• International Journal of Technology (IJTech)
  • Vol 10, No 5 (2019)

Microstructure and Deformation of 57Fe17Cr25NiSi Austenitic Super Alloy after Arc Plasma Sintering

Microstructure and Deformation of 57Fe17Cr25NiSi Austenitic Super Alloy after Arc Plasma Sintering

Title: Microstructure and Deformation of 57Fe17Cr25NiSi Austenitic Super Alloy after Arc Plasma Sintering
Mohammad Dani, Arbi Dimyati, Parikin , Damar Rastri Adhika, Aziz Khan Jahja, Andon Insani, Syahbuddin , Ching An Huang

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Cite this article as:
Dani, M., Dimyati, A., Parikin., Adhika, D.R., Jahja, A.K., Insani, A., Syahbuddin., Huang, C.A., 2019. Microstructure and Deformation of 57Fe17Cr25NiSi Austenitic Super Alloy after Arc Plasma Sintering. International Journal of Technology. Volume 10(5), pp. 988-998

Mohammad Dani Center for Science and Technology of Advanced Materials, BATAN Kawasan Puspiptek Serpong, Tangerang 151314, Indonesia
Arbi Dimyati Center for Science and Technology of Advanced Materials – BATAN, Kawasan Puspiptek Serpong, Tangerang 151314, Indonesia
Parikin Center for Science and Technology of Advanced Materials – BATAN, Kawasan Puspiptek Serpong, Tangerang 151314, Indonesia
Damar Rastri Adhika -Research Center for Nanosciences and Nanotechnology, Bandung Institute of Technology, Jl. Ganesha 10, Bandung 40132, Indonesia -Engineering Physics Research Group, Faculty of Industrial Technology,
Aziz Khan Jahja Center for Science and Technology of Advanced Materials, BATAN Kawasan Puspiptek Serpong, Tangerang 151314, Indonesia
Andon Insani Center for Science and Technology of Advanced Materials, BATAN Kawasan Puspiptek Serpong, Tangerang 151314, Indonesia
Syahbuddin Pancasila University, Department of Mechanical Engineering, Faculty of Technik, Srengseng Sawah, Jagakarsa, Jakarta 12640 Indonesia
Ching An Huang Department of Mechanical Engineering, Chang Gung University, Taoyuan, Taiwan
Email to Corresponding Author

Microstructure and Deformation of 57Fe17Cr25NiSi Austenitic Super Alloy after Arc Plasma Sintering

The microstructure and deformation of 57Fe17Cr25NiSi super alloy are investigated in this study. The super alloy was produced from a mixture of granular ferro-scrap, ferro chrome, ferro silicon and ferro manganese raw materials by the casting method and then sintered using arc plasma for 4 and 8 minutes. The super alloy has been proposed in nuclear as well as fossil power plant facilities, such as vessels and heat exchangers. A combination of microscopy investigations by means of X-ray diffraction and high-resolution powder diffraction, optical microscopy, scanning electron microscopy and transmission electron microscopy techniques was conducted in order to obtain detailed information about the deformation of super alloy steel and its microstructures, especially fine structures. It was found that the austenitic super alloy microstructure is composed of dendrites of g-austenite, which are separated by a eutectic structure of Fe-Cr-C alloy. Arc plasma sintering for 4 to 8 minutes leads to a decrease in the area of the eutectic structure at the inter-dendrites and forms micro straine, from 4.60×10-3 to 5.39-4.06×10-4.

APS, HRPD, SEM, TEM, X-Ray Diffraction (XRD)


In the last decade, Indonesia has been preparing new energy plans to start on a nuclear energy option in anticipation of the country’s impending energy crisis. Within this framework, the Indonesian National Nuclear Energy Agency (BATAN) is at the forefront of realizing the government’s plan to utilize nuclear energy to overcome the energy problem. In this context, part of the BATAN energy master plan provides for the development of an experimental nuclear power plant with a capacity of 10 MW. The proposed subsequent BATAN nuclear reactor plant will be a High Temperature Gas Cooled Reactor (HTGR) type. Certain requirements for the structural reactor materials, such as heat-exchanger pipes and vessels, must be met; among these is that the materials should have good corrosion and creep resistance. Further requirements include good high-temperature response to an applied mechanical load, as well as good neutron irradiation resistance (Yvon & Carré, 2009). Meanwhile, to support the master plan, the research group for nuclear reactor material at BATAN has successfully synthesized the 57Fe17Cr25NiSi super alloy using local materials. Such material has great potential for use in a variety of high-temperature applications (Effendi et al., 2012; Effendi & Jahja, 2014). In this study, a new 57Fe17Cr25NiSi non-standard super alloy is produced using a new Arc Plasma Sintering (APS) method (Bandriyana et al., 2017) conducted at high temperature. APS has been developed at PSTBM-BATAN and has proven to be successful in reducing both time and energy consumption in the manufacturing process.

