The accumulation of hydrogen reduces the strength of structures and may lead to emergency situations. The discovered effect calls into question the existing industrial standards.

Usually we associate hydrogen with something environmentally friendly and efficient. However, this is not quite true for metallurgy. Over the past 100 years, specialists have been striving to remove hydrogen from metals for their greatest strength, plasticity and durability.

They struggle with the so-called «dissolved» hydrogen. In the 80-ies of the last century, the «hydrogen problem» in metallurgy was solved through the development of new alloys and the introduction of various technologies for removing hydrogen from metals. The solution to the problem seemed final, so the control of hydrogen in metals weakened all over the world.

In our country, in 2002, the corresponding GOST standards, which were developed for all groups of alloys, became optional, and incoming inspection of finished metal products was completely discontinued. This state of affairs is already causing problems in manufacture of metal products, and may be emergency-dangerous, especially when using pure hydrogen in the rapidly developing hydrogen power industry.

Hydrogen control technologies are now at the intersection of many modern technologies, ranging from the production of ultra-strong alloys, additive technologies and ending with hydrogen energy.

Scientists of IPMash RAS have been investigating this problem for more than 20 years, creating methods of hydrogen diagnostics that will help to avoid man-made disasters caused by hydrogen degradation of metals and alloys. Employees of the Institute were directly involved in the development of the domestic industrial hydrogen analyzer, which is now being mass-produced, and of the domestic system of state standards for hydrogen content.

«We have discovered and studied a new effect which occurs when metals are saturated with hydrogen in an aggressive environment. This is the so-called „hydrogen skin effect“. It consists in the fact that for a long time hydrogen accumulates only in a thin surface layer of metal and destroys it. Only after about 1000 hours it begins to spread to a depth of more than 50 micrometers (1 micrometer is 0.001 mm). The presence of such an effect, on the one hand, slows down the destruction of structures, on the other hand, calls into question the results of industrial tests and many scientific achievements that were obtained using hydrogen saturation in aqueous solutions of electrolytes,» commented Vladimir Polyanskiy, the Head of the study, Director of IPMash RAS. The effect was discovered by occasion. It turned out that cleaning a hydrogen-saturated sample manually with a sanding paper changes the average concentration of hydrogen in the sample significantly. Further studies were carried out using microscopes, by grinding layer-by-layer and by lathe-turning of hydrogen-saturated samples. It was found that degradation of a thin surface layer of metal reduces significantly the fatigue strength of the entire massive metal part, but this degradation differs from the operational one that occurs when metal products are saturated with hydrogen during long-term operation.

This discovery explains the large spread of data on the parameters of the interaction of metals with hydrogen. It requires a revision of the entire system of industrial tests and explains the fact that present-day metals pass the tests well, while machines and structures made of them crack and break in an aggressive environment, which is hydrogen gas and mixtures of hydrogen with other gases as well.