Ulla Ehrnstén

Principle Scientist

  • Phone+358405354057
1989 …2020

Research output per year

If you made any changes in Pure these will be visible here soon.

Research Output

Filter
Report
2019

Microstructural characterization of thermally aged Barsebäck RPV head weld metal

Lydman, J., Hytönen, N., Que, Z., Ehrnstén, U. & Nevasmaa, P., 11 Aug 2019, VTT Technical Research Centre of Finland. 36 p. (VTT Research Report; No. VTT-R-01003-19).

Research output: Book/ReportReport

2018

Thermal ageing and mechanical performance of narrow-gap dissimilar metal welds

Ahonen, M., Lindqvist, S., Leskelä, E., Lydman, J., Nevasmaa, P., Seppänen, T., Arffman, P., Ehrnsten, U., Sarikka, T., Mouginot, R. & Hänninen, H., Jun 2018, Espoo: VTT Technical Research Centre of Finland. 189 p. (VTT Technology; No. 333).

Research output: Book/ReportReport

Open Access
2015

Results from pre-tests on liquid metal embrittlement

Autio, J-M. & Ehrnsten, U., 2015, VTT Technical Research Centre of Finland. 26 p. (Helsinki University of Technology: Systems Analysis Laboratory. A: Research Reports, Vol. VTT-R-00308-15).

Research output: Book/ReportReport

2014

DL-EPR measurements on a sensitised Type 304 stainless steel pipe section

Autio, J-M. & Ehrnsten, U., 2014, VTT Technical Research Centre of Finland. 19 p. (Helsinki University of Technology: Systems Analysis Laboratory. A: Research Reports; No. VTT-R-05905-14).

Research output: Book/ReportReport

Status report on project MICRIN, Mitigation of Crack Initiation

Ehrnsten, U., 2014, VTT Technical Research Centre of Finland. 7 p. (Helsinki University of Technology: Systems Analysis Laboratory. A: Research Reports; No. VTT-R-05439-14).

Research output: Book/ReportReport

Structural integrity of Ni-base alloy welds

Hänninen, H., Brederholm, A., Sarikka, T., Mouginot, R., Holmström, P., Saukkonen, T., Toivonen, A., Karjalainen-Roikonen, P., Nevasmaa, P., Keinänen, H., Leskelä, E., Ahonen, M., Ehrnsten, U. & Aaltonen, P., 2014, Espoo: VTT Technical Research Centre of Finland. 264 p. (VTT Technology, Vol. 175).

Research output: Book/ReportReport

Open Access

Super slow strain rate testing in simulated LWR conditions

Ehrnstén, U., 2014, VTT Technical Research Centre of Finland. 37 p. (VTT Research Report; No. VTT-R-06114-14).

Research output: Book/ReportReport

Supplementary tests with CRIEPI mini CT-specimens

Valo, M., Ehrnsten, U., Planman, T., Lappalainen, P. & Wallin, K., 2014, VTT Technical Research Centre of Finland. 71 p. (Helsinki University of Technology: Systems Analysis Laboratory. A: Research Reports; No. VTT-R-05628-14).

Research output: Book/ReportReport

The biaxial creep testing device, Crebello

Moilanen, P. & Ehrnstén, U., 2014, Espoo: VTT Technical Research Centre of Finland. 23 p. (VTT Research Report; No. VTT-R-01863-14).

Research output: Book/ReportReport

2013

Ageing degradation of hard-facing alloy after long-time exposure BWR conditions II

Aaltonen, P., Karjalainen-Roikonen, P., Autio, J-M., Ehrnstén, U., Saukkonen, T. & Hänninen, H., 2013, VTT Technical Research Centre of Finland. 29 p. (VTT Research Report; No. VTT-R-06904-14).

Research output: Book/ReportReport

2011

Environment-assisted cracking and hot cracking susceptibility of nickel-base alloy weld metals

Hänninen, H., Brederholm, A., Saukkonen, T., Ivanchenko, M., Toivonen, A., Karlsen, W., Ehrnstén, U. & Aaltonen, P., 2011, Espoo: VTT Technical Research Centre of Finland. 157 p. (VTT Tiedotteita - Research Notes; No. 2582).

