How to Correctly Choose the Material of Thick-walled Seamless Steel Pipes?

Correctly selecting the material of thick-walled seamless steel pipes is crucial, as it is directly related to the performance, safety and economy of the steel pipes. Improper selection can lead to premature failure, safety accidents and even economic losses. Permanent Steel Manufacturing Co., Ltd carefully summarizes the key factors to consider when selecting the material of thick-walled seamless steel pipes:
 
1. Clarify the operating conditions
 
This is the first step in selecting materials, and requires a detailed understanding of the use environment and loads of the steel pipe:
Working temperature: At what temperature will the steel pipe work? High temperature will cause problems such as decreased strength and creep of steel; low temperature will increase the brittleness of steel.
Working pressure: How much internal or external pressure does the steel pipe need to withstand? The higher the pressure, the higher the strength and toughness requirements of the steel.
Medium characteristics: What is the medium being transported or contacted? Is it corrosive? For corrosive media, steel with good corrosion resistance should be selected.
Load type: Is the steel pipe subjected to static load, dynamic load or impact load? Different load types have different performance requirements for steel.
Service life requirements: How long does the steel pipe need to be used? In situations where service life is required, it is necessary to choose steel with good durability.
 
2. Determine the performance indicators required
 
According to the working conditions, determine the performance indicators that the steel pipe needs to have:
Strength: includes tensile strength, yield strength, etc., to ensure that the steel pipe does not break or plastically deform when subjected to load.
Toughness: Ensure that the steel pipe is not prone to brittle fracture when subjected to impact loads.
Corrosion resistance: Resist erosion by various corrosive media and extend the service life of the steel pipe.
High temperature performance: Maintain sufficient strength and creep resistance in high temperature environments.
Low temperature performance: Maintain sufficient toughness in low temperature environment to prevent brittle fracture.
Welding performance: Good welding performance facilitates the connection and manufacture of steel pipes.
Fatigue performance: The ability to resist fatigue damage under cyclic loading.
 
3. Understand the materials and characteristics of commonly used thick-walled seamless steel pipes.
 
carbon Steel
20# steel: Commonly used low-carbon steel with good plasticity and weldability, but low strength, suitable for general-purpose pipes and structural parts.
45# steel: Medium carbon steel with high strength and hardness, but poor weldability, suitable for manufacturing mechanical parts that bear large loads.
 
alloy steel
16Mn (Q345B): Low alloy high strength structural steel with good strength, toughness and weldability, widely used in bridges, buildings, engineering machinery and other fields.
CrMo alloy steel (such as 42CrMo): It has high strength, high toughness, wear resistance and good high temperature performance, and is suitable for manufacturing high temperature and high pressure equipment and important mechanical parts.
CrNi stainless steel (such as 304, 316L): It has excellent corrosion resistance, high temperature resistance and good weldability, and is suitable for chemical, food, medicine and other fields.
 
Other special purpose steel
High-pressure boiler steel: Used to manufacture high-temperature and high-pressure pipes for power station boilers, with excellent high-temperature strength, creep resistance and oxidation resistance.
Steel for oil casing and oil pipe: used in oil and natural gas extraction, needs to withstand high pressure, high temperature and erosion of corrosive media in the formation.
 
4. Comparative analysis and selection
 
Based on the above information, compare and analyze the performance and price of various materials and choose the most suitable material:
Give priority to meeting performance requirements: First of all, it is necessary to ensure that the selected material can meet the various performance requirements under the working conditions. This is the most basic principle.
Comprehensively consider economic efficiency: Under the premise of meeting performance requirements, choose reasonably priced materials to reduce costs.
Refer to relevant standards and specifications: Select materials that comply with relevant national standards or industry standards.
 
5. Consult a professional
 
If necessary, you can consult material experts or technical personnel from the steel pipe manufacturer to get professional advice. For example, if you need to select a high-pressure pipeline for conveying corrosive media, you should choose stainless steel or special alloy steel with good corrosion resistance. If you need to choose a pipeline for manufacturing mechanical parts that withstand impact loads, you should choose alloy steel with high toughness.

Read more: Cutting Methods of Thick-walled Seamless Steel Pipes