PSI - Issue 59

T. Maydanchuk et al. / Procedia Structural Integrity 59 (2024) 399–406 403 T. Maydanchuk, Y. Lukianchenko, S. Kozulin, V. Porohonko, S. Marynenko / Structural Integrity Procedia 00 (2019) 000 – 000 5 The analysis of the obtained results reveals the following: - When using CuNiFeSiTi filler wire (a), pores are absent. However, undercut is present. - When using CuZn37 filler wire (Fig. 5 (b), Fig. 4 (b)), isolated pores are present throughout the length of the weld. Dark spots at the end and middle of the weld indicate incomplete edge fusion (undercut). The weld is uneven and shows unsatisfactory weld formation. - When using CuSn4Zn3 filler wire (c), pores are absent in the weld. - When using CuSi3Mn1 filler wire (d), there are two groups of small chain-like pores at distances of 25 mm and 55 mm from the start of the weld, as well as occasional small isolated pores along the entire length of the weld. The weld formation is satisfactory. Overall, the assessment of weld quality results is provided in Table 3.

Table 3. Quality results of welding Parameters

Welding Materials CuNiFeSiTi

CuSi3Mn1

CuSn4Zn3

CuZn37

Direct

Direct Good

Direct

Direct

Current type

Weld Formation Macrostructure Presence of Pores

Satisfactory Fine-grained

Satisfactory

Unsatisfactory Coarse-grained

Coarse-grained Chain-like pores

Coarse-grained

None

None

Multiple isolated pores

Microhardness measurements were conducted across the welds using the Rockwell method. The results of micro hardness measurements at various distances from the weld centerline are presented in Fig. 5. The conducted microhardness measurements of the welds and the heat-affected zone showed significant hardening, resulting from the thermal influence of the welding process on the cold-rolled CuZn37 brass. Unsatisfactory microhardness values were obtained on samples where CuSi3Mn1 and CuZn37 wires were used, with a percentage decrease in microhardness values of 47% and 66.6% respectively. On samples where CuSn4Zn3 and CuNiFeSiTi wires were used, the percentage decrease in micro hardness values of the welds and the adjacent zone was 33% and 44% respectively. Other results of the physical and mechanical investigations of the welds, with the cutting scheme depicted in Fig. 2, are presented in Table 4.

Table 4. Physical and mechanical investigations of the welds Parameters

Welding Materials

CuNiFeSiTi

CuSi3Mn1 180 0 -180 0 180 0 315-347 332 50.7-60.0 56.0 26.0-33.0 30.0

CuSn4Zn3 180 0 -180 0 180 0 318-338 324 47.0-7.0 57.0 33.5-42.5 38.0

CuZn37 50 0 -180 0 99 0 144-244 200

180 0 -180 0 180 0 307-315 311 42.0-52.0 57.0 29.0-34.0 32.0

Bending Test, 0°

Tensile Strength, σ, MPa

Elongation, ε, %

43.0

18.0-20.0 19.0

Microhardness, HRA

Hardness Reduction Compared to Base Metal, %

44.0

47.0

33.3

66.6

As seen from Table 4, all the welds passed the 180° bending test except for the one where CuZn37 wire was used as the welding material. The tensile strength ( σ v , MPa) and elongation ( ε , %) values are relatively similar and range from 307 to 315 MPa and 56 to 57%, respectively, when CuNiFeSiTi, CuSn4Zn3, and CuSi3Mn1 wires were used. Lower values were obtained when CuZn37 wire was used.