When the carbon steel tube is in use, the oxide film on the surface is not easy to fall off. Usually, oxide films are produced in a heating furnace. So, how to clean the oxide film on the surface of the carbon seamless steel tube?
1. Iron oxide scale cleaning machine treatment
The scale cleaning machine is mainly composed of steel brush roller, driving device, high pressure water system, cooling water system and clamping device. Two rollers with steel wires (called steel brush rollers) are installed on the roller table seat. The steel brush rollers rotate at high speed in the opposite direction of the slab running.
The scale cleaning machine is suitable for many steel grades, but it cannot clean the scale thoroughly enough.
2. Water burst pool
The water blasting pool uses circulating water at room temperature as the cooling medium, puts the high-temperature billet into the pool, and uses “water blasting” to remove the oxide scale on the surface of the billet. The principle is that when the water encounters the high-temperature billet, it vaporizes instantly, resulting in a “water explosion” and a large amount of high-pressure steam. The impact force of the steam acts on the surface of the cast slab to peel off the scale. At the same time, the slab and the oxide scale on its surface are rapidly cooled at high temperature, resulting in shrinkage stress. Due to the different stresses between the slab and its surface, the oxide scale breaks and falls off.
The invention has the advantages of low investment, low maintenance and low production and operation cost. But it is only suitable for some austenitic stainless steels, such as 301, 304, etc.
3. Clean the shot blasting machine
Shot blasting machines are often used to clean the oxide scale on the surface of the billet. The shot blasting machine is mainly composed of shot blasting chamber, shot blasting head, shot blasting conveying system, shot blasting cleaning device, shot blasting supplementary device, dust removal system, lubrication system and electrical control system. Its working principle is to use the high-speed steel projectile thrown by the shot blasting machine to impact the iron oxide scale on the surface of the billet to make it fall off.
The shot blasting machine has a high operating rate, and the cleaning speed can reach 3m/min. There are many types of steel that can be used. Iron oxide scale removal effect is good. However, the shot blasting machine cannot handle the high temperature billet, and the billet temperature is generally required to be lower than 80 °C. Therefore, the shot blasting machine cannot be used to clean the scale of the billet online, and the billet needs to be cooled below 80 °C before shot blasting.
Strengthening the maintenance of seamless tubes in use can effectively extend the service life of seamless steel tubes.
A) Ensure that the warehouse or site where seamless steel pipes are stored is clean and hygienic, with smooth ventilation and drainage, and that the ground is free of weeds and debris.
B) Make sure that the seamless steel pipe is not put together with harmful substances and materials. If mixed, corrosion reaction can easily occur.
C) The seamless steel pipe should not be mixed with other building materials to avoid pollution caused by different materials.
D) Large-scale seamless steel pipes cannot be placed in warehouses, but the storage site must also meet the above conditions, and slate or wooden boards should be placed at the bottom of seamless steel tubes to isolate them from the ground.
E) Be sure to keep the site ventilated and waterproof.
Post time: Oct-26-2022