大型低压转子FM法锻造工艺模拟研究

百万千瓦核反应堆中汽轮机低压转子锻件是目前世界上所需制造的最大锻件,需采用600 t级钢锭直接锻造成形.根据成形特点和需要,采用物理模拟的方法,研究了FM法锻造成形工艺,建议采用砧宽比为0.6左右,压下率为15%.FM法压下时试件表面存在产生裂纹的倾向,合理选择凸型砧角度可减弱表面裂纹的产生,角度选择8°左右效果较好.研究了拔长时坯料形状及多工序连砧拔长的影响作用,为最终生产工艺的制定提供理论指导.

Modeling research on FM forging process of heavy low-pressure turbine rotor

The low-pressure turbine rotor in 1000 MW-class nuclear power plant is presently the largest forging in the world. It should be forged by ingot of 600 t. According to the rotor's forming specialty, its forging process using FM method was studied by physical modeling. W/H ratio about 0.6 and reduction ratio as 15% were suggested. Cracks on billet's surface were revealed. Proper angle about 8° of protuberant anvil to reduce crack impact, billet shape and multi-path drawing process were researched. The results provide a theoretical guidance for practical manufacture process.