Effects of multiple reductions on grain refinement during hot working of alloy 718
Effects of multiple reductions on grain refinement during hot working of alloy 718
复制标题
多次还原对718合金热加工晶粒细化的影响
DOI：
10.7449/1989/superalloys_1989_155_178
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
D. Matlock
中科院分区：
文献类型：
--
作者：
M. Mataya;D. Matlock
通过对一根晶粒度为254µm的锻造和热处理棒材的圆柱形试件进行多次轴向压缩试验，模拟了已生产的718合金铸锭径向锻造一次击穿过程中的组织演变。4个冲程压缩热序列在恒定的真应变率1.0 S/sup/-1/1/和温度95 0/℃、10 5 0/度/℃和115 0/度/C下进行。静态再结晶而不是动态再结晶是导致观察到的晶粒度细化的原因，其在背靠背变形期间的重复发生导致了在多道次变形序列中保持细小的晶粒组织。影响再结晶的关键热加工参数依次为温度、道次间保温时间和道次应变。通过施加不同的保压时间序列模拟，发现显微组织随工件位置而变化。参考文献9，图17，表7。
The simulation of microstructural evolution during primary breakdown of production sized alloy 718 ingots by radial forging was accomplished via multiple stroke axial compression testing of cylindrical specimens taken from a wrought and heat treated bar with a 254..mu..m grain size. Four stroke compression heat sequences were performed at a constant true strain rate of 1.0 s/sup /minus/1/ and at temperatures of 950/degree/C, 1050/degree/C, and 1150/degree/C. The applied strain per stroke for each four stroke sequence was either 0.14 to 0.23. Static, rather than dynamic, recrystallization was found to be responsible for the observed grain size refinement and its repetitive occurrence during back to back dwell periods resulted in the maintenance of a fine grain microstructure during multiple pass deformation sequences. In order of importance, the critical hot working parameters for recrystallization are temperature, dwell time between passes, and strain per pass. Microstructure was found to vary with work piece position, simulated by the applied sequence of dwell periods. 9 refs., 17 figs., 7 tabs.