Vol.24, No.2 2024, pp. 217–221
 https://doi.org/10.69644/ivk-2024-02-0217

DAMAGE ANALYSIS AND RESTORING OF STRUCTURAL INTEGRITY OF PELTON RUNNER AFTER REPAIR WELDING: CASE STUDY

Milan Miladinov1, Branislav Đorđević2*, Simon Sedmak2, Ciprian Bratu3, Dorin Radu3, Aleksandar Sedmak4, Nikola Aleksić5

1) Metal Rehabilitation and Testing Ltd, Belgrade, SERBIA

2) Innovation Centre of the Faculty of Mechanical Engineering, Belgrade, SERBIA

B. Đorđević 0000-0001-8595-6930 *email: bdjordjevic@mas.bg.ac.rs

S. Sedmak 0000-0002-2674-541X

3) Transilvania University of Brașov, Faculty of Civil Engineering, Brașov, ROMANIA

D. Radu 0000-0001-5043-2723

4) University of Belgrade, Faculty of Mechanical Engineering, Belgrade, SERBIA

A. Sedmak 0000-0002-5438-1895

5) Bauer Magyarorszag Specialis, Budapest, HUNGARY

 

Abstract

This paper presents the repair welding technology of a Pelton runner blade, including an analysis of damage caused by cavitation. Extreme exploitation conditions resulted in crack initiation followed by its propagation, with a length 200 mm, detected during regular annual maintenance, compromising Peltron turbine’s structural integrity. The base material of the Pelton turbine was steel X3CrNiMo13-4, and as well as the blade geometry itself, required special attention during the process of defining repair welding technology. An austenitic electrode was used for this purpose along with a welding technology defined in a way to counter the initiation of new cracks at the same location. Following the NDT, the Pelton runner was put back into exploitation, along with recommendations for its further monitoring.

Keywords: repair welding, Pelton runner, X3CrNiMo13-4 steel, damage analysis

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