How to reasonably control the temperature of zinc liquid and the temperature of the strip into the zinc pot?
In the process of hot dip galvanized, zinc liquid required to maintain the normal work of the temperature at 450 ~ 460 ℃ (455 soil "5 ℃), while the strip into the zinc pot temperature depends on A1 content in zinc pot on the strip thickness, generally speaking when iron A1 content in zinc pot in 0. 10 ~ 0. 12%,
If the aluminum content is lower in zinc pot, it should be taken to a higher in zinc pot temperature, strip into the zinc pot at high temperature, the coating of aluminum content in the corresponding is high, at the same time, coating adhesion, at this point, may cause the zinc liquid temperature is too high, so, when using iron zinc pot, must around the zinc pot of forced air cooling is used to decrease the temperature of liquid zinc, if use induction zinc pot, it shall not adopt any of the above methods.
In induction zinc pot, temperature and liquid zinc strip into the pot at almost the same temperature, in order to get good coating material attached, you must keep the induction of aluminum content in zinc pot at about 0.15%, in practice, often make the strip temperature higher than zinc liquid temperature 25 to 30 ℃.
What is the effect of galvanizing speed on the thickness of pure zinc coating?
Generally speaking, increasing the speed of galvanization will lead to the coating of pure zinc layer thickening, because the strip steel from zinc liquid
Came out of the liquid zinc adhesion on steel strip surface, and the vertical movement above the zinc pot, because the function of vertical force oneself, adhesion on the strip surface zinc liquid flows to strip from a liquid zinc zinc pot if speed is slow, from the upper back to zinc pot liquid zinc, the pure zinc thin layer, if galvanized faster, zinc strip on the surface of a liquid to flow back to zinc pot was taken away by the strip and cold coagulation, the pure zinc layer is thick.
How to control strip speed reasonably?
Strip speed should be in accordance with the established curve to a given table or annealing process, the productivity of strip speed is decided to strip annealing time and important process parameters of zinc dipping time, in the modern strip continuous hot galvanizing line, when poor coating adhesion, in the absence of clear the real reason, first reduces the running speed is the most efficient way.Secondly, when the specification of each coil of strip steel changes, the strip speed must be adjusted accordingly, the strip speed must be changed, and other parameters must be adjusted accordingly. In short, the continuity of the production process must be paid attention to before and after the adjustment of various technological parameters.