Microstructure and properties of martensitic precipitation-hardening steel MLX 17 after long-term ageing at 475 °C

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F25870807%3A_____%2F18%3AN0000005" target="_blank" >RIV/25870807:_____/18:N0000005 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.metalconference.eu/cz/sbornik-metal-2018/" target="_blank" >https://www.metalconference.eu/cz/sbornik-metal-2018/</a>

DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Microstructure and properties of martensitic precipitation-hardening steel MLX 17 after long-term ageing at 475 °C

Popis výsledku v původním jazyce

Steel MLX 17 (X1CrNiMoAlTi 12-11-2) belongs to a family of martensitic precipitation-hardening steels for use in demanding applications in aviation and offshore oil and gas industry. The unique combination of high strength, toughness, fatigue strength and corrosion resistance is obtained in this steel based on 11 % Ni, 12 % Cr and precipitation hardened by Mo, Al and Ti after ageing of low carbon martensite above 500 °C. Due to its chromium content the steel MLX 17 is a material threatened by embrittlement at 475 °C induced by decomposition of the microstructure into two arranged solid solutions +´ and/or embrittlement caused by precipitation of chromium-rich brittle -phase. Although this steel is not typically exploited at higher temperatures, it is interesting to know the effect of long-term ageing on the material properties, microstructure and substructure. Therefore, the ageing at 475 °C for 1,000, 2,000 and 3,000 hours was performed and material properties, microstructure and substructure were evaluated. Analysis of substructure confirmed the additional precipitation of Lave phase, the main source of precipitation hardening in MLX 17 steel, as well as the decomposition of the solid solution  into the chromium-rich particles of nanometric size. Ageing at 475 °C was also accompanied by increasing of the reverse austenite content, which overcame the possible effect of the additional precipitation hardening of martensite.

Název v anglickém jazyce

Microstructure and properties of martensitic precipitation-hardening steel MLX 17 after long-term ageing at 475 °C

Popis výsledku anglicky

Steel MLX 17 (X1CrNiMoAlTi 12-11-2) belongs to a family of martensitic precipitation-hardening steels for use in demanding applications in aviation and offshore oil and gas industry. The unique combination of high strength, toughness, fatigue strength and corrosion resistance is obtained in this steel based on 11 % Ni, 12 % Cr and precipitation hardened by Mo, Al and Ti after ageing of low carbon martensite above 500 °C. Due to its chromium content the steel MLX 17 is a material threatened by embrittlement at 475 °C induced by decomposition of the microstructure into two arranged solid solutions +´ and/or embrittlement caused by precipitation of chromium-rich brittle -phase. Although this steel is not typically exploited at higher temperatures, it is interesting to know the effect of long-term ageing on the material properties, microstructure and substructure. Therefore, the ageing at 475 °C for 1,000, 2,000 and 3,000 hours was performed and material properties, microstructure and substructure were evaluated. Analysis of substructure confirmed the additional precipitation of Lave phase, the main source of precipitation hardening in MLX 17 steel, as well as the decomposition of the solid solution  into the chromium-rich particles of nanometric size. Ageing at 475 °C was also accompanied by increasing of the reverse austenite content, which overcame the possible effect of the additional precipitation hardening of martensite.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

20501 - Materials engineering

Projekt

<a href="/cs/project/LO1203" target="_blank" >LO1203: Regionální materiálově technologické výzkumné centrum - Program udržitelnosti</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 statě ve sborníku

METAL 2018 Conference Proceedings

ISBN

978-80-87294-84-0

ISSN

—

e-ISSN

—

Počet stran výsledku

6

Strana od-do

831-836

Název nakladatele

Tanger Ltd., Ostrava

Místo vydání

Ostrava

Místo konání akce

Brno

Datum konání akce

23. 5. 2019

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

000461832200130