TA15鈦合金大鍛件兩種模鍛工藝的組織性能對比研究Comparison of Microstructure and Mechanical Properties for TA15 Titanium Alloy Large Forgings under Two Die-forging Equipments

采用相同規格TA15棒材分別利用800MN模鍛壓力機、1MJ對擊模鍛錘制備同種形狀鈦合金大型航空模鍛件,對兩種模鍛條件下的鍛件組織及力學性能進行了對比研究。結果表明:800MN制備的鍛件塑性流線分布好,每火次變形量大、變形速率低,比1MJ鍛件再結晶晶粒尺寸小、等軸初生α相比例高且顆粒更加細小,室溫、500℃高溫拉伸性能以及沖擊韌性和斷裂韌性均有所提高。

800MN die-forging press and 1MJ die-forging hammer were employed on TA15 titanium alloy to produce large aerial forgings. Microstructure and mechanical properties of TA15 forgings under the two forging equipments were investigated and compared. Results show that the forgings under 800MN die-forging press have a preferable plastic flow. The 800MN die-forging press will cause lager deformation and lower strain rate during every heating. The forgings under 800MN die-forging press have more fine grain size after recrystallization compared with those under 1MJ die-forging hammer. It also had a higher percentage of primary alpha phase as well as more fine α precipitation under 800MN die-forging press. As a result, its tensile properties and impact toughness and fracture toughness of the forgings are higher than those under 1MJ forging. Furthermore, the costs and quality are more ideal under 800MN die-forging press because the strain and strain rate are more controllable and the forging times are less.