Alternative Advantages of Laser Cleaning to Metal Pickling（2）
May 09,2023 | TOPTEK
Alternative Advantages of Laser Cleaning to Metal Pickling (divided into two explanations of 1 and 2, this is 2)
Comparative advantages of laser cleaning
①Process flow and operation requirements
Compared with the pickling method with as many as a dozen processes, laser cleaning has the simplest process and can basically be completed in one step. Significantly reduces cleaning time and material loss.
The pickling method has strict requirements on the operation process: the workpiece must be degreased at the bottom to ensure the quality of rust removal; the concentration of the washing liquid is controlled to prevent corrosion of the workpiece due to excessive acid concentration; the temperature is controlled according to the process specification to avoid damage to the workpiece and Corrosion; Control devices such as sludge gradually deposited in the pickling tank and sludge heating pipes need to be cleaned regularly; in addition, pickling time, spraying pressure, laser operation, exhaust equipment, etc. all need to be carefully waited for.
After the previous parameters are set, laser cleaning can realize foolish operation, and even realize automatic unmanned operation.
② Cleaning effect and environmental pollution
In addition to stronger cleaning effect, laser cleaning also has the advantages of greater fault tolerance:
Due to improper pickling operation, oxygen spots, yellow spots, redness, blackening and other phenomena often appear, and the reject rate is high.
Experiments have proved that even if laser cleaning is supersaturated, it still has a strong metallic luster, will not produce pollutants such as hydroxide radicals, and will not affect subsequent processing methods such as welding. Laser cleaning will not cause environmental pollution such as waste liquid and slag. Produced, is the greenest cleaning method.
③ Unit cost and conversion cost
The pickling method requires chemicals as consumables, so the unit cost is equipment depreciation + cost of consumables
Laser cleaning does not require other consumables other than the purchase of equipment. The unit cost is the equipment depreciation:
Therefore, the larger the cleaning scale, the longer the service life and the lower the unit cost of laser cleaning
The composition process of the pickling production line is complex, and the proportion of pickling agents for different metal materials is also different. Therefore, the replacement of the production line requires a large production conversion cost, and the metal material that needs to be cleaned in a short time is single and cannot be replaced flexibly. No switching cost for laser cleaning: After switching the software parameters, the same cleaning machine cleans the steel plate one minute, and cleans the aluminum alloy the next minute. It is convenient for enterprises to implement flexible production.
metal pickling
① Common defects of metal pickling:
Scale Intrusion: Scale indentations are surface defects formed during hot rolling. After pickling, it is generally pressed into black dots and strips, the surface is rough, generally has a hand feeling, sporadic or dense. It is often caused by imperfect pickling heating process, descaling process, rolling process, etc.
Oxygen spot (surface landscape painting): refers to the dot, line or pit-like phenomenon left after the oxide skin on the surface of the hot coil is washed off. System press) matrix, highlighted after pickling. Has some effect on appearance, but has no effect on performance.
Yellow spots: Yellow spots appear on part or the entire surface of the board, which cannot be covered after oiling, affecting product quality and appearance. The main reason is that the surface activity of the strip steel that has just been pickled is high, the rinsing water cannot normally play the role of rinsing the strip steel, the water jets and nozzles of the rinsing tank are blocked, and the angles are not equal.
Insufficient pickling: The surface of the steel strip has local oxide scales that are not removed cleanly and insufficiently. The surface of the steel strip is gray-black, with fish scales or horizontal water ripples. It is related to the acid solution process, mainly because the concentration of the acid solution is not enough, the temperature is low, the running speed of the strip steel is too fast, and the strip steel cannot be immersed in the acid solution.
Pickling: The surface of strip steel is often dark black or brownish black, with massive, flaky black spots or yellow spots, and the surface of strip steel is generally rough. The reason is the opposite of insufficient pickling.
②Environmental pollution by metal pickling:
The main pollutants in the production process are the cleaning waste water generated by the washing processes at all levels, the dust generated by the spraying process, the hydrogen chloride acid mist generated by the pickling process, pickling, bleaching, phosphating, neutralization, and rust prevention processes. Liquids, waste residues, waste filter elements, raw material empty barrels and packaging waste, etc. The main pollutants are hydrogen chloride, PH value, SS, COD, BOD, ammonia nitrogen, petroleum, etc.
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