ASME SA106 Seamless Carbon Steel Tube for High Temperature Service

1、 Standards and Grading

Standard specifications

ASME SA106 and ASTM A106 belong to the same specification system and are suitable for seamless carbon steel pipes under high temperature conditions, covering requirements such as chemical composition and mechanical properties.

The material classification corresponds to carbon steel grades 25, 30, and 35 in the GB/T699 standard.

Level classification

Divided into three levels based on performance differences: A, B, and C

Grade A: Minimum strength requirement, suitable for general high-temperature scenarios.

B-level: The best comprehensive performance and the most widely used.

Grade C: With the highest carbon content (0.25-0.35%), it has higher strength and toughness, and can withstand more harsh high-temperature and high-pressure environments.

2、 Chemical composition and material properties

Core element control

Carbon (C): Grade A ≤ 0.25%, Grade B 0.18-0.25%, Grade C 0.25-0.35%, directly affecting strength and hardening tendency.

Manganese (Mn): 0.29-1.06%, refines grain size and strengthens ferrite, enhancing tensile/compressive strength.

Impurity limit: Phosphorus (P) and sulfur (S) are both ≤ 0.035%, reducing the negative impact of inclusions on mechanical properties.

Mechanical properties

Tensile strength: Grade C ≥ 485MPa, Grade B ≥ 415MPa 45.

Yield strength: Grade C ≥ 275MPa, Grade B ≥ 240MPa 45.

Temperature resistance range: Long term use temperature -29 ℃~482 ℃, short-term limit can reach 538 ℃.

3、 Production process and performance optimization

Manufacturing process

Hot rolling process: used for conventional size steel pipes, with good surface quality and tissue uniformity.

Cold drawing process: suitable for high-precision, small-sized pipes, with better mechanical properties but higher costs.

Welding performance

Grade B (carbon content ≤ 0.25%) has good weldability; Grade C (carbon content 0.25-0.35%) requires preheating and post weld heat treatment to avoid cracking due to its high carbon content.

4、 Typical application areas

Energy industry: high-pressure boiler heating surface pipelines, superheaters, reheaters, etc.

Petrochemical industry: high temperature and high pressure medium transportation pipelines, heat exchangers, pressure vessels.

Other fields: ship power systems, aerospace thermal pipelines, and engineering infrastructure pipelines.

5、 Delivery and testing requirements

Delivery status: Usually supplied in a hot-rolled and heat-treated state to ensure organizational stability.

Quality control: It must comply with the requirements of ASME standards for dimensional tolerances, surface smoothness, and non-destructive testing (such as ultrasonic testing).

The above content integrates the core parameters and engineering applicability of ASME SA106 steel pipes, and the specific selection needs to be matched based on the operating temperature, pressure, and medium characteristics.