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

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Different methods and techniques for the determination of the individual weld joint properties were used for characterization of weld joint properties, such as:  tensile test,  Charpy impact test,  fracture mechanics SENB test. Tensile tests : Geometry of the tensile specimens, which were machined from weld joint and base material is exposed in Fig.4. Tensile tests were carried out according to EN ISO 6892-1 standard. The AMSLER 599/594 servo hydraulic machine, with capacity of 200 kN, was used for testing.

Fig. 4. Geometry of the tensile specimen Instrumented Charpy impact tests: Geometry and shape of the reduced Charpy specimen are presented in Fig. 5. The standardized 2 mm deep ISO-V notch, with the radius of the 0.25 mm, was used as a stress concentrator during the Charpy impact tests. Instrumented impact tests were performed according to EN ISO 148-1 and ASTM E2290-15 standards. Energy for fracture was divided into the energy for initiation and the energy for propagation of the crack from ISO-V-notch stress concentrator. Force versus time diagrams were recorded during the tests. The Charpy specimens with ISO-V notch located on different regions in the weld joint were used in this investigation, such as weld metal (WM) and heat-affect zone HAZ. Fracture mechanics tests: Single edge notch bend specimens (SENB) were machined from the weld metal according to ASTM E1820-15a standard. The shape and geometry of the specimen are presented in Fig. 6. Fatigue pre- crack was done by using “Rumul Cractronic” machine (Fig. 7). Fatigue pre -crack was done by load ratio R = 0.1. Testing and evaluation of the results of the SENB specimens were perform on the SMITWELD 1405 tensile machine unit (Fig. 8). Marking of the stable crack propagation was carried out by fatigue, using load ratio R = 0.7 and load level 0.5  F max , where F max is maximal force obtained during the SENB test.

Fig. 5. Geometry of the Charpy specimen

Fig. 6. Geometry of the SENB specimen