Study of Corrosion and Mechanical Resistance of Structural Pipe Steels of Long-Term Operation in Hydrogen Sulfur Containing Environments

Abstract

Analysis of literature sources, as well as practical data indicate that the existing scientific, technical and technological developments to ensure reliable corrosion-mechanical resistance and durability of oil and gas pipelines and other shell metal structures of critical use and subordinate to the State Service for Mining Supervision and Industrial Safety of Ukraine largely find contradictions and uncertainty; there are no quantitatively substantiated recommendations for practical application in order to ensure corrosion and mechanical resistance of pipelines operating in technologically aggressive environments under alternating temperature and barometric conditions and loads; there is a need for a systematic study of the causes, conditions and mechanisms of corrosion and mechanical damage of long-term equipment, which will significantly increase the operational reliability of industrial equipment. Experimental studies have established the causes and substantiated the mechanisms of metal softening with increasing service life (from 0 to 25 years) that leads to its degradation, especially during long-term operation in corrosive environments. A method for forecasting the residual working (accident-free) life of pipeline metal structures has been developed, which makes it possible to purposefully regulate their operational condition. This allows the timely use of technical, design and technological measures to improve the performance of such structures. Numerous and diverse results of experimental tests of metal samples for various purposes have been obtained, which provide an opportunity to create a base for comparative analysis of steels in many parameters of crack resistance, which will become a reliable basis for scientific and practical substantiation of the equivalent replacement of some steel grades with other grades, taking into account technological loads, corrosive environments and others.

Structuring of the Main Directions of Research Regarding the Determination of the Remaining Resource of Transport Structures and Buildings

“…A systematic study of the causes, conditions, and mechanisms of corrosion and mechanical damage to long-term pipe products is described in [25]. Contradictions and uncertainties in the regulatory and technical documentation of the services for monitoring the condition of pipelines operating in aggressive environments and the need to create a base for comparative analysis of crack resistance parameters are indicated.…”

Degradation of the internal well equipment steel under continuous service in the corrosive and aggressive environments

“…In the context of α-Fe, almost 35-40% of cementite carbon atoms (Table 4) pass into α solid solution during decay if service life of the internal well tube structures is from 7 to 15 years. It is believed that the cementite phase reduction results in the decreased strength metal characteristics [24]. Durable operation of the internal well tubes (T and WC), results in cementite quantity decrease in the equipment; according to X-ray spectral analysis, it is almost 30-35%, and almost 20-25% according to the electron microscopic data.…”

Analysis of corrosion fatigue steel strength of pump rods for oil wells

“…It is known [22] that REEs are characterized by high thermodynamic activity. Moreover, they have close chemical connections with oxygen, nitrogen, and hydrogen while making rather stable combinations (i.e.…”