ASTM A606-2 weathering steel is not designed or recommended for high-temperature service.
Why it is NOT suitable for high temperatures
It is a high-strength low-alloy (HSLA) atmospheric weathering steel, optimized for outdoor room-temperature structural use, not thermal resistance.
Its mechanical properties (especially yield strength and toughness) drop significantly at elevated temperatures, leading to softening, deformation, or even structural failure.
The alloying elements (Cu, Cr, Ni) that give it corrosion resistance in air do not provide oxidation resistance or creep strength at high temperatures.
Prolonged high-temperature exposure will destroy the material's microstructure, reduce durability, and prevent normal patina formation.
Temperature limits for safe use
Maximum recommended service temperature: around 260°C (500°F)
Above this temperature, strength decreases rapidly, and surface oxidation becomes excessive.
It is not rated for continuous high-temperature, creep, or pressure-containing service at all.
What to use instead for high temperatures
If you need high-temperature performance with good corrosion resistance, use:
Heat-resistant alloy steels
Stainless steels (304, 316, 310S)
Boiler or pressure vessel steels (e.g., SA‑106, SA‑240, SA‑387)
