1. Classification of steel plates (including strip steel):
1. Classification by thickness: (1) thin plate (2) medium plate (3) thick plate (4) extra-thick plate
2. Classification by production method: (1) Hot-rolled steel sheet (2) Cold-rolled steel sheet
3. Classification by surface characteristics: (1) Galvanized sheet (hot-dip galvanized sheet, electro-galvanized sheet) (2) Tin-plated sheet (3) Composite steel sheet (4) Color coated steel sheet
4. Classification by use: (1) Bridge steel plate (2) Boiler steel plate (3) Shipbuilding steel plate (4) Armor steel plate (5) Automobile steel plate (6) Roof steel plate (7) Structural steel plate (8) Electrical steel plate (silicon steel sheet) (9) Spring steel plate (10) Others
2. Hot rolling: pickling coil, hot-rolled coil, structural steel plate, automobile steel plate, shipbuilding steel plate, bridge steel plate, boiler steel plate, container steel plate, corrosion-resistant plate, heat-replacing cooling, Baosteel wide and thick plate, fire-resistant and weather-resistant steel
3. Cold rolling: hard-rolled coil, cold-rolled coil, electro-galvanized sheet, hot-dip galvanized sheet, galvanized sheet, color-coated coil, tin-coated coil, Baosteel electrical steel, composite steel sheet, cold-rolled steel strip, aluminized sheet, GB hot-dip galvanized sheet, galvanized color Paint Color card GB tin-plated WISCO silicon steel
4. Boiling steel plate and killed steel plate: 1. Boiling steel plate is a hot-rolled steel plate made of ordinary carbon structural steel boiling steel. Boiling steel is a kind of steel with incomplete deoxidation. Only a certain amount of weak deoxidizer is used to deoxidize molten steel. The oxygen content of molten steel is relatively high. , hence the name of the boiling steel. Boiling steel has low carbon content, and since ferrosilicon is not deoxidized, the silicon content in steel is also low (Si<0.07%). The outer layer of boiling steel is crystallized under the condition of vigorous stirring of molten steel caused by boiling, so the surface layer is pure and dense, with good surface quality, good plasticity and punching performance, no large concentrated shrinkage holes, cut ends. less, the yield is high, and the production process of boiling steel is simple, the consumption of ferroalloy is less, and the cost of steel is low. Boiling steel plate is widely used in the manufacture of various stamping parts, construction and engineering structures and some less important machine structural parts. However, there are many impurities in the core of the boiling steel, the segregation is serious, the structure is not dense, and the mechanical properties are not uniform. At the same time, due to the high gas content in the steel, the toughness is low, the cold brittleness and aging sensitivity are high, and the welding performance is also poor. Therefore, the boiling steel plate is not suitable for the manufacture of welded structures and other important structures that are subjected to impact loads and work under low temperature conditions. 2. Killed steel plate is a steel plate made of ordinary carbon structural steel killed steel by hot rolling. Killed steel is completely deoxidized steel. The molten steel is fully deoxidized with ferromanganese, ferrosilicon and aluminum before pouring. The oxygen content of the molten steel is low (usually 0.002-0.003%), and the molten steel is relatively calm in the ingot mold. No boiling phenomenon occurs, hence the name of the killed steel. Under normal operating conditions, there are no bubbles in the killed steel, and the structure is uniform and dense; due to the low oxygen content, the steel has less oxide inclusions, high purity, and low cold brittleness and aging tendency; at the same time, the killed steel has small segregation, The performance is relatively uniform and the quality is high. The disadvantage of killed steel is that it has concentrated shrinkage cavities, low yield and high price. Therefore, killed steel is mainly used for components that are impacted at low temperatures, welded structures and other components that require high strength. Low alloy steel plates are killed steel and semi-killed steel plates. Due to its high strength and superior performance, it can save a lot of steel and reduce the weight of the structure, and its application has become more and more extensive. 5. High-quality carbon structural steel plate: High-quality carbon structural steel is carbon steel with a carbon content of less than 0.8%. This steel contains less sulfur, phosphorus and non-metallic inclusions than carbon structural steel, and has excellent mechanical properties. . High-quality carbon structural steel can be divided into three categories according to the carbon content: low carbon steel (C≤0.25%), medium carbon steel (C is 0.25-0.6%) and high carbon steel (C>0.6%). High-quality carbon structural steel is divided into two groups according to different manganese content: normal manganese content (manganese 0.25%-0.8%) and higher manganese content (manganese 0.70%-1.20%), the latter has better mechanical properties. performance and processability. 1. High-quality carbon structural steel hot-rolled sheets and strips High-quality carbon structural steel hot-rolled sheets and strips are used in the automotive, aviation industry and other sectors.
The grades of its steel are boiling steel: 08F, 10F, 15F; killed steel: 08, 08AL, 10, 15, 20, 25, 30, 35, 40, 45, 50. 25 and below are low-carbon steel plates, 30 and Above 30 is medium carbon steel plate. 2. High-quality carbon structural steel hot-rolled thick steel plates and wide steel strips High-quality carbon structural steel hot-rolled thick steel plates and wide steel strips are used for various mechanical structural parts.
Its steel grades are low carbon steel including: 05F, 08F, 08, 10F, 10, 15F, 15, 20F, 20, 25, 20Mn, 25Mn, etc.; medium carbon steel includes: 30, 35, 40, 45, 50, 55, 60, 30Mn, 40Mn, 50Mn, 60Mn, etc.;
High carbon steel includes: 65, 70, 65Mn, etc.
6. Special structural steel plate:
1. Steel plate for pressure vessel: It is indicated by capital R at the end of the grade, and the grade can be expressed by yield point or carbon content or alloying element. Such as: Q345R, Q345 is the yield point. Another example: 20R, 16MnR, 15MnVR, 15MnVNR, 8MnMoNbR, MnNiMoNbR, 15CrMoR, etc. are all represented by carbon content or alloying elements.
2. Steel plates for welding gas cylinders: use uppercase HP at the end of the grade, and the grade can be expressed by the yield point, such as: Q295HP, Q345HP; it can also be expressed with alloying elements such as: 16MnREHP.
3. Steel plates for boilers: use lowercase g at the end of the grade. Its grade can be expressed by yield point, such as: Q390g; it can also be expressed by carbon content or alloying element, such as 20g, 22Mng, 15CrMog, 16Mng, 19Mng, 13MnNiCrMoNbg, 12Cr1MoVg, etc.
4. Steel plates for bridges: use lowercase q at the end of the grade, such as Q420q, 16Mnq, 14MnNbq, etc. 5. Steel plate for automobile frame: It is indicated by capital L at the end of the grade, such as 09MnREL, 06TiL, 08TiL, 10TiL, 09SiVL, 16MnL, 16MnREL, etc.