Oxidation treatment of cold drawn seamless tubing

The air oxide film on the surface of the cold drawn seamless tubing  is thin and high in density, and it is not easy to fall off. Under normal circumstances, the cold drawn seamless tubing will cause an oxide scale of 0.2 to 0.3mm in the heat treatment equipment. Defects can be removed with air oxidation of galvanized iron. If the defects are not within this range, the surface defects on the billet will inevitably be brought into the final product if they are not treated in all aspects. Cold drawn seamless tubing generally cannot use flame to eliminate surface defects of the billet. Flame elimination will cause changes in the composition and crystal phase composition of the region where the billet is eliminated, which will affect the corrosion resistance of the sheet. Therefore, industrial equipment elimination is a widely effective method for sheet metal surface solution. The general methods include air oxidation galvanized iron cleaning mechanical treatment, water explosion, shot blasting machine elimination.

Air Oxidation Galvanized Iron Cleaning Mechanical Treatment

The air oxidation galvanized iron cleaning machine is mainly composed of steel brush rollers, controller machinery and equipment, high-pressure water system, refrigeration system and clamping machinery and equipment. Two rollers with stainless steel wires (called steel brush rollers) are installed on the roller seat, and the steel brush rollers run at high speed in the opposite direction of the slab running. Surface air oxidation galvanized iron. There are many steel grades available for air oxidation galvanized iron cleaning machinery, but the elimination of air oxidation galvanized iron is not thorough enough.

Water burst pool

The water blasting pool uses the refrigerating and cooling circulating water at room temperature as the refrigeration chemical substance, puts the high-temperature billet into the water storage tank, and uses "water blasting" to remove the air-oxidized galvanized iron on the surface of the billet. The basic concept is that when the water encounters the high-temperature billet, it vaporizes in an instant, resulting in a "water explosion", resulting in a lot of high-pressure steam. The impact force of the steam acts on the surface of the billet to cause the air-oxidized galvanized iron to fall. In addition, the air-oxidized galvanized iron on the billet and its surface is greatly cooled by water under high temperature conditions, resulting in a shrinkage stress field. Due to the different specifications of the stress field between the billet and the air-oxidized galvanized iron on its surface, the air-oxidized galvanized iron cracks and falls off. go down. The water explosion pool has low investment projects, less maintenance and low cost of production, processing and operation. However, there are few steel grades available, and only a part of austenitic stainless steel sheets, such as 301, 304 and other steel grades, can be used.

Shot blasting machine

Shot blasting machines are mostly used to eliminate air oxidation of galvanized iron on the surface of the billet. The shot blasting machine is mainly composed of sandblasting and rust removal room, grinding rod, sandblasting and rust removal conveying system, shot removal machinery and equipment, shot make up device, dust collector equipment, air inlet and electrical equipment automatic control system, etc. The basic principle is to use the spring steel shot thrown out by the shot blasting machine to destructively oxidize the galvanized iron on the surface of the billet to make it fall.

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