As mentioned last time, the processing technology of precision casting is complex, and it takes many processes to complete the production and processing work. The process of precision casting is also very different from the traditional process. In order to obtain better appearance quality, some precision castings need to go through the pickling process, and then undergo electroplating, enamel, rolling and other processes.
Pickling of precision castings is also a complex process. Before pickling the workpiece, the staff need to wear hats, work clothes, masks, protective glasses, rubber gloves, rubber aprons and long rubber boots in advance to prevent the acid from splashing on the skin. When the staff is making the acid solution, they must first fill the tank with water, and then slowly pour the acid solution into the tank. If you need to prepare mixed acid, you need to strictly follow the sequence of acid injection into the tank, add hydrochloric acid first, then add nitric acid, and add sulfuric acid at the end. It will cause serious harm to the personal safety of the staff and the subsequent production of castings. When transporting acid, choose a dedicated gripping and lifting tool. If the staff is working in the pickling tank with the edge of the tank higher than the ground, they cannot stand on the edge of the tank to carry out the operation process.
The pickling tank should be equipped with a separate air extraction device. When configuring the acid solution and performing the pickling process of the casting, the fan needs to be turned on. The pickling process can proceed normally. In the pickling work, the temperature should be well controlled, and the working environment of the pickling should meet certain specified standards. When the precision casting is put into the tank, it should be slowly put into the acid solution to avoid the acid splashing. At the same time, to ensure the acidic environment of the acid solution, it is strictly forbidden to bring alkaline substances into the acid tank. After pickling, the casting should be cleaned immediately, and the acidity of the surface of the casting should be neutralized according to the process regulations.
Hoisting equipment, tool clips, ventilation ducts and other devices should be inspected regularly. If they are found to be corroded, they should be replaced in time. The wire ropes and spreaders of the hoisting machinery should be replaced regularly to ensure the safety of pickling large castings. When the pickling tank is not in use, the pickling tank should be covered. If the skin of the staff is contaminated with acid during the pickling process, it should be washed with clean water immediately, and the workplace should be equipped with the necessary medicines.
Pickling is an important link in the processing of precision castings, which is related to the subsequent quality of the product. Therefore, for the pickling process, not only should pay attention to the safe operation in production, but also pay attention to the operation quality of the pickling process.