Актуальные проблемы в машиностроении том 4 №4

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Актуальные проблемы в машиностроении. Том 4. № 4. 2017 Технологическое оборудование,
оснастка и инструменты
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THE REASON AND PREVENTION OF BOUNCE SPINDLES WELDED
SCREW-STEERING COLUMNS
Tokarev A.O., (Engineering), Professor, e-mail:
Mironenko I.G., (Engineering), Professor, e-mail:
Fedotova E.S., Ph.D. student, e-mail:
Siberian State University of Water Transport, 33 Schetinkina st., Novosibirsk, 630099, Russian
Federation
Abstract
In this work the analysis of the reasons for frequent breakdowns hollow, assembled by welding
shafts – ballers serving to rotate the nozzle propeller - steering ship "Balt Fleet".
The baller consists of a middle part made of seamless pipe, laminated steel 35 (0,32 – 0,39%
carbon). At the end of the hollow shaft are wear resistant slot bushings, welded butt joints. The ma-
terial of bushing – alloy steel 42 Cr Mo (С - 0,38 – 0,45%; Si - 0,17 – 0,37%; Mn - 0,50 – 0,80%;
Cr - 0,90 – 1,20%; Mo - 0,15 – 0,25%).
It is established that the damage was due to faulty fusion of the weld with the base metal. A con-
tributing factor to the propagation of cracks that caused the lack of penetration, it was the presence
of hardening structures in the heat affected zone of the weld. Cracks occurred on the surfaces of the
cutting of the weld extend in the direction of greatest mechanical stress along the boundaries of
dendrite grains of the welding. Proposed measures to address faulty fusion, is the welding of the
hollow shaft in a pre-heated condition and subsequent annealing.
Keywords
propeller – steering column (PSC), vertical shaft, crash, hairline fracture, weld seam,
microstructure, heat-affected zone