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Title:
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Metallographic characterisation of EUROFER97 plate and bar materials
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Author(s):
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Published by:
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Publication date:
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ECN
Environment & Energy Engineering
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1-10-2000
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ECN report number:
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Document type:
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ECN-C--00-108
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ECN publication
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Number of pages:
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Full text:
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22
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Download PDF
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Abstract:
Three heats of modified 9%Cr-steels of the EUROFER97 program wereinvestigated. The samples were taken from three plates: 8, 14 and 25 mm
thick, and one bar, 100 mm diameter. All three planes of the plates and the
bar were investigated by optical and electron microscopy (SEM- EDX) and
hardness measurements were made over the cross sections. All samples show a
fine homogeneous tempered martensitic microstructure with a prior austenite.
grain size of ASTM 10.0-10.3. No elongated austenite grains were found. The
microstructure is free of delta-ferrite and segregation bands of carbides.
However, some segregation was found in bands of Ti-rich particles and
inclusions (sulphides and oxides). To a lesser extent, concentrations of
Ta-rich phases were also found. Ta appears to precipitate as relatively large
particles, with respect to carbides present. The hardness shows an even
distribution over the cross sections, without evident hardness decrease at
the plate surfaces. The plate materials show hardness values of about
212HV30. The bar material has a somewhat higher hardness, with an average of
220HV30. No significant variation in hardness with orientation was observed.
3 refs.
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