller was designed , which ingredient includes 2%-2.5%C,9%- 11%W,4.0%-5.0%Mo,4.0%- 7.0%Cr,3.0%-5.0%V,0.8%-3.0%Co,0.3%- 0.8%Ni,0.4%-1.5%Al,0.8%-1.5%Nb,Si<1.5%,Mn<1.2%,S<0.05% and P<0.05%. The roller material have the good characters of simple melting,casting property, hardenability, abradability, and so on.High speed steel roller smelted by electrical furnace in the article. RE-K-Na compound alterative was used in casting ladle by the way of pitching. When the temperature of dischargement was restrainted from 1580℃to 1620℃, high quality molten steel can be produced that fulfilled the request of roller. A high quality of high speed steel roller was got by optimizing the centrifugal casting parameter of that. These casting parameters includes the preheating temperatures of mouldings (250~320℃) , the thickness of coatings (1.2~1.8mm), the temperatures of mouldings (160~220℃)., the number of moulding's turns(850~980r/min) , the temperatures of casting (1450~1480℃), the time of centrifugal freezing (15~20min).The flaw for example the gas porosity, shrinkage porosity, loosen and lard in the centrifugal casting high speed steel roller when the freezing voiety of liquid steel is accelerated, pouring hose is changed and coating bending workcraft is improved. The use of high speed steel roller on roller machine in cuttingΦ12 bar and wair stock in the branch of struction section is good. The wear of rolling ark is uniform. No alligator crack, abradability well, rolled metal's surface smoothness, precision high. Its'operational span life was improved five times, almost equal to sintered-carbide roller. Thus, the cost of production decrease 70% than that. At the same time, the brust for its'low ductility can be erased thoroughly. The use of high speed steel roller can improve the work effiency, decrease the cost of production, have good economic returns.