CAJ | 학술논문

采用等离子电极旋转雾化法和热等静压法(hot isostatic press, HIP)分别制备FGH96粉末与合金,对原始及高温(1150℃)预热处理后的FGH96粉末表面析出相以及HIPed FGH96合金的原始粉末颗粒边界(prior particle boundary,简称PPB)进行分析,进而研究PPB对合金室温和750℃拉伸断裂行为的影响.研究发现:原始粉末表面无明显析出相,1150℃预热处理后粉末表面有块状MC和细小氧化物分布;热等静压法制备的FGH96合金及其热处理后,PPB析出相主要由颗粒和块状的金属碳化物MC及富Zr的氧化物颗粒组成;该合金经过固溶和时效处理后,颗粒状MC部分溶解而块状MC长大,PPB碳化物的尺寸分布由单峰分布转变为双峰分布;常温拉伸时微孔在PPB上形成并扩展,合金沿PPB断裂;750℃拉伸时,合金强度与塑性较常温下明显降低,部分M23C6在晶界析出,块状和颗粒状碳化物部分溶解,为M23C6提供碳源,合金断口呈现沿晶和沿PPB混合断裂的形貌.
채용등리자전겁선전무화법화열등정압법(hot isostatic press, HIP)분별제비FGH96분말여합금,대원시급고온(1150℃)예열처리후적FGH96분말표면석출상이급HIPed FGH96합금적원시분말과립변계(prior particle boundary,간칭PPB)진행분석,진이연구PPB대합금실온화750℃랍신단렬행위적영향.연구발현:원시분말표면무명현석출상,1150℃예열처리후분말표면유괴상MC화세소양화물분포;열등정압법제비적FGH96합금급기열처리후,PPB석출상주요유과립화괴상적금속탄화물MC급부Zr적양화물과립조성;해합금경과고용화시효처리후,과립상MC부분용해이괴상MC장대,PPB탄화물적척촌분포유단봉분포전변위쌍봉분포;상온랍신시미공재PPB상형성병확전,합금연PPB단렬;750℃랍신시,합금강도여소성교상온하명현강저,부분M23C6재정계석출,괴상화과립상탄화물부분용해,위M23C6제공탄원,합금단구정현연정화연PPB혼합단렬적형모.
The precipitates on the prior and 1 150 ℃ vacuum-treated FGH96 powder surface, as well as the prior particle boundary (PPB) were investigated. Besides, the influences of PPB precipitate during tensile test at room temprature and 750 ℃ were also studied. The results show that precipitates seldom distribute on the surface of the prior powders. Block shaped carbides MC and oxide particles are observed on the surface of the powders treated at 1 150 ℃. PPB precipitates of hot isostatic pressed (HIPed) and heat treated (HTed) FGH96 alloy are made up of block-shaped MC, granular MC and Zr rich oxides particles. After solution and aging treatment, the block carbides grow up and the rounded carbides partly dissolve. As a result, the particle size distribution of PPB carbides changes from unimodal distribution of HIPed alloy to bimodal distribution of HTed alloy. When tension testing performs at room temperature, the micro flaws form around PPB of carbides and then enlarge, which results in the fracture along PPB. As the tension temperature increases to 750 ℃, M23C6 carbides precipitate at the grain boundary, block-shaped and granular carbides serving as a carbon resource partly dissolved. The fracture surface of 750 ℃specimen shows a mixture fracture mechanism of grain boundary and PPB fracture.