ASTM A213 T9 Alloy Steel Seamless Furnace and Heat Exchanger Tubes

ASME SA213/ASTM A213 This specification covers seamless ferritic and austenitic steel boiler, superheater, and heat-exchanger tubes, designated Grades T5, TP304, TP321, etc. ASTM A213 T9 (SA213 T9) is a chromium-molybdenum (Cr-Mo) alloy steel specifically designed for high-temperature and high-pressure environments. Its unique composition (9% Cr, 1% Mo) provides excellent oxidation resistance, creep strength, and corrosion resistance.

Chemical Composition (%) max

Carbon: 0.15

Manganese: 0.30-0.60

Phosphorus: 0.025

Sulfur: 0.025

Silicon: 0.25-1.00

Chromium: 8.0-10.0

Molybdenum: 0.90-1.10

Mechanical Properties

Subcritical Annealing /Tempering Temperature,min or range : 1250 °F [ 675°C ]

Tensile Strength, min. : 60ksi [415MPa ] ; Yield Strength, min.: 30ksi [ 205MPa ]

Elongation in 2 in. or 50mm, min.: 30% ; Brinell/Vickers: 179HBW/190HV ; Rockwell: 89HRB

Advantages

Better Oxidation Resistance than T11/T22 at higher temps.

Higher Creep Strength compared to carbon steel.

Good Weldability (though pre/post-weld heat treatment is needed).

Cost-Effective compared to stainless steels (e.g., 304H, 321H) for certain temp ranges.

Applications

Power Generation (Boilers & Superheaters)

Superheater & Reheater Tubes: T9 tubes withstand steam temperatures up to 650°C (1200°F) without excessive scaling.

Boiler Tubes: Used in high-pressure boilers where carbon steel would fail due to oxidation.

Heat Recovery Steam Generators (HRSGs): Resists thermal fatigue in combined-cycle power plants.

Petrochemical & Refinery Applications

Furnace Tubes & Heat Exchangers: Handles sulfur-rich environments better than low-alloy steels.

Catalyst Tubes in Refineries: Resists carburization and hydrogen attack at high temps.

Chemical Processing Plants

High-Temperature Process Piping: Used where corrosive gases or steam are present.

Thermal Cracking Units: Maintains strength under cyclic heating conditions.