Vliv tepelného zpracovní po svařování elektronovým svazekm na strukturu svarů slitiny Ti-6Al-4V

Influence of post weld heat treatments on structure of electron beam welds of Ti-6Al-4V alloy

conference paper

en

Electron beam (EB) welding belongs among the most appropriate welding methods for joining of titanium alloys mainly due to the advantages which are resulting from the using of this method. The required presence of vacuum during EB process may lenghten the overall processing time, but also provide protective enviroment which is necessary for the quality welds of titanium alloys. The precision control of EB welding process allows irradiating the workpiece by EB with high density of energy. This reduces the quanitity of heat input to the material and results in deep and narrow welds with the minimum heat affected zone. In many materials this can lead to the formation of significant thermal stresses during solidification of weld metal which can promote the nucleation of cracks. The post-weld heat treatment (PWHT) may be used to eliminate these stresses. In this article the microstructure and microhardness of EB welds of Ti-6Al-4V alloy is studied. The welds are evaluated in the as-welded state and after five different modes of the PWHT. Additionally, the presence and distribution of defects was examined depending on the used parameters of EB irradiation.

Svařování elektronovým svazkem (EB) patří mezi nejvhodnější metody pro svařování titanových slitin díky výhodám, kteeré tato metoda poskytuje. Nutnost použití vakua pro proces EB může prodloužit čas celého procesu, ale také poskytuje ochranné prostředí nutné pro kvalitní svary titanových slitin. Přesné řízení procesu EB svařování umožňuje použití EB s vysokou hustotou energie. Redukce vneseného tepla vede k hlubokým a úzkým svarům s minimálni tepelně ovlivněnou oblastí. V mnoha materiálech to může způsobovat výrazná tepelná pnutí, které mohou podporovat tvorbu trhlin. Tepelné zpravování po svařování lze použít k odstarnění těchto napětí. V tomto článku je hodnocena struktura a mikrotvrdost EB svarů slitiny T-6Al-4V. Svary byly hodnoceny ve stavu po svařování a po pěti různých módech tepelného zpracování. Dále byl hodnocen vliv parametrů EB svařování na přítomnost a množství vad ve svarových spojích.

Electron beam (EB) welding belongs among the most appropriate welding methods for joining of titanium alloys mainly due to the advantages which are resulting from the using of this method. The required presence of vacuum during EB process may lenghten the overall processing time, but also provide protective enviroment which is necessary for the quality welds of titanium alloys. The precision control of EB welding process allows irradiating the workpiece by EB with high density of energy. This reduces the quanitity of heat input to the material and results in deep and narrow welds with the minimum heat affected zone. In many materials this can lead to the formation of significant thermal stresses during solidification of weld metal which can promote the nucleation of cracks. The post-weld heat treatment (PWHT) may be used to eliminate these stresses. In this article the microstructure and microhardness of EB welds of Ti-6Al-4V alloy is studied. The welds are evaluated in the as-welded state and after five different modes of the PWHT. Additionally, the presence and distribution of defects was examined depending on the used parameters of EB irradiation.

electron beam welding; titanium alloys; post-weld heat treatment

2015

28.05.2015

Brno University of Technology, Antonínská 548/1, 601 90 Brno

Velké Bílovice

978-80-214-5146-9

MULTI-SCALE DESIGN OF ADVANCED MATERIALS CONFERENCE PROCEEDINGS

131–138

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