Experimental Determination of Residual Stresses in Multi-Pass Girth Welding of Thermo-Mechanical Steel Pipe

علوم کاربردی و محاسباتی در مکانیک

Article 8, Volume 25, Issue 2, October 2014, Pages 111-120   

Document Type: مقاله کوتاه

DOI: 10.22067/fum-mech.v25i2.40481

Authors

M. Sabokrouh^* ; S.M. Hashemi; M.R. Farahani

Abstract

In this paper, two API X70 steel pipes (with spiral seam weld) of 56 inch outside diameter and 0.780 inch wall thickness were girth welded first. Next, hole drilling tests were conducted for strain measurement on the surfaces of the pipes. The values of residual stresses on the internal and external surfaces of the pipe were determined, from strain data using ASTM 837 standard. The experimental data showed that the maximum tensile residual stress (318MPa) was located on the centre line of the weld gap on the pipe outer surface alongside with the pipe hoop direction. Moreover, the maximum compressive (hoop and axial) residual stresses (137MPa) occurred on the pipe inner surface at 30mm from the centre line of the weld gap.

Keywords

Residual stress؛ multi-pass girth weld؛ thermomechanical steel pipe؛ natural gas transmission؛ hole drilling; API X70

References

1. مقدمه کتاب خلاصه مقالات اولین کنفرانس لوله و صنایع وابسته، شرکت ملی گاز ایران، تهران، (1386).

2. "New Joining Technology for Metal Pipe in the Construction Industry", Construction Industry Institute & Breakthrough Strategy Committee, Texas, pp.15-35, (2003).

3. کوکبی، امیرحسین، "تکنولوژی جوشکاری"، نشر آزاده، تهران، (1388).

4. حائری، محمود، "بررسی متالورژیک عیوب در جوش"، نشر کیانا، تهران، (1383).

5. Gladman, T., "The Physical Metallurgy of Microalloyed Steels", Institute of Materials, London, pp. 175-193, (1997).

6. سبک روح، مجید، "بررسی علل ترک‌خوردگی جوش در لوله‌های حامل سیال"، پایان‌نامه‌ی کارشناسی ارشد، دانشکده‌ی مکانیک، دانشگاه مازندران، (1387).

7. "Guide to methods for assessing the acceptability of flaws in metallic structures" British Standards Institution, BS7910, (2001).

8. فراهانی، محمدرضا، "بررسی طراحی اتصال جوش بر بزرگی و توزیع تنش‌های پسماند"، پایان‌نامه‌ی ‌کارشناسی ارشد، دانشکده‌ی مکانیک، دانشگاه صنعتی امیرکبیر، تهران، (1385).

9. Bouchard, R.P.J., "Validated residual stress profiles for fracture assessments of stainless steel pipe girth welds", International Journal of Pressure Vessels and Piping, Vol.84, 195-222, (2007).

10. Leggatt, R.H., "Residual stresses in welded structures", International Journal of Pressure Vessels and Piping, Vol.85, 144-151, (2008).

11. Kandil, F., Lord, J., Fry, A., Grant, P., "Measurement of residual stress in components, a review of residual stress measurement methods", NPL Report, pp. 23-37, (2001).

12. "Handbook of Measurement of Residual Stress", Society for Experimental Mechanics, 1st edition, 2-7, (1996).

13. Sattari-Far, I., Farahani, M.R., "Effect of the weld groove shape and pass number on residual stresses in butt-welded pipes", International Journal of Pressure Vessels and Piping, Vol. 86, pp. 723-731, (2009).

14. Ruibin, G., Yiliang, Z., Xuedong, X., Liang, S., Yong, Y., "Residual stress measurement of new and in-service X70 pipelines by x-ray diffraction method", NDT&E International, Vol. 44, pp. 397-393, (2011).

15. Paddea, S., Francis, J.A., Paradowska, A.M., Bouchard, R.P.J., Shibli, I.A., "Residual stress distributions in a P91 steel-pipe girth weld before and after post weld heat treatment", Materials Science and Engineering, Vol. 534, pp. 663-672, (2012).

16. "Determining Residual Stresses by the Hole-Drilling Strain-Gage Method", ASTM Standard E 837 , (2003).

17. "Measurement of Residual Stresses by the Hole-Drilling Strain Gage Method", Tech Note TN-503503, Micro-Measurements, 19-33, (2010).

18. فروزان، محمدرضا، حیدری، علی، گلستانه، سیدجعفر، "شبیه‌سازی اجزای محدود فرآیند جوشکاری زیرپودری لوله‌های API 5L-X70 با درز جوش مستقیم مورد استفاده در صنایع نفت و گاز"، استقلال، اصفهان، شماره 1، صفحه 93-110، (1388).