Continuous hot dip galvanizing with copper adopts online continuous annealing
Continuous hot galvanizing of process strip steel adopts online continuous annealing. Annealing process is produced by hot galvanizing products of high strength steel such as two-phase steel.Key, it has a great influence on the enrichment of Mn, Si and other elements on the surface of steel plate, which will affect the plating property of high strength steel and its surface quality. The annealing process of galvanized steel plate usually includes preheating, heating, equalizing and cooling. With the use of heating exhaust gas pretreatment, tropical steel can not only save fuel, but also avoid the deformation of strip steel caused by the rapid heating speed of strip steel, which is very beneficial to the plate shape of products with thin specifications. Of some units in the cooling process using cold catch cold, quick way of segmented cooling, can avoid cold, but too fast caused bad flatness, and can meet the requirements of high strength steel cooling speed of dual phase steel, etc. Some manufacturer after cooling section, also set up the balanced section, the purpose is to provide a buffer between galvanized and cooling section area, so that the strip has a much better, flatness and more uniform temperature into the zinc galvanized steel, improve the quality of the galvanized. In addition, annealing furnace furnace roll roll shape design, retreated inside furnace, atmosphere and the dew point of fire control, tension control in furnace and annealing furnace furnace roller surface spraying is a focus in the study of hot galvanizing annealing process, and high strength steel for thin strip flatness and plate stability also need further research. & nbsp4 alloying process alloying is refers to the hot dip plating of pure zinc coating immediately in 450 ~ 550 ℃ under the coating diffusion annealing, the iron content is between 7% ~ 15% of zinc alloy plating process. The main factors influencing alloying include the content of available aluminum in zinc solution, the temperature of zinc pot, the temperature of zn steel with steel, the alloying temperature, the speed of steel strip, the chemical composition of substrate and the thickness of coating. The coating of high quality alloying products usually does not contain dentate "phase" (F3Z n 10) between the steel plate and the coating, and the surface of the coating does not contain a large number of columnar ethyl phase (FeZn). 13). It needs to choose the appropriate alloying coating annealing process, the heating rate, soaking time and cooling rate on strict control system. The alloying technology in China is relatively weak, coating powder or flake is seen during stamping defects, urgent need for alloy, technology are studied systematically, especially the study of the phase structure of coating and its influence. & nbsp5 Leveling process, to eliminate strip yield platform, access to good strip flatness and appropriate strip surface roughness, hot galvanized steel sheet, to the line is flat and level. Smooth process parameters including rolling force, bending force, tension and smooth export smooth entry. In improving the board, and raising the quality of the strip surface is obviously better than the four-roll temper mill roller leveler. At present, Japan has developed the work roll can be, for different four-roll temper mill, roller diameter can be better control of different specifications and grade of steel galvanized products of flatness and surface roughness.Galvanized sheet surface roughness control is one of the key technologies in the high quality of galvanized products, mainly is for flat roller roller surface, mode and its parameters and formation parameters are studied, such as another temper mill work roll roll diameter size and roll surface roughness and so on, also has effect on the product surface coarse accuracy. Roughen, among them, the roll surface peening roughen and edm roughen the most widely used, cream, light roughen due to the long period and too high cost, seldom used, and chrome plated roughen and electron beam roughen more research in recent years, rapid development, but hasn't been widespread. In addition.