PSI - Issue 14

Vijay Sai et al. / Procedia Structural Integrity 14 (2019) 491–498

498

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Ch. Vijay Sai/ Structural Integrity Procedia 00 (2018) 000–000

Table 3. Summary of peak tensile and compressive residual stress in circumferential weld joints. SS304 weld joint P91 weld joint

Dissimilar weld joint

Outer radius

Inner radius Outer radius

Inner radius

Outer radius

Inner radius

Peak tensile residual stress

58 92

280 124

286 198

573 281

205 400

336 500

Peak compressive residual stress

4. Conclusions This paper discusses, and elaborates the longitudinal and hoop residual stresses in joints of P91, SS304 and dissimilar joints between them. Following observations can be made based on the study:  The magnitude of residual stress, depends on Eigen strain present in the body and the mechanical properties of the material. Eigen strain depends on peak temperature, spatial variation of temperature and coefficient of expansion.  The peak temperature profile in the dissimilar weld joint is more similar to that of P91 joint, indicating a greater effect of P91 over SS304, on the heat transfer in the joint.  In comparison to their individual joints, in the dissimilar joint, residual stress in P91 decreases and increases in SS304.  Martensite formation at lower temperatures in P91 leads to formation of a compressive zone which induces dilation and tensile residual stresses in adjacent locations. The magnitude of difference between the compressive and adjacent tensile residual stresses is observed to be similar in all joints.  The compressive residual stress introduced by martensite, reduces in a plate joint owing to its open structure in comparison to pipe joint. This is accompanied by increase in tensile residual stress. Thus peak tensile residual stresses are observed in plate joints while peak compressive stresses are observed in circumferential pipe joints.  In both plate and circumferential pipe joints, peak tensile residual stress is observed in P91 weld joint and peak compressive residual stress is observed in P91 side of the dissimilar weld joint.  In dissimilar plate joint, the release of Compressive strain, is akin to stress proofing of the SS304 plate and results in decrease of its residual stress. This is in virtue of its lower yield strength and higher magnitude of residual strain in comparison to P91 joint. References Shi Jinhua, Booth, S, 2013. An investigation of effects of welding residual stresses on creep crack growth for a low alloy butt weld. Intl. Journal of Pressure Vessel and Piping, Vol 108-109, pp. 67-71. Lammi, J., Christopher, Lados, A., Diana, 2011. Effects of residual stresses on fatigue crack growth behavior of structural materials. International Journal of Fatigue, Vol 33, pp. 858-867. Lundin, C., D., 1982 . Dissimilar Metal Welds-Transition Joints Literature Review. Welding Journal Research Supplement, WRC. Ul-Hamid, Anwar, Tawancy. M., Hawid, Nureddin M. Abbas, 2005. Failure of weld joints between carbon steel pipe and 304 stainless steel elbows. Engineering Failure Analysis, pp.181-191. Hyung, Lee, Chin, Kyong-Ho Chang, Jeong-Ung Park, 2013. Three-dimensional finite element analysis of residual stresses in dissimilar steel pipe welds. Nuclear Engineering and Design, Vol.256,pp. 160– 168. Wenchun, Jiang, Wanchuck, Woo, 2016. Residual Stress Distribution in a Dissimilar Weld Joint by Experimental and Simulation Study. Journal of Pressure Vessel Technology, 139(3). Aalami-aleagha, M.E., Eslampanah,A., H., 2012. Mechanical Constraint Effect on Residual Stress and Distortion in T-fillet welds by three dimensional finite element analysis. Journal of Engg. Manufacture, Institute of Mechanical Enginneers, Vol 227,pp.315-323. Velaga, K., Satish, Rajput, Gaurav, Murugan, S., et al., 2015. Comparison of weld characteristics between longitudinal seam and circumferential butt weld joints of cylindrical components. Journal of Manufacturing Process;18: pp. 1-11. Zubairuddin, M., Albert, S., K., Vasudevan, M, 2017. Numerical Simulation of Multi Pass GTA Welding of Grade 91 Steel. Journal of Manufacturing Processes 27, pp. 87-97. Zhao, Lei, Liang, Jun, Zhong, Qunpeng, 2014. Numerical simulation on the effect of welding parameters on welding residual stresses in T92/S30432 dissimilar welded pipe. Advances in Engineering Software 68,pp.70–79. Javadi, Y., Smith, M., C., Abburi, Venkata, K., Dey, H., C., et.al, 2017. Residual stress measurement round robin on an electron beam welded joint between austenitic stainless steel 316L(N) and ferritic steel P91. International Journal of Pressure Vessels and Piping 154,PP. 41-57.