Wuxi Guoyin Metal Material Co., Ltd.

Functions and effects of various main elements in stainless steel

‌Chromium (Cr)‌: Chromium is the main ferrite-forming element. When combined with oxygen, it can form a corrosion-resistant Cr2O3 passivation film, which significantly improves the corrosion resistance of stainless steel. Increased chromium content can improve the passive film repair ability of steel. Generally, the chromium content in stainless steel must be above 12%‌

‌Carbon (C)‌: Carbon is a strong austenite-forming element that significantly increases the strength of steel, but reduces the plasticity and impact resistance. Excessive carbon content will also reduce the welding performance and corrosion resistance of steel‌

‌Nickel (Ni)‌: Nickel is the main austenite-forming element, which can slow down the corrosion phenomenon of steel and the growth of grains during heating, while maintaining good plasticity and toughness. Nickel has high corrosion resistance to acids and alkalis, and is especially rust-proof and heat-resistant at high temperatures‌

‌Molybdenum (Mo)‌: Molybdenum can refine the grains of steel, improve hardenability and thermal strength properties, and maintain sufficient strength and creep resistance at high temperatures. Molybdenum can also make the passivation film denser and stronger, improving the Cl-corrosion resistance of stainless steel‌

‌Manganese (Mn)‌: Manganese is a good deoxidizer and desulfurizer, which increases the strength of steel, but too high a content will reduce corrosion resistance. Manganese steel has high strength and hardness and is often used where high wear resistance is required‌

‌Silicon (Si)‌: Silicon is the main reducing agent and deoxidizer, improving the elastic limit, yield point and tensile strength of steel. Silicon can also improve the corrosion resistance and oxidation resistance of steel and is often used in the manufacture of heat-resistant steel and silicon steel sheets in the electrical industry‌

‌Phosphorus (P) and sulfur (S)‌: Phosphorus and sulfur are generally considered harmful elements in steel, reducing the plasticity and toughness of steel and increasing cold brittleness. Phosphorus and sulfur content need to be strictly controlled to avoid adverse effects on weldability and corrosion resistance‌

‌Titanium (Ti) and niobium (Nb)‌: Titanium and niobium are strong carbide-forming elements that improve the resistance of steel to intergranular corrosion. Titanium also acts as a strong deoxidizer, making the internal structure of steel dense, refining the grains, reducing cold brittleness, and improving weldability‌

‌Nitrogen (N)‌: Nitrogen is a strong austenite-forming element that significantly increases the strength of steel, but has a greater impact on the age cracking of stainless steel. The nitrogen content needs to be strictly controlled to meet specific application requirements.