Changes in Steam Pipeline Properties after Long-term Exposure

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F44555601%3A13420%2F20%3A43896045" target="_blank" >RIV/44555601:13420/20:43896045 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.journalmt.com/artkey/mft-202004-0009_changes-in-steam-pipeline-properties-after-long-term-exposure.php" target="_blank" >https://www.journalmt.com/artkey/mft-202004-0009_changes-in-steam-pipeline-properties-after-long-term-exposure.php</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.21062/mft.2020.104" target="_blank" >10.21062/mft.2020.104</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Changes in Steam Pipeline Properties after Long-term Exposure

Popis výsledku v původním jazyce

Steam pipeline steels are stressed for a long time at higher temperatures and elevated pressure. Their operating con-ditions are not constant due to various operating factors, for example, there are changes in temperature and pressure conditions during unavailability time. Long-term thermal exposure of these steels for steam pipelines, such as 15 128 (K11591) steel, leads to degradation processes associated with structural changes and changes in mechanical proper-ties. Structural changes are related to the reduction of free energy of the steel system [2]-[9]. During structural changes, the original ferritic-pearlite structure with lamellar pearlite and the presence of carbides inside ferritic grains changes. As a result of the reduction of the free energy, the lamellar cementite gains globulitic character and the carbide particles move to the ferritic grain boundaries, thereby occurs to the weakening the grain boundaries. In the consequence of the structural changes, there are the changes of mechanical properties. Extremely sensitive, in terms of mechanical proper-ties, to structural changes, is the resistance of steel to failure characterized by impact resistance. The transit curve de-termined by this method shifts to the right towards higher temperatures relative to the initial (primary) state of the steel, thereby the steel can, in extreme cases, to get brittle already at room temperature. This can have catastrophic con-sequences when pressurizing the pipeline after an unavailability time. The contribution presents the results of structural and fractographic analyzes and impacts strength values of steam pipeline of steel 15 128 after long-term exposure - 186.728 hours.

Název v anglickém jazyce

Changes in Steam Pipeline Properties after Long-term Exposure

Popis výsledku anglicky

Steam pipeline steels are stressed for a long time at higher temperatures and elevated pressure. Their operating con-ditions are not constant due to various operating factors, for example, there are changes in temperature and pressure conditions during unavailability time. Long-term thermal exposure of these steels for steam pipelines, such as 15 128 (K11591) steel, leads to degradation processes associated with structural changes and changes in mechanical proper-ties. Structural changes are related to the reduction of free energy of the steel system [2]-[9]. During structural changes, the original ferritic-pearlite structure with lamellar pearlite and the presence of carbides inside ferritic grains changes. As a result of the reduction of the free energy, the lamellar cementite gains globulitic character and the carbide particles move to the ferritic grain boundaries, thereby occurs to the weakening the grain boundaries. In the consequence of the structural changes, there are the changes of mechanical properties. Extremely sensitive, in terms of mechanical proper-ties, to structural changes, is the resistance of steel to failure characterized by impact resistance. The transit curve de-termined by this method shifts to the right towards higher temperatures relative to the initial (primary) state of the steel, thereby the steel can, in extreme cases, to get brittle already at room temperature. This can have catastrophic con-sequences when pressurizing the pipeline after an unavailability time. The contribution presents the results of structural and fractographic analyzes and impacts strength values of steam pipeline of steel 15 128 after long-term exposure - 186.728 hours.

Druh

J_SC - Článek v periodiku v databázi SCOPUS

CEP obor

—

OECD FORD obor

20501 - Materials engineering

Projekt

—

Návaznosti

V - Vyzkumna aktivita podporovana z jinych verejnych zdroju

Rok uplatnění

2020

Kód důvěrnosti údajů

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

Název periodika

Manufacturing Technology

ISSN

1213-2489

e-ISSN

—

Svazek periodika

20

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

CZ - Česká republika

Počet stran výsledku

4

Strana od-do

534-537

Kód UT WoS článku

—

EID výsledku v databázi Scopus

2-s2.0-85098716348