Skip to content
Licensed Unlicensed Requires Authentication Published by De Gruyter May 26, 2013

An examination of the mechanical properties of dissimilar steel welds

Eine Untersuchung von mechanischen Eigenschaften bei ungleichen Schweißverbindungen
A.Volkan Uygun, Ali Durmuş, Ali Bayram and Sedat Ülkü
From the journal Materials Testing

Abstract

Microstructure, hardness, tensile, three-point bending and fractography properties were investigated for the following dissimilar steel welds: P91-P22 (W1), P91-P11 (W2), and P91-P1 (W3). These materials were first joined at the root by gas tungsten arc welding; the second, third, and fourth passes were deposited manually by shielded metal arc welding. After welding, these pairs were tempered 760, 735, and 700°C for 1, 2, and 3 hours, respectively (i.e. T1, T2, and T3). The highest hardness values were revealed in the heat-affected zone of P22 for the W1-T2 pair. The lowest hardness was observed in the base metal-P91 for the W2-T2 and W2-T3 pairs. Fracture failure in tensile tests occurred in base metals-P22, P11, and P1. In a few samples, failure took place during three-point bending tests. Cracks which formed as a result of bend testing were within tolerance limits. All weld regions were martensitic, with an acicular structure. The base metal P91 steel revealed a martensitic structure, whereas P22, P11, and P1 base metals had a ferrite-pearlite structure.

Kurzfassung

Im vorliegenden Beitrag sind das Gefüge, die Härte, die Festigkeits- und die Zähigkeitseigenschaften sowie die Brucheigenschaften von folgenden Schweißverbindungen untersucht worden: P91-P22 (W1), P91-P11 (W2) und P91-P1 (W3). Diese Werkstoffe wurden zunächst mittels WIG-Wurzelschweißungen und dann mittels Elektrodenhandschweißens in vier Lagen gefügt. Nach dem Schweißen wurden die Verbindungen bei 760, 735 und 700°C für 1, 2 und 3 Stunden angelassen (T1, T2, and T3). Die höchsten Härtewerte ergaben sich in der Wärmeeinflusszone des Stahles P22 in der W1-T2 Verbindung. Die niedrigsten Härtewerte wurden im Grundwerkstoff P91 in den Verbindungen W2-T2 und W2-T3 registriert. In den Zugversuchen versagten die Grundwerkstoffe P22, P11 und P1, jedoch nicht die Schweißverbindungen. Einige der Dreipunkt-Biegeproben versagten, jedoch lagen die Risse während dieser versuche im Toleranzbereich. Alle Gefüge der Schweißungen waren martensitisch mit einer Acicular-Struktur. Der Grundwerkstoff des Stahles P 91 weist ein martensitisches Gefüge auf, die Stähle P22, P11 und P1 haben hingegen ein ferritisch-perlitisches Gefüge.


A. Volkan Uygun was born in Bursa, Turkey in 1977. He received his BSc degree from the Mechanical Engineering Department of Kocaeli University, Kocaeli, Turkey in 1999. He studied for an MSc in Mechanical Engineering at Uludag University, Bursa. He has been working at CIMTAS / Pipe Fab. and Trading Ltd. Co as a project coordinator since 1999.

Dr. Ali Durmuş was born in Bursa, Turkey in 1977. He received his BSc degree from the Mechanical Engineering Department of Uludag University, Bursa, Turkey in 1998. He studied for an MSc in Mechanical Engineering at Uludag University, Bursa, Turkey to broaden his knowledge in this field. He obtained his PhD in 2004 from the Faculty of Engineering and Architecture of Uludag University. He is currently working as a research assistant in the Mechanical Engineering Department.

Assoc. Prof. Dr. Ali Bayram was born in 1958 in Bursa, Turkey. He graduated from Istanbul Technical University as a metallurgical engineer. He received his PhD in materials science from Uludag University in 1994. He is currently a lecturer at the Mechanical Engineering Department of Uludag University. His current research interests are the fracture characteristics of dual phase steels, surface treatment and Al-based alloys.

Prof. Dr. Sedat Ülkü was born in 1950 in Nigˇde, Türkey. He completed his studies at the Academy of Engineering and Architecture in 1972. He received his MSc in Industrial Engineering from Ege University, Izmir in 1975. He obtained his PhD from the University of Bath in UK in 1982. He is currently a lecturer at Uludag University, Faculty of Engineering and Architecture, Mechanical Engineering Department. His current research interests are composite materials.


