The influence of various elements in steel pipe on steel properties

　　Influence of main elements in API 5l Gr. B Carbon Steel Line Pipe on the performance of steel pipe: carbon (c): carbon content increases, yield point and tensile strength increase, but plasticity and impact performance decrease, and too high carbon content is easy to cause intergranular corrosion unqualified. The boundary between steel and iron is controlled by C content: < 2.11% is steel silicon (SI): Si is deoxidizer and desulfurizer, which has high strength and hardness, and can improve the hot working performance of steel Chromium (CR): chromium can significantly improve the strength, hardness and wear resistance of steel, but at the same time, it can reduce the plasticity and toughness Nickel (Ni): nickel can improve the strength of steel and keep the steel in good plasticity and toughness The effect of several main elements in steel on the properties of steel molybdenum (MO): adding molybdenum to steel can improve the mechanical properties of steel Titanium (TI): titanium is a deoxidizer in steel. Reduce the effect sensitivity and cold brittleness. Adding a certain amount of titanium into the steel has the ability of resisting intergranular corrosion Phosphorus (P): phosphorus is a harmful element in steel. It can increase the cold brittleness of steel, make the welding performance worse, reduce the plasticity, and make the cold bending performance worse. Generally, the lower the content of phosphorus in steel, the better Sulfur (s): sulfur is a harmful element in steel, which causes hot brittleness of steel, reduces ductility and toughness of steel, easily causes cracks during forging, and reduces corrosion resistance of steel. So the sulfur content should be controlled as low as possible Nitrogen (n): nitrogen can improve the strength, low temperature toughness and weldability of steel. Increase effectiveness sensitivity. Proper amount of nitrogen can improve the corrosion resistance and strength of stainless steel.