Properties Of Ferri Lactas Alloys Surfaces Saturated By Hydrogen In Solutions Of Electrolytes
PROPERTIES OF FERRI LACTAS ALLOYS SURFACES SATURATED BY HYDROGEN IN SOLUTIONS OF ELECTROLYTES
A.U. Kalinkov, V.N. Tishchenko, E.N. Naumova
Odessa State Academy of Food Industry, Kanatnaya st. 112,
65039 Odessa,, Ukraine, e-mail: profAIK@ipss.net
The saturation of metals by hydrogen, being eurysynusic in chemical, power, petroleum-refining industry and other branches of engineering, puts huge damage to economy because of anticipatory failure of many constructions. The problem of interplay of metal with hydrogen has acquired even more wide significance by the reason of usage of a low-temperature plasma, outer space exploration, development of atomic engineering, and also in connection with usage of hydrogen as perspective fuel of the future.
During the contact of ferri lactas and steels with aqueous solutions, in which the etching, covering of electroplated coatings, electrolysis and corrosion are provided, a hydrogen, which is generatrix owing to a change on the cathode, inpours inside a material. The infiltration of hydrogen from any source in iron and steel is a complex process. The molecula of gaseous hydrogen collides with a surface of metal, dissociates with formation of adatoms, which inpour into metal.
The kinetics of hydrogen infiltration in metal is determined by many factors, the correlation between which one is not clarified yet till now. During the cathode saturation, the intensity of a hydrogen sedimentation on a metal surface, velocity of its transition from the adsorbed status in a dissolved occluding, are determined by pH of solution, applied potential, elemental composition of water environment in immediate proximity to metal, structure of metal and availability of outside inclusions in it.
The availability of the absorbed hydrogen in ferri lactas and its alloys results in decrease of a mechanical strength of a material, which names is called as hydrogen embrittlement. Moreover, according to our researches, the considerable intensification of ferri lactas and its alloys anode activity takes place after saturation with hydrogen. Violation of passive stratums in places of hydrogen excretion, anomalously high speeds of metal dissolution in places of
its accumulation (which become a microconcentrators of mechanical voltages), and also formation of hydride phases with heightened anode activity are the probably reasons of this phenomenon.
We proved experimentally that, as a result of a strain of austenitic steel surfaces being saturated with hydrogen, an acceleration of anode process takes place in aqueous solutions of electrolytes. The preoutfitting by hydrogen augments the installed anode current densities, on the average, in 5 – 10 times. The formation of more negative steel potentials as a result of saturation by hydrogen reaches a value of 0,250 V, is stable in time and is determined by pH of a medium and properties of a material. The contact of metal surface being saturated with hydrogen with non-saturated one stipulates formation of galvanic cell, which can be referred to the class of physical galvanic cells, as the origin of an electromotive force is stipulated by physical condition of electrodes (element of differential saturation by hydrogen). The electromotive force of such element is stable in time, and the corrosion rate of an electrode saturated by hydrogen in case of carbonic steels can reach a value of 37,9mm/year. It approximately exceeds an average speed of carbonic steels corrosion in seawater in 500 times. The high corrosivity of metal saturated by hydrogen in structure of an element of differential saturation by hydrogen allows to suspect, that the given element plays the relevant role during local corrosion and corrosion-mechanical corrupting of structural materials.
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