After the wire rod or the intermediate wire blank is chemically descaled and coated, in order to remove hydrogen and moisture, it is required to be heated at a low temperature or dried. Drying temperature is generally 26%; 300 ° C, the temperature should not be too high to prevent the lubrication coating from failing. Dehydrogenation eliminates the intrusion of hydrogen into the steel matrix during the pickling process in order to eliminate hydrogen embrittlement and restore the plasticity of the wire rod. The moisture on the surface of the wire rod is removed and dried to prevent the moisture from deteriorating the use effect of the lubricant steel wire suppliers. There are 3 common drying facilities:
Tunnel drying oven
The heat source is provided by the combustion chamber under the furnace, and the temperature of the drying chamber can reach about 280 °C. A trolley track and arched cast iron fins are placed on the bottom of the furnace. The dried wire rod or intermediate wire blank is hung on the trolley by means of a lifting bar, and is fed into the furnace through a hoist or manually. Each furnace can be loaded with 10 to 12 trolleys. The equipment has a large capacity and a high output, but the labor intensity of the worker is large when entering and leaving the trolley, and the drying temperature is not uniform, and the temperature at the bottom of the trolley is high.
Chain drying oven
The bottom of the furnace is the combustion chamber, and the flame can be returned from the bottom to the furnace walls on both sides and then run out through the flue. The furnace temperature is 200 to 400 °C. When drying, the wire rod is placed on a moving chain, and the chain moves at a speed of about 12 m/min. This is a more advanced type of furnace, which has large capacity, high speed and high output. At the same time, it overcomes the shortcomings of the labor intensity of the tunnel furnace workers and the uneven drying temperature.
The coating treatment is formed by coating a surface of the wire rod or the intermediate wire blank which has been removed by the iron oxide skin with a solid material which can effectively adsorb and carry the lubricant into the deformation zone when it has certain lubricating properties, especially drawing. Film %26mdash; coating. Therefore the coating is essentially a carrier for the lubricant (see Lubrication Carrier). The purpose of the coating is to create good lubrication conditions for drawing to reduce friction and heat during drawing. The treatment methods include physical methods and chemical methods. The main forms are strontium lime, yellowing, phosphating, copper plating, borax treatment,stainless steel sheet etc.
For a box with an upper cover, the effective size is determined by the maximum diameter of the reel. When working, the box is heated with 150~250 °C hot air. The drying speed of the device is fast, the time is about 2 to 15 minutes, and the drying is relatively uniform.