Research output: Book/ReportReport

Open Access
2 Citations (Scopus)
2007

Hot cracking and environment-assisted cracking susceptibility of dissimilar metal welds

Hänninen, H., Brederholm, A., Saukkonen, T., Gripenberg, H., Toivonen, A., Ehrnsten, U. & Aaltonen, P., 2007, VTT Technical Research Centre of Finland. 181 p. (VTT Tiedotteita - Meddelanden - Research Notes; No. 2399).

Research output: Book/ReportReport

Open Access
2006

Dissimilar metal weld joints and their performance in nuclear power plant and oil refinery conditions

Hänninen, H., Aaltonen, P., Brederholm, A., Ehrnstén, U., Gripenberg, H., Toivonen, A., Jorma, P. & Virkkunen, I., 2006, Espoo: VTT Technical Research Centre of Finland. 212 p. (VTT Tiedotteita - Meddelanden - Research Notes; No. 2347).

Research output: Book/ReportReport

Open Access
12 Citations (Scopus)
2004

Structural features of solid oxide fuel cells before and after simulated service cycles

Veivo, J., Auerkari, P., Ehrnstén, U., Varis, P. & Gustafsson, T. E., 2004, VTT Technical Research Centre of Finland. 24 p. (VTT Research Report; No. BTUO74-043778).

Research output: Book/ReportReport

2000

Consistency of fracture assessment criteria. Final report. NESC, Network of evaluating structural components

Rintamaa, R., Wallin, K. & Ehrnsten, U., 2000, Petten. 31 p. (NESC Report; No. NESC DOC ETF(99)35). (Report EUR; No. 19637 EN).

Research output: Book/ReportReport

1997

Development of explosion welding (EXW) technique and characterisation of EXW joints

Tähtinen, S., Ehrnsten, U., Karjalainen-Roikonen, P., Moilanen, P., Kauppinen, P., Auerkari, P. & Rahka, K., 1997, Espoo: VTT Technical Research Centre of Finland. 30 p. (Liekki 2: Poltto- ja kaasutustekniikan tutkimusohjelma; No. VALB-220).

Research output: Book/ReportReport

NDE of explosion welded copper stainless steel first wall mock-up

Tähtinen, S., Kauppinen, P., Jeskanen, H., Lahdenperä, K. & Ehrnsten, U., 1997, VTT Technical Research Centre of Finland. 18 p. (Liekki 2: Poltto- ja kaasutustekniikan tutkimusohjelma; No. VALB-221).

Research output: Book/ReportReport

1996

Environmentally assisted cracking behaviour of copper in simulated ground water

Hietanen, S., Ehrnsten, U. & Saario, T., 1996, Helsinki. 42 p. (STUK-YTO-TR; No. 105).

Research output: Book/ReportReport

Open Access
1993

Cyclic crack growth evaluation of a 20MnMoNi55 piping steel in high oxygen reactor water

Aaltonen, P., Rintamaa, R., Hänninen, H., Ehrnsten, U. & Arilahti, E., 1993, Espoo: VTT Technical Research Centre of Finland. 22 p. (VTT Metallilaboratorio. Tutkimusraportti B; No. 235).

Research output: Book/ReportReport

ICG-EAC bolt-loaded WOL-specimen round robin results of VTT for RPV-steel weldments tested in PWR water

Aaltonen, P., Hänninen, H., Ehrnsten, U. & Arilahti, E., 1993, VTT Technical Research Centre of Finland. 46 p. (VTT Metallilaboratorio. Tutkimusraportti B; No. 242).

Research output: Book/ReportReport

1989

Static and cyclic crack growth of a 23NiMoCr36 steel specimen in simulated 8 ppm oxygen containing reactor water at 240 C

Hänninen, H., Rintamaa, R., Hietanen, S., Ehrnsten, U. & Arilahti, E., 1989, VTT Technical Research Centre of Finland. 44 p. (VTT Metallilaboratorio. Tutkimusraportti B; No. 154).

Research output: Book/ReportReport

Zur Frage der Werkstoffversprödung nach zyklischer Thermoshockbelastung

Blauel, J., Rintamaa, R., Arilahti, E. & Ehrnsten, U., 1989, Fraunhofer- Institut für Werkstoffmechanik. 52 p. (Bericht, Vol. V3/89).

Research output: Book/ReportReport