What Is The Key To The Quality Of High Solvent Hot Galvanized Sheet?
- Jun 04, 2018 -
What is the key to the quality of high solvent hot galvanized sheet?
(1) the quality of pickling directly affects the product quality.
(2) volume quality directly affects product quality;
Solvent component: zinc chloride (ZnC1) 750~800g/L ammonium chloride (NH purge C1) 50~80g/L
Solvent quality requirements: specific gravity 1.5~1.6 (baume meter) hydrochloric acid content no more than 6g/L
Iron salts (in FeC1 pools) do not exceed 6g/L sulfur dioxide (SO uncle) does not exceed 1.5g/L
Completely transparent and free of suspended matter.
(3) it is related to the operation and maintenance of galvanized rollers, which is a key factor that directly affects product quality.In general, galvanized roll before using, its surface should use HCL scrub clean, then apply solvent, and on the zinc pot preheating 1.5 ~ 2 hours, pay attention to the turning rolls when preheating, don't put the solvent layer of burnt.Galvanized roll down zinc liquid temperature should be controlled at 465 ℃, must quickly to roll a into liquid zinc, galvanized roll after 1 ~ 1.5 hour in zinc liquid, put the roll surface is put forward, quickly and for roll zinc liquid temperature is not lower than 455 ℃. At the same time, the roll immediately when the roll rotation, to maintain uniform roll humidity.Let the roll idle running 1 hour or so, on both sides of the roll to produce a layer of flexible after oxidation film, can be put into production, in the process of production, we must keep the rollers on both sides of the integrity of the oxide film and tidy, make its have the effect of the "doctor".As production proceeds, the oxide film on both sides of the roll increases and thickens continuously. At this point, the renewal of the oxide film is required.Generally speaking, the old mould should be taken out from its outer edge every 2~3 hours, so that the surface of the roll always keeps the new oxide film, so that it can fully play the role of "scraper".If oxide film don't update in time, will be continuously increasing, when the oxide film on the roll Angle is greater than 30 °, lose the "blade" role, and easy to produce zinc scar on the surface defects.