Hydrogen Attack Test
Hydrogen attack testing is a vital process used to detect any hydrogen embrittlement from within a material. Hydrogen embrittlement can occur if a material is able to absorb hydrogen atoms from its environment, causing the material to become weak, which consequently leads to mechanical failures. Hydrogen attack testing can help to identify and prevent hydrogen embrittlement from occurring.
Hydrogen attack testing is often performed on powder metallurgy (PM) components to check for the presence of hydrogen embrittlement, especially after hot-isostatic pressing. It is also used to check for potential embrittlement risks that could occur when steel is electroplated or welded. The test can be conducted as part of a routine test or it can be used in an investigation to determine the root cause of mechanical failures.
The test usually takes place in a vacuum or hydrogen environment. This allows the sample to be placed into a special container, where it can be exposed to a mixture of hydrogen gas and vapor. The container is heated and the hydrogen gas is slowly diffused into the sample, if the sample contains hydrogen-absorbent components then it will absorb hydrogen atoms from the gas.
When the sample is exposed to a high enough concentration of hydrogen atoms, it can start to experience hydrogen attack. This is when the hydrogen forms small voids within the material and the material becomes weak and brittle.
During the hydrogen attack, the material will be exposed to a variety of tests. This includes visual inspections for evidence of hydrogen-induced cracks or a decrease in the material’s ductility. In some cases, tests using an electron microscope or other specialized analytical techniques may be used to visualize hydrogen residuals and the extent of hydrogen damage.
Hydrogen attack testing is an important process that can help to identify any potential hydrogen embrittlement within a material. It is important to conduct the test in order to help minimize the risk of any mechanical failure or hazardous situation that could occur due to hydrogen embrittlement.
