performance requirement
(1) High strength: generally, its yield strength is above 300MPa.
(2) High toughness: the required elongation is 15%~20%, and the impact toughness at room temperature is greater than 600kJ/m~800kJ/m. For large welded components, higher fracture toughness is also required.
(3) Good welding performance and cold forming performance.
(4) Low cold brittle transition temperature.
(5) Good corrosion resistance.
3. Composition characteristics of galvanized pipe
(1) Low carbon: due to the high requirements for toughness, weldability and cold forming performance, the carbon content shall not exceed 0.20%.
(2) Manganese based alloy element is added.
(3) Addition of niobium, titanium or vanadium: a small amount of niobium, titanium or vanadium forms fine carbide or carbonitride in the steel, which is conducive to obtaining fine ferrite grains and improving the strength and toughness of the steel. In addition, adding a small amount of copper (≤ 0.4%) and phosphorus (about 0.1%) can improve the corrosion resistance. Adding a small amount of rare earth elements can remove sulfur and gas, purify steel, and improve toughness and process performance.
Post time: Dec-26-2022