309 Stainless Steel Pipe 

Carbon content ≤ 0.08%, offering higher mechanical strength at both ambient and elevated temperatures, with slightly lower cost. 

Applications: limited spot welding, non-continuous high-temperature welding, furnace support structures, and long-term immersion in environments without direct contact with high-temperature flue gases. 

Limitations: After large-area continuous high-temperature welding, intergranular corrosion may occur in the weld zone; welds are prone to damage in prolonged exposure to high-temperature sulfidation environments.

Product Parameters

Chemical materials compare information(%)：

Core Advantages

High Temperature and Oxidation Resistance

Sustainable operating temperature 900℃, short-term temperature resistance 1050℃. A stable oxide film forms on the high-temperature surface, making it less prone to peeling, delamination, and burn-through, far superior to 304 and 316L.

Resistant to Sulfur-Containing High-Temperature Flue Gas Corrosion

Excellent resistance to sulfide corrosion from incineration exhaust gases and sulfur-containing hot gases from metallurgical kilns, reducing the likelihood of pipe wall rust and perforation.

Stable High-Temperature Structural Strength

Does not easily soften or creep in high-temperature environments, preventing deformation and sagging of load-bearing and pressure-bearing furnace tubes during long-term use.

Good Crack Resistance Under Thermal Cycling Conditions

Under repeated heating and cooling, and intermittent furnace conditions, the pipes are less prone to cracking and damage.

Room Temperature Rust Prevention Superior to Ordinary 304

Can be used for short periods in humid indoor environments and slightly acidic environments, combining heat resistance and basic corrosion protection.

Applicable Industries:

Heat Treatment Equipment: Annealing furnaces, quenching furnace internal support pipes, hot air conveying pipes;

Environmental Incineration: High-temperature flues for small incineration equipment, waste heat exchange auxiliary pipes;

Boiler Hot Air Systems: High-temperature hot air pipelines, auxiliary piping for heating furnaces;

Ceramic and Metallurgical Kilns: High-temperature gas conveying pipes, furnace body structural components;

Petrochemical Small Heating Equipment: Short-term high-temperature fluid fittings.