Comparison of different methods to estimate the fracture toughness of metal of welded structure operated in Arctic conditions

Comparison of different methods to estimate the fracture toughness of metal of welded structure operated in Arctic conditions

Authors: A.V. llyin, V.Yu. Filin, D.M. Artemiev 
Abstract

Fracture toughness of the metal of welded joints is determined as per the Register rules with specimens of particular types (rectangular SENB, C(T)) in full thickness providing for a high constraint in a crack tip. For test temperatures below — 40 °C a high data scatter is observed, fracture toughness values often do not meet the requirements. The problem of excessive conservatism of test conditions in comparison to loading of a crack-like flaw containing structure is actively discussed abroad owing to the forthcoming revision of ISO standards for Arctic materials. The test results are compared and brittle fracture conditions for different specimen types are analyzed, including specimens with simulated welding heat. 
Key words: fracture toughness tests, Arc-steels, welded joints, SENT.

References

1. Rossijskij morskoj registr sudohodstva. Pravila klassifikacii i postrojki morskih sudov. SPb, 2015.
2. Rossijskij morskoj registr sudohodstva. Pravila klassifikacii, postrojki i oborudovanija PBU i MSP. SPb, 2014.
3. ASTM E 399 - 09. Standard Test Method for Plain-Strain Fracture Toughness of Metallic Materials
4. BS 7448 Fracture Mechanics Toughness Test. Part 1. Method for determination of K1c, critical STOD and critical J - values of metallic materials, 1991
5. GOST 25.506-85 Metody mehanicheskih ispytanij metallov. Opredelenie harakteristik treshhinostojkosti (vjazkosti razrushenija) pri staticheskom nagruzhenii. M: Izd-vo standartov, 1985. - 18 s.
6. Vinogradov O.P., Il'in A.V., Filin V.Ju. Nauchno-metodicheskie voprosy attestacionnyh ispytanij na treshhinostojkost' strukturno-neodnorodnogo metalla svarnyh soedinenij. Voprosy materialovedenija, 2004 g., № 1(37), str. 75 -89.
7. Gorynin I.V., Il'in A.V., Leonov V.P., Malyshevskij V.A. Sovershenstvovanie trebovanij k materialam dlja LSBU na osnove podhodov mehaniki razrushenija. Rossijskij Morskoj Registr Sudohodstva, nauchno-tehnicheskij sbornik, No 23, 2000 g, s 93-113.
8. Horn A.M., Hauge M. Material Challenges for Arctic Offshore Applications, a Reliability Study of Fracture of a Welded Steel Plate Based on Material Toughness Data at -60°C . Proceedings of the Twenty-first (2011) International Offshore and Polar Engineering Conference, Maui, Hawaii, USA, June 19-24, 2011.
9. Hauge M. Arctic Offshore Materials and Platform Winterization. Proceedings of the Twenty-second (2012) International Offshore and Polar Engineering Conference, Rhodes, Greece, June 17–22, 2012.
10 . Il'in A.V., Mizeckij A.V., Filin V.Ju. K opisaniju masshtabnogo jeffekta pri ispytanijah na treshhinostojkost' na osnove modificirovannogo podhoda Griffitsa.- Voprosy materialovedenija, № 1(41), 2005 g, s 55-69.
11. Larsson S.G, Carlsson A.J. Influence of non-singular stress terms and specimen geometry on small-scale yielding. J Mech Phys Solids 1973;21:263–77.
12. Du ZZ, Hancock JW. The effect of non-singular stresses on crack-tip constraint. J Mech Phys Solids 1991;39:555–67.
13. O_Dowd NP, Shih CF. Family of crack-tip fields characterised by a triaxility parameter: Part I––Structure of fields. J Mech Phys. Solids 1991;39:989–1015.
14. Beremin F.M. A local criterion for cleavage fracture of a nuclear pressure vessel steel// Metallurgical Transactions A, 14A (1983), P 2277 – 2287.
15. M. Kroon, J.Faleskof A probablistic model for cleavage fracture with a length scale-influence of material parameters and constraint// Int. Journ. of Fracture, 118, 2002, P 99 -118.
16. Thaulow C., Ostby E., Nyhus B., Zhang Zh., Skallerud B. Constraint correction of high strength steel. Selection of test specimens and application of direct calculations/ Eng. Fract. Mech., 71 (2004), 2417 – 2433. 



About authors

Ilyin Aleksey - DSc, FSUE "Central Research Institute of Structural Materials "Prometey, St. Petersburg " 
mail@crism.ru


Filin Vladimir - PhD, FSUE "Central Research Institute of Structural Materials "Prometey", St. Petersburg 


Artemiev  D.M. - FSUE "Central Research Institute of Structural Materials "Prometey", St. Petersburg 



Issue: 40/41 (2015)






For citation: A.V. llyin, V.Yu. Filin, D.M. Artemiev. Comparison of different methods to estimate the fracture toughness of metal of welded structure operated in Arctic conditions. Research Bulletin by Russiann Maritime Register of Shipping. 2015, No. 40/41, pp. 62-71.


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UDC:  669.14:620.17:539.4
Pages:  62 - 71