Combining 3D scanning with standard microscopy methods for assessment of pitting corrosion in turbine blades

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F26722445%3A_____%2F17%3AN0000058" target="_blank" >RIV/26722445:_____/17:N0000058 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.4028/www.scientific.net/SSP.270.168" target="_blank" >http://dx.doi.org/10.4028/www.scientific.net/SSP.270.168</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.4028/www.scientific.net/SSP.270.168" target="_blank" >10.4028/www.scientific.net/SSP.270.168</a>

Result language

angličtina

Original language name

Combining 3D scanning with standard microscopy methods for assessment of pitting corrosion in turbine blades

Original language description

Pitting corrosion is a known process in metals. Pitting, observed in turbine blades, is caused by corrosion mechanisms in operation environment that may contain aggressive chemical compounds. Environment, material composition and operating conditions determine the corrosion process causing a cavity formation and their critical growth. Crack initiation can be a following mechanism. Thus the critical cavity size is the important parameter and its precise estimation can avoid a turbine blade failure. Cavity shape as well as corrosion products inside cavities should be taken into account. 3D scanning technique performed during turbine shutdowns is shown to be a suitable method for measurement of critical cavity size. In this study, the accuracy of 3D technique was confirmed by standard sample preparation methods followed by microscopy focused on corrosion products observation. Cross-sectioning of blades was performed close to the cavities, sections were grinded to show the maximum cavity dimensions and finally polished. Cavity size was measured in few steps by Light Optical Microscopy during grinding to find the maximum dimensions and compare to 3D measurements. Local corrosion in cavities was evaluated by Scanning Electron Microscopy using Backscattered Electrons and Energy Dispersive X-ray Spectroscopy. Non-uniform Fe, Cr, Si rich oxides with dimensions from tens up to hundreds of micrometres were analysed in cavities. No significant effect on oxide removing was observed after using sandblasting technology except possible effect in larger pits. Cracks and pores were detected close to the vicinity of trailing edge of blade. © 2017 Trans Tech Publications, Switzerland.

Czech name

—

Czech description

—

Type

D - Article in proceedings

CEP classification

—

OECD FORD branch

20501 - Materials engineering

Project

<a href="/en/project/LQ1603" target="_blank" >LQ1603: Research for SUSEN</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Article name in the collection

Solid State Phenomena, Volume 270 SSP, 2017

ISBN

978-303571241-4

ISSN

16629779

e-ISSN

—

Number of pages

6

Pages from-to

168-173

Publisher name

Trans Tech Publications Ltd

Place of publication

Switzerland

Event location

Mariánské Lázně

Event date

Jun 6, 2017

Type of event by nationality

WRD - Celosvětová akce

UT code for WoS article

—