| 摘要 |
The present invention discloses a process for a steel piece manufacturing for forged pieces manufacturing having a bainitic structure, characterized in that: a fragment is heated at a T1 heating temperature comprised between 1,000 degree C and 1,320 degree C and it is forged, hammered being finished at a T2 temperature, T1 heating temperature being chosen so that, at T2 temperature, content in Bnc non combined boron is superior or equal to 0,0005 percent - piece is cooled directly after forging up to room temperature, in such a way that, in every part of the piece, piece cooling mean speed between T2 temperature and 100 degree C is superior to 14 degree C/s and, preferably, inferior than 250 degree C/s. |
