Research On Anti-penetration Technology Of Cast Steel Cooling Wall And Prevention Of Sand Sticking Defects

The cast steel cooling wall used in blast furnace has the characteristics of high elongation,high tensile strength,high melting point and good thermal shock resistance.However,The casting temperature of cast steel cooling wall is high,the cooling water pipe preset during casting solidification is easy to deformation and melt through,after solidification,the cooling wall surface surface is more serious adhesion sand.In order to solve the above problems,this paper studies the anti-penetration technology of cast steel cooling wall and develops the anti-sand coating for cast steel parts,which is of great significance for the application of cast steel cooling wall to replace cast iron cooling wall in blast furnace.In this paper,the mold filling solidification process of cast steel cooling wall is simulated by using casting finite element simulation software.The results show that when the casting temperature is 1550 ?,the maximum heating temperature of the cooling water pipe during mold filling is less than 1100?,which is lower than the solid-phase line temperature(1473.2 ?),and the cooling water pipe will not melt through during mold filling.During the solidification process,the maximum heating temperature of the cooling water pipe is 1502??1510?,exceeding or approaching its melting point(1503.6?),and the cooling water pipe may melt through during the solidification process.If the cooling pipe is filled with solid cooling materials,the maximum heating temperature of the cooling pipe during the solidification process of the cooling wall is 1492.4?(below the melting point of cooling water pipe),the minimum heat temperature of 1476.2?(above the solidus temperature of the cooling water pipe),can not only keep the cooling water pipe from melt through,also can realize the cooling water pipe and metallurgical combination between cooling stave matrix.Based on the numerical simulation results of the cast steel cooling wall,the concrete process method of filling the experimental pipe with resin sand as the solid cooling material was studied,and whether the process method could guarantee thecooling pipe not to be melted through during the pouring process was verified in the production site.The results show that the filling efficiency of resin sand can reach99.1% when the solid cooling material is resin sand with baozhusha as the original sand,the filling pressure is 0.5 MPa and the binder content is 1.2%.If the amount of corundum sand added accounts for 15% of the total weight of the original sand(Treasure sand accounts for 85% of the total weight of the original sand),the cleaning efficiency of resin sand can reach 96.8%.In the production site,it is found that the cooling wall matrix is well combined with the cooling water pipe,no obvious macroscopic clearance is observed,and the cooling water pipe has no deformation or penetration.According to the metallographic structure analysis,metallurgical bonding occurred between the cooling wall matrix and the cooling pipe,and the average shear strength in the bonding area reached 318 MPa.Developed a kind of white corundum as aggregate steel coating,adhering sand through the single factor experiment and orthogonal experiment to study the influences of coating composition on properties of coatings,get the optimization of the following formula: "100% powder(white corundum,potassium feldspar,iron oxide = 100:24:12)+ 9.8% water swelling after the lithium base bentonite + 1.8%phenolic resin + 0.36% methenamine + 0.12% PVB + 66% alcohol".During the production site casting verification,it was found that most of the sand mold on the surface of the cooling wall could be directly detached,and only spot-like sticky sand was found in the groove of the cooling wall.The cleaning area of the cooling wall casting reached more than 95% of its surface area,which could meet the requirements of the production site.