Carbon equivalent is CE for short. The carbon equivalent gives a visual indication of the weldability of the steel and its sensitivity to cracks during the welding process. It has great influence on the welding quality of steel pipe and the stability and reliability of the project.
Carbon Equivalent Calculator and Formula
Carbon Equivalent Calculator
Carbon Equivalent (A/SA106 S6.)
Carbon Equivalent Formula
Different countries and organizations have different formulas for calculating carbon equivalent. The most common formula for calculating CE is EN 1011-2.
CE=C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15
Using ASTM A53-B as an example, the CE can be estimated by the calculation formula above as:
CE=0.26+0.90/6+(0.30+0.10)/5+(0.40+0.20)/15=0.55
Carbon Equivalent In Steel Pipes Chart
The carbon equivalent value of different types and standard grades of steel pipes is very different. This affects both the performance of carbon steel pipes and the workplace where they are used.
Tuspipe In order to facilitate you to understand the CE in different types of steel pipes, carbon content, and other alloying element content on the welding performance of steel pipes. We provide you with a chemical composition table of steel pipe, covering API 5L X42, API 5L X52, ASTM A53-B, ASTM A106-B and other grades of steel pipe.
Pipe Type | Carbon Content (C) | Manganese Content (Mn) | Chromium Content (Cr) | Molybdenum Content (Mo) | Nickel Content (Ni) | Copper Content (Cu) | Carbon Equivalent (CE) |
ASTM A53-B | 0.26% | 0.90% | 0.30% | 0.10% | 0.40% | 0.20% | 0.55 |
ASTM A106-B | 0.28% | 0.90% | 0.30% | 0.10% | 0.40% | 0.20% | 0.57 |
API 5L X42 | 0.21% | 1.30% | 0.20% | 0.10% | 0.30% | 0.20% | 0.53 |
API 5L X52 | 0.22% | 1.20% | 0.20% | 0.10% | 0.30% | 0.20% | 0.5 |
API 5L X42 | 0.21% | 1.30% | 0.20% | 0.10% | 0.30% | 0.20% | 0.53 |
API 5L X52 | 0.22% | 1.20% | 0.20% | 0.10% | 0.30% | 0.20% | 0.5 |
ASTM A53-B | 0.26% | 0.90% | 0.30% | 0.10% | 0.40% | 0.20% | 0.55 |
ASTM A106-B | 0.28% | 0.90% | 0.30% | 0.10% | 0.40% | 0.20% | 0.57 |
Effect Of Carbon Equivalent On Weldability Of Steel Pipe Carbon
Effect On Cold Cracks In Welding
The steel pipe with high carbon equivalent is easy to produce welding cold crack in low temperature welding environment. Because the high CE leads to high hardness, the chromium element can be appropriately increased to change the melting point and cooling speed of the steel, reduce its toughness, and reduce the thermal stress during the welding process, thereby reducing the possibility of cracking.
When the CE is greater than 0.40%, the number of welding cracks is 5, and the crack sensitivity of steel is greatly increased to medium risk. When the CE is greater than 0.50%, the number of welding cracks is 10 times, and the crack sensitivity of steel is high risk.
Effect On Welding Deformation
On the other hand, in the welding process of steel pipes, carbon equivalent will have a significant impact on welding deformation such as shrinkage and warping. Compared with steel pipes with low CE, steel pipes with high CE are prone to greater welding deformation due to thermal stress and high hardness during welding.
Through many experiments, the CE increased from 0.35% to 0.45%, and the welding deformation increased by about 20%.
Conclusion
Tuspipe has a very professional team, first-class laboratory and mature production line. At tuspipe, excellent welding performance and service life of steel pipes are ensured through careful calculation and reasonable control of carbon equivalent. It is more important to focus on providing you with high quality and high performance steel pipes to improve the safety and reliability of your projects.
You can learn more by watching a video on the manufacturing process of tuspipe’s steel pipes.
FAQs:
1. What is the coefficient of thermal expansion of mild steel
The carbon content of mild steel is usually between 0.05% and 0.25%. Mild steel has an expansion coefficient of 10.8 ×10−6℃−1 to 12.5 x −6℃−1 or per degree Fahrenheit (6.0 to 7.0 μin/in°F).
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2. What is the difference between carbon content and carbon equivalent
Carbon equivalent is mainly used to evaluate the performance of steel pipes during welding.
Carbon content is the content of carbon elements in the steel pipe, which affects the basic mechanical properties such as the strength and ductility of the pipe.
