TC21合金高温渗氢组织变化研究

Change of Microstructure for Casting TC21 Alloys after Thermohydrogen Treatment

利用氢作为暂时合金元素的氢处理技术可以细化钛合金组织,可使钛合金性能得到很大提高,这对铸造钛合金组织和性能的提高具有很大的意义。本文研究了α+β型钛合金TC21铸态组织的高温渗氢行为,通过对合金渗氢前、后和除氢后的显微组织观察发现,渗氢后β相的数量明显增加,并有氢化物的生成;除氢后,晶粒组织得到细化,原始晶界变得模糊,其相应的硬度也发生了一定变化。分析了氢致组织细化的机理。

Thermohydrogen treatment which uses hydrogen as a temporary alloying element can fine microstructure of titanium alloy and improve its properties. It has importance meaning on casting titanium alloy. The behavior of hydrogen absorption on microstructure of TC21 alloy as cast was studied. The results show that the β-phase amount increase and a few hydrides precipitate after charging hydrogen. When hydrogen is desorbed, the resulting structure is fine and homogeneous,and the hardness change a lot with it. The mechanism of fining microstructure was analyzed.