Mild steel pipe is a kind of steel with low carbon content. It is widely used in various fields due to its excellent performance. Understanding the chemical composition of mild steel pipe is crucial to understanding its performance characteristics. Next, let's analyze the main chemical composition of mild steel pipe in detail.
Main chemical composition of mild steel pipe
1. Carbon (C)
Carbon is the main alloying element of carbon steel pipe, and its content is usually below 0.25%. The carbon content determines the strength, hardness and wear resistance of steel. As the carbon content increases, the strength and hardness of mild steel pipe will also increase accordingly, but the plasticity and toughness will decrease.
2. Silicon (Si)
Silicon mainly exists in the form of silicide in mild steel pipe, which helps to improve the strength and corrosion resistance of steel. The right amount of silicon can also improve the welding performance of mild steel pipe. In the construction field, mild steel pipes used to manufacture steel structures and bridges can enhance their corrosion resistance and welding performance through the action of silicon, ensuring the stability and safety of the structure.
3. Manganese (Mn)
Manganese is an important alloying element in mild steel pipes, which can improve the strength and toughness of steel. At the same time, manganese can also reduce the brittle transition temperature of steel and improve low-temperature toughness. When manufacturing pipelines such as boiler tube that need to withstand large pressures and temperature changes, the role of manganese is particularly important. It can keep the pipelines in low-temperature environments. Good toughness can reduce the risk of rupture.
4. Phosphorus (P)
Phosphorus mainly exists in the form of solid solution in mild steel pipes, which helps to improve the strength and hardness of steel. However, excessive phosphorus content will reduce the plasticity and toughness of steel, so the phosphorus content needs to be controlled. For example, when producing oil casing pipe, it is particularly important to control the phosphorus content. Excessive phosphorus content can easily lead to brittle fracture.
5. Sulfur (S)
Sulfur is a harmful element in mild steel pipes, which will reduce the plasticity and toughness of steel and increase the hot brittleness of steel. Therefore, the sulfur content needs to be strictly controlled during the production process.
Table of content ranges of main chemical components |
||
Element |
Model |
Content range |
C (carbon) |
Q235、A106 |
0.05–0.25% |
Si (silicon) |
—— |
0.10–0.35% |
Mn (manganese) |
—— |
0.30–1.60% |
P (phosphorus) |
—— |
≤ 0.045% |
S (sulfur) |
—— |
≤ 0.050% |
Cu (copper) |
—— |
0.20–0.55% |
Cr (chromium) |
—— |
≤ 0.30% |
Ni (nickel) |
—— |
≤ 0.30% |
Effect of chemical composition on the performance of mild steel pipes
1. Elements such as carbon, silicon, and manganese can improve the strength and hardness of steel, but excessive carbon content will reduce the plasticity and toughness of steel.
2. Although phosphorus can improve the strength and hardness of steel, excessive phosphorus content will also reduce the plasticity and toughness of steel.
3. Sulfur is a harmful element and its content needs to be strictly controlled to avoid adverse effects on steel performance.
Typical applications and key points of material selection
Application fields |
Typical grades |
Key performance |
Requirements |
Construction and bridges |
Q235 |
Welding performance, corrosion resistance |
Emphasis on low hydrogen embrittlement and easy welding |
Automobile chassis |
A53 |
Strength, impact toughness |
Requires lightweight, high strength and fatigue resistance |
Oil and gas pipelines |
X42–X65 |
Compression resistance, low temperature resistance |
Control carbon equivalent to ensure no brittle fracture at –40 ℃ |
Boiler and heat exchanger |
16Mn |
High temperature resistance, creep resistance |
Add elements such as manganese and chromium to improve stability at high temperatures |
Mechanical manufacturing |
20# |
Machinability, wear resistance |
Ensure good turning and boring processing performance, and have certain wear resistance |
Summary
In short, ms pipe is an important metal material, and its chemical composition has an important influence on its performance. Understanding the chemical composition of mild steel pipe can help us better apply this material and give full play to its excellent performance. At the same time, with the continuous advancement of science and technology and the continuous development of industry, the application prospects of mild steel pipe will be broader.
Read more: Difference between mild steel pipe and carbon steel pipe