AP1000核电站主管道用316LN超低碳控氮奥氏体不锈钢锻造温度区间窄、变形抗力大,锻造过程中容易开裂,尤其发生在侧表面鼓肚部位。研究了316LN不锈钢大型钢锭的镦粗工艺,利用Deform-3D软件获得了锻件侧表面的最大损伤值,并将其与相应条件下的临界损伤值做了对比。结果表明,始锻温度为900℃时不会发生开裂,温度越高,可选择的工艺参数范围越小。当应变速率约为0.02 s-1时,锻件侧表面更易发生开裂。 AP1000 nuclear power plant main channel with 316LN ultra-low carbon nitrogen-austenitic stainless steel forging temperature range narrow, large deformation resistance, forging process easy to crack, especially in the side surface bulging parts. The upsetting process of 316LN stainless steel ingot was studied. The maximum damage value of the forging side surface was obtained by Deform-3D software and compared with the critical damage value under the corresponding conditions. The results show that the initial forging temperature of 900 ℃ does not occur cracking, the higher the temperature, the smaller the range of optional process parameters. When the strain rate is about 0.02 s-1, the forging side surface is more prone to cracking.