Causes of Failure of Weld Joint During Long Time Creep Testing

Kód výsledku v IS VaVaI

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Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Causes of Failure of Weld Joint During Long Time Creep Testing

Popis výsledku v původním jazyce

The trial weld joint made of P91 steel was prepared using GTAW & SMAW method. Creep testing of smooth cross-weld samples was carried out at a temperature range from 525°C to 625°C and under stresses from 40 MPa to 240 MPa. Fracture occurred in HAZ and inthe WM near the fussion line, if high stresses were applied at 525 °C. Cracks propagated through the central part of the WM after low loading at 625 °C. All other fractures were located in the fine grained HAZ; type IV cracking occurred. Failure in theHAZ is caused with fine grained polygonal ferritic structure with a high density of coarse chromium carbides and Laves phase at grain and subgrain boundaries and relatively low density of intragranular vanadium nitride. At 625 °C growth of Laves phase occurs especially in the weld metal and causes depletion of solid solution. After creep exposure for about 30,000hrs this process resulted in a significant softening of ferritic matrix and occurrence of a ductile fracture in WM (type I frac

Název v anglickém jazyce

Causes of Failure of Weld Joint During Long Time Creep Testing

Popis výsledku anglicky

The trial weld joint made of P91 steel was prepared using GTAW & SMAW method. Creep testing of smooth cross-weld samples was carried out at a temperature range from 525°C to 625°C and under stresses from 40 MPa to 240 MPa. Fracture occurred in HAZ and inthe WM near the fussion line, if high stresses were applied at 525 °C. Cracks propagated through the central part of the WM after low loading at 625 °C. All other fractures were located in the fine grained HAZ; type IV cracking occurred. Failure in theHAZ is caused with fine grained polygonal ferritic structure with a high density of coarse chromium carbides and Laves phase at grain and subgrain boundaries and relatively low density of intragranular vanadium nitride. At 625 °C growth of Laves phase occurs especially in the weld metal and causes depletion of solid solution. After creep exposure for about 30,000hrs this process resulted in a significant softening of ferritic matrix and occurrence of a ductile fracture in WM (type I frac

Druh

D - Stať ve sborníku

CEP obor

JG - Hutnictví, kovové materiály

OECD FORD obor

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Projekt

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Návaznosti

Z - Vyzkumny zamer (s odkazem do CEZ)

Rok uplatnění

2010

Kód důvěrnosti údajů

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

Název statě ve sborníku

Proc. of 19th International Metallurgical and Materials Conference METAL 2010

ISBN

978-80-87294-17-8

ISSN

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e-ISSN

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Počet stran výsledku

6

Strana od-do

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Název nakladatele

Tanger, spol. s r.o., Ostrava

Místo vydání

Ostrava

Místo konání akce

Rožnov pod Radhoštěm

Datum konání akce

1. 1. 2010

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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