碳对一种单晶镍基高温合金铸态组织的影响

Effect of Carbon Content on the As-Cast Microstructures in a Nickel Base Single Crystal Superalloy

研究了不同碳含量对一种单晶镍基高温合金的铸态组织的影响。结果表明:随着碳含量的增加,合金的初熔温度逐渐降低,合金中的共晶数量和尺寸也减少。随着碳含量的增加,合金中的碳化物数量逐渐增多,碳化物的形态从斑点状变为斑点状和骨架状相结合的网状结构。随着碳含量的增加,一次枝晶间距变化较大,但是二次枝晶间距变化不大,W和Al元素的偏析降低,Ta和Mo元素的偏析增大。

The effect of carbon content on the as-cast microstructures was investigated in a nickel base single crystal superalloy. The results show that, with the increasing of carbon content, the incipient melting temperature of alloys decreases, the number and the size of γ/γ′ eutectic microstructure in alloys decrease. With the increasing of carbon content, the content of carbide also increases, the carbide morphologies change from spot shape to net shape. Secondary dendrite arm spacing of alloys with the increasing of carbon has a little change, but the primary dendrite arm spacing of alloys has remarkable change. The solidification segregation also changes with the increasing of carbon content, the segregation of W and Al decreases, but the segregation of Ta and Ti increases.