PSI - Issue 13

Luka Grubiša et al. / Procedia Structural Integrity 13 (2018) 430–437 Luka Grubiša, Darko Bajić, Tomaž Vuherer / Structural Integrity Procedia 00 (2018) 000 – 000

437

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Table 6. Results of SENB tests Location

K Q (MPa m

J Q (KJ/m

2 )

0.5 )

 Q (mm)

SENB-WM

99.25

0.301

112.05

SENB-HAZ

127

0.342

126.96

The appearance of the fracture surfaces of the SENB specimens after testing is presented in Fig. 15 and Fig. 16, for weld metal and HAZ microstructure as well.

Fig. 15. The fracture surfaces of the weld metal; SENB-WM

Fig. 16. The fracture surface of HAZ; SENB-HAZ

6. Conclusion

Tensile testing shows that the welded joint has high mechanical properties parameters. The breakage of the specimen occurred in the HAZ zone. The tensile strength of the welded joint (600 MPa) is slightly higher than the BM tensile strength (594 MPa). The elongation of the welded joint is only 27.2% in comparison to base material where elongation was 56.1%. This means that the elongation in base material is higher for more than 55% in comparison to elongation of welded joint. Total energy for fracture, energy for initiation and energy for propagation are relatively high in weld metal. The energy for initiation is about 40% and the energy for propagation is 60% of the total energy for fracture. In HAZ microstructure the ratio between the energy for initiation and the total energy for fracture is close to 50%. The results of the fracture mechanics tests point out a high degree of resistance to fracture of the WM and HAZ microstructure. Acknowledgements This contribution is the result Project No. BI-BA/16-17-011of the bilateral sciences and technology cooperation between Montenegro and Republic of Slovenia: TIG and Plasma Arc Welding of High Alloy Cr-Ni Austenitic Steels and Pearlitic Steels by Using Activating Fluxes. Bajić, D. , 2003. Investigation of the possibility of welding energy equipment sets using an activating fluxes, doctoral thesis, University of Montenegro, Faculty of Metallurgy and Technology, Department of Physical metallurgy, Podgorica, 140. Xu Y.L., Dong Z.B., Wei Y.H., Yang C.L., 2007. Marangoni convection and weld shape variation in A-TIG welding process, Theoretical and Applied Fracture Mechanics, Volume 48, Issue 2, 178-186. Tseng, Kuang-Hung; Hsu, Chih-Yu, 2011. Performance of activated TIG process in austenitic stainless steel welds, Journal of Materials Processing Technology, 211, 503 – 512. Fekonja L. 2016. Influence of active powder on weld penetration on stainless steel by plasma welding, master thesis, University of Maribor, Faculty of Mechanical Engineering, Maribor, 25-39. References