0467327 - ÚFM 2017 RIV PL eng C - Conference Paper (international conference)
Horváth, J. - Král, Petr - Janovec, J.
The effect of σ-phase formation on long-term durability of welding joints in SUPER 304H steels.
Acta Physica Polonica A, Vol. 130, č. 4. Warszawa: Polish Academy of Sciences Publishing House, 2016, s. 960-962. ISSN 0587-4246. E-ISSN 1898-794X.
[Conference on Applied Crystallography /23./. Krynica Zdrój (PL), 20.09.2015-24.09.2015]
Institutional support: RVO:68081723
Keywords : Durability * Scanning electron microscopy * Welding
Subject RIV: JG - Metallurgy
DOI: https://doi.org/10.12693/APhysPolA.130.960

Article presents results on the analysis of secondary phases formed in the medium-term static isothermal ageing welding joints of a SUPER 304H (675°C/2 × 104 h). The investigations of the precipitates were focused on the occurrence of σ-phase because its formation leads to significant deterioration of mechanical properties. The microstructure was investigated on microscopic level by scanning/transmission electron microscopy. The distribution and quantification of brittle σ-phase were studied on macroscopic level by color etching method using light optical microscopy. The effect of microstructural changes (σ-phase formation) on the impact strength of an aged base material was investigated. For comparison impact tests on received state material were also performed. The results showed that long-term ageing led to the significant reduction of impact strength as a result of the formation of the σ-phase. It was found that the σ-phase distribution is influenced by welding process. The influence of brittle σ-phase on long-term durability of the degraded steel regarding its insufficient impact strength has been discussed.
Permanent Link: http://hdl.handle.net/11104/0265652