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大量实验证明,铸态组织中二次枝晶臂距主要受冷却速度或凝固时间的影响。本文对FGH95和Rene’95氩气雾化的、不同粒度级的粉末颗粒测定了二次枝晶臂距,计算了冷却速度(?)、完成凝的固时间tf、凝固速度R及固—液界面前沿温度梯度G。结果表明:两种粉末粒度在-60—+320目范围内冷却速度为10~3-10~4℃/s,凝固时间为10~(-1)—10~(-2)s。随着粉末颗粒减小,冷却速度增加,G/R值增大,粉末颗粒的凝固从以树枝晶为主的方式逐渐转变成以胞状晶为主的方式,用G/R值来判断凝固组织中的碳化物形态不是唯一因素。
A large number of experiments show that the secondary dendrite arm in the as-cast microstructure is mainly affected by the cooling rate or the setting time. In this paper, the secondary dendrite arm spacing was measured on argon atomized FGH95 and Rene’95 powder particles with different particle sizes. The cooling rate (?), The solidified time tf, the solidification rate R and the solid-liquid Interface front temperature gradient G The results show that the cooling rate of the two powders is 10 ~ 3-10 ~ 4 ℃ / s in the range of -60 ~ + 320 meshes and the solidification time is 10 ~ (-1) -10 ~ (-2) s. With the reduction of the powder particles, the cooling rate increases and the G / R value increases. The solidification of the powder particles gradually changes from dendrite-based to cell-crystal-based, and the G / R value determines the solidified structure The carbide morphology in is not the only factor.