Straight seam steel pipe can be divided into many different specifications and names, among which the names are, straight seam welded pipe, double-sided submerged arc welded pipe, thick wall straight seam steel pipe, straight seam steel pipe, large diameter straight seam steel pipe, API5L straight seam steel pipe, JCOE large diameter straight seam welded pipe, large diameter straight seam welded pipe, welded straight seam steel pipe, double-sided submerged arc welded steel pipe, straight seam structural pipe, PSL2 steel pipe, X steel grade steel pipe, L steel grade steel pipe, large diameter thick wall submerged arc welded steel pipe, Large diameter straight seam steel pipe, carbon steel straight seam steel pipe, ordinary carbon steel pipe, API5L, X80 steel pipe. Straight seam steel pipes are mainly used in water supply engineering, the petrochemical industry, the chemical industry, the electric power industry, agricultural irrigation, and urban construction. Used for liquid transportation: water supply and drainage. For gas transportation: gas, steam, liquefied petroleum gas, for structure: for piling pipes, wharves, roads, building structure pipes, etc.
1. The site or warehouse for storing straight seam steel pipe products should be selected in a clean and well-drained place, away from factories and mines that produce harmful gases or dust. Remove weeds and sundries on the field and keep the steel clean;
2. Do not stack together with acid, alkali, salt, cement, and other materials that are corrosive to steel in the warehouse. Different types of steel should be stacked separately to prevent confusion and prevent contact corrosion;
3. Large steel sections, rails, steel plates, large-diameter steel pipes, forgings, etc. can be stacked in the open air;
4. Small and medium-sized steel bars, wire rods, steel bars, medium-caliber steel pipes, steel wires, and steel wire ropes can be stored in a ventilated material shed with thatch on top and bottom on top;
5. Some small steel products, thin steel plates, steel strips, silicon steel sheets, small-diameter or thin-walled steel pipes, various cold-rolled and cold-drawn steel products, and high-priced and easily-corroded metal products can be stored in the warehouse;
6. The warehouse should be selected according to geographical conditions. Generally, an ordinary closed warehouse is used, that is, a warehouse with a roof, a wall, tight doors and windows, and a ventilation device.
Regarding the influence of deoxidizers on straight seam steel pipes, we have summarized the following:
For ω(Als≤0.01% longitudinal seam welded pipe, the use of two deoxidizers has little effect on the total oxygen in the steel after VD treatment, and both can control ω(T.O below 20×10-6; Si-Al-Ba deoxidizer After that, lower total oxygen content can be obtained in each process, and the deoxidation effect of each process is stronger than that of Si-Ca deoxidation.
When using Si-Ca and Si-Al-Ba two different deoxidizers for straight seam welded pipes, the number and size of inclusions in the smelting process are quite different, and the number of inclusions in each process after Si-Al-Ba deoxidation is less than After Si-Ca is deoxidized, the size is smaller. When two different deoxidizers, Si-Ca and Si-Al-Ba, are used for longitudinal welded pipes, the molten steel undergoes obvious secondary oxidation during the casting process, but the secondary oxidation of the Si-Al-Ba deoxidized molten steel is the most serious. The composition of inclusions and the content of aluminum inclusions in forgings are quite different. When using Si-Al-Ba deoxidation, the inclusions in forgings are mainly block and chain alumina. When using Si-Ca deoxidation, the forging The inclusions in the forging are mainly strip-shaped silico-manganese aluminate composite inclusions; the content of aluminum inclusions in the Si-Ca alloy deoxidized forging is less than that of the Si-Al-Ba alloy deoxidized.
In addition, the production process of thick-walled straight seam steel pipe, production process of large-diameter thick-walled steel pipe generally includes hot rolling, hot coiling, casting, and other production methods, and the production process of double-sided submerged arc welding is generally used for large-diameter thick-walled steel pipe. The products meet the requirements of petrochemical standards through multiple processes such as bending, seaming, internal welding, external welding, straightening, and flattening. The use of thick-walled straight seam steel pipes is mainly used for body support parts, such as bridge piling, submarine piling, and high-rise building piling. The materials used are generally Q345B and Q345C. Areas with lower temperatures will also use Q345D, and Q345E large-diameter thick-walled steel pipes are mostly used in large-scale steel structure construction.
