Definition - What does Hydrogen Disintegration mean?
Hydrogen disintegration refers to deep internal cracks caused by hydrogen. It is very common phenomenon that causes industrial failure of steel. Disintegration may take place due to interfacial segregation of hydrogen in high-strength steel, which leads to delamination or decohesion.
Engineering materials are exposed to hydrogen and they may interact with it, resulting in various kinds of structural damage. Hardening, embrittlement and internal damage are the main hydrogen damage processes in metals.
Hydrogen disintegration is also known as hydrogen damage and hydrogen embrittlement.
Corrosionpedia explains Hydrogen Disintegration
Hydrogen present in metals can produce several kinds of internal defects:
- Shatter fractures
Carbon steels exposed to hydrogen at high temperatures experience hydrogen attack, which leads to internal decarburization and weakening.
Hydrogen can enter metals during:
- Regular use
Atomic hydrogen is absorbed initially by the metal surface and transforms to molecular hydrogen when the concentration reaches a high value. The molecular hydrogen accumulates in voids, pores and interfaces as well as other defect sites. If these defects are not present in the vicinity of the high-hydrogen areas, blisters or hairline cracks are formed to release the high pressure. Such hydrogen-induced blister cracking has been observed in steels and other alloys.
The ingress of hydrogen into a component, an event that can seriously reduce the ductility and load-bearing capacity, causes cracking and catastrophic brittle failures at stresses below the yield stress of susceptible materials. The most vulnerable are high-strength steels, titanium alloys and aluminum alloys. For example, hydrogen disintegration of titanium and its alloys is manifested as embrittlement and/or reduction in the stress-intensity threshold for crack propagation.
Hydrogen disintegration can be inhibited through controlling contact between the metal and hydrogen as well as controlling the environment.
The Effects of Stress Concentration on Crack Propagation