摘要
采用真空感应熔炼炉制备了不同W含量(质量分数26%、30%、35%)和Ti含量(质量分数0、0.5%、1.2%)的GH3539合金铸锭并对其进行均匀化热处理。采用扫描电子显微镜(SEM)、能谱仪(EDS)、电子探针微量分析仪(EPMA)和电子背散射衍射技术(EBSD)表征合金的微观组织,并通过等温压缩试验研究了Ti、W元素对GH3539合金在1200℃温度、0.01~1 s^(-1)应变速率、50%应变量下热变形行为的影响。结果表明,随着Ti、W含量的提高,合金γ基体中的颗粒状析出相逐渐增多。增加Ti元素含量提高了合金中富Ti的MC碳化物的体积分数,明显降低了合金的变形抗力,使其热加工塑性显著提高。此外,Ti元素的加入还减小了热变形合金的再结晶晶粒尺寸,提高了再结晶体积分数。增加W元素含量促进了M_(6)C碳化物及α-W颗粒相的析出。当添加35%W时,均匀化热处理合金中析出了大量被M_(6)C碳化物包裹的块状α-W相,这种富W颗粒相虽在一定程度上促进了基体的动态再结晶,但也极易成为高温变形过程的裂纹源,从而恶化合金的热加工性能。
GH3539 alloy ingots with different W contents(26%,30%,and 35%by mass)and Ti contents(0,0.5%,and 1.2%by mass)were prepared in a vacuum induction melting furnace and subjected to ho-mogenization heat treatment.The microstructure of the alloy was characterized using scanning electron microscope(SEM),energy dispersive spectrometer(EDS),electron probe microanalyzer(EPMA)and electron backscatter diffraction technique(EBSD).The influence of Ti and W elements on the hot deformation behavior of GH3539 alloy was studied by isothermal compression tests at a temperature of 1200℃,strain rates of 0.01~1 s^(-1),and a strain of 50%.The results indicate that as the content of Ti and W increases in the GH3539 alloy,the number of granular precipitates in theγmatrix of the alloy also increases gradually.Increasing the content of Ti element raises the volume fraction of Ti-rich MC carbides in the alloy,significantly reducing the deformation resistance and markedly improving the hot workability of the alloy.Additionally,the addition of Ti also reduces the recrystallized grain size of the hot-deformed alloy and increases its recrystallization volume fraction.Increasing the content of W element promotes the precipitation of M_(6)C carbides andα-W particle phase.When 35%W is added,a large number of blockyα-W phase wrapped by M_(6)C carbides precipitates in the homogenized heat-treated alloy.Although this W-rich particulate phase promotes the dynamic recrystallization of the matrix to a certain extent,it also readily becomes crack sources during high-temperature deformation,thus deteriorating the hot workability of the alloy.
作者
吕斌
周子荐
崔传勇
王新广
叶祥熙
高炳亮
LYU Bin;ZHOU Zi-jian;CUI Chuan-yong;WANG Xin-guang;YE Xiang-xi;GAO Bing-liang(School of Metallurgy,Northeastern University,Shenyang 110004,China;Shi Changxu Advanced Materials Innovation Research Center,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China)
出处
《稀有金属与硬质合金》
北大核心
2025年第2期116-128,共13页
Rare Metals and Cemented Carbides
基金
国家重点研发计划项目(2021YFB3700601)。
关键词
GH3539合金
铸态组织
均匀化热处理
碳化物
α-W相
热变形
动态再结晶
GH3539 alloy
as-cast microstructure
homogenization heat treatment
carbide
α-W phase
hot deformation
dynamic recrystallization