To develop alloys with reliable and improved mechanical and thermal properties, various methods are used by adding different elements such as Nb, Ti, Zr, V, W, Co and Mo into the super alloy, and by the hardening of solid solutions for the matrix and hardening precipitation for both the matrix and grain boundaries. Several studies (for example, Hong et al., 2001; Geddes et al., 2010;; Fukunaga et al., 2014; Silva et al., 2017; Dani et al., 2018) have conducted heat treatment and cooling with various media to modify the microstructure of g-austenite and the grain boundary to achieve alow density of (Fe,Cr)23C6 particles and Cr deflection zones. In fact, grain boundary in the austenitic super alloy may be constructed by the eutectic structures of Fe-Cr-C alloys consisting of M23C6 islands and a precipitate free zone (Choi et al., 1996); M23C6 particles (Kaneko et al., 2011);or just the Cr deflection zones of g-austenite. Some continuous carbide islands and Cr deflection zones were still found at the boundary of inter-dendrites. The high density of carbide islands and Cr deflection zones at grain boundaries contributes to the decrease in creep resistance (Choi et al., 1996). Some efforts have been made to reduce this formation, but the results have been not satisfactory. In order to overcome these problems, in this study the super alloy is qualitatively improved and produced using the new technology of Arc Plasma Sintering. This technique causes the onset of an inter diffusion process among the dendrites and in general is expected to be able to modify the structure of the austenitic super alloy and the dendrite boundary area, particularly its environment. In this work, the evolution of the microstructures including the boundaries of the inter-dendrites, and the deformation of the austenitic super alloy after APS treatment, are studied. Both the XRD and the neutron High Resolution Powder Diffraction (HRPD) methods are employed to determine and confirm the formation of the austenitic phase in the alloy. In addition, the Williamson-Hall (WH) method is used to analyze the XRD FWHM parameter (Irfana et al., 2018) obtained from the Gaussian function fit to the XRD reflection intensity. From the WH changes in the grainsize, the micro strain of the sample can be observed, and the micro deformation confirmed. To assess the extent of deformation associated with the sintering time of the super alloy samples, optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed for the detailed observation of the sample’s microstructures.


Based on the extensive discussion of the effect of sintering time on the microstructure, deformation and sythesis of the 57Fe17Cr25NiSi austenitic super alloy presented above, the following conclusion can be drawn. The microstructure of 57Fe17Cr25NiSi austenitic super alloy formed either as-cast or as sintered samples consists of dendrites of  g-austenite as the matrix, separated by a eutectic structure of the Fe-Cr-C alloy. 4 to 8 minutes’ sintering time decreases the number of islands of the (Cr,Fe)23C6 carbide in the eutectic structure at the grain boundary. No significant effect of sintering time was observed in the particles of the (Cr,Fe)7C3 carbide at the dendrite edges. Finally, the 4 to 8 minutes sintering time also decreases the microstrain of the 57Fe17Cr25NiSi austenitic super alloy.



The authors would like to express their gratitude to the Head of the Center for Science and Technology of Advanced Material for his valuable support. They would also like to thank the head of BSBM and BTBN who facilitated the research, Mr. Agus Sudjatno for assisting us with the SEM and Mr. Bambang Sugeng for the help with the XRD experiments.

Supplementary Material
R3-MME-2991-20190823154241.jpg Figure 2. X-Ray Diffraction Pattern and Rietveld refinement result of 57Fe17Cr25NiSi super alloy
R3-MME-2991-20190823154300.jpg Figure 3. Gaussian fit to the (111) reflection peak of the 57Fe17Cr25NiSi super alloy
R3-MME-2991-20190823154316.jpg Figure 4. Williamson-Hall plot for the 57Fe17Cr25NiSi super alloy
R3-MME-2991-20190823154329.jpg Figure 5. HRPD neutron diffraction pattern and Rietveld refinement result of the 57Fe17Cr25NiSi super alloy after Arc Plasma Sintering for time of 4 minutes

Bandriyana, Sujatno, A., Salam, R., Sugeng, B., Dimyati, A., 2017. High temperature Oxidation of ODS alloy with zirconia dispersions synthesized using Arc Plasma Sintering. IOP Conference Series: Materials Science and Engineering, Volume 176, pp. 16

Bowman, A.L., Arnold, G.P., Storms, E.K., Nereson, N.G., 1972. The Crystal Structure of Cr23C6. Acta Crystallographica Section B: Structural Crystallography and Crystal Chemistry, Volume 28(10), pp. 31023103

Choi, B.G., Nam, S.W., Yoon, Y.C., Kim, J.J., 1996. Characterization of the Cavity Nucleation Factor for Life Prediction under Creep-fatigue Interaction. Journal of Materials Science, Volume 31, pp. 49574966

Cullity, B.D., Stock, S.R., 2001. Elements of X-ray Diffraction. 3rd edition, Prentice Hall Publications, New Delhi, India

