Optimization Of Technology For Continuous Galvanizing Line

Steel is the most widely used metal in the world.Galvanized sheet is more and more widely used in construction,household appliances,automobile and other fields because of good corrosion resistance coating and welding performance.Shougang group moved to Tangshan caofeidian from Beijing in 2006,the new project built four continuous hot galvanizing lines and production capacity is 1.6 million tons.Continuous hot galvanizing line has been put into production in September and November 2009.With the rapid development for SGJT's product,some strip surface requirement becomes higher and higher,especially high-grade car plate and household appliances plate and customer requires surface to be perfect.In the long run,we must do the future research and optimize galvanizing process.It will play an important role in overall development and benefit the cold rolling plant.Regarding the CGL present situation and the demand,this text shows the research for several main procedures for the galvanizing section as follows:(1)It has been that the distance of cleaning section brush rolls from rolling line is not the bigger the better.Brush roll diameter becomes smaller and smaller as with strip running,the brush roll location must be adjusted constantly.Ultimately the brush roller current control instead of position control is determined.(2)Confirmation of the material and using mode of wringer rolls.Rubber aging,improper using,and the surface adhesion of the steel strip foreign body lead to zinc leakage.And the use of magnetic separator and cleaning checking is confirmed.(3)in order to get good galvanizing surface,analysis on the influence factors of galvanized process has been done:including zinc liquid compositions,zinc pot level,temperature and strip temperature in the snout,etc.For technology research of galvanized core areas,we have a achieved several technology improvements:slag cleaning snout,scraper for sink roll,humidification equipment for snout and so on.Based on the research of the process parameters and the implementation of the technical project,the zinc ash,zinc slag,zinc flow lines and zinc layer unequal problems are eliminated,and the quality of the galvanized plate surface is improved.(4)by increasing the dew point in furnace pre-oxidation technology,line speed and dew point in furnace matching,reduced the hydrogen content in the furnace,the galvanized surface and corrosion resistance of high-strength steel are improved obviously.(5)In order to avoid the effect of light edge and plume on the strip,research and optimization the working roll shape,rolling parameter and accuracy of skin pass mill.Research on the use of liquid finishing and speed of moving car,clear up the mark on strip come from high pressure cleaning of SPM.