摘要
研究了改变Thermo-Span合金的Al,Cr含量对合金热膨胀系数、力学性能和650℃氧化性能的影响。当合金中Al含量由0.45%提高到1.5%,Cr含量由5.5%降低到3.0%,合金20～800℃的膨胀系数显著降低,650℃,600MPa的光滑持久性能由354h提高到597h,室温拉伸强度明显增大,650℃,100h氧化速率稍有提高。Al含量增加,γ′相析出增多。Cr含量较高时,氧化层和基体界面处的Cr浓度较高,提高了抗氧化性。降低Cr含量,提高Al含量,氧化层与基体界面处的Cr富集程度降低,Al的富集程度提高,合金的抗氧化性虽然有所降低,但幅度不大,仍保持为完全抗氧化级别。
The influences of Al, Cr contents on the thermal expansion coefficient, mechanical properties and oxidation resistances at 650 ℃ for Thermo-Span alloy were studied. When Al content was increased from 0.45% to 1.5%, and Cr content decreased from 5.5% down to 3.0%, the thermal expansion coefficient in the range of 20-800 ℃ for the alloy decreased obviously, the rupture life at 650 ℃ and 600 MPa increased from 354 h to 597 h, the tensile strength at R.T increased greatly, the oxidation rate at 650℃, 100 h increased slightly The increased of Al addition promoted the γ＇ precipitation. The higher content of Cr improved oxidation resistance due to higher concentration of Cr at the interface of oxidation layer and matrix. The decrease of Cr content and the increase of Al content lowered the oxidation resistance slightly owing to lower Cr enriching and higher Al enriching at the interface of oxidation layer and matrix, but the decrease magnitude was not too big, the alloy kept a satisfactory oxidation resistance still.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2007年第10期1788-1792,共5页
Rare Metal Materials and Engineering
基金
国家自然科学基金项目(50271072
50471083)
关键词
Thermo—Span合金
力学性能
氧化性
thermo-span alloy
mechanical properties
oxidation resistance
low thermal expansion superalloy
