5 Factors Affecting Surface Brightness and Cleanliness of 8" NPT Schedule 40 carbon steel pipe fitting
(1) The oil content in the emulsion is too high. The emulsion used in cold rolling mills is composed of water, emulsifier and oil. The emulsion has both a cooling and smoothing effect, and the oil cracks into carbon at high temperatures. If these carbons are not removed in time, they will accumulate on the surface of the 8" NPT Schedule 40 carbon steel pipe fitting, and will form indentations after being flattened by a flat engine. Therefore, the oil content in the emulsion is an essential factor affecting the quality of the steel plate. one.
(2) A lot of carbon black is attached to the inner wall of the maintenance cover. Because the oil level in the emulsion is very high, carbonization will occur after annealing in a bell furnace. As a result, carbon accumulates on the inner wall of the protection cover, and with the addition of annealing furnaces, carbon black is added. If it is not cleaned in time, under certain conditions, the carbon black will be scattered on other steel coils, and after processing, the carbon will be attached to the surface of the 8" NPT Schedule 40 carbon steel pipe fitting.
(3) The amount of HNX annealing furnace purging is lacking. The recovery function is poor. Because the purging sensitivity of the maintenance gas in the HNX annealing furnace is only about 20-25 cubic meters (standard)/h, the gasified oil is often difficult to be blown off during heating and heating, so that the outer ring of the steel coil still remains A black band appeared early. It polluted the surface of the 8" NPT Schedule 40 carbon steel pipe fitting. In addition, because the normal hydrogen content of this maintenance gas is only 3% to 6%, most of it is nitrogen. Therefore, the carbon content cannot be recovered. Because nitrogen is an inert gas, it cannot be combined with the vaporized gas, so it can only be blown out, and the accumulation of carbon cannot be avoided.
(4) The furnace table and convection plate are not cleaned. Similarly, some carbon black, oil, dust, etc. will also accumulate on the surface of the furnace table and convection plate. If the furnace is not cleaned immediately before loading, the carbon black, oil and dust will also be scattered on the steel coil, affecting the appearance quality.
(5) The emulsion on the steel coil is not clean after blowing off. The outlet of the tandem cold rolling mill is equipped with a purge installation, which is used to continuously remove the residual emulsion and oil stains on the surface of the strip.