I know most of us have heard about the metal arc welding process. However, the terminology ‘automatic hydrogen welding’ otherwise abbreviated as AHW sounds strange to so many people. However, this is just one of the types of the arc welding processes. It is one of the techniques that are renown for implementing superior welding processes. On this page, we will help you to learn more about the automatic hydrogen welding process. If you believe that this is what your project needs, feel free to contact us at Aluminum Welding.

By definition, the arc welding process utilizes an electric arc that is placed between 2 tungsten electrodes with the presence of hydrogen. In the automatic hydrogen welding, the shielding atmosphere is made up of the hydrogen.

The History of AHW

The arc welding process has been around for so many years. However, not everyone knows about the application of hydrogen in the arc welding process. Irving Langmuir, the Nobel Prize winner, is the one who invented this technique in the process of studying atomic hydrogen.

Hydrogen and the electric arc have a critical role to play in the automatic hydrogen welding process. The electric arc is highly efficient when it comes to breaking the electric molecules. The hydrogen molecules later recombine to release a very tremendous amount of heat. As the heat is released, temperatures that range from 3400 to 4000 degrees centigrade are reached.

What will happen if you undertake such an exercise without hydrogen? Several studies reveal that in the absence of an electric arc, it renders the entire process inefficient. You can use the oxyhydrogen torch in the place of an electric arc but in such a case, you can get to temperatures of 2800 degrees centigrade.


  • A controller with a power supply of 300 V. The AC power supply is utilized in the case of atomic hydrogen welding.
  • Filler rod or metal.
  • Hydrogen gas cylinder.
  • A torch or an electrode holder.
  • Two tungsten electrodes.

The equipment that is utilized on automatic hydrogen welding comprises of a welding torch that has two tungsten electrodes. The 2 electrodes are inclined to one another and are adjusted in such a manner that they maintain a stable arc.

There is an angular nozzle around the two tungsten electrodes that carries the hydrogen gas. The required hydrogen gas is normally stored in gas cylinders.

Why Use AC Power and Not DC?

This is a question that will cross your mind as you think of the supply of e-power in the automatic hydrogen welding process. The process requires you to maintain an equal heat supply at the two ends of the electrode. If there is no equal supply at both ends of the electrode, you can’t undertake this exercise in the right manner. Thus, to get the right supply of heat at the two ends, the AC power supply is used instead of DC when carrying out the AHW process.

The Working of Atomic Hydrogen Welding

Arc generation occurs when you keep two tungsten electrodes in contact with on another. After you make this contact, you separate them with a small distance of approximately 1.5mm. When the electric gas goes via the hydrogen gas, it will dissociate into atomic hydrogen. Dissociating into atomic hydrogen takes place because of the absorption of a huge heat amount that is produced in this process. The endothermic reaction that takes place can be represented by;

H2 = H + H – 422 KJ

After this, we now have the combination of atomic hydrogen taking place. The recombination occurs when the atomic hydrogen does touch the cold workpiece. It is a process that liberates a large heat amount.

H + H = H2 = 422 KJ

At this point, the exothermic reaction occurs during the process of recombination.

The Atomic Hydrogen Welding Process

The amount of heat that is supplied should not be too little or too large. In case the process of fusion takes a very long period, it shows that the heat supply is too little.

You should also maintain the right arc gap. It should neither be too small or too large. In case you fail to maintain the right arc gap, a very little amount of heat will be released. Less heat supply results into a very small pool. Maintaining the right surface porosity will be very hard in case there is little heat.

On the other hand, a large amount of heat supply leads to a wide pool. The excess heat amount will create a big hole in the material that you are welding.

We have for factors that determine the success of the AHW process. The first one is the presence of the right contact between the arc and the workpiece. The others include the current setting, arc size, and lastly the speed of travel. Experts have to pay close attention to this if they want to succeed in automatic hydrogen welding.

Advantages of AHW

Automatic hydrogen welding produces a very small amount of heat distortion. The reason for less distortion is because of the very intense flames. These intense flames that are generated may be concentrated at a specific welding joint.

AHW will guarantee you a high-speed welding process. It is beneficial to use a welding process that is faster as it saves the time of the welder. It is a benefit that you can be sure of whenever you are using AHW.

When doing automatic hydrogen welding, there isn’t a need to have the flux separately. The hydrogen gas acts as the shielding gas and blocks metal oxidation and also the tungsten electrode.

In some of the welding procedures, the metal workpiece forms part of the electric circuit and because of this, instances such as maintaining the arc or striking the arc column arises. However, because the workpiece isn’t part of the electric circuit in automatic hydrogen welding, such issues cannot arise during the welding process.

Key Features of AHW

  • The average temperature that this process produces is 4000 degrees centigrade. It is considered to be the third hottest flame.
  • The di-cyanoacetylene flame has an approximate temperature of 4987 degrees centigrade and the one for the cyanogen flame is about 4525 degrees centigrade.
  • The life of the electrode n the atomic hydrogen welding is increased by passing the tungsten electrodes through the hydrogen gas. As the hydrogen gas passes through these electrodes, the electrodes tend to become cooler.
  • The heat that the AHW process generates can efficiently weld tungsten.
  • Of late, we have had the development of automatic hydrogen welding. The process does not use hydrogen from very high-pressure cylinders. Hydrogen is instead obtained from anhydrous ammonia.

Disadvantages of Automatic Hydrogen Welding

You need a skilled welder to be able to implement the process of AHW effectively. There is no way you will implement this process effectively in the absence of a skilled laborer. Therefore, you need an experienced and talented welding professional to do this type of work. These professionals are readily available at Aluminum Welding.

Secondly, the cost of AHW is slightly more than the other welding methods in the market. Therefore, the automatic hydrogen welding process requires a minimal capital.

The application is automatic hydrogen welding is limited to the flat positions only. The welding process cannot be applied in the other positions. It is a limitation that really prevents most people from using the technique.

Because the process entails the use of hydrogen, you need to take certain precautions. As you know, hydrogen is a gas that is highly inflammable. Therefore, you have to put the desired safety measures in place before you start using AHW.

Applications of AHW

AHW is widely used in cases where you need fast welding results. It is a welding process that is mainly applied on stainless steel and some other special alloys. You can also use AHW on almost all non-ferrous and ferrous materials. The process is ideal in the welding of both thick as well as thin metal sheets with a diameter that ranges from 2 to 10mm.

Most welders currently replace the AHW process with gas metal arc welding (GMAW). The reason is that the in inexpensive inert gases are available in large amounts which accounts for the replacement of AHW with GNAW.

By now, you understand how the automatic hydrogen welding gas works. If it is the best fit for your metal fabrication project, feel free to get in touch with us at Aluminum Welding. Our customers are spread in all the cities of Ventura, San Bernardino, Riverside, Los Angeles, and even Orange County. You can be sure of getting high quality services pocket-friendly prices.

From our offices in California, Aluminum Welding serves households and businesses in Ventura, Riverside, San Bernardino, Los Angeles and Orange County. We offer a broad range of metal fabrication services to our esteemed customers. Contact us today to learn the kind of services that you can get from us.

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