Abstract: In this paper, the structural integrity of welded specimens is assessed. The specimens were welded using a conventional technique, MAG, and an unconventional one, laser technology. Welded specimens were of the central crack under tension (CCT) type. The elements were loaded, the maximum load was recorded, and the second and the third options of the FITNET procedure were utilized to estimate the critical loading. Estimated and recorded loads were compared to verify the conservatism of the estimated results. For comparison, the results obtained using Option 1 of the FITNET procedure (not recommended in the case analysed) are also presented. Results of the mechanical properties, hardness, fracture toughness for the base and the weld material and residual stress distributions are reported for both MAG and laser welding techniques. The results obtained confirm that the FITNET procedures were properly deigned. The higher the level of analysis, the smaller the conservatism of predictions observed. The overconservative conclusions, following from the lower level of analysis, suggest that the structural element is endangered, do not have to exclude it from exploitation. The higher level of analysis can, in some cases, confirm that the structural element containing a crack can still be exploited.
B I B L I O G R A F I A1. Blogdett, O.W., "Design of welding structures", 1991
2. Pan, J.L.& Zhang, R.H.& Wu, Z.O.& Chen, Q., "Adaptive control of MIG/MAG welding-feedback system for weld penetration control", Int Inst Weld, vol. 7, 1988
3. Teng, T.L.& Lin, C.C., "Effect of welding conditions on residual stresses due to but welds", Int J Pressure Vessels Piping, vol. 75, 1998, p.857-864
4. Ferenc, K.& Ferenc, J., "Spawalnicze gazy osłonowe i palne", 2005, [in Polish]
5. Kusiński, J., "Lasery i ich zastosowanie w inżynierii materiałowej", 2000, [in Polish]
6. Arai, Y.& Kikuchi, M.& Watanabe, T.& Nakagaki, M., "Residual stress due to welding and its effect on the assessment of cracks near the weld interface", Int J Pressure Vessels Piping, vol. 63, 1995, p.237-248
7. British Standard BS 7910. Guide on methods for assessing the acceptability of flaws in metallic structures, 2005.
8. R6, "Assessment of the integrity of structures containing defects, rev. 4", 2001
9. American Petroleum Institute, API 579: Recommended practice for fitness-for-service. Washington, DC, 2000.
10. SINTAP: Structural integrity assessment procedures for European industry. Final procedure, Brite-Euram Project No BE95-1426. Rotherham: British Steel
1999.
11. FINTET fitness for service (FFS) procedure-final draft, 2006.
12. Neimitz, A., "The strength assessment of the structural elements containing cracks (the basic elements of the SINTAP Procedures)", 2004, [in Polish]
13. Standard test method for determination of reference temperature, T0, for ferritic steels in the transition range. ASTM E1921-03, 2003.
14. E 1820-05 standard test method for measurement of fracture toughness. ASTM, 2005.
15. PN-EN 10002-1+AC1. Metallic materials. Tensile testing. Part 1: method of test at ambient temperature, 1998.
16. Skrzypek, S.J., "New methodological approach in surface residual stress examinations", Inżynieria Mater, vol. 4, 1998, p.1035-1038
17. Skrzypek, S.J., "Makronaprężenia własne cienkich warstw-pomiar metodą g-sin2ψ w nowej geometrii dyfrakcji przy stałym kącie padania", Inżynieria Powierzchni, vol. 2, 2001, p.47-55, [in Polish]
18. Skrzypek, S.J.& Baczmański, A., "Progress in X-ray diffraction of residual macro-stresses determination related to surface layer gradients and anisotropy", Adv X ray Anal, vol. 44, 2001, p.134-145
19. Price, J.W.H.& Paradowska, A.& Joshi, S.& Finlayson, T., "Residual stress measurement by neutron diffraction and theoretical estimation in single weld bead", Int J Pressure Vessels Piping, vol. 83, 2006, p.381-387
20. Dzioba, I.& Skrzypczyk, A., "Properties and microstructure of MAG butt-welded joints for 18G2A steel", Welded Rev (Przegląd Spawalnictwa), vol. 9-10, 2006, p.32-35, [in Polish]
21. Dzioba, I., "The strength analysis of welded joint elements containing cracks according to SINTAP/FITNET procedure", Mech Rev (Przegląd Mechaniczny), vol. 6, 2006, p.14-22, [in Polish] 
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