Product Description:

Key Features:

Excellent resistance to intergranular corrosion, particularly suitable for high-temperature environments, achieved through the addition of titanium.

Simply put, you can think of 321 as "304 with added stabilizers."

Chemical Composition:

Its basic components, such as chromium (Cr) and nickel (Ni), are very similar to 304 stainless steel (approximately 18% Cr, 9% Ni).

The most crucial difference: Titanium is added, and the titanium content is at least five times the carbon content (usually expressed as Ti ≥ 5 × C).

The Role of Titanium: Titanium has a much stronger affinity for carbon than chromium. At high temperatures (450°C - 850°C), carbon preferentially combines with titanium to form stable titanium carbide, thus preventing carbon from combining with chromium to form chromium carbide.

Key Performance Characteristics:

Excellent Resistance to Intergranular Corrosion:

Root Cause: In ordinary 304 stainless steel, during welding or prolonged exposure to the aforementioned "sensitization temperature" range, chromium at the grain boundaries combines with carbon to form chromium carbide, leading to chromium depletion near the grain boundaries. This results in rapid corrosion along the grain boundaries (i.e., intergranular corrosion) in corrosive media, severely reducing material strength.

Solution for 321: The addition of titanium fundamentally prevents the formation of chromium-depleted zones, thus 321 is immune to intergranular corrosion. This makes it ideal for welding and high-temperature applications.

Good High-Temperature Performance:

Maintains good strength and oxidation resistance at high temperatures. The stabilizing effect of titanium ensures structural stability during long-term high-temperature service.

Typically usable continuously within a temperature range of 600°C - 800°C.

Good Overall Performance:

Retains the general corrosion resistance, formability, and toughness of austenitic stainless steels.