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采用Gleeble-1500热模拟机,在变形温度750-900℃,应变速率0.01-10s~(-1)的条件下,对连续柱状晶BFe10-1-1合金进行了高温压缩变形,研究了合金的动态再结晶行为.结果表明,动态再结晶温度在850℃左右;热激活能Q=427.937kJ/mol,高于同成分的等轴晶BFe10-1-1合金;当ln Z<43时,合金发生部分动态再结晶;当43≤ln Z≤51时,发生部分动态再结晶(850和900℃)或不发生动态再结晶(750和800℃),为该合金发生动态再结晶的中间区域;当ln Z>51时,该合金不发生动态再结晶.存在发生动态再结晶的ln Z值中间区域以及热激活能较高,表明具有连续柱状晶组织的金属与等轴多晶金属发生动态再结晶的机理有所不同.在本文工艺参数范围内,随应变速率增大,合金发生动态再结晶的区域有所扩大;动态再结晶晶粒易在合金晶界处以晶界弓弯方式形核,形成的再结晶晶粒在晶界扩张的同时,在晶内形成孪晶,并以“孪生动态再结晶”方式演变成晶粒带.
Using the Gleeble-1500 thermal simulator, the continuous columnar crystal BFe10-1-1 was subjected to high temperature compression deformation at the temperature of 750-900 ℃ and the strain rate of 0.01-10s ~ (-1) The results show that the dynamic recrystallization temperature is about 850 ℃, the thermal activation energy is Q = 427.937kJ / mol, which is higher than the equiaxed BFe10-1-1 alloy with the same composition. When ln Z <43, the alloy Partial dynamic recrystallization occurred; some dynamic recrystallization (850 and 900 ℃) or dynamic recrystallization (750 and 800 ℃) occurred when 43≤ln Z≤51, which was the central region of dynamic recrystallization of the alloy; When ln Z> 51, the alloy does not undergo dynamic recrystallization, and there is a middle region of ln Z with dynamic recrystallization and higher thermal activation energy, indicating that the dynamic recrystallization of the metal with equiaxed polycrystalline metal The mechanism of crystallization is different.With the increase of strain rate, the area of dynamic recrystallization of the alloy is broadened in the process parameters of this article. The dynamic recrystallized grains are easy to nucleate at the grain boundaries by the grain boundary bowing, The formation of recrystallized grains in the grain boundary expansion at the same time, the formation of twins in the crystal, and “twin Dynamic recrystallization ”way into a grain belt.