Effect of Multipass Welding Using a Low Transformation Temperature Filler Metal on Residual Stress and Toughness

Abstract:

Residual stresses in welded components are consequence of stress and/or thermal gradients and influenced by factors such as joint geometry, variation in strength of the material, preheat temperature, heat input, post-weld heat treatment and phase transformation strains. During the 70’s, it was observed that the level of residual stress accumulated in a constrained sample during cooling from austenite could be reduced after transformation to martensite or bainite. Some works have evaluated effect of welding using a low transformation temperature martensitic filler metal on the level of residual stress in single pass joints. According to these studies, martensite start temperature in the range 200–250°C can be extremely effective for mitigation of tensile residual stresses. The outcome of most of these works was on one hand increase of fatigue life due to the mitigation of tensile residual stresses via transformation strains, on the other a significant reduction of the fracture toughness.In the present study, sections of API 5L class B steel tubes were multipass welded using a 12Cr-5Ni low transformation temperature filler metal in addition to a conventional filler metal. Residual stresses in the inner and outer surfaces were measured by X-ray diffraction. Aspects related to the improvement of toughness in the weld metal due to the tempering of one pass by the subsequent were also discussed.

• Periodical: Materials Science Forum (Volumes 783-786)
• Pages: 627-632
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.783-786.627
• Online since: May 2014
• Authors: H.F.G. Abreu*, W.S. Tavares, Hélio Cordeiro de Miranda, Maria P. Cindra Fonseca, H.N. Virgens-Neto, M. Béreš
• Keywords: Low Transformation Temperature, Martensitic Transformation (MT), Residual Stress, Toughness, Welding

References

[1] H. Dai, J.A. Francis, H.J. Stone, H.K.D.H. Bhadeshia and P.J. Withers, Characterizing Phase Transformations and Their Effects on Ferritic Weld Residual Stresses with X-rays and Neutrons, Metallurgical and Materials Transactions A, (2008).

DOI: 10.1007/s11661-008-9616-0

[2] H. Murakawa, M. Béreš, C.M. Davies, S. Rashed, A. Vega, M. Tsunori, K.M. Nikbin and D. Dye, Effect of low transformation temperature weld filler metal on welding residual stress, Science and Technology of Welding and Joining, (2010).

DOI: 10.1179/136217110x12714217309614

[3] A. Ohta, K. Matsuoka, N. T. Nguyen, Y. Maeda, and N. Suzuki, Fatigue strength improvement of lap joints of thin steel plate using low- transformation-temperature welding wire, American Welding Journal, (2003), 82, 78-83.

DOI: 10.1007/bf03266382

[4] A. Ohta, N. Suzuki, Y. Maeda, K. Hiraoka, and T. Nakamura, Superior fatigue crack growth properties in newly developed weld metal, International Journal of Fatigue, (1999), 21, 113-118.

DOI: 10.1016/s0142-1123(99)00062-6

[5] J.A. Francis, H.J. Stone, S. Kundu, R.B. Rogge, H.K.D.H. Bhadeshia, P.J. Withers and L. Karlsson, Transformation temperatures and welding residual stresses in ferritic steels, Proceedings of the ASME Pressure Vessels and Piping Conference, San Antonio, Texas, (2007).

DOI: 10.1115/pvp2007-26544

[6] A. A. Shirzadi, H.K.D.H. Bhadeshia, L. Karlsson and P.J. Withers, Stainless steel weld metal designed to mitigate residual stresses, Science and Technology of Welding and Joining, (2009), 14, 559-565.

DOI: 10.1179/136217109x437178

[7] A.F. Mark, J.A. Francis, H. Dai, M. Turski, P.R. Hurrell, S.K. Bate, J.R. Kornmeier, P.J. Withers, On the evolution of local material properties and residual stress in a three-pass SA508 steel weld, Acta Materialia, (2012), 60, 3268-3278.

DOI: 10.1016/j.actamat.2012.03.022

[8] J. Altenkirch, J. Gibmeier, A. Kromm, Th. Kannengiesser, Th. Nitschke-Pagel, M. Hofmann, In situ study of structural integrity of low transformation temperature (LTT)-welds, Materials Science and Engineering A 528, (2011), 5566-5575.

DOI: 10.1016/j.msea.2011.03.091

[9] Ph.P. Darcis, H. Katsumoto, M.C. Payares-Asprino, S. Liu, and T.A. Siewert, Cruciform fillet welded joint fatigue strength improvements by weld metal phase transformations, Fatigue and Fracture of Engineering Materials and Structures, (2008).

DOI: 10.1111/j.1460-2695.2007.01205.x

[10] L. Karlsson and L. Mráz, Increasing fatigue life with Low Transformation temperature (LTT) welding consumables, Zváranie Svarováni, (2011), 1-2, 8-15.

[11] S. Zenitani, N. Hayakawa, J. Yamamoto, K. Hiraoka, Y. Morikage, T. Yauda and K. Amano, Development of new low transformation temperature welding consumable to prevent cold cracking in high strength steel welds, Science and Technology of Welding and Joining, (2007).

DOI: 10.1179/174329307x213675

[12] W.K.C. Jones and P.J. Alberry, Metal Technology, (1977), 11, 557-566.

[13] H.K.D.H. Bhadeshia, H.F.G. Abreu, S. Kundu: Int. J. Mat. Res., (2008), 99, 342–346.

[14] K. Wallin, Methodology for selecting Charpy toughness criteria for thin high strength steels: Part 1 - determining the fracture toughness, Jernkontorets Forskning, Report from Working Group 4013/89, 28 December (1994).