PSI - Issue 81

Anatolii Babinets et al. / Procedia Structural Integrity 81 (2026) 353–359

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is explained by a higher packing density and greater homogeneity of the core, formed from particles of similar and relatively small size compared to specimens deposited with MPWs of standard granulometric composition. The improved structure of the core in MPW No. 5 ensures a reduction in the coefficients of current and voltage variation, which positively affects arc stability and contributes to increased melting and deposition coefficients, while simultaneously reducing the loss coefficient.

Fig. 2. Appearance of the ground surfaces of the deposited specimens at boron content: 1 – without additives; 2 and 5 – 0.01%; 3 – 0.02%; 4 – 0.05%. Powder granulometry: 1 – 4 – 50 –300 µm; 5 – 50 –100 µm .

Fig. 3. Transverse macrosections of the deposited specimens at B content: 1 – without additives; 2 and 5 – 0.01%; 3 – 0.02%; 4 – 0.05%. Powder granulometry: 1 – 4 – 50 –300 µm; 5 – 50 –100 µm.

Table 2. Comparative assessment of the welding and technological properties of experimental MPWs

Coefficients, %

Quality of deposited metal formation

Quality of slag crust removal

Type of MPW core: additive content, particle size

Arc ignition behavior

Presence of defects

Total score

No

Current variation

Voltage variation

Melting Deposition Losses

Reference: without additives, 50…300 µm

2

2

2

1

7

16.2

15.1

6.8

15.2

7.6

1

2 0. 01 % B, 50…300 µm 3 0. 02 % B, 50…300 µm 4 0. 05 % B, 50…300 µm 5 0. 01 % B, 50…100 µm

2 2 2 2

2 2 2 2

2 0 0 2

1 1 1 1

7 5 5 7

16.0 16.2 16.1 17.5

14.9 15.2 15.0 16.7

6.9 6.2 6.8 4.6

15.7 15.1 15.3

7.5 7.5 7.6 4.5

8.8

Metallographic studies of the deposited metal obtained using experimental MPWs (Fig. 4) showed the absence of defects near the fusion line between the deposited and base metal in specimens No. 1 (without B) and Nos. 2 and 5 (0.01% B). In specimens Nos. 3 and 4, a significant number of microcracks were detected, which are mainly localized at grain boundaries and propagate into the depth of the deposited metal. With an increase in boron concentration, both the number and size of the cracks also increase. The structure shows rounded inclusions within the crystallites, which are likely borocarbides; their quantity also increases with higher boron content.