The formation of packaging steel strip steel surface oxidation iron

The formation of the packaging steel strip steel surface oxidation iron steel after roughing to strip along the roller during. Temperature about 1000 ℃, then the generated on the surface of the rolled piece to a thin layer of iron oxide, which the iron oxide can before into strip machine by the hydraulic removed, it can be cleaned away. When the rolled piece of rolling mills, plate between each stand mill suddenly and violently bad rumours of a very short time, and quantity of the big block thick iron oxide is formed on the strip between tables, and the formation of the oxide film which was damaged by water flushing. Therefore, it can be said that just came out from the finished frame of strip steel 780 - although wen defended High temperature of 850 ℃, but iron oxide on the surface of the steel strip is very thin. Strip out of the finished product frame, into the people behind the jet pack rolled strip coil and slow cooling is during this time, strip steel table and tin oxide and subjects. From the finished product stand out on the strip surface, iron atoms firstly combined with oxygen from the air to form the first layer of oxide. The oxide layer may be tight Fe3O4, or osteoporosis of FeO in the former case, further growth process of iron oxide can only rely on the oxygen and iron ion diffusion, in the latter case. The oxygen in air to freely through porous and loose of iron oxide and tin oxide thickening and densification. Regardless of the above cases, name of final wide formed as a result, we often see iron oxide on the surface of the steel strip. , of course, on the strip surface is generated after a layer of iron oxide, oxygen and iron ion diffusion has also been a certain block, and. The thicker the iron oxide, the ion diffusion is the greater the obstacle code, generate the tin oxide speed is slower. Iron oxide, therefore, grew up is not a constant speed, namely tin oxide thickness increased quickly at the beginning, after tin oxide thickness increase speed increases with touch oxidation iron out degree and slower and slower. In fact, under the condition of high temperature oxidation of sheet metal forming particularly strong, generally the higher the temperature, the production of iron oxide faster, when the temperature is below 600 ℃, the formation of iron oxide has been very slow, almost stopped can be thought of.