高温合金GH4065A的恒温静态氧化行为

研究了新型镍基高温合金GH4065A在650～750℃的静态氧化行为,基于对氧化动力学与氧化产物的分析,探讨了合金的氧化机制.结果表明:采用平均氧化增重速率指标评定GH4065A合金在650～750℃温度范围内均为完全抗氧化级别,试验条件下合金的抗氧化能力与典型涡轮盘材料FGH96、GH4720Li合金相当;合金的氧化产物主要为内层富铝的氧化物颗粒、外侧富铬的氧化物膜及表面金红石型TiO2颗粒,TiO2颗粒在氧化温度超过700℃后开始生成;合金的氧化动力学遵循抛物线型规律,受钛离子与铬离子穿过氧化膜的扩散过程共同控制.

Isothermal and static oxidation behavior of superalloy GH4065A

The static oxidation behavior of new nickel-based superalloy GH4065A at the temperature range of 650??750?? in air was investigated by isothermal static oxidation testing. The oxidation mechanism was discussed on the basis of oxidation kinetics and the analyses of oxidation product. The results show that GH4065A alloy characterizes with full oxidation resistance at the temperature range of 650-750??, assessed by the indicator of average oxidation weight gain rate. The oxidation resistance performance of GH4065A alloy is equivalent to typical high performance turbine disc alloy FGH96 and GH4720Li under the experimental conditions. The main oxidation products are internal Al-enriched oxide particles, outside Cr-enriched oxide scale and rutile TiO2 particles on the surface which generate at the temperature higher than 700??. The oxidation kinetics obeys parabolic rate law and is controlled mainly by the transmissions of Ti and Cr ions through the oxide scale.