“25*2.5″ indicates that the outer diameter of the seamless steel pipe is 25mm and the wall thickness is 2.5mm. For petroleum cracking pipes, this specification of 10HSC seamless steel pipe is mainly used for small-flow media transportation in petroleum cracking units or in some complex pipeline systems with small pipe diameter requirements. 10HSC is usually a special alloy steel used to cope with the complex and harsh working conditions in the petroleum cracking process, such as high temperature, high pressure, and environments containing corrosive media.
First, what are the chemical composition and performance characteristics of 10HSC seamless steel pipes?
(1) Chemical composition of 10HSC seamless steel pipes: The chemical composition of 10HSC seamless steel pipes is designed to meet the special requirements of petroleum cracking. It mainly contains basic elements such as carbon, silicon, and manganese, and may also contain alloying elements such as chromium, molybdenum, and nickel. Among them, the carbon content is generally low to ensure good welding performance and toughness; the addition of alloying elements is mainly to improve the high-temperature oxidation resistance, corrosion resistance, and heat strength of the seamless steel pipe. For example, chromium helps form a dense oxide film, enhancing the corrosion resistance of seamless steel pipes; molybdenum can improve the strength and creep resistance of seamless steel pipes under high temperature and pressure.
(2) Mechanical Properties:
(A) Strength Properties: Due to its 2.5mm wall thickness, this seamless steel pipe possesses a certain strength to withstand internal pressure. Its yield strength and tensile strength are designed according to the operating conditions of petroleum cracking. In petroleum cracking units, pipelines need to withstand certain pressures; for example, their yield strength may reach approximately 200-300MPa, and their tensile strength is between 335-470MPa, ensuring that the pipeline will not rupture or deform excessively under normal operating pressure.
(B) Toughness Properties: Good toughness is one of the important characteristics of 10HSC seamless steel pipes. During the operation of petroleum cracking units, pipelines may be subjected to external forces such as fluid impact and vibration. This seamless steel pipe has sufficient toughness to resist these external forces and avoid brittle fracture. Its impact toughness indicators (such as Charpy V-notch impact absorption energy) generally meet the requirements of the petrochemical industry, ensuring safety and reliability in complex working environments.
(C) Corrosion Resistance: In petroleum cracking environments, various corrosive media exist, such as sulfides and organic acids. 10HSC seamless steel pipes, due to their alloy composition and special surface treatment, possess good corrosion resistance. The protective film formed by the alloying elements effectively prevents corrosive media from contacting the seamless steel pipe substrate. For example, in media containing hydrogen sulfide (H2S), seamless steel pipes can resist hydrogen sulfide corrosion, reducing the risk of sulfide stress corrosion cracking (SSCC) and extending the service life of the pipeline.
Secondly, what are the key points to note in the processing technology of 10HSC seamless steel pipes?
(A) Smelting Process: The smelting process of 10HSC seamless steel pipes requires precise control of the chemical composition. It typically employs electric arc furnace steelmaking or converter steelmaking, followed by ladle refining. During steelmaking, various alloying elements must be added strictly according to the designed chemical composition, and refining methods (such as vacuum degassing and stirring) must be used to ensure uniform element distribution. This is because the uniformity of alloying elements directly affects the performance of seamless steel pipes, such as corrosion resistance and mechanical properties.
(B) Rolling Process: During rolling, parameters such as rolling temperature, rolling speed, and reduction must be rationally controlled according to the outer diameter and wall thickness requirements of the seamless steel pipe. For seamless steel pipes of the 25*2.5 specification, attention must be paid to ensuring the uniformity of the pipe wall thickness during rolling. Since this seamless steel pipe is used in petroleum cracking, a field with high quality requirements, the dimensional accuracy requirements after rolling are high. For example, the outer diameter tolerance may be controlled within ±0.1mm, and the wall thickness tolerance within ±0.15mm.
(C) Heat Treatment Process: Heat treatment is crucial for optimizing the performance of 10HSC seamless steel pipes. Normalizing and tempering heat treatment processes are generally performed. Normalizing can refine grains and improve the strength and toughness of seamless steel pipes; tempering can eliminate internal stress and improve the comprehensive mechanical properties of seamless steel pipes. Temperature and time control during heat treatment are crucial, as different combinations of temperature and time significantly affect the performance of seamless steel pipes. For example, normalizing temperatures are generally between 900-950℃, and tempering temperatures are between 600-700℃. By precisely controlling these parameters, seamless steel pipes can achieve optimal performance.
Third, what are the application scenarios and advantages of 10HSC seamless steel pipes?
(1) Application scenarios of 10HSC seamless steel pipes:
In catalytic cracking units in petroleum refining, 10HSC seamless steel pipes can be used to transport small-flow media such as catalysts and additives. These media may be corrosive and require high cleanliness of the pipelines; the corrosion resistance and dimensional accuracy of this seamless steel pipe meet these requirements. In the instrumentation and control systems of petroleum cracking units, it serves as a signal transmission pipeline or a small sampling pipeline. Due to its small size, it can be flexibly arranged inside complex devices and can resist the corrosive environment that may exist inside the device.
(2) Advantages of 10HSC seamless steel pipe:
(A) Strong corrosion resistance: It can work stably in the corrosive environment of petroleum cracking, reducing the frequency of pipeline maintenance and replacement, and lowering production costs.
(B) Good mechanical properties: The good combination of strength and toughness enables it to withstand the pressure and external impact in petroleum cracking units, ensuring the safe operation of the pipeline system.
(C) High-dimensional accuracy: It is suitable for applications requiring high accuracy in pipe diameter and wall thickness, such as small-flow media transportation and instrumentation pipelines, facilitating precise connection with various pipe fittings and equipment.
Post time: Jan-23-2026