References

1 Ellis, F. V.; Henry, J. F.; Roberts, B. W.: Welding Fabrication, and Service Experience with Modified 9Cr-1Mo Steel, New Alloys for Pressure Vessels and Piping, PVP Volume 201, American Society of Mechanical Engineers, NY (1990), pp. 5563Search in Google Scholar

2 Wada, T.: The Continuous Cooling Transformation Diagram and Tempering Response of 9Cr-1Mo-V-Nb Steels, J-4672, Climax Molybdenum Company of Michigan, Ann Arbor, MI (1981)Search in Google Scholar

3 Willby, C.; Walters, J. in: Pauh, S. F.; Little, E. A. (eds.) Proceedings of the International Conference on Ferritic Steels for Reactor Steam Generators, BNES, London (1978), p. 40Search in Google Scholar

4 Booker, M. K.; Sikka, V. K.; Booker, B. L. K. in: Ashok, Khare (eds), Proceedings of the International Conference on Production, Fabrication, Properties and Application of Ferritic Steels for High Temperature Application, ASM, Metals Park, OH (1982), p. 257Search in Google Scholar

5 Shiue, R. K.; Lan, K. C.; Chen, C.: Toughness and Austenite Stability of Modified 9Cr-1Mo Welds after Tempering, Materials Science and Engineering A287 (2000), pp. 1016Search in Google Scholar

6 Mythili, R.; Paul, V. T.; Saroja, S.; Vijayalakshimi, M.; Raughunathan, V. S.: Microstructural Modification due to Reheating in Multipass Manual Metal arc Welds of 9Cr-1Mo Steel, Journal of Nuclear Materials312 (2003), pp. 199206Search in Google Scholar

7 Lee, W. H.; Shiue, R. K.; Chen, C.: Mechanical Properties of Modified 9Cr-1Mo steel welds with notches, Materials Science and Engineering A356 (2003), pp. 153161Search in Google Scholar

8 Cadek, J.; Sustec, V.; Pahutova, M.: An Analysis of A Set of Creep Data for A 9Cr-1Mo (P91) Steel, Materials Science and Engineering A225 (1997), pp. 2228Search in Google Scholar

9 Norris, R. H.; Saxena, A.: WRC Bull.416 (1996), p. 1Search in Google Scholar

10 Long, X.; Cai, G.; Svenson, L. E.: Investigation of Fracture and Determination of Fracture Toughness of Modified 9Cr-1Mo Steel Weld Metals Using AE Techniques, Materials Science and Engineering A270 (1999), pp. 260266Search in Google Scholar

11 Moitra, A.; Parameswaran, P.; Sreenivasan, P. R.; Mannan, S. L.: A Toughness Study of The Weld Heat-Affected Zone o A 9Cr-1Mo Steel, Materials Characterization48 (2002), pp. 5561Search in Google Scholar

12 Le Mat Hamata, N.; Shibli, I. A.: Creep Crack Growth of Seam-Welded P22 and P91 Pipes with Artificial Defects, Part I, Experimental Study and Post-Test Metallography, International Journal Of Pressure Vessels and Piping78 (2001), pp. 819826Search in Google Scholar

13 Shibli, I. A.; Le Mat Hamata, N.: Creep Crack Growth in P22 and P91 Welds-Overview from SOTA and HIDA Project, International Journal Of Pressure Vessels and Piping78 (2001), pp. 785793Search in Google Scholar

14 Homolava, V.; Janovec, J.; Zahumenky, P.; Vyroskova, A.: Influence of Thermal-Deformation History on Evolution of Secondary Phases in P91 Steel, Materials Science and Engineering A349 (2003), pp. 306312Search in Google Scholar

15 Spigarelli, S.; Quadrini, E.: Analysis of the Creep Behaviour of Modified P91 (9Cr-1Mo-NbV) Welds, Materials and Design23 (2002), pp. 547552Search in Google Scholar

16 Avner, S. H.: Introduction to Physical Metallurgy, Mc Graw-Hill, New York (1974)Search in Google Scholar

Published Online: 2013-05-26
Published in Print: 2005-06-01

© 2005, Carl Hanser Verlag, München

Scroll Up Arrow