(1) Carbon: The higher the carbon content, the higher the hardness of the steel, but the poorer its plasticity and toughness.
(2) Sulfur is a harmful impurity in steel. When the steel with high sulfur content is subjected to pressure processing at a high temperature, it is likely to be brittle, which is usually called hot brittleness.
(3) Phosphorus; can significantly reduce the plasticity and toughness of steel, especially at low temperatures, this phenomenon is called cold brittleness. In high-quality steel, sulfur and phosphorus must be strictly controlled. However, on the other hand, the higher sulfur and phosphorus content in low carbon steels can make the cutting easier, and it is beneficial to improve the machinability of steel.
(4) Manganese; can increase the strength of steel, can weaken and eliminate the adverse effects of sulfur, and can improve the hardenability of steel, high-alloy steel (high manganese steel) with high manganese content has good wear resistance And other physical properties.
(5) Silicon; it can increase the hardness of steel, but its plasticity and toughness are reduced. Electrical steel contains a certain amount of silicon, which can improve the soft magnetic properties.
(6) Tungsten; can improve the red hardness and thermal strength of steel, and can improve the wear resistance of steel.
(7) Chromium; can improve the hardenability and wear resistance of steel, can improve the corrosion resistance and oxidation resistance of steel.
In order to improve the corrosion resistance, the general steel pipe (black pipe) is galvanized. Galvanized steel pipe is divided into hot dip galvanized steel and electric steel zinc. The thickness of hot dip galvanized galvanized layer is low, and the cost of electrogalvanizing is low, so there is galvanized steel pipe.