肖强
机械工程材料
doi:10.11973/jxgccl201604016
采用DEFORM-3D有限元软件模拟了2Cr18Ni8W2不锈钢在两种精锻工艺下的温度和等效应变分布,分析了工艺条件对精锻过程中温度场和应变场的影响,并进行了试验验证.结果表明:采用优化工艺条件锻造时钢坯表面及内部温度均比现场工艺条件下的低,其内部应变分布也比现场工艺条件下的均匀;在精锻过程中增加倒数第二道次的变形量会导致锻造后的钢坯内部应变分布的不均匀性,造成晶粒大小不均,从而引起探伤误报警;采用优化工艺条件锻造后的圆棒经探伤完全合格,其组织均匀,在等轴晶的内部出现大量的形变孪晶.
关键词:
精锻
,
2Cr18Ni8W2不锈钢
,
温度场
,
应变场
,
有限元
张琦
,
梁正龙
,
曹苗
,
刘梓璠
,
张安峰
,
卢秉恒
中国有色金属学报(英文版)
doi:10.1016/S1003-6326(17)60121-3
为提高合金的力学性能,在温度950℃不同应变和应变速率条件下对SLM成形的Ti6Al4V合金试样进行精密锻造处理,使用光学显微镜和X射线衍射仪分析原试样和锻造处理试样在水平和竖直截面内显微组织的演化,并计算了每个截面的孔隙率.结果表明,大应变速率以及大变形量可以改善显微组织并降低孔隙率,进而提高材料的疲劳性能.精密锻造处理后的试样显微硬度小于SLM成形原件的显微硬度;同时,精密锻造处理试样在水平截面和竖直截面的显微硬度差小于SLM成形原件在两个截面的显微硬度差.这说明精密锻造工艺可以改善SLM成形零件的各向异性.
关键词:
选择性激光熔覆
,
Ti6Al4V合金
,
精密锻造
,
显微组织
,
各向异性
Y.L. Liu
,
H. Yang
,
T. Gao
,
M. Zhan
,
W. Cai
金属学报(英文版)
The blade precision forging process is a forming process with high temperature and large plastic deformation. Interaction of deformation and heat conduction leads to large uneven distribution of temperature. The unevenness of temperature distribution has a great effect on mechanical properties and the microstructure of materials. So it is necessary to consider the influence of temperature on the precision forging process of blades. Taking a blade with a tenon into consideration, a 3D mechanical model in precision forging is built up. The distribution laws of temperature field and the influence of the temperature on the equivalent stress in the process are obtained by using 3-D coupled thermo-mechanical FEM code developed by the authors. The results obtained illustrate that the influence of the temperature field on the blade forging process is considerable. The achievements of predicting microstructure and mechanical properties for forged blades is significant.
关键词:
blade with a tenon
,
null
,
null
