关键词: 高温合金GH3128, 自由锻, 碳含量, 晶粒度

Abstract: GH3128 alloy samples with carbon content of 0.031% and 0.015% are forged from Φ500 mm ingots to 350 mm × 350 mm square billet by the same open-die forging process，then forge the 350 mm × 350 mm square billet to Φ200 mm round bar by using the heating temperature 1 180 ℃ and 1 100 ℃ and the deformation rate of 27.5% and 36% per operation respectively. The results show that the forging process of 1 100 ℃ heating temperature and 27.5% deformation rate per operation lead to optimal grain size；At the same time the amount of carbide and microstructure is closely related to C content， but has little relationship with forging process； Compared 0.031%C with 0.015%C ， the tensile strength of room temperature is increased by 5%-10%， and the 950 ℃ high temperature stress-rupture time increased by 30%.

Key words: High-temperature Alloy GH3128, Open-die Forging, Carbon Content, Grain Size