1.4404 stainless steel vs. 1.4571: Corrosion resistance

Both 1.4404 (SUS316L) and 1.4571 (AISI 316Ti) stainless steels are austenitic stainless steels. They are similar in chemical composition, but there are some differences in corrosion resistance, which are mainly reflected in the following points:

1.4404 (316L): A low-carbon version of 316 stainless steel, containing approximately 2.0–2.5% molybdenum (Mo) and a maximum carbon content of 0.03%. Offers excellent weldability and intergranular corrosion resistance.

1.4571 (316Ti): A titanium-stabilized version of 316, typically containing around 0.5% titanium (Ti). The titanium binds with carbon to prevent the formation of chromium carbides, enhancing resistance to intergranular corrosion at elevated temperatures or after welding.

Chemical Composition Comparison: 1.4404 (316L) vs. 1.4571 (316Ti)

Element	1.4404 (316L)	1.4571 (316Ti)
Carbon (C)	≤ 0.03%	≤ 0.08%
Silicon (Si)	≤ 1.00%	≤ 1.00%
Manganese (Mn)	≤ 2.00%	≤ 2.00%
Phosphorus (P)	≤ 0.045%	≤ 0.045%
Sulfur (S)	≤ 0.030%	≤ 0.030%
Chromium (Cr)	16.5–18.5%	16.5–18.5%
Nickel (Ni)	10.0–13.0%	10.5–13.5%
Molybdenum (Mo)	2.0–2.5%	2.0–2.5%
Nitrogen (N)	≤ 0.10%	≤ 0.10%
Titanium (Ti)	-	≥ 5 × C and ≤ 0.70%

1.4404 (316L) vs. 1.4571 (316Ti) Corrosion Resistance Comparison

Property	1.4404 (316L)	1.4571 (316Ti)
Intergranular Corrosion	The very low carbon content prevents chromium carbide precipitation. Excellent resistance after welding. Ideal for welded components.	Ti binds with carbon to form stable titanium carbides, preventing chromium carbide formation. More reliable under high-temperature conditions.
Pitting and Crevice Corrosion	Molybdenum enhances resistance, superior to 304L.	Similar performance due to molybdenum content.
Chloride Environments (e.g., seawater)	Better than 304, but chloride concentration and temperature must still be considered.	Similar resistance, with slightly better performance in long-term, high-temperature, or pressurized environments.
Corrosion at High Temperatures	Caution is needed above 400°C due to potential carbide precipitation.	Ti addition makes it more suitable for long-term use at elevated temperatures. Better stability against intergranular corrosion.