Advantages & Disadvantages of Boiler Tubes in Different Materials

With the rapid development of industry, boilers are used more and more widely, and the materials of tubes used in boilers are becoming more and more. Boiler tubes are a special steel pipe used for boilers and related thermal equipment. They are mainly divided into seamless steel pipes and welded steel pipes. When choosing the material of boiler tubes, multiple factors need to be considered, such as sealing, pressure resistance, corrosion resistance, etc. This article will analyze the commonly used boiler tube materials and explore their respective advantages and disadvantages.

Characteristics of boiler tube materials

1. Corrosion resistance

In the working environment of the boiler, the pipes often contain corrosive substances such as water vapor and acidic gases, so the boiler tube material is required to have high corrosion resistance.

2. High temperature and high pressure resistance

When the boiler is working, the temperature and pressure are very high, so the boiler tube material must be able to withstand the environment of high temperature and high pressure.

3. Good mechanical properties

The boiler tube material must have good mechanical properties to ensure that it will not produce plastic deformation or fracture under high temperature and high pressure.

Material classification of boiler tubes

1. Carbon steel boiler tubes

Made of mild steel tubes and low alloy structural steel tubes, it is characterized by low hardness and poor heat resistance, suitable for use at low temperatures and general working conditions.

2. Alloy steel boiler tubes

By alloying and improving carbon steel, its hardness and heat resistance are improved to a certain extent, suitable for use under high temperature, high pressure and special working conditions.

3. Stainless steel boiler tubes

Common ones include 316 and 304 stainless steel tubes, which have strong corrosion resistance and are suitable for use in special environments such as chemical, petroleum and sanitary industries.

4. High-pressure boiler tubes such as 20G and 12Cr1MoVG

Suitable for use under ultra-high pressure, requiring high temperature and high pressure resistance and high thermal strength.

Advantages and disadvantages of boiler tubes in different materials

1. Carbon steel boiler tubes

Advantages:

Low cost and good economy.

Good processing performance, easy to weld and form.

Moderate strength, suitable for medium and low pressure boilers.

Disadvantages:

Poor high temperature resistance, not suitable for high temperature and high pressure environments.

Poor corrosion resistance, easy to rust.

2. Alloy steel boiler tube (such as 15CrMoG)

Advantages:

Good high temperature resistance, can work for a long time under high temperature and high pressure environment.

High strength, good corrosion resistance.

Good anti-oxidation performance.

Disadvantages:

High cost.

It is difficult to process, and special processes are required for welding and forming.

3. Stainless steel boiler tube:

Advantages:

Excellent corrosion resistance, suitable for corrosive media.

Good high temperature resistance, can work for a long time under high temperature environment.

High strength, good mechanical properties.

Disadvantages:

Very high cost.

It is difficult to process, and special equipment and technology are required for welding and forming.

4. 20G high pressure boiler tube (carbon manganese steel high pressure boiler tube):

Advantages:

Relatively low cost.

Good process performance (processing and welding require standardized heat treatment and cold bending).

Meet medium high temperature and high pressure requirements (≤450℃).

Disadvantages:

Limited high temperature strength (significantly decreased at >450℃).

Poor oxidation resistance.

General corrosion resistance.

Scope of application

1. Carbon steel boiler tube

Applicable to low temperature and general working conditions, such as heating boilers, industrial boilers, etc.

2. Alloy steel boiler tube

Applicable to high temperature, high pressure and special working conditions, such as power plant boilers, nuclear power plant boilers, etc.

3. Stainless steel boiler tube

Applicable to special environments such as chemical, petroleum and sanitary industries, such as high temperature corrosion environment, high purity water vapor environment, etc.

4.20G, 12Cr1MoVG and other high pressure boiler tubes

Applicable to ultra-high pressure, such as ship boilers, pressure vessels, etc.

Precautions for selecting boiler tube materials

1. Determine the working environment

Before selecting materials, it is necessary to clarify the environment that the material will withstand during work, such as working temperature, working pressure, etc., which will determine the choice of material.

2. Consider the corrosion resistance of the material

Pressure boilers will produce acidic solutions during operation, so the corrosion resistance of pipeline materials is the key consideration for selection.

3. Consider cost and operability

When selecting the material of boiler tubes, in addition to considering factors such as performance and corrosion resistance, it is also necessary to coordinate cost issues and the ease of processing of the material to facilitate later use and maintenance.