高温合金细晶铸造技术研究

Investigation of Fine Grain Castings Technique of Superalloy

研制成功了国内第一台细晶铸造真空炉。在该炉上 ,用控制参数法获得的 K 418合金细晶叶片的晶粒度可达 ASTM3～ 5级 ,在普通铸造温度下用铸型搅动法获得的整体涡轮 ,其幅板轮毂部位的晶粒度可达 ASTM M11.5～ ASTM3级。与普通铸造相比 ,K418合金细晶铸造的低周疲劳寿命至少提高 3倍。

The first domestic fine grain casting vacuum furnace has been developed suc- cessfully by Beijing Institute of Aeronautical Materials.By use of this furnace,the K41 8alloy fine grain blades of grain size in the ASTM3～ 5range can be obtained by controlling casting thermal parameters,and under conventional pour temperature condition,the K41 8alloy integral turbine wheel which grain size of hub and spoke is in the ASTM M1 1 .5～ ASTM3range can be obtained by adopting mould stir process.Compared with conventional,low cycle fatigue life of the fine grain castings of K41 8alloy at60 0℃ can be increased by3times at least.