Stainless steel thick plate refers to a stainless steel plate with a thickness of more than 25mm.
Successfully rolled a 200mm thick stainless steel super-thick plate The physical properties of each chemical element of the stainless steel plate and the function of each element:
1. Carbon (C): The carbon content in the steel increases, the yield point and tensile strength increase, but the ductility and impact decrease. When the carbon content exceeds 0.23%, the welding performance of the steel deteriorates, so the low welding performance is used for welding. Alloy structural steel, carbon content generally does not exceed 0.20%, high carbon content will also reduce the atmospheric corrosion resistance of steel, high carbon steel in the open stock yard is easy to rust; in addition, carbon can increase the cold brittleness and aging sensitivity of steel sex.
2. Silicon (Si): Silicon is added as a reducing agent and deoxidizer in the steelmaking process, so killed steel contains 0.15-0.30% silicon. If the silicon content in the steel exceeds 0.50-0.60% silicon, it is regarded as an alloying element. Silicon can significantly improve the elastic limit, yield point and tensile strength of steel, so it is widely used as spring steel. Adding 1.0-1.2% silicon to the quenched and tempered structure can increase the strength by 15-20%. The combination of silicon and molybdenum, tungsten, chromium, etc. can improve corrosion resistance and oxidation resistance, and can manufacture heat-resistant steel. Low carbon steel containing 1-4% silicon, with extremely high magnetic permeability, used in electrical industry to make silicon steel sheets. An increase in the amount of silicon will reduce the weldability of the steel.
3. Manganese (Mn): In the steelmaking process, manganese is a good deoxidizer and desulfurizer. Generally, the steel contains 0.30-0.50% of manganese. When more than 0.70% is added to carbon steel, it is considered "manganese steel", which not only has sufficient toughness, but also has higher strength and hardness than ordinary steel, which improves the hardenability of steel and improves the hot workability of steel. For example, the yield point of 16Mn steel is 40% higher than that of A3. Steel containing 11-14% manganese has extremely high wear resistance and is used for excavator buckets, ball mill linings, etc. The increase of manganese content weakens the corrosion resistance of steel and reduces the welding performance.
4. Phosphorus (P): In general, phosphorus is a harmful element in steel, which increases the cold brittleness of steel, deteriorates the welding performance, reduces the plasticity, and deteriorates the cold bending performance. Therefore, the phosphorus content in steel is usually required to be less than 0.045%, and the requirements for high-quality steel are lower.
5. Sulfur (S): Sulfur is also a harmful element under normal circumstances. It makes the steel hot brittle, reduces the ductility and toughness of the steel, and causes cracks during forging and rolling. Sulfur is also detrimental to weldability, reducing corrosion resistance. Therefore, the sulfur content is usually required to be less than 0.055%, and the high-quality steel is required to be less than 0.040%. Adding 0.08-0.20% sulfur to steel can improve machinability, usually called free-cutting steel.
6. Chromium (Cr): In structural and tool steels, chromium can significantly improve strength, hardness and wear resistance, but at the same time reduce ductility and toughness. Chromium can also improve the oxidation resistance and corrosion resistance of steel, so it is an important alloying element of stainless steel and heat-resistant steel.
