硼对K4169高温合金流动性及缩松的影响

Effect of Element B on Fluidity and Microporosity of K4169 Superalloy

摘要:

研究了微量硼对K4169高温合金相变温度、比热、表面张力、流动性及缩松的影响。采用自主设计的两种表征高温合金流动性的模型，研究了微量元素硼对K4169高温合金流动性的影响，测定了铸件缩松的面积百分含量。结果显示，当合金中硼含量由26 mg/kg增至59 mg/kg，合金的流动性明显提高。而合金中缩松含量随硼含量的增加先减后增，在硼含量由59 mg/kg时缩松最少。运用差热扫描分析仪（DSC）对合金的凝固特征参数进行了测定，结果显示，随着硼含量增加，凝固温度区间逐渐变窄，当硼含量超过59 mg/kg时，凝固温度区间增加。用JMatPro软件计算结果显示，随着硼含量的增加，合金的表面张力逐渐降低。经过EDS分析，当硼含量为70 mg/kg时，合金中会析出硼化物。

Abstract:

The effect of trace boron on phase transition temperature, specific heat, surface tension, fluidity and microporosity of K4169 superalloy has been investigated. The influence of different contents of minor element boron on liquidity of K4169 superalloy and quantitative measurement of the area percentage of microporosity were also studied by two different fluidity models of superalloy designed by ourselves. The results show that when the content of boron increases from 26 mg/kg to 59 mg/kg, the fluidity of K4169 superalloy can be greatly improved; however, the percentage of microporosity decreases and then increases. When the content of boron reaches 59 mg/kg, the microporosity is the smallest. Solidification parameters were measured by differential scanning calorimeter (DSC). The results indicate that with the increasing of boron content the solidification range becomes narrow, while when the content of boron exceeds 59 mg/kg, the solidification range increases. JMatPro software calculation results show that with the increasing of boron content, the surface tension of the alloy is gradually reduced. EDS analysis reveals that when the content of boron reaches 70 mg/kg, boride will precipitate in the superalloy.