The Influence of Electron Beam Oscillation on the Crystallization and Structure of Dissimilar Steel-Bronze Welds

Abstract

The paper contains the findings of the metallographic study of dissimilar metal welds (steel 12Х21Н5Т and bronze BrХ-06) made by electron-beam welding (EBW) with beam modulation (transversal and X-shaped oscillation with triple beam splitting). The research shows that beam oscillation causes the metals to stir in the weld pool. As a result, welds have a very heterogeneous structure by width. X-shaped oscillation causes more intensive stirring than transversal oscillation. This leads to more homogenous stirring of crystallizing phases in the centre of the weld. The heterogeneous structure caused by beam oscillation gives the weld a very heterogeneous solidity both by width and depth. Triple beam splitting heated from bronze promotes the homogenous weld structure which is a fine-dispersed mechanical mixture of two systems: a eutectic based on copper and a mixture of solid solutions based on [alpha]-Fe and [gamma]-Fe. Such a structure makes the weld equalizes the solidity of the weld both by width and depth.

"Investigation of the influence of low-frequency harmonic oscillations on deposited metal "

“…Over recent years quite a large number of works have been devoted to the investigation of microstructure formation under the conditions of periodic impact. This impact of the generator of oscillations or vibrations is most often imparted to weld pool melt by welding current [4][5][6], magnetic field [7,8], laser and electron beam [9][10][11][12][13][14][15][16], as well as the weld pool or tool [17][18][19][20][21][22][23][24]. Here, the respective increase of the degree of deposited metal microstructure dispersivity, compared to samples produced without peri-*Corresponding author: e-mail address: novykov76@ukr.net odic impact, essentially improves such service properties of the welded joint as-deposited metal hardness [4,11,13,19,22,24], wear resistance [5], impact toughness [4,20,24], brittle fracture resistance [4], and tensile strength [4,8,11,14,17,18,21,24].…”

“…This impact of the generator of oscillations or vibrations is most often imparted to weld pool melt by welding current [4][5][6], magnetic field [7,8], laser and electron beam [9][10][11][12][13][14][15][16], as well as the weld pool or tool [17][18][19][20][21][22][23][24]. Here, the respective increase of the degree of deposited metal microstructure dispersivity, compared to samples produced without peri-*Corresponding author: e-mail address: novykov76@ukr.net odic impact, essentially improves such service properties of the welded joint as-deposited metal hardness [4,11,13,19,22,24], wear resistance [5], impact toughness [4,20,24], brittle fracture resistance [4], and tensile strength [4,8,11,14,17,18,21,24]. Proceeding from the analysis of the data of these works, it can be roughly considered that the frequency range in modern studies is usually within 10 Hz [5]-27 kHz [24], that of amplitudes -6 µm [24] -0.5-2 mm [8,…”