Microstructural changes in weld joint of COST F and FB2 steels after long term creep tests

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F47718684%3A_____%2F17%3AN0000027" target="_blank" >RIV/47718684:_____/17:N0000027 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1080/09603409.2017.1380909" target="_blank" >https://doi.org/10.1080/09603409.2017.1380909</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1080/09603409.2017.1380909" target="_blank" >10.1080/09603409.2017.1380909</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Microstructural changes in weld joint of COST F and FB2 steels after long term creep tests

Popis výsledku v původním jazyce

A trial weld joint of COST F and FB2 steels was produced using the GTAW HOT-WIRE method in conditions used in industry for welding steam turbine rotors. Long-term creep tests to the rupture of smooth cross-weld samples were carried out. Creep strength and hardness profiles across the weld joint were evaluated and correlated with the microstructure. Microstructures of ruptured samples were investigated using light, scanning and transmission electron microscopy and compared with virgin samples. Fracture occurred in COST F steel and its heat affected zone. Precipitation of Laves phase and structure recovery were the main reasons for the failure. Quantitative evaluation of M23C6 carbides and Laves phase particles in different parts of the weld joint was carried out. In the initial conditions, small Laves phase particles occurred only exceptionally in the weld metal. During creep at temperatures above 575 °C Laves phase precipitated in all parts of the weld joint and especially in the heat affected zones. Coarse Laves phase particles and their clusters with chromium carbides served as nucleation centres for cavities. As the fine grained heat affected zone of COST F steel was the softest part of the weld joint, many cavities originated and cracks were propagated.

Název v anglickém jazyce

Microstructural changes in weld joint of COST F and FB2 steels after long term creep tests

Popis výsledku anglicky

A trial weld joint of COST F and FB2 steels was produced using the GTAW HOT-WIRE method in conditions used in industry for welding steam turbine rotors. Long-term creep tests to the rupture of smooth cross-weld samples were carried out. Creep strength and hardness profiles across the weld joint were evaluated and correlated with the microstructure. Microstructures of ruptured samples were investigated using light, scanning and transmission electron microscopy and compared with virgin samples. Fracture occurred in COST F steel and its heat affected zone. Precipitation of Laves phase and structure recovery were the main reasons for the failure. Quantitative evaluation of M23C6 carbides and Laves phase particles in different parts of the weld joint was carried out. In the initial conditions, small Laves phase particles occurred only exceptionally in the weld metal. During creep at temperatures above 575 °C Laves phase precipitated in all parts of the weld joint and especially in the heat affected zones. Coarse Laves phase particles and their clusters with chromium carbides served as nucleation centres for cavities. As the fine grained heat affected zone of COST F steel was the softest part of the weld joint, many cavities originated and cracks were propagated.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20501 - Materials engineering

Projekt

<a href="/cs/project/TE01020118" target="_blank" >TE01020118: Elektronová mikroskopie</a><br>

Návaznosti

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

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název periodika

Materials at High Temperatures

ISSN

0960-3409

e-ISSN

1878-6413

Svazek periodika

34 (2017)

Číslo periodika v rámci svazku

5-6

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

8

Strana od-do

482-591

Kód UT WoS článku

000418753400021

EID výsledku v databázi Scopus

—