Microstructural refining during friction stir processing of SAF 2205 duplex stainless steel

Document Type : Research Paper

Authors

1 Faculty of materials engineering, sahand university of technology, Tabriz, Iran

2 Faculty of Materials Engineering, Sahand university of technology

3 Faculty of materials engineering, Sahand University of Technology, Tabriz, Iran

Abstract

Friction stir processing (FSP) was conducted on a SAF 2205 duplex stainless steel at advancing speed of 50 mm/min and rotational speed of 400 rpm.  Characterization of evolved material was studied using electron microscopy equipped with electron back scattered diffraction (EBSD) system. The results indicated that the severe plastic deformation and the heat generated during the FSP developed a very fine microstructure in the stir zone (SZ). It was found that the finest grains with average grain size less than 1 µm were formed in the bottom of the SZ where the material was more likely to receive the lowest temperature in both constituent phases of ferrite and austenite. Therefore, it can be inferred that the material in the bottom of the SZ was less affected from the heat generated by the shoulder. The presence of such severe deformation along with the elevated temperature during the welding procedure inside the SZ activates the occurrence of continuous dynamic recrystallization mechanism throughout the material which seems to be responsible for grain refinement. Moreover, 111 and 110 pole figures of both constituent phases demonstrated that the rotating tool broke the initial microstructure, modified the pre-existence rolling texture of the starting material, and introduced simple shear texture components into the SZ.

Keywords

References

1. Mishra RS, Ma ZY. Friction stir welding and processing. Materials Science and Engineering: R: Reports. 2005;50(1-2):1-78.
2. Abbaschian R, Reed-Hill RE. Physical metallurgy principles. Cengage Learning; 2008 Dec 11.
3. Humphreys FJ, Hatherly M. Recrystallization Textures. Recrystallization and Related Annealing Phenomena: Elsevier; 2004. p. 379-413.
4. Rezaei-Nejad SS, Abdollah-zadeh A, Hajian M, Kargar F, Seraj R. Formation of Nanostructure in AISI 316L Austenitic Stainless Steel by Friction Stir Processing. Procedia Materials Science. 2015;11:397-402.
5. Azushima A, Kopp R, Korhonen A, Yang DY, Micari F, Lahoti GD, et al. Severe plastic deformation (SPD) processes for metals. CIRP Annals. 2008;57(2):716-35.
6. Paupler P. G. E. Dieter. Mechanical Metallurgy. 3rd ed., Mc Graw-Hill Book Co., New York 1986. XXIII + 751 p., DM 138.50, ISBN 0–07–016893–8. Crystal Research and Technology. 1988;23(2):194-.
7. Saeid T, Abdollah-zadeh A, Assadi H, Malek Ghaini F. Effect of friction stir welding speed on the microstructure and mechanical properties of a duplex stainless steel. Materials Science and Engineering: A. 2008;496(1-2):262-8.
8. Mishra MK, Rao AG, Balasundar I, Kashyap BP, Prabhu N. On the microstructure evolution in friction stir processed 2507 super duplex stainless steel and its effect on tensile behaviour at ambient and elevated temperatures. Materials Science and Engineering: A. 2018;719:82-92.
9. Xie GM, Cui HB, Luo ZA, Misra RDK, Wang GD. Microstructrual evolution and mechanical properties of the stir zone during friction stir processing a lean duplex stainless steel. Materials Science and Engineering: A. 2017;704:311-21.
10. Saeid T, Abdollah-zadeh A, Shibayanagi T, Ikeuchi K, Assadi H. On the formation of grain structure during friction stir welding of duplex stainless steel. Materials Science and Engineering: A. 2010;527(24-25):6484-8.
11. Santos TFdA, López EAT, Fonseca EBd, Ramirez AJ. Friction stir welding of duplex and superduplex stainless steels and some aspects of microstructural characterization and mechanical performance. Materials Research. 2016;19(1):117-31.
12. Mironov S, Sato YS, Kokawa H. Microstructural evolution during friction stir-processing of pure iron. Acta Materialia. 2008;56(11):2602-14.
13. Jorge-Badiola D, Iza-Mendia A, Gutiérrez I. Study by EBSD of the development of the substructure in a hot deformed 304 stainless steel. Materials Science and Engineering: A. 2005;394(1-2):445-54.
14. Sato YS, Nelson TW, Sterling CJ. Recrystallization in type 304L stainless steel during friction stirring. Acta Materialia. 2005;53(3):637-45.
15. Suwas S, Ray RK, Crystallographic Texture of Materials, Springer; 2009.
16. Sato YS, Nelson TW, Sterling CJ, Steel RJ, Pettersson CO. Microstructure and mechanical properties of friction stir welded SAF 2507 super duplex stainless steel. Materials Science and Engineering: A. 2005;397(1-2):376-84.
17. Fonda RW, Knipling KE. Texture development in friction stir welds. Science and Technology of Welding and Joining. 2011;16(4):288-94.
Journal of Ultrafine Grained and Nanostructured Materials
Volume 51, Issue 1
June 2018
Pages 20-25

Files

History

  • Receive Date: 07 February 2018
  • Revise Date: 01 May 2018
  • Accept Date: 12 May 2018

Share

How to cite

Statistics