reducing the weight of zinc layerSince
The price of zinc has risen, many domestic hot-dip galvanizing enterprises are trying to reduce the weight of zinc coating to avoid excessive increase of production cost.
The company also faces the same choice, otherwise, will fall in the fierce market competition, into the disadvantaged position.
Of course, reduce the weight of zinc layer as much as possible, only in the customer acceptance, market acceptance conditions.
When the customer specifies the weight of the zinc layer, it must be produced according to the weight of the zinc layer signed by both parties.There are many factors that affect the weight of zinc layer. In order to reduce the weight of zinc layer to the greatest extent, it is necessary to start from various aspects and make all-round efforts to push forward comprehensively.1. Improve the content of zinc and aluminum and enhance the fluidity of zincLiquid zinc is not very liquid and liquid aluminum is very liquid.
As the content of aluminum in zinc liquid increases, the fluidity of zinc liquid will be enhanced, so the amount of zinc liquid taken out of the zinc pot by the surface of the steel strip will be increased, and the remaining amount will decrease, and the thickness of zinc layer will be reduced. Plating factory 2 # hot galvanizing line, in the spring of 2007, the production of export without zinc plate, due to the substrate in the cold rolling reduction is relatively small when, board face iron powder is relatively small, and hot dip galvanizing line of degreasing roller scrub normal start up, remove the floor of the vast majority of iron powder, steel belt into zinc pot quantity iron powder is greatly reduced, therefore consume greatly reduced the amount of liquid zinc aluminum, so, in the same use big zinc containing 1.07% aluminum ingot, zinc pot in the aluminum content is increased significantly than in the past, remain at around 0.67%. Due to the increase in aluminum content, the mobility of zinc liquid has been enhanced. The steel belt with a thickness of 0.35mm runs 120m /min, and the weight of zinc layer can be controlled at 70g/m2.Effective.
The trend shows that the weight of zinc layer will decrease with the further increase of the content of zinc liquid aluminum.
You can do this by adding small zinc alloy ingots (" zn-10% A1" or "zn-15% Al", preferably" zn-5%"The method of "A1" gradually improves the content of zinc liquid aluminum and the relationship between the content of test aluminum and the weight of zinc layer, so as to determine the content of new aluminum in the zinc liquid with thin zinc layer.Adjusting the content of zinc liquid aluminum should be subject to the following constraints. First, coating adhesion cannot be deteriorated. Second, the zinc layer does not deteriorate in corrosion resistance.
Thirdly, the surface quality of the zinc layer shall not deteriorate, and there shall not be surface defects that did not exist in the past.
Fourth, the coating appearance features can not be changed basically, the appearance features without zinc spend board to want with before without zinc spend board basic consistent, the appearance features of big zinc spend board should want with before big zinc spend board basic consistent, otherwise, the user can not approve.Another product adjacent to the chemical composition of a common hot zinc plate is the Galfan plate, or GF plate, which contains 5% aluminum.Galfan's research history shows that the transition from 0.10 percent to 5 percent aluminum content, with increased coating adhesion and corrosion resistance, is of no concern to both.
The content of zinc liquid aluminum can be gradually and steadily increased step by step. During this process, the coating surface can be closely watched. As long as the surface quality remains good, no defects such as leakage plating point and "depression" occur, and the original appearance is maintained, the content of aluminum can be continuously improved.
Otherwise, it will no longer raise the content of aluminum. Through the test, we can find the aluminum content of the zinc liquid under the premise of full compliance with the four requirements. (.However, the aluminium content should not be closer to 5 per cent, as it can be exposed to a shortcoming in the surface gloss of the Galfan plating which is not visible at the time of production. The upper limit of aluminum content in the test shall be no more than 2% or 2.5% and no more than 3%.