固溶及稳定化工艺对GH738合金碳化物和γ'相析出规律的影响  

Influence of solution and stabilization heat treatment on carbide and gamma prime for super alloy GH738

作　　者：姚志浩[1] 董建新[1] 张麦仓[1] 洪成淼[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083

出　　处：《材料热处理学报》2013年第10期43-49,共7页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(51071017)

摘　　要：实验研究固溶及稳定化处理工艺对GH738合金碳化物及γ'强化相析出规律的影响。以标准热处理:1020℃×4 h/AC(空冷)+845℃×4 h/AC+760℃×16 h/AC和1080℃×4 h/AC+845℃×24 h/AC+760℃×16 h/AC为基础,调整稳定化阶段保温时间。研究了该合金稳定化过程中碳化物及γ'强化相析出和回溶规律,绘制了γ'强化相长大曲线。结果表明,1020℃固溶后,稳定化时间的延长使晶界析出碳化物增多且呈现半连续分布;而经1080℃固溶后,碳化物析出沿着晶界呈连续状分布;同时,经两种固溶温度处理后,稳定化时间延长,γ'强化相长大符合Oswald熟化规律;经1020℃标准热处理后,合金具有较好强塑性配合,尤其在塑性指标方面有明显优势;而经1080℃标准热处理后,合金持久性能表现更佳。Precipitation and dissolution behavior of carbides and gamma prime were studied for super alloy GH738 during solution and stabilization heat treatment. Based on two standard heat treatments： 1020 ℃ × 4 h/AC ＋ 845 ℃ × 4 h/AC ＋ 760 ℃ × 16 h/AC and 1080 ℃ ×4 h/AC ＋ 845 ℃ x 24 h/AC ＋ 760 ℃ × 16 h/AC, the stabilization holding time was adjusted to examine the evolution of carbides and gamma prime in the process of heat treatments. The results indicate that the solution and stabilization process have great influence on carbides and gamma prime. The carbides are precipitated discountinuously at grain boundaries for solution treatment at 1020 ℃ and the continuous distribution of the carbides at grain boundaries is observed for the alloy after solution treatment at 1080 ℃. The rate of growth for gamma prime is consistent with Ostwald rule during the stabilization treatment. The two standard heat treatments exhibit different effects on microstructure and mechanical properties for the alloy. The better tensile properties can be obtained after the standard treatment at 1020 ℃ , while better stress rupture properties can be acquired after standard treatment at 1080 ℃ for super alloy GH738.

关 键 词：GH738合金 碳化物 γ′强化相 热处理 力学性能 

分 类 号：TG132.32[一般工业技术—材料科学与工程]