Special features of the formation of the composition, structure and properties of the metal deposited with the Sv-MNZhMtsTK 40-1-1-0.3-0.1 wire on BrA9Zh4N4Mts1 bronze

Selected from Svarochnoe Proizvodstvo 2017(2) 3–8

Abstract

The problem of increasing the service life of fittings made of bronzes of the BrA9Zh4N4Mts1 type is very urgent. The service life of the fittings can be doubled or increased even more by depositing sealing layers with corrosion-resisting copper–nickel alloys with more than 30% nickel. The results of investigations of the special features of the formation of the composition, structure and properties and cracking resistance of the metal, deposited with a new copper-nickel welding wire with 40% nickel of the Sv-MNZhMtsTK 40-1-1-0.3-0.1 grade on the BrA9Zh4N4Mts1 bronze are presented. In depositing the BrA9Zh4N4Mts1 wire on the BrA9Zh4N4Mts1 bronze, the deposited metal shows the formation of the Ni₃Al intermetallic phase which supports the formation of cracks in the deposited metal. The experimental results show that at the aluminium content not higher than 1.5% the intermetallic phase and cracks do not form in the deposited metal. To ensure that the aluminium content of the deposited metal is not higher than 1.5% it is recommended to deposit a sublayer with the MNZhKT 5-1-0.2-0.2 wire on the bronze. The deposited metal is a solid solution of nickel, manganese and other elements of the copper-nickel alloy in copper with the crystal lattice parameter 3.661–3.666 Å. The strength of the welded joint between the BrA9Zh4N4Mts1 bronze and the metal deposited with the Sv-MNZhMtsTK 40-1-1-0.3-0.1 wire is in the range from 356 to 406 MPa, which is similar to the strength of the MNZhMtsTK 40-1-1-0.3-0.1 alloy (≥350 MPa).

Keywords:

• Ship fittings
• argon arc deposition
• corrosion-resistant copper–nickel alloy
• aluminium bronze
• intermetallic compounds
• fracture strength
• sublayer
• quality
• mechanical properties

Notes

Selected from Svarochnoe Proizvodstvo 2017(2) 3–8