Wu, L.1, Isaac, A.1, and Ramirez, A.J.1
Laborat´orio Nacional de Luz S´ıncrotron - Campinas SP Brazil
This project will combine a thermomechanical simulator (Gleeble system) with syn- chrotron x-ray diffraction. The Gleeble system allows for producing microstructural changes representative of those experienced during solid-state phase transforma- tion, high-temperature corrosion, materials processing (e.g. welding, heat treat- ment and metal forming), and thermomechanical loads (e.g. uniaxial tensile and compressive deformation, fatigue and creep). This physical simulator comprises a 44kN hydraulic uniaxial testing machine for tension and compression. Heating and cooling rates up to 1,000oC/s may be readily achieved, with mechanical loads superimposed, if required. It is also capable of cyclic deformation and/or cyclic temperature. The materials science activities will focus on three intersecting top- ics which are industrial, applied, and fundamental research. The beamline shall combine two main features. First, the high flux associated to fast detector systems allowing complex and dynamic in situ experiments. Second, a high flexibility in beam shaping will be available, fully exploiting the high brilliance of the source.
This novel set-up will enable us to followin situphase transformations and residual stresses development under service and/or manufacturing conditions.
Acknowledgements: This work is funded by PETROBRAS
Friction Stir Welding of ISO 3183 X80M Steel
Santos, T. F. A.1, Ramirez, A.J.1, Hermenegildo.T,F1, Benati, D. M.1, and Afonso, C R M1
Laborat´orio Nacional de Luz S´ıncrotron - Campinas SP Brazil
Friction Stir Welding (FSW) is a solid-state joining process with numerous ad- vantages as good dimensional stability and repeatability. 12 mm thick ISO 3183 X80M (API-5L-X80) steel plates were friction stir welded in two passes using ce- ramic tools. Different heat inputs were obtained using a fix travel (welding) speed in combination with several spindle speeds aiming the achievement of better me- chanical properties. The microstructure of base material (BM) was formed by fer- rite (F), degenerated perlite (DP) and Martensite-Austenite constituent (M-A).
The heat affected zone (HAZ) microstructure was composed by F, some carbides (Fe3C), and M-A. The microstructure of the stir zone (SZ) presented F, M-A con- stituent, and degenerated upper bainite (DUB). Tensile tests were performed in joints according API 1104. The samples failed at the BM indicating higher tensile strength within the SZ and HAZ. The HAZ showed minor increment of hardness whereas the SZ showed considerable increment. The fracture toughness of the two- pass joint BM, HAZ and SZ was evaluated at 25C using single edge bend specimen CTOD. The joint showed CTOD-values above the offshore standard requirements (DNV-OS-F101), turning FSW a technically viable technology for high strength structural steel welding, without compromising the material fracture toughness.
Therefore, FSW should be considered and developed as a key technology in the energy generation industry, especially for advanced construction and critical repair applications.
Acknowledgements: The authors are indebt to Petrobras and Finep for financial support.
Numerical Modelling and Experimental Analysis during Solidification of Arc Weld in Ni-Cr-Fe Alloys with Hf Additions
Unfried S., J.1, Fonseca, E. B.2, Afonso, C R M1, and Ramirez, A.J.1
1 Laborat´orio Nacional de Luz S´ıncrotron - Campinas SP Brazil
2 Universidade Estadual de Campinas - Campinas SP Brazil
In this work were studied the effects of small additions of Hafnium (Hf) in Ni-Cr-Fe based solid solution hardened superalloys. The effects are related to precipitation of primary carbides, partitioning of elements and grain boundary format. A numer- ical modelling based on the Calphad methodology was used to simulate eutectic transformation and distribution of elements in experimental alloys with different levels of Hf content. Characterization based on optical, electron microscopy and, XEDS techniques were used to obtain experimental evidence of grain boundary for- mat, carbides precipitation and partitioning of elements, respectively. It has been observed that increasing Hafnium additions increase the fraction of carbides, grain boundaries serrated and probability of welding solidification cracking.
Acknowledgements:
Parte VIII
M´ etodos e Instrumenta¸c˜ ao
Pressure cell for XPD, XAS and SAXS experiments using Synchrotron Light
Orlando, M. T. D.1, J.L.Passamai Jr1, Martinez, L. G.2, Rossi, J. L.2, Corrˆea, H.