Dani, M., Parikin, Dimyati, A., Rivai, A.K., Iskandar, R., 2018. A New Precipitation-hardened Austenitic Stainless Steel Investigated by Electron Microscopy. International Journal of Technology, Volume 9(1), pp. 328337

Effendi, N., Jahja, A.K., Bandriana, Adi, W.A., 2012. Some Data of Second Sequence Non-standard Austenitic Ingot A2-Type. Urania, Scientific Journal of Nuclear Fuel Cycle, Volume 18(1), pp. 4858

Effendi, N., Jahja, A.K., 2014. Structural Characterization and Its Physical Properties of Non-Standard A1 Austenite Steel. International Journal of Materials and Mechanical Engineering, Volume 3(2), pp. 3844

Fukunaga, T., Kaneko, K., Kawano, R., Ueda, K., Yamada, K., Nakada, N., Kikuchi, M., Barnard, J.S., Midgley, P.A., 2014. Formation of Intergranular M23C6 in Sensitized Type-347 Stainless Steel. ISIJ International, Volume 54(1), pp. 148152

Geddes, B., Leon, H., Huang, X., 2010. Superalloys: Alloying and Performance. ASM International, Materials Park, Ohio, USA

Godec, M., Balantic, D.A.S., 2016. Coarsening Behaviour of M23C6 Carbide in Creep-resistant Steel Exposed to High Temperatures. Scientific Reports, Volume (6-29734), pp. 17

Honeycombe, R.W.K., Bhadeshia, H.K.D.H., 2006. Steel: Microstructure and Properties. 3rd Edition, Elsevier, New York, USA

Hong, H.U., Rho, B.S., Nam, S.W., 2001. Correlation of the M23C6 Precipitation Morphology with Grain Boundary Characteristic in Austenitic Stainless Steel. Materials Science and Engineering: A, Volume 318(1-2), pp. 285292

Irfana, H., Racik K.M., Anand, S., 2018. Microstructural Evaluation of CoAl2O4 Nanoparticles by Williamson–Hall and Size–Strain Plot Methods. Journal of Asian Ceramic Societies, Volume 6(1), pp. 54–62

Kaneko, K., Fukunaga, T., Yamada, K., Nakada, N., Kikuchi, M., Saghi, Z., Barnard, J.S., Midgley, P.A., 2011. Formation of M23C6-type Precipitates and Chromium-deflected Zone in Austenite Stainless Steel. Scripta Materialia, Volume 65(6), pp. 509512

Lee, T-H., Lee, Y-J., Joo, S-H., Nersisyan, H.H., Park, K-T., Lee, J-H., 2015. Intergranular M23C6 Carbide Precipitation Behavior and Its Effect on Mechanical Properties of Inconel 690 Tubes. Metallurgical and Materials Transactions A, Volume 46(9), pp. 40204026

Lee, T-H., Suh, H-Y., Han, S-K., Noh, J-S., Lee, J-H., 2016. Effect of a Heat Treatment on the Precipitation Behaviour and Tensile Properties of Alloy 690 Steam Generator Tubers. Journal of Nuclear Materials, Volume 479, pp. 8592

Parikin, Dani, M., Jahja, A.K., Iskandar, R., Mayer, J., 2018. Crystal Structure Investigation on the Ferritic 73Fe24Cr2Si0.8Mn0.1Ni Steel for Multi Purpose Structural Material Applications. International Journal of Technology, Volume 9(1), pp. 7888

Plaut, R.L., Herrera, C., Escriba, D.M., Rios, P.R., Padilha, A.F., 2007. A Short Review on Wrought Austenitic Stainless Steels at High Temperatures: Processing, Microstructure, Properties and Performance. Materials Research, Volume 10(4), pp. 453460

Sapna, S., Budhiraja, N., Kumar, V., Singh, S.K., 2017. X-ray Analysis of NiFe2O4   Nanoparticles by Williamson-Hall and Size-Strain Plot Method. Journal of Advanced Physics, Volume 6(4), pp. 14

Silva, F.J.G., Santos, J., Gouveia, R., 2017. Dissolution of Grain Boundary Carbides by the Effect of Solution Annealing Heat Treatment and Aging Treatment on Heat-Resistant Cast Steel KH30. Metals, Volume 7(251), pp. 112

Suryanarayana, C., Norton, M.G., 1998. X-ray Diffraction: A Practical Approach. Springer, New York

Wieczerzak, K., Bala, P., Stepien, M., Cios, G., Koziel, T., 2015. The Characterization of Cast Fe-Cr-C Alloy. Archives of Metallurgy and Materials, Volume 60(2), pp. 779782

Xu, Z., Ding, Z., Liang, B., 2018. The Observation of the Structure of M23C6/g Coherent Interface in the 100Mn13 High Carbon High Manganese Steel. Metallurgical and Materials Transaction A, Volume 49(3), pp. 836841

Yvon, P., Carre, F., 2009. Structural Materials Challenges for Advanced Reactor Systems. Journal of Nuclear Materials, Volume 385(2), pp. 217222