Lube-Tech PUBLISHED BY LUBE: THE EUROPEAN LUBRICANTS INDUSTRY MAGAZINE


variant of classical fatigue failure, possibly initiated at material inclusions or microstructural inhomogeneities.


The second school of thought focuses on hydrogen involvement, proposing that hydrogen ingress— either from moisture, lubricant decomposition, or electrical discharges—weakens the steel from within. This theory includes concepts like hydrogen embrittlement and hydrogen-enhanced local plasticity, both of which help explain how WECs can form even under seemingly benign conditions. Stray currents, tribochemical reactions, and elevated temperatures all contribute to an environment where hydrogen can accumulate in critical areas of the steel.


Both perspectives provide valuable insights, yet neither has produced a consistent, practical method of preventing WECs. This has led researchers to propose more integrated hypotheses—ones that consider mechanical, electrical, and chemical stressors as interconnected drivers of failure. Until such models are validated and turned into actionable engineering solutions, WECs will remain one of the most pressing reliability challenges in tribological design and industrial lubrication.


Revisiting an overlooked theory The mystery of white etching cracks may not be entirely modern. In fact, part of the answer may lie in research that was largely overlooked in the West but foundational in Soviet tribology. In the 1960s, Professor Dmitry N. Garkunov—a leading figure in Soviet-era tribology—proposed two radical ideas that challenged the prevailing assumptions of wear science: the phenomenon of hydrogen wear and the counterintuitive concept of the wearlessness effect.


Garkunov’s work was based on the insight that not all wear was mechanical. He and his followers argued that under certain frictional conditions, electrochemical processes could become dominant. When steel components rub together under pressure and


30 LUBE MAGAZINE NO.188 AUGUST 2025


No.159 page 2


temperature—especially at micro-asperity contacts— chemical reactions occur not only within the lubricant but also at the steel surface itself. These reactions, Garkunov believed, are not merely side effects; they are active contributors to material degradation.


The first major contribution of Garkunov’s school of science, the concept of hydrogen wear, describes how hydrogen atoms are generated in the friction zone and then absorbed into the steel. These hydrogen atoms originate from the breakdown of hydrocarbon lubricants, water contaminants, or other polar species in the presence of high surface energy. At elevated flash temperatures—often well above 1000°C at the microscopic contact points—iron can undergo polymorphic transitions that release electrons. These delocalised electrons contribute to the dissociation of molecules in the lubricant or adsorbed water, releasing hydrogen ions (H+


).


Figure 1: Electrons’ release during polymorphic transition of iron


Figure 2: H+ released from lubricant and water molecules


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64