Creep Rupture Behaviour of Homogeneous Welds Made of HR3C Steel at 650 and 700 °C

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F26722445%3A_____%2F18%3AN0000048" target="_blank" >RIV/26722445:_____/18:N0000048 - isvavai.cz</a>

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Creep Rupture Behaviour of Homogeneous Welds Made of HR3C Steel at 650 and 700 °C

Popis výsledku v původním jazyce

Steel grade HR3C (X6CrNiNbN 25-20) represents an advanced austenitic steel for applications in superheater or reheater systems of modern blocks of fossil fuel power plants. Relevant information about long-term creep resistance and microstructural stability of this new steel grade is missing. This makes the prediction of residual life of components made of this steel very difficult. Critical parts of structures represent first of all weldments. This paper deals with creep rupture behaviour of homogeneous welds made of the HR3C steel during creep exposure at 650 and 700 °C. Similar weld joints made of the HR3C steel tubes were manufactured using a combination of GTAW and SMAW welding technologies. Weld joints were studied in both the as-welded state (PW), and after the post-weld heat treatment at 1230 °C for 15 minutes (PWHT). Results of creep tests were better for welds subjected to post weld heat treatment at 1230 °C. Extrapolation of experimental results predicted that with increasing testing temperature and time to rupture both the base material HR3C and homogeneous welds in the state after post-weld heat treatment at 1230 °C had almost identical level of creep strength. Metallographic investigations proved coarsening of austenitic grain size in the HAZ of homogeneous welds, which resulted from the thermal cycle during welding. The heat treatment after welding at 1230 °C resulted in further coarsening of austenitic grains in the HAZ. Creep failure in most “cross-weld” specimens occurred in the HAZ.

Název v anglickém jazyce

Creep Rupture Behaviour of Homogeneous Welds Made of HR3C Steel at 650 and 700 °C

Popis výsledku anglicky

Steel grade HR3C (X6CrNiNbN 25-20) represents an advanced austenitic steel for applications in superheater or reheater systems of modern blocks of fossil fuel power plants. Relevant information about long-term creep resistance and microstructural stability of this new steel grade is missing. This makes the prediction of residual life of components made of this steel very difficult. Critical parts of structures represent first of all weldments. This paper deals with creep rupture behaviour of homogeneous welds made of the HR3C steel during creep exposure at 650 and 700 °C. Similar weld joints made of the HR3C steel tubes were manufactured using a combination of GTAW and SMAW welding technologies. Weld joints were studied in both the as-welded state (PW), and after the post-weld heat treatment at 1230 °C for 15 minutes (PWHT). Results of creep tests were better for welds subjected to post weld heat treatment at 1230 °C. Extrapolation of experimental results predicted that with increasing testing temperature and time to rupture both the base material HR3C and homogeneous welds in the state after post-weld heat treatment at 1230 °C had almost identical level of creep strength. Metallographic investigations proved coarsening of austenitic grain size in the HAZ of homogeneous welds, which resulted from the thermal cycle during welding. The heat treatment after welding at 1230 °C resulted in further coarsening of austenitic grains in the HAZ. Creep failure in most “cross-weld” specimens occurred in the HAZ.

Druh

J_ost - Ostatní články v recenzovaných periodicích

CEP obor

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OECD FORD obor

20501 - Materials engineering

Projekt

<a href="/cs/project/LQ1603" target="_blank" >LQ1603: Výzkum pro SUSEN</a><br>

Návaznosti

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

Rok uplatnění

2018

Kód důvěrnosti údajů

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

Název periodika

Hutnické listy

ISSN

0018-8069

e-ISSN

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Svazek periodika

71

Číslo periodika v rámci svazku

6

Stát vydavatele periodika

CZ - Česká republika

Počet stran výsledku

67

Strana od-do

63

Kód UT WoS článku

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EID výsledku v databázi Scopus

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