P. S.3, Garcia, F.4, Ferreira, F. F.4, Melo, F. C. L.5, and Souza Jr, F. G.6
1 Universidade Federal do Esp´ırito Santo - Vit´oria ES Brazil
2 Instituto de Pesquisas Energ´eticas e Nucleares - S˜ao Paulo SP Brazil
3 Universidade Federal do Mato Grosso do Sul - Campo Grande MS Brazil
4 Laborat´orio Nacional de Luz S´ıncrotron - Campinas SP Brazil
5 Centro T´ecnico Aeroespacial - S˜ao Jos´e dos Campos SP Brazil
6 Universidade Federal do Rio de Janeiro - Rio de Janeiro RJ Brazil
A high pressure CuBe cell with B4C anvil has being developed since 2004 for small- and wide-angle synchrotron x-ray scattering experiments under hydrostatic pressure up to 2GPa, at room temperatures. Recently, an optimized version of this cell was used to measure the pressure effect on structure of Cardanol-Furfural-PAni Green Blend in SAXS beam line at Laborat´orio Nacional de Luz Sincrotron - LNLS - Campinas . This cell has also been applied to investigate solid samples behaviour under external hydrostatic pressure since 2007 at LNLS. Moreover, it might also be used to investigate biological system as lipid-water dispersions without changes in its design. Magnetic field up to 1.6 kGauss can be applied together the hydro- static pressure in this cell, taken into account there is no magnetic signal from de CuBe, B4C anvil, and CuBe gasket used. Investigations about ReO2 behavior un- der hydrostatic pressure up to 1.6 GPa were performed at LNLS-XPD and XAFS Synchrotron beam line, and the results revealed to be the ReO2 a good inner gauge pressure for 8keV-13keV energy range. This project has been developed by LNLS, UFES, IPEN/CNEN and IEA/CTA collaboration.
Acknowledgements: We would like to thank CNPq Grant 471536-2004-0, CT-Energ 504578-2004-9, and CAPES for financial supports. Thanks also to Cia. Vale do Rio Doce (CVRD), Cia Siderurgica de Tubarao (AcelorMittal), and National Laboratory of Syn- chrotron Light - LNLS, Brazil (XPD 2950-04, XPD 4742-05, XPD 5720-06, DXAS 2950-04, DXAS 2952-04, DXAS 5741-06, D02A - SAXS2 8519/09).
Current Status of the High Energy Resolution System of the XRF Beamline
P´erez, C. A.1and H. J. S´anchez2
1 Laborat´orio Nacional de Luz S´ıncrotron - Campinas SP Brazil
2 Universidad Nacional de Cordoba - C´ordoba Cba Argentina
This work presents the status of the high energy resolution system that is being currently commissioned in the XRF beamline of the LNLS.
A high energy resolution system for detecting characteristic radiation, based in a wavelength dispersive system, is currently mounted and in the final stages of commissioning in the XRF beamline of the LNLS. The module was tested many times with a conventional x-ray tube and then mounted in the beamline in order to be used as a routine experiment of the line. The system has been mounted on a special device placed in the beamline. This device allows fine movements in order to align the module very precisely. This is a critical point to get the best available resolution. The radius of the Rowland Circle of the spectrometer is 140 mm, the detector is a proportional counter one with a 300 microns windows. Currently a Si(111) crystal is being used and the resolution of the angular stage is 0.017◦. The energy resolution strongly depends on the dimensions of the incident beam. A final configuration of 0.1 mm (horizontal) and 0.5 mm (vertical) was adopted.
Pure foils samples of Fe, V and Ti were used to characterize the system. Mea- surements of Kαand Kβ lines were obtained using the high resolution module and a conventional solid state detector. Measured spectra were analyzed with typical programs for spectrum analysis and the Full Width Half Maximums (FWHM) were calculated for all the samples and lines. In addition, theoretical calculations of the expected resolution were carried out. The results and their comparison with the theoretical values are summarized in the following table.
Line Measured Resolution (eV) Calculated Resolution (eV)
Fe Kα 28±3 35
Fe Kβ 47±5 46
V Kα 13±3 15
V Kβ 27±3 21
Ti Kα 13±1 12
Ti Kβ 21±2 15
The results indicate an obvious significant improvement in the energy resolution of the high resolution system as compared with a conventional energy dispersive system. The calculated values of resolution agree very well with the measured ones.
The future implementation of other crystals will allow getting even higher res-