ASTM A213 T12 seamless alloy steel pipe

ASTM A213 T12 belongs to 1Cr-1/2Mo pearlescent low-alloy high-temperature steel. ASTM A213 T12 seamless alloy pipe is a type of high-pressure seamless pipe, possessing good processing and welding properties, and exhibiting high thermal strength and oxidation resistance below 550℃.

ASTM A213 and ASME SA213 are American standards for seamless alloy steel pipes used in boilers, superheaters, and heat exchangers, and their technical requirements are highly consistent.

T12 belongs to the ferritic alloy steel series. Compared to ordinary carbon steel, T12 alloy pipe significantly improves oxidation resistance, creep resistance, and high-temperature strength by adding elements such as chromium and molybdenum.

Chemical composition of T12 alloy steel pipe:

Carbon (C): ≤ 0.15% (ensures strength while preventing weld brittleness);
Chromium (Cr): 0.80% – 1.25% (forms a dense oxide film to resist high-temperature oxidation and sulfur corrosion);
Molybdenum (Mo): 0.44% – 0.65% (improves high-temperature creep resistance and refines grain size);
Silicon (Si): 0.50% – 1.00% (deoxidizer, enhances oxidation resistance);
Manganese (Mn): 0.30% – 0.61% (improves hardenability);
Impurity control: Phosphorus (P) ≤ 0.025%, Sulfur (S) ≤ 0.025% (reduces hot brittleness and grain boundary segregation).

Mechanical properties and technical specifications of T12 alloy steel pipes:

After heat treatment (normalizing or quenching and tempering), T12 steel pipes must meet the following key properties (based on typical ASME standard requirements):

Tensile strength: ≥415 MPa;

Yield strength: ≥205 MPa;

Elongation (δ5): ≥30% (ensuring plastic deformation capacity);

Hardness: ≤163 HBW (Brinell hardness, avoiding excessive hardness leading to processing cracks);

Reduction of Area: ≥26% (reflecting material toughness).

Its advantage lies in high-temperature stability: it can maintain more than 80% of its room temperature strength at 500℃~600℃ and resist pipe blockage caused by oxide scale peeling.

Specifications and process control:

Dimensions: outer diameter 6.35 mm to 101.60 mm;
Size Range: outer diameter 1/2 inch to 5 inches, custom diameters also available;
Specifications: SCH 40, SCH 80, SCH 160, SCH XS, SCH XXS, all specifications, maximum thickness up to 12 mm.

Manufacturing method: hot-rolled or cold-drawn seamless tube production process.

Heat treatment requirements: annealing, normalizing, or normalizing + tempering. recommended heat treatment temperature: 675°C – 740°C.

Surface requirements: the tube surface should be free of defects such as cracks, folds, scars, or delamination; minor grinding repairs are permitted, but the wall thickness must not be reduced below the standard.

ASTM A213 and ASME SA213 are specifically designed for high-temperature and high-pressure applications and are widely used in:

Power plant boilers: critical pressure-bearing components such as high-temperature superheaters, reheaters, and evaporators;
Chemical equipment: high-temperature reactors, pyrolysis furnace piping, and other corrosion-resistant environments;
Heating networks: high-temperature transmission pipelines such as those in urban district heating systems;
Petroleum refining: heat exchanger tube bundles in high-temperature pyrolysis units.

In summary

ASTM A213 T12 alloy steel seamless tubes, with their excellent high-temperature strength, oxidation resistance, and stable microstructure, have become an indispensable material in high-temperature boilers, heat exchangers, and steam pipelines. They are widely used in high-temperature transmission systems in the chemical, power, and petroleum refining industries and are a highly cost-effective medium-temperature ferritic alloy steel material.

Read more：ASTM A335 P5 alloy steel seamless pipe