| 摘要 |
The invention relates to a process for manufacturing a pole piece which is a component of an alternator equipping a motor vehicle. According to the invention, the process comprises the hot forging of a steel piece in a die similar to the final shape of the piece to be obtained, said step including the use of a half- core and a plurality of circumferentially spaced spurs, the obtained piece being treated in a phosphating bath for lubricating its external surfaces, followed by cold processing the piece in order to obtain a flattened granulitic structure of the piece, while maintaining the shape of the piece subjected to this treatment, then hardening the half-core and spur surfaces and forming a central orifice threrethrough, this forming step including the extrusion through a restrictive orifice and bending the spurs to their final shape, thereby producing the third shape of pieces, followed by treating the piece in this mould in a strongly basic bath having the pH equal to 14, annealing the piece at a temperature of 800 ... 900 degree C, for 20-60 minutes and gradually cooling to the environment temperature in 270 ... 310 minutes. |
