Liquation Cracking in Row 3 Twin Turbine Vane Segment Caused by Malfunctioning Plasma Coating Gun
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A. Neidel
Tobias Gädicke was born in 1986 and joined the Siemens Energy Sector in 2005 as apprentice in the Berlin Gas Turbine Works. As materials testing technician, his main field of expertise is metallographic target preparation of laser-drilled holes in turbine blading. Also, he is expert in the field of portable metallography by means of the replica technique with both putty and replica foils which he regularly applies to microstructural analyses of large gas turbine casings made of ductile iron and steel castings. He is a lecturer in the DGM seminar on portable metallography. Metallurgical failure analysis of gas turbine engine hot gas path components are another field of expertise of his. Thomas Ullrich born in 1974, trained as a materials tester in physics at Energiewerke Nord AG in Greifswald, where his work included nuclear service. He then gained further experience in power plant service at TÜV Rheinland Berlin-Brandenburg, particularly in the context of non-destructive testing and component metallographic residual life assessments. He joined the Berlin gas turbine plant in 2001. In addition to component metallography, he is primarily involved in the target preparation of bores and welded joints in the metallography laboratory.
Abstract
Transverse through-wall airfoil cracking was found in a row 3 twin turbine vane segment of a type used in heavy-duty gas turbine engines for power generation. A laboratory investigation determined liquation cracking (LC), a hot cracking mechanism, as the metallurgical cause of failure. As became apparent only after the investigation, the root cause of failure was a malfunctioning plasma gun used for thermal spraying the thermal barrier ceramic top coat onto the subject part.
Kurzfassung
An einem in einer Großgasturbine zur Stromerzeugung verwendeten Zwillings-Turbinenleitschaufelsegment der dritten Stufe wurde eine die Schaufelblattwand durchdringende Querrissbildung festgestellt. Im Rahmen einer Laboruntersuchung wurde als metallurgische Ursache für das Versagen Wiederaufschmelzungsrissbildung (Liquation Cracking, LC), ein Heißrissmechanismus, ermittelt. Wie sich erst nach der Untersuchung herausstellte, war die Grundursache des Versagens die Fehlfunktion einer für das thermische Aufspritzen der keramischen Wärmedämmdeckschicht auf die entsprechende Komponente verwendete Plasmaspritzdüse.
About the authors
Tobias Gädicke was born in 1986 and joined the Siemens Energy Sector in 2005 as apprentice in the Berlin Gas Turbine Works. As materials testing technician, his main field of expertise is metallographic target preparation of laser-drilled holes in turbine blading. Also, he is expert in the field of portable metallography by means of the replica technique with both putty and replica foils which he regularly applies to microstructural analyses of large gas turbine casings made of ductile iron and steel castings. He is a lecturer in the DGM seminar on portable metallography. Metallurgical failure analysis of gas turbine engine hot gas path components are another field of expertise of his.
Thomas Ullrich born in 1974, trained as a materials tester in physics at Energiewerke Nord AG in Greifswald, where his work included nuclear service. He then gained further experience in power plant service at TÜV Rheinland Berlin-Brandenburg, particularly in the context of non-destructive testing and component metallographic residual life assessments. He joined the Berlin gas turbine plant in 2001. In addition to component metallography, he is primarily involved in the target preparation of bores and welded joints in the metallography laboratory.
References / Literatur
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Articles in the same Issue
- Content
- Editorial
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- Garment buttons from a Hallstatt period tumulus
- Impact of tool rotational speed on the microstructural transitions and tensile properties of the dissimilar AZ80A-Mg – AA6061-Al joints fabricated by friction stir welding
- Failure Analysis
- Liquation Cracking in Row 3 Twin Turbine Vane Segment Caused by Malfunctioning Plasma Coating Gun
- Picture of the Month
- Picture of the Month
- Kommentar
- For THEY do not know what THEY are doing
- News
- Neuer BAM Report 2022/23: Transformation gemeinsam gestalten
- Meeting Dairy
- Meeting Diary
