Phosphorus (P): In general, phosphorus is a harmful element in steel, which increases the cold brittleness of steel, worsens the welding performance, reduces the plasticity, and worsens the cold bending performance. Therefore, the phosphorus content in steel is generally required to be less than 0.045%, and the requirements for high-quality steel are lower.
Chromium (Cr): In structural steel and tool steel, chromium can significantly improve strength, hardness and wear resistance, but reduce plasticity and toughness at the same time. Chromium can also improve the oxidation resistance and corrosion resistance of steel, so it is an important alloy element of stainless steel and heat resistant steel.
Nickel (Ni): Nickel can improve the strength of steel while maintaining good plasticity and toughness. Nickel has high corrosion resistance to acid and alkali, rust prevention and heat resistance under high temperature. However, as nickel is a scarce resource, other alloy elements should be used instead of nickel chromium steel as much as possible.
