Resul Hamzić 1,a, Namik Džibrić 1,b, Sead Avdić 1,c
1Institut za zavarivanje d.o.o. Tuzla, Tuzla, Bosna i Hercegovina
aresul.hamzic@izz-bh.ba
a0009-0008-8864-9205; b0009-0006-3742-233X; c0009-0003-6992-7509
DOI: 10.5937/zzk2404171H
Article type: Professional paper
Article language: English/Serbian
Abstract: This study examined the microstructure of the main steam pipes in thermal power plant using the method of metallographic replicas. The aim of the research was to analyze and assess the condition of the pipes after 200 000 hours of operation, as well as to evaluate their remaining service life and endurance under long-term loads according to the VGB-S 517 standard. This standard establishes rigorous guidelines for inspecting and assessing the microstructural composition and damage due to creep in creep-resistant steel for high-pressure piping, boiler components, welded joints, considering the parameters such as material, wall thickness and construction. In addition to microstructure analysis, particular emphasis was placed on studying the time-dependent strength of the steam pipes, especially in the context of creep. Creep or deformation under constant load over time at high temperatures is a key factor influencing the long-term performance of the pipes. The results of the conducted research will provide a broader understanding of the condition of the steam pipes after 200 000 hours of operation, identify potential defects or weaknesses in the material and enable timely implementation of appropriate maintenance or replacement measures, thereby reducing the risk of accidents and failures.
Keywords: microstructure; creep; standard VGB-S 517; metallographic replica
Article received: September 2024
Article accepted: November 2024
Acknowledgements: The paper was published in its original form in the Proceedings of the 33rd Conference with international participation “Welding 2024” held in Vrnjačka Banja, Serbia from October 2 to 5, 2024.