摘要
研究了标准热处理工艺1220℃×4h(AC,air cooling)+1050℃×4h(AC)+870℃×24h(AC)对定向凝固镍基高温合金组织和力学性能的影响。研究结果表明:DZ951合金经热处理后,碳化物由铸态时的骨架状变成块状,γ′相变成规则排列的立方形,尺寸约为300nm,体积分数增加到68%。枝晶偏析降低,合金强度升高;错配度减小,组织稳定性增加。合金元素在γ和γ′相中的分布更加均匀,提高两相强度。合金在1100℃和50MPa的持久性能及在室温和760℃的拉伸性能得到较大提高。
The effect of standard heat treatment （SHT） procedure 1220℃ × 4h（ AC, air cooling） ＋ 1050℃ × 4h（AC） ＋ 870℃ × 24h（AC） on microstructure and mechanical property of directionally solidified nickel-base superalloy was investigated. The results indicate that the shape of carbide changes from bone like of as-cast alloy into block after SHT. Cuboidal γ′ phase with the size of 300nm and the volume fraction of 68 % is regularly arranged. The dendritic segregation reduces, which results in the increases of strength. The lattice mismatch between γ/γ′ phases decreases and the microstructure stability increases. The distribution of alloy element in γ and γ′ precipitates is more homogeneous, which improves the strength of the two phases. The stress rupture life at 1100℃ and 50MPa and the yield strength at room temperature and 760℃ significantly increase for DZ951 alloy after SHT.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2008年第4期96-99,共4页
Transactions of Materials and Heat Treatment
关键词
热处理
γ′相
位错
力学性能
heat treatment
γ′ phase
dislocation
mechanical property
