Stainless Steel Grade 316L: Low-Carbon Weldable Stainless Steel

 

Chemical Composition

 

C	Si	Mn	P	S	Cr	Ni	Mo
≤ 0.030	≤ 0.75	≤ 2.00	≤ 0.045	≤ 0.015	16.00 – 18.00	10.00 – 14.00	2.00 – 3.00

 

 

Elements and Their Roles:

C (Carbon) ≤ 0.030%
Low carbon content helps prevent sensitization (a type of corrosion that occurs at weld joints). This improves the material's resistance to intergranular corrosion.

Si (Silicon) ≤ 0.75%
Silicon improves oxidation resistance and enhances strength at high temperatures. It also aids in the steel production process by removing oxygen from molten steel.

Mn (Manganese) ≤ 2.00%
Manganese contributes to the material's toughness and strength. It also enhances resistance to wear and assists in the steel's deoxidation during manufacturing.

P (Phosphorus) ≤ 0.045%
Phosphorus increases strength and machinability but is kept low because excess phosphorus can reduce ductility and increase brittleness.

S (Sulfur) ≤ 0.015%
Sulfur improves machinability but is carefully controlled because higher levels can reduce toughness and corrosion resistance.

Cr (Chromium) 16.00–18.00%
Chromium is the key element in stainless steel that forms a passive chromium oxide layer, providing excellent corrosion and oxidation resistance.

Ni (Nickel) 10.00–14.00%
Nickel enhances corrosion resistance, especially in acidic environments, and improves the material's toughness, ductility, and overall strength.

Mo (Molybdenum) 2.00–3.00%
Molybdenum provides enhanced corrosion resistance, particularly in environments with chlorides or other harsh conditions. It is a distinguishing feature of grades like 316 stainless steel, making it more resistant to pitting and crevice corrosion than 304 stainless steel.