Preventing Hydrogen Embrittlement and Metal Corrosion


Metals in their various forms provide a vital component in heavy industry, manufacturing and construction. We rely on them heavily which is why it is important that their quality and integrity is maintained at all times. Unfortunately, the various treatment processes that metals can be subjected to in an effort to increase performance can also have a negative effect on certain characteristics.

If you rely on the highest standard of metal being available for your projects, this article is for you.

What is Hydrogen Embrittlement?

As you will be aware, steel is actually an alloy which is created by the process of refining other materials, including a base metal and various ores. The process of creating steel is what gives it its strength and versatility – taking the desirable properties of certain base metals and adding to them with the addition of ore through the forging process.

For the most part, this results in a perfectly useable section of steel which can be used as reinforcement in buildings and as the chassis of a car.

When steel, or any other metal is treated further before it is put into use, these treatment processes can introduce hydrogen into the equation. These hydrogen atoms and molecules will bind and diffuse into the surface of any metal, causing it to weaken and produce visible cracking.

Hydrogen embrittlement is most prevalent when trying to change the colour of a metals surface or through the metal blackening process. It is here, when plating a metal, that it is possible to trap these atoms within the surface leaving them with no room to escape.

Is all Metal Affected?

To some extent, yes. What you will actually find is that harder metals are far more susceptible to embrittlement than softer metals. The official hardness scale, referred to as HRC, states that any metal with a hardness level of below 35 HRC should be fine. On the other hand, if a metal reaches or surpasses a score of 40 HRC, embrittlement will likely be a problem.

Metal Blackening

As mentioned, changing the colour of any metal is where this undesirable process is likely to take place. Luckily, there is a solution. Several companies, one of which is Blackfast based in Surrey, have developed a way to halt this process whilst undergoing blackening or colour transformation. It is this process which is so heavily relied upon that can make all the difference.

Rather than plating a metal with another material, the key is to submerge it into a special solution where the desired colour change will take place. This solution is alkaline based rather than acidic in nature which is usually where problems occur. The presence of alkaline neutralises most of the ability for hydrogen to damage a metals surface, giving you the colour you want without changing a metals structural integrity.

Metal blackening is now a well known procedure with several companies offering their services throughout the UK. Most will be more than happy to provide a free demonstration so that you can see first hand just how this metal friendly colour change process could benefit you.

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