Desulfurization process of carbon steel elbow

　　Desulfurization in oxygen converter is difficult and uneconomical. In recent years, the supply of high-quality metallurgical coke is insufficient, the sulfur content of coke is the highest, and the sulfur content of heavy oil injected to strengthen blast furnace smelting is also high, which makes the quantity and cost of low-sulfur molten iron meeting the requirements of steelmaking increasingly problematic. The practice has proved that it is a good way to solve the above contradiction to take off the bowl of molten iron outside the furnace between the blast furnace and the converter.

　　It can improve the technical and economic indicators of ironmaking and carbon steel elbow at the same time. It is particularly important for the converter to simplify operation and realize automatic control. It is developing rapidly in many countries. The basic principle of desulfurization outside the furnace is the same as that of desulphurization inside the furnace. That is to use elements or compounds with greater affinity to sulfur than iron and sulfur to transform iron sulfide into more stable, rarely soluble or completely insoluble sulfide in molten iron; At the same time, create good kinetic conditions to accelerate the diffusion of sulfur in molten iron to the reaction area and expand the reaction area between desulfurizer and molten iron. ASTM 440 is called high-strength carbon steel elbow.

　　It includes Mn-Cu high-strength low-alloy steel profiles, plates and bars. It is mainly used for riveting or bolting bridges and buildings. Generally, welding is not suitable. However, the material can also be welded after taking certain measures. Since it contains a minimum of 0.2% Cu, its atmospheric corrosion resistance is about twice that of carbon structural steel without Cu. The minimum yield strength of steel plate with thickness less than 19mm is 345MPa.