Almalyk branch of the National University of Science and Technology "MISiS", Almalyk, Republic of Uzbekistan:

E. S. Nabiev, Cand. Eng., Associate Prof., Dept. of Metallurgy, e- mail: nes.2406@mail.ru
S. K. Kakhkharov, Cand. Eng., Associate Prof., Head of the Mining Dept.

The issues of structure formation in a multilayer metal deposited by a multi-electrode method with PP-Np-25Kh5FMS wire on 9KhV steel with reduced welding characteristics are considered. It is established that the deposited metal consists of martensite, austenite and a small amount of bainite. Intensive grain growth in the near-weld zone of three-layer surfacing is not observed. The average hardness of the top layer beads is 5,400 MPa, which corresponds to the hardness of the metal deposited with PP-Np-25Kh5FMS wire. In the heat affected zone, the same structural components are preserved as in the deposited metal. Optimally selected technological parameters of surfacing, temperature conditions of preliminary and concomitant heating, as well as heat treatment after surfacing made it possible to avoid macro- and microcracks in the near-weld zone. The results obtained can be used in the development of technology for multi-electrode surfacing of rolling mill rolls.

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