【摘要】 采用光学显微镜、扫描电镜和透射电镜研究了固溶温度对定向凝固DZ951镍基高温合金组织和持久性能的影响。结果表明:合金经固溶处理后,枝晶偏析降低,合金强度增加。碳化物由铸态时的骨架状变成块状,呈不连续状分布在晶界,对裂纹的萌生和扩展都有抑制作用。γ′相经固溶处理后,尺寸变小,分布更加均匀。合金在1100℃/60MPa的持久性能得到提高。在1300℃固溶处理时,合金元素分布更加均匀,γ′相体积分数增加,使DZ951合金具有较高的持久寿命。更多还原

【Abstract】 The effect of solution temperature on microstructure and stress rupture property of DZ951 directionally solidified nickel-base superalloy was investigated by optical electron microscope,SEM and TEM.The results show that dendritic segregation decreases and the alloy strength increases after solution treatment.Carbide changes block from bone-like of as-cast alloy and discontinuously distributes in the grain boundary,which inhibits the initiation and propagation of cracks during stress rupture test.The size of γ′ phase reduces and γ′ distribution is more homogeneous after solution treatment.The stress rupture property of the alloy after solution treatment is improved.The stress rupture life of the alloy at the solution temperature of 1300℃ is higher because the distribution of alloy elements is more homogeneous and the γ′ volume fraction increases.更多还原