PSI - Issue 59

T. Maydanchuk et al. / Procedia Structural Integrity 59 (2024) 399–406 401 T. Maydanchuk, Y. Lukianchenko, S. Kozulin, V. Porohonko, S. Marynenko / Structural Integrity Procedia 00 (2019) 000 – 000 3 Before welding, the edges of the base metal and filler wire were degreased using organic solvents such as acetone and methyl alcohol. The samples were welded pairwise in a butt joint configuration with the edges prepared at a 90° angle without any chamfering (Fig. 1a). The samples for welding were assembled in special equipment that ensured their rigid fixation and tight clamping against a graphite backing (Fig. 1b). Welding was performed from both sides using short beads measuring 50-60 mm.

1. Fixture base 2. Graphite lining 3. Clamps 4. Brass plates

b

а

Fig. 1. (a) Scheme of edge preparation; (b) fixture for sample fixation.

The presence of pores and macrostructure was visually determined at 5-7 times magnification using a MIM-7 microscope. Microstructure analysis was conducted using light microscopy methods (Neophot-32 and Versamet-2 microscopes, Japan) at magnifications of x90, x140, x200, and x400. Hardness testing was performed using a Super Rockwell HRSD-3 hardness tester (MICROTECH, Ukraine) with a 150 H load applied to a diamond pyramid. Mechanical properties of the welded joint were also evaluated, including tensile strength ( σ v , MPa), elongation ( ε , %), and bend testing (°). Three samples were taken for each test, as shown in Fig . 2. Additionally, three samples were extracted for metallographic examinations and micro hardness testing (Fig. 2b).

Fig. 2. (a) General layout of the samples; (b) sample for metallographic examinations and microhardness determination; (c) tensile sample; (d) bend testing sample.