Ti-35V-15Cr-Si-C合金退火过程中组织演化行为

Microstructure Evolution of Ti-35V-15Cr-Si-C after Annealing Treatment

摘要:

采用不同的分析测试方法对Ti-35V-15Cr-xSi-yC合金不同退火和固溶温度下组织形态和相结构演变进行了研究。研究结果表明，Ti-35V-15Cr-xSi-yC合金在900℃以下退火，退火组织的晶界小晶粒增多，但长大趋势不明显，不同退火温度条件下，合金组织差别不大。当退火温度超过900℃，晶界小晶粒开始明显长大，合金组织形态发生明显变化。合金组织中有四种析出相：球状颗粒的Ti2C、鸡爪型的(TiV)C、点状颗粒的Ti5Si3以及少量的针状α相。鸡爪型(TiV)C开始溶解的温度范围为950℃～1000℃；点状颗粒Ti5Si3开始溶解的温度范围为100℃～1050℃。在1200℃的高温条件下，球状Ti2C发生部分溶解。

Abstract:

Microstructures morphology and phases of Ti-35V-15Cr-xSi-yC alloy after different annealing and solution treatments were studied using different analysis methods. The results show the amount of grain-boundary small grain increases but their sizes shows little change for the specimen annealing below 900℃. The microstructure morphology shows little different for different annealing specimen below 900℃.When the annealing temperature is above 900 ℃，the small grain at grain-boundary growth obviously and the microstructure morphology shows visible change. Tere are four precipitations in the alloy microstructure, they are spherical particle precipitation of Ti2C, “chicken feet” type precipitation of (TiV)C, dot particle precipitation of Ti5Si3 and needle-like precipitation of α. The solvus temperature for precipitation of (TiV)C and Ti5Si3 in Ti-35V-15Cr-xSi-yC are separately in temperature range form 950℃ to 1000℃ and 1000℃ to 1050℃. When the solution temperature increase to 1200℃，there is only partial solution of Ti2C.