固溶温度及冷却方式对00Cr40Ni55Al3Ti合金组织性能的影响

Influence of solution temperature and cooling method on microstructure and properties of 00Cr40Ni55Al3Ti alloy

以热轧态00Cr40Ni55Al3Ti合金为研究对象,采取1150~1250℃固溶+水冷/空冷的试验方案,探究了固溶温度及冷却方式对显微组织与力学性能的影响规律。研究结果表明,在1150~1250℃范围内,合金晶粒及α⁃Cr相的尺寸随固溶温度升高而增加,超过1150℃后晶粒急剧长大,超过1200℃固溶并空冷后,α⁃Cr相在晶界片层状析出。合金的显微硬度随固溶温度的升高而下降,冲击吸收能量在1200℃达到峰值;水冷条件下α⁃Cr相和纳米级γ′相析出受到抑制,与空冷条件相比,硬度、冲击吸收能量分别降低和升高;拉伸性能受冷却方式的影响显著,空冷条件抗拉强度相对较高,1250℃固溶后空冷引起混晶及晶界粗大片层组织出现,导致伸长率与水冷相比下降了26.5%。

Hot rolled 00Cr40Ni55Al3Ti alloy was studied and 1150⁃1250℃solution treatment+air cooling/water quenching process was conducted on the tested alloy in order to find out the influence of solution temperature and cooling method on microstructure and mechanical properties of the 00Cr40Ni55Al3Ti alloy.The results show that the size of grain andα⁃Cr phase increases with the increase of solution temperature in the range of 1150⁃1250℃,and the grain size grows rapidly when the solution temperature is over 1150℃.When the alloy is solution treated over 1200℃followed by air cooling,α⁃Cr phase precipitates in a layered pattern at the grain boundary.The microhardness of the alloy decreases with the solution temperature increasing,and the impact absorbed energy peaks at 1200℃.When the water cooling is conducted,there is an inhibition in the precipitation ofα⁃Cr phase and nano⁃sizedγ′particles,consequently,the hardness and impact absorbed energy decreases and increases,respectively,compared with air cooling.Tensile properties are strongly influenced by the cooling method,the tensile strength is relatively higher under air cooling.And there is a 26.5%decrease in the elongation when solution treated at 1250℃followed by air cooling,due to the mixed grain and coarse layered microstructure at grain boundary.