What Happens To High Carbon Steel When Welded?

May 1, 2022

Carbon steel welding is an everyday activity that most welders are exposed to during their careers. High carbon steel is an alloy of iron and carbon, with carbon content ranging from 0.04% to 2%. It’s a strong and durable material often used in construction for various applications, such as pipes, beams, buildings, and more. 

Carbon welding service is complex as carbon steel is difficult to weld. When welding high carbon steel, there are some challenges that you should expect. 

1. Cracking

Over the years, experts have found that one of the most severe problems when welding high carbon steel is cracking of the welding metal. The carbon content in the metal can cause brittleness, leading to cracking during the cooling process. The most common type of cracking is intergranular cracking, which occurs along the grain boundaries of the metal. This kind of cracking can be prevented using a low carbon electrode or preheating the metal before welding.

2. Lack of Fusion

In carbon steel welding, lack of fusion is another severe issue you should be aware of. This happens when the filler metal and the base metal don’t fuse properly, resulting in a weak joint. Lack of fusion can be caused by several factors, such as wrong welding techniques and incorrect welding parameters. To prevent this problem, setting the right welding parameters is essential.

3. Porosity

You will constantly experience porosity as you weld high carbon steel. Porosity is the formation of small holes in the weld metal, and it’s caused by gas bubbles trapped in the molten weld pool. Experienced welders who have the necessary experience can easily avoid this problem. However, if you’re a beginner, it’s best to use welding parameters less likely to cause porosity, such as lower amperage and voltage.

4. Hardness

The high carbon content in the metal can also make the weld metal very hard. This is an issue because it can make the metal challenging to work with and reduce the impact strength of the weld. Also, hardness can cause the metal to become brittle, leading to cracking. In most cases, hardness can be eliminated through post-weld heat treatment.

5. Warping

Huge carbon content in the metal is also the leading cause of warping. Warping is the deformation of the metal during the cooling process, and it can happen because of the high carbon content in the metal. In addition, warping can also be caused by incorrect welding techniques, such as improper electrode selection. Warping is not permanent and can be fixed by straightening the metal.

6. Weld Discoloration

Traditionally, weld discoloration has emerged as an esthetic issue in carbon steel welding. However, it can also indicate other problems such as lack of fusion, porosity, and more. In some cases, weld discoloration can also be caused by using the wrong welding consumables. This is not a significant challenge and can be easily fixed using suitable welding consumables.


The problems mentioned above are just some of the complex issues you may encounter when welding high carbon steel. To prevent these problems, it is vital to use the proper welding technique and ensure that the metal is prepared correctly before welding. With reasonable precautions, you can weld high carbon steel successfully. JB Electric LLC is a licensed and insured electrical contractor that can help you with your welding needs.

Categorised in:

JB Electric LLC