Research On The Hot Tandem Rolling Process Of Ti-811 Alloy In Aero-engine Compressor Blade

Ti-811(Ti-8Al-Mo-1V)alloy is semi-? type titanium alloy with the heat resisting,which is development in the United states of America.The biggest characteristic of this alloy are low-density,high-elastic modular,and the superiority creep,endurance property,and the higher vibration dampen property with the temperature at 400~450?.It has been widely used in many kinds of type on the engine as the Aero-engine Compressor blade with the temperature at 400~450?.The research efforts on the alloy was carried out in the 1990 s,including the chemical constitution,evolving of the microscopic structure,the fore processing technic,the heat treatments,and the effects on performance all has been extensively studied industrial production.But there are also problem with the rolling Bar in forging process,such as the poorly coMPatibility microscopic,instability crop property in high temperature,the clutter over proof of supersonic detector.This paper study the hot tandem rolling process production line of the Ti-811 alloy on aero-engine compressor blade,it has an important guide on boosting the microscopic structure of blade bar,stabilizing the mechanical properties,reslizing the bath production of the hot tandem rolling.This paper adopted the method of finite element with numerical simulation on the process on four-fire hot tandem rolling of Ti-811 alloy,it's based on the line of hot tandem rolling in Baiji Titanium industry co.,itd.Then checking the matching stub between section length after rolling and rolling pass of two-phase titanium alloy and also getting the stress field,strain field and temperature field parameters on continuous rolling deforming of Ti-811 alloy,it can provide guidance on rolling temperature,rolling speeding.We can get the best processing parameter of the batch process which study the effect of different processing parameter on microstructure and property on different rolling temperature and deforming size of dia45 rolling bar.After the analysis with finite element method with number modeling on Ti-811 alloy barefoot continuous rolling,we can get that the broadening in continuous rolling of Ti-811 is similar as two-phase titanium.The continuous rolling production line of Baiji Titanium industry co of two-phase alloy is appliance the rolling of Ti-811 alloy bar.From the distribute of stress field,strain field and temperature fieldwe we can know that stress value of rolled piece is gradual falling down,strain capacity is gradual increasing and the deforming of core is greater than edge,there is also existence non-homogeneous between them,at the same time,the elevated temperature of core in rolled piece can reach 14 degree.At the same rolling apeed and the fire-rolling deforming,this artcle study the effect of different rolling temperature on microstructure and property of bar,when adoting two fire-rolling temperature at 960~990?(50-80?blow ?-phase transformation temperature)and the deforming size is controled at 60~80percent,the index of microstructure,property of the rolling bar can meet the challenge product standard.Considerations in the influence of the rolling temperature on structure homogeneity,mechanical property and the level of supersonic flaw detecting,when adopting two fire-rolling temperature at 50?blow ?-phase transformation temperature,we can achieve the better combination property.At the same rolling temperature and rolling speed,this artcle study the effect of different fire-rolling on microstructure and property of bar,when adopting the temperature at 990?(50? blow?-hase transformation temperature),as the fire-rolling deforming'increaseing and the first fire deforming size's reduceing,we can achieve the champion microstructure and the croop property in high temperature,and the plastic extension percentage can reach 0.111 in minimum.Also achieve the supersonic flaw detecting property,and the measured value of the clutter can reach ?0.8-16 dB.General,in real production of Ti-811 alloy bar.At the same rolling temperature and rolling speed,we recommend adopting three fire-rolling and controling the deforming size at 40~60%,then can getting combination property.By the technical studying on hot tandem rolling rolling of Ti-811 alloy bar and the above research findings,we can gain that when use the diameter at 150 mm forging bar to roll the diameter at 45 mm bar,the best rolling technology is adopting three-firerolling,setting the first and the second fire rolling speed at 2.3m/s,the third fire rolling speed at 0.3m/s,and controling the rolling temperature at 990?(50? blow?-hase transformation temperature),the rolling deforming size at 40~60%.