Packaging contaminants on the surface of the steel strip for galvanizing what effect?

Packaging contaminants on the surface of the steel strip for galvanizing what effect? If oil is pure cold rolled steel strip surface, the evaporation temperature is about 180 ℃, basic can be vaporized in the galvanizing annealing furnace, participate in anaerobic furnace combustion or with the furnace gas from outside. So the impact is not big. But cold cream with grease, iron powder, dust mixed together, form the oil viscosity is very strong, firmly stick to the steel band, so to remove solid pollutants must first be skimmed. Grease is yellow staining appeared on the surface of the steel belt, and cleaning to remove a hard, a small amount of lubricating oil can also be volatile in the oven, but the oil often acres the pollution steel belt, so can't completely volatile inside the furnace, it increases in galvanized steel strip surface tension, affect the invasive of liquid zinc and steel strip, steel strip and liquid zinc isolated, steel, galvanized harmful defects such as, make products to be scrapped. Iron powder on the surface of the steel strip is very harmful to the galvanizing process. In the condition of high temperature inside the furnace, it will stick into the furnace bottom roll, form the bottom of the furnace roller nodules, when bottom roll with relative movement occurs between steel belt, can cause scratches. It will react with liquid zinc in zinc pot, generate zinc Cha. Zinc zinc slag composition is much less, 1 kg of iron powder can form 8 kg of zinc slag, zinc adsorption of certain liquid, so very little iron powder can cause great impact. Part of the zinc slag in zinc pot to form bottom slag and scum, but most of the adhesive steel strip surface defects such as zinc, zinc slag, zinc scar, seriously affect the product performance and appearance. Iron powder adhesive in zinc pot, on the stability of the roll and sink roll forming roll surface viscous slag of fillings in the steel strip surface embossing, is a major cause of downtime roll change. Dust on the surface of the steel belt and alkali stains left over after degreasing, in zinc liquid solidification will become the core of a crystal, a dust particles or alkaline stain point form a crystallization of the core, to generate the same flower. In dust or alkaline stain point crystal at the heart of the more populated area, before solidification clean place, zinc flower number, zinc is restricted and grow up to be a small asymmetrical zinc flower, it not only affects the uniformity of zinc flower, more importantly affect the adhesion strength of the zinc layer and substrate, leading to use coating fall off. So, before treatment is galvanized wire affect the quality of products the first key working procedure, it adopts the method of physical, chemical, remove most of the grease on the surface of the steel belt, iron powder, dirt and other contaminants, but also can remove rust and other adhesion strong pollutants. This is the one of the most basic of galvanized before work, as long as the pre-treatment passed, galvanized is half the battle. Pretreatment by more and more attention, the importance of early design improvement, Jimmy's method of boiler production line due to the presence of oxygen, purging of steel belt, degreasing effect is stronger, it had been before the design processing, modification, but in recent years have increased before processing. The current design of production line no matter adopt what kind of technological process, design the pretreatment, and technology is more and more long, technology is more and more advanced, the effect is better and better, investment is also more and more.