What are the differences between seamless steel pipes and boiler pipes?

Posted by BAOWI STEEL MANUFACTURING CO.,LTD on August 21st, 2024

Seamless steel pipes and boiler pipes play a vital role in industrial production. Although they are similar in appearance, they have significant differences in use, production processes and technical requirements. This article will deeply analyze the differences between the two and the differences in production processes from multiple dimensions.
Seamless steel pipes, as the name suggests, are steel pipes with no seams along the periphery of their cross-sections. It is widely used in many fields such as petroleum geological drilling, petrochemicals, boiler manufacturing, bearing manufacturing, and aerospace because of its hollow cross-section, high bending and torsional strength, and light weight. Seamless steel pipes can be divided into hot-rolled seamless steel pipes, cold-rolled seamless steel pipes, cold-drawn seamless steel pipes, extruded seamless steel pipes, etc. according to the production method; they can be divided into ordinary carbon structural steel, low alloy steel, alloy steel and stainless acid-resistant steel, etc. according to the material; and they can be divided into general uses (such as water supply, gas pipelines and structural parts) and special uses (such as boilers, geological exploration, bearings, etc.) according to the use.

Production process of seamless steel pipe

The production of seamless steel pipe mainly goes through the following key steps:

1. Preparation of tube billet: Select standard steel ingots or solid tube billets as raw materials.

2. Heating: Heat the tube billet to an appropriate temperature to improve its plasticity and facilitate subsequent processing.

3. Perforation: The heated tube billet is perforated into a rough tube by a perforator to form a preliminary hollow structure.

4. Rolling/extrusion/cold drawing: Depending on the production process, the rough tube is hot rolled, cold rolled, cold drawn or extruded to achieve the required size and shape. Hot-rolled seamless steel pipes are rolled through a rolling mill at high temperature, with high production efficiency and low cost; cold-rolled and cold-drawn seamless steel pipes are processed at room temperature, with higher precision and smoother surface.

5. Heat treatment: Through heat treatment methods such as normalizing, annealing, and quenching, the residual stress inside the steel pipe is eliminated and its organizational properties are improved.

6. Finishing and inspection: Finishing work such as straightening, cutting heads, cutting tails, and surface treatment is performed on the finished steel pipes, and strict quality inspection is carried out to ensure that the products meet the standards.

Overview of boiler tubes

Boiler tubes are steel tubes specially used to manufacture boiler heating surface tubes. Their working environment is harsh and they need to withstand high temperature, high pressure and corrosive media. Therefore, boiler tubes have extremely strict requirements on materials, production processes and quality control. Boiler tubes are mostly made of seamless steel tubes or welded steel tubes, and the materials are mostly carbon steel, alloy steel, etc.
Production process of boiler tubes

The production process of boiler tubes is similar to that of seamless steel tubes, but it also has its own unique features:

1. Material selection: The material selection of boiler tubes needs to consider their working environment and use requirements to ensure that the material has sufficient strength, toughness, high temperature resistance and corrosion resistance.

2. Forming: Similar to seamless steel tubes, boiler tubes can also be formed by hot rolling, cold drawing, extrusion and other methods. However, boiler tubes have higher requirements for dimensional accuracy and surface quality, so various parameters need to be strictly controlled during the forming process.

3. Welding (for welded boiler tubes)**: Welding operations are required during the production process of welded boiler tubes, and the quality of welding directly affects the use effect and safety of boiler tubes. Common welding methods include manual arc welding, submerged arc welding, TIG welding, etc. It is necessary to select appropriate welding materials and processes to ensure the quality of the weld.

4. Heat treatment: Like seamless steel pipes, boiler tubes also need to undergo heat treatment to eliminate residual stress and improve mechanical properties and corrosion resistance.

5. Inspection and surface treatment: Boiler tubes must undergo strict appearance inspection, size inspection, mechanical property inspection and metallographic structure inspection to ensure product quality. At the same time, surface treatment is also required to remove impurities such as surface oil and rust to improve corrosion resistance and service life.
1. Different uses: Seamless steel pipes are widely used and involve multiple industrial fields; while boiler tubes are dedicated to boiler manufacturing and have a special working environment.

2. Different technical requirements: Boiler tubes have higher requirements for material, dimensional accuracy, surface quality and mechanical properties due to the harsh working environment.

3. Different focuses of production process: the production of seamless steel pipes focuses on improving production efficiency and reducing costs; while the production of boiler tubes focuses more on quality control and safety performance.

In summary, there are significant differences between seamless steel pipes and boiler tubes in terms of use, technical requirements and production processes. Understanding these differences will help us better select and use these two steel pipe products to ensure their effective application in their respective fields.