Manufacturing Technology 2025, 25(1):86-94 | DOI: 10.21062/mft.2025.003

Microscopic analysis of selected materials used for hot water heating using SEM

Ľuboš Marček ORCID..., Ján Vavro, jr. ORCID..., Jan Vavro ORCID...
Faculty of Industrial Technologies, Alexander Dubček University of Trenčín. Ivana Krasku 491/30, 020 01, Púchov. Slovak Republic

The introduced work deals with the microscopic analysis of metallographically prepared selected metal materials structures, using a scanning electron microscope (SEM). Prepared samples of seamless steel pipes were subjected to a thorough microscopic examination from the outer surface to the inner regions in order to interpret the spe-cific structure, including the change of the inner surfaces due to wear. The experiment showed that the micro-structure and character of the surfaces play a crucial role in the behavior of metallic materials under real condi-tions. Four types of pipes were monitored according to their use. The unused steel pipe (designated as sample No. 1) exhibited a rough outer surface with identified inclusions, while the used pipe (designated as sample No. 2) showed marks of intergranular corrosion and significant wear after long-term use. The older pipe (designated as sample No. 3) showed a decarburized area and inclusions containing sulfides and aluminum. The steel pipe with corrosion layers (designated as sample No. 4) exhibited a continuous corrosion layer with cavitation and cracks. The results of this study offer a comprehensive view relating to the influence of the nature of the micro-structure and wear on the water flow (performance) of metal pipes, with an emphasis on the identification of possible risks associated with geometry change, corrosion and wear. The recommendations create a basis for predicting the degradation as well as appropriate maintenance to ensure their long and reliable service life under real-world conditions of use.

Keywords: Analysis, Microscopic, Structure, Material wear, Pipes
Grants and funding:

This work was supported by the Slovak Grant Agency – project KEGA 011TnUAD-4/2024.This work was supported by the Slovak Grant Agency – project KEGA 011TnUAD-4/2024

Received: June 26, 2024; Revised: January 22, 2025; Accepted: January 24, 2025; Prepublished online: February 20, 2025; Published: April 25, 2025  Show citation

ACS AIP APA ASA Harvard Chicago IEEE ISO690 MLA NLM Turabian Vancouver
Marček Ľ, Vavro J, Vavro J. Microscopic analysis of selected materials used for hot water heating using SEM. Manufacturing Technology. 2025;25(1):86-94. doi: 10.21062/mft.2025.003.
Download citation

References

  1. MORAVČÍK, R., HAZLINGER, M.: Science of materials II. STU Bratislava, 2009, 1st ed., 243 pages, ISBN 978-80-8096-081-0.
  2. PALČEK, P., HADZIMA, B., CHALUPOVÁ, M.: Material characteristics. University of Žilina, Žilina, 2004.
  3. NOVÁK, P. Basic principles of corrosion of metals in electrolytes, In: Corrosion in energy. 2006, Košice. s.1.
  4. Lipiński T. Influence of Impurity Morphology on the Fatigue Strength of High-Purity Structural Steel Melted in an Electric Furnace. Manufacturing Technology. 2023;23(1):53-59. doi: 10.21062/mft.2023.001. Go to original source...
  5. MARČEK, Ľ. Comparison of the use of materials in hot water conduction of media for heating elements. Trenčín: FPT KMI Púchov, 2020. Diploma thesis.
  6. Augustín G, Ingrid G. Stability analysis of roundness profiles of drawn tubes. Manufacturing Technology. 2020;20(3):307-312. doi: 10.21062/mft.2020.051. Go to original source...
  7. STN EN 14 868 Protection of metallic materials against corrosion. Assessment instructions the probability of corrosion in closed systems with water recirculation.
  8. Svobodova J, Benes L, Brabec J. Changes in Steam Pipeline Properties after Long-term Exposure. Manufacturing Technology. 2020;20(4):534-537. doi: 10.21062/mft.2020.104. Go to original source...
  9. Náprstková N, Šramhauser K, Hren I, Novotný J, Sviantek J. Microscopic Wear Analysis of Indexable Inserts after Machining of 34CrNiMo6 Steel. Manufacturing Technology. 2023; 23 (5): 676-684. doi: 10.21062/mft.2023.077. Go to original source...
  10. KREIBICH, V. Theory and technology of surface treatments, Prague: Czech Technical University in Prague, 1996.
  11. BARTONÍČEK, R. Corrosion and corrosion protection of metals. Prague: Academia, 1966.
  12. HADZIMA, B. LIPTÁKOVÁ, T.: Fundamentals of electrochemical corrosion of metals. 1st edition, Žilina: Edis, 2008. 112 p. ISBN 978-80-8070-876-4.
  13. Directive for heating water VDI 2035 - 1 Properties of heat transfer fluids.
  14. ANISIMOV, E., PEŠLOVA, F., HAJDUCHOVÁ, Ľ. Corrosion attack of pipes for heating medium distribution. Chem. Letters 105, p 616-p 617, 2011.
  15. KARLÍK, M.: Introduction to transmission electron microscopy. Ed. 1. Prague: Czech Technical University in Prague, 2011. 321 pp. ISBN 978-800-1047-293.

This is an open access article distributed under the terms of the Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0), which permits non-comercial use, distribution, and reproduction in any medium, provided the original publication is properly cited. No use, distribution or reproduction is permitted which does not comply with these terms.