Why are ASME SA210C seamless carbon steel pipes commonly used in the high-pressure boiler industry

First, what are the standards and materials of SA210C seamless carbon steel pipes?
Standard Basis: SA210C seamless steel pipes follow ASME standards, specifically ASME SA-210/SA-210M, "Seamless medium carbon steel tubing for boilers and superheaters." This standard has strict regulations on the chemical composition, mechanical properties, and manufacturing process of the steel pipes, ensuring that the steel pipes can be used safely and reliably in high-temperature, high-pressure boiler environments.
Material Grade: SA210C is a medium carbon manganese steel, belonging to the pearlitic heat-resistant steel category, possessing good high-temperature strength and creep resistance. Its chemical composition mainly includes elements such as carbon, manganese, silicon, phosphorus, and sulfur. The carbon content is generally between 0.17% and 0.23%, the manganese content between 0.87% and 1.13%, the silicon content is ≤0.10%, and the phosphorus and sulfur contents are both ≤0.025%.

Second, what are the specifications and dimensions of SA210C carbon seamless steel pipes?
Specification range: SA210C seamless steel pipes come in various specifications, with outer diameters ranging from 21.3mm to 762mm and wall thicknesses from 2.0mm to 130mm. Appropriate specifications can be selected based on actual needs.
Common specifications: For example, 60×7.5 high-pressure seamless steel pipes have an outer diameter of 60mm and a wall thickness of 7.5mm. They are suitable for water-cooled walls, economizers, low-temperature superheaters, and other heat-receiving surface components, especially suitable for applications requiring high pipe strength and temperature resistance.

Third, what are the mechanical properties of SA210C carbon seamless steel pipes?
Tensile strength: The tensile strength of SA210C seamless steel pipes is generally ≥415MPa, with some standards requiring ≥485MPa. This indicates that SA210C carbon seamless steel pipes can withstand high stress without breaking under tensile force.
Yield Strength: The yield strength is generally ≥255MPa, with some standards requiring ≥275MPa or higher. This ensures that SA210C carbon seamless steel pipes will not easily undergo irreversible plastic deformation under normal working pressure, thus ensuring the stability and safety of the pipeline system.
Elongation: With a gauge length of 50mm, the elongation is generally ≥30%. A higher elongation indicates that the steel pipe has good toughness, enabling it to absorb energy through plastic deformation under external impact or local overload, preventing sudden fracture.
Hardness: The hardness is generally ≤179HB or ≤89HRB, ensuring the plasticity of the steel pipe during processing and use.

Fourth, what is the manufacturing process of SA210C carbon seamless steel pipes?
Blank Preparation: High-quality steel billets are used, undergoing strict quality inspection, including chemical composition analysis and low-magnification microstructure inspection, to ensure compliance with SA210C standard requirements.
Hot Rolling Process: After heating, the billet is hot-rolled and pierced to form a rough tube. During hot rolling, parameters such as heating temperature, rolling speed, and roll pressure must be carefully controlled to ensure uniform wall thickness and good internal and external surface quality of the SA210C carbon seamless steel pipe.
Cold rolling (drawing) process: For applications requiring higher dimensional accuracy and surface quality, cold rolling or cold drawing can be performed on top of hot rolling. Cold rolling (drawing) can further improve the dimensional accuracy of the steel pipe and reduce surface roughness, but it increases production costs.
Heat treatment: To achieve the mechanical properties specified in the standard, SA210C carbon seamless steel pipe may require heat treatment, such as normalizing. Normalizing can refine the grains and homogenize the microstructure, thereby improving the strength and toughness of the SA210C carbon seamless steel pipe, while also eliminating some internal stress.

Fifth, what are the inspection and testing procedures for SA210C carbon seamless steel pipe?
Visual inspection: Carefully inspect the internal and external surfaces of the SA210C carbon seamless steel pipe. It should be free of defects such as cracks, folds, rolling defects, delamination, and scale. For minor surface defects in SA210C carbon seamless steel pipes, such as scratches and dents, their depth and length should also conform to the allowable range specified in the standard.
Dimensional Accuracy Inspection: Accurately measure the outer diameter, inner diameter, wall thickness, length, and other dimensional parameters of the SA210C carbon seamless steel pipe. The tolerances for the outer diameter and wall thickness should be strictly controlled within the range specified in the standard to ensure that the dimensional accuracy of the SA210C carbon seamless steel pipe meets the installation and usage requirements of high-temperature and high-pressure equipment piping systems.
Mechanical Property Testing: Includes tensile tests and impact tests. Tensile tests are used to check whether the yield strength, tensile strength, and elongation of the SA210C carbon seamless steel pipe meet the standard requirements; impact tests focus on examining the impact toughness of the SA210C carbon seamless steel pipe in low-temperature environments to ensure its normal use under possible low-temperature conditions.
Non-destructive Testing: Ultrasonic testing, eddy current testing, and other methods are used to perform non-destructive testing on the SA210C carbon seamless steel pipe. Ultrasonic testing can detect internal defects such as cracks, inclusions, and incomplete penetration in SA210C carbon seamless steel pipes; eddy current testing is mainly used to detect surface and near-surface defects in SA210C carbon seamless steel pipes, ensuring the reliable quality and absence of potential safety hazards.

Sixth, what are the application areas of SA210C carbon seamless steel pipes?
Power plant boilers: SA210C seamless steel pipes are widely used in water-cooled walls, economizers, low-temperature superheaters, and other heating surface piping systems, headers, and steam-water pipelines in power plant boilers. These pipelines need to withstand high-temperature and high-pressure working environments, requiring SA210C carbon seamless steel pipes to have good heat transfer performance, which SA210C seamless steel pipes can well meet.
Other areas: They can also be used in boiler flue pipes, safety ends, domes, and support pipes, as well as other industrial fields requiring high-temperature and high-pressure environments, such as high-temperature steam pipelines in oil refining units and heating pipelines in chemical reaction units.