1 / 26

Effects of Ti, P, and S on the Physical Metallurgy of 9Cr Martensitic Steels

This study investigates the effects of titanium (Ti), phosphorus (P), and sulfur (S) on the physical metallurgy of 9Cr martensitic steels. It explores the formation of hydrides, sulfides, and phosphides, as well as the potential embrittlement and segregation at interfaces. The study aims to determine the mechanical and cleavage properties of martensitic steels with Ti, P, and S in solid solution.

vcox
Download Presentation

Effects of Ti, P, and S on the Physical Metallurgy of 9Cr Martensitic Steels

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Journées d ’Automne 2001 Structural Materials for Hybrid SystemParis, 29-31 octobre 2001O. Danylova1, Y. de Carlan2 , D. Hamon2, J-C. Brachet2, J. Henry2, A. Alamo21Centre de recherche d’Imphy2CEA Saclay, Service de Recherches Métallurgiques Appliquées, 91 191 Gif-Sur- Yvette CEDEX. Effects of spallation products Ti, P and S on the physical metallurgy of 9Cr martensitic steels

  2. Formation of hydrides, sulphides...? Embrittlement of the material ? - Segregation at interfaces ? - Formation of sulphides and phosphides ? Preliminary calculations of quantities of spallation products created in the window (J. Henry, C. Volant, R. Legrain)

  3. Experimental heats to study the effects of Ti, P, S on the metallurgical and mechanical properties Aim of the study : To obtain 9Cr martensitic steels by conventional elaboration with (Ti, S, P) in solid solution to determine mechanical and cleavage properties

  4. Phase stability fields in Fe 9Cr 1Mo 0.1C martensitic steels Calculations at the thermodynamic equilibrium Software MTdata with data bases : Plus and Sub_sgte

  5. EM10Ti (9Cr 1Mo 0.1C 0.17Ti)

  6. EM10Ti (9Cr 1Mo 0.1C 0.17Ti)

  7. Tn =1250°C/20min Tn =1250°C/20min TiN EM10Ti (9Cr 1Mo 0.1C 0.17Ti)

  8. EM10Ti (9Cr 1Mo 0.1C 0.17Ti) Globular particles Ti(Mo)C Ti(N,C) b) a) Ti(N,C) TiN TiN ferrite TiC Ti(Mo)C TiN Steel normalised at 1200 °C/30min and quenched

  9. EM10Ti (9Cr 1Mo 0.1C 0.17Ti) Concentration profiles (obtained with a micro probe analyser) of Cr, Mo, Si and Ti within the matrix of the steel normalised at 1150°C/ 30 min. Ti is in solid solution.

  10. EM10 LMnS (9Cr 1Mo 0.1C LMn 0.04S)

  11. EM10 LMnS (9Cr 1Mo 0.1C LMn 0.04S)

  12. Tn = 1350°C / 20min EM10 LMnS (9Cr 1Mo 0.1C LMn 0.04S) The proportions of austenite and ferrite as a function of temperature are close to those observed in the EM10 standard steel. A strong modification of the repartition of chromium sulphides is observed as a function of heat treatment (at 1350°C, probably dissolution and reprecipitation of chromium sulphides).

  13. EM10 LMnS (9Cr 1Mo 0.1C LMn 0.04S) Concentration profiles (micro probe analyser) of S and Mo within the matrix of the steel (normalised at 1300°C and quench at 100 °C/s).

  14. 100 nm EM10 LMnS (9Cr 1Mo 0.1C LMn 0.04S) TEM examinations show small chromium sulphides (chemical composition close to 50% Cr and 50% S with a small amount of Fe) => solubility of S is very low (close to 10 ppm at 1100 °C, according literature)

  15. EM10TiPS (9Cr 1Mo 0.1C 0.2Ti 0.03P 0.04S)

  16. EM10TiPS (9Cr 1Mo 0.1C 0.2Ti 0.03P 0.04S) Calculations with the software Thermocalc predict also the formation of Ti4C2S2

  17. EM10TiPS (9Cr 1Mo 0.1C 0.2Ti 0.03P 0.04S) Alignments of TixSy Steel normalised at 1150°C/30min and quenched Ti(N,C) Ferritic Zones

  18. Ti(NC) Ti, Al, S TixSy Ti, Al, S TixSy TixSy Ti(NC) Ti, Al, S EM10TiPS (9Cr 1Mo 0.1C 0.2Ti 0.03P 0.04S) Steel normalised at 1150°C/30min and quenched

  19. EM10TiPS (9Cr 1Mo 0.1C 0.2Ti 0.03P 0.04S) Steel normalised at 1150°C/30min and quenched Phosphorus is probably in solid solution

  20. Conclusions 1) Better knowledge of the effects of Ti, S and P on the physical metallurgy of Fe 9Cr martensitic steels. 2) Assessment of heat treatments to obtain doping elements in solid solution in the different steels : - alloys doped with only Ti : after heat treatment, 1000 ppm can be retained in solid solution - alloys doped with sulphur : sulphides are very stable MnS, CrS, Ti(C,S) and it appears difficult to put it in solid solution even in a low manganese heat => very strong tendency of sulphur to precipitate. - alloy doped with phosphorus : possibility to have P in solid solution

  21. Perspectives Alloys doped with titanium in solid solution : - possibility to perform mechanical tests and hydrogen loading to study the interactions between Ti and H. Alloy doped with phosphorus in solid solution (EM10 TiPS) : - possibility to study the evolution of microstructure after thermal ageing or step cooling - the steel contains many inclusions that limit the possibility to assess the influence of P on mechanical properties Alloys with sulphur : - check if sulphur segregation is detectable in the EM10LMnS steel after homogenisation at high temperature and step cooling. -Other specific experiments, like diffusion couple at 500 or 600°C, between FeS and a matrix Fe-9Cr (Ti, P) may be proposed. For all the alloys : study of the stability under irradiation of phases with doping elements.

  22. Impact properties • (Sub-size specimens 3x4x27 mm)

  23. EM10MnS (9Cr 1Mo 0.1C 0.5Mn 0.04S)

  24. Ti Ka SE 10 mm 10 mm N Ka C Ka 10 mm 10 mm EM10Ti (9Cr 1Mo 0.1C 0.17Ti) 10 mm Courtesy of CAMECA

More Related