热处理对Ti6321钛合金铸态组织及性能的影响

Effect of Heat Treatment on the Microstructure and Properties of Ti6321 Titanium Alloy in Cast State

为促进Ti6321钛合金在铸造领域的推广应用,研究了不同热处理工艺对Ti6321钛合金铸态组织和性能的影响。结果表明,热等静压处理后,抗拉强度有所降低,塑性提高;热等静压处理后,在相变点以上大气下退火空冷热处理的试样,室温抗拉强度及550℃高温抗拉强度均是最好的;在相变点以上进行真空退火处理,随着热处理冷却速率的提高,试样的室温抗拉强度及550℃高温抗拉强度均呈现上升的趋势,室温冲击韧性也不断提高。合金真空退火后的金相组织为针状α+晶界α+晶间β,随着热处理冷却速率的降低,组织的片层结构逐渐宽化,冲击性能逐渐降低。

In order to promote the application of Ti6321 titanium alloy in casting industry,the effect of different heat treatments on the microstructure and properties of Ti6321 titanium alloy in casting state was studied.The results show that the tensile strength decreases and the plasticity increases after hot isostatic pressing.The tensile strength at room temperature and 550℃is the best when the samples are annealed in the atmosphere above the phase change point after hot isostatic pressing.The tensile strength at room temperature and 550°C increased with the increase of cooling rate,and the impact toughness at room temperature also increased.After vacuum annealing,the metallographic structure of the alloy is needle-likeα+grain boundaryα+intergranularβ.From the perspective of structure,with the decrease of heat treatment cooling rate,the lamellar structure of the structure gradually widens,and the impact property gradually decreases.