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采用Gleeble-3800热模拟试验机研究Fe-36Ni合金在900~1200℃的热塑性行为,并用Fact Sage软件、扫描电镜及透射电镜等研究该合金热塑性的影响因素及作用机理.结果表明:合金中主要形成Al_2O_3+Ti3O5+Mn S复合夹杂,夹杂物颗粒尺寸集中分布在0.5μm以下.合金热塑性在900~1050℃受晶界滑移及动态再结晶共同影响.晶界上分布的纳米级别(<200 nm)夹杂物有效钉扎晶界,抑制动态再结晶发生的同时减小晶界结合力.微米级别(>200 nm)夹杂物则促进显微裂纹在晶界滑移过程中的形成和扩展,损害合金热塑性.当温度高于1050℃时,较高的变形温度使再结晶驱动力大于钉扎作用力,合金发生动态再结晶,有效提高热塑性.在1100~1200℃区间内,枝晶间裂纹的形成、晶界滑移的加剧及动态再结晶晶粒尺寸增大都降低合金热塑性.
The thermoplastic behavior of Fe-36Ni alloy at 900-1200 ℃ was investigated by Gleeble-3800 thermal simulator and the influence factors and mechanism of the thermoplasticity were investigated by Fact Sage software, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that the main The grain size of the inclusions is concentrated below 0.5μm, and the thermal plasticity of the alloy is affected by the grain boundary slip and dynamic recrystallization at 900-1050 ℃ .Nano-scale (<200 nm inclusions can effectively pinch the grain boundaries and restrain the dynamic recrystallization while reducing the grain boundary binding force.Microstructures (> 200 nm) promote the formation and propagation of micro-cracks in the grain boundary slip process, Damage the alloy’s thermoplasticity.When the temperature is higher than 1050 ℃, the higher deformation temperature makes the recrystallization driving force greater than the pinning force, the alloy dynamic recrystallization, effectively improve the thermoplastic.In the range of 1100 ~ 1200 ℃, interdendritic cracks The formation of grain boundaries, the increase of grain boundary slip and the increase of dynamic recrystallization grain size all reduce the alloy’s thermoplasticity.