Research On High Temperature Ring Rolling Forming Process Of Ring Workpiece Of GH4738 Alloy

The seal ring has been an important part of aero-engines and are also used as seals on some gas turbines,the sealing ring has been used GH4169 alloy from the development to the formal commissioning,but found in the process of deformation of the alloy at high temperature,GH4738 alloy after switching to deformation Relative to the GH4169 really reduced.Due to the lack of previous experience in the production of ring forgings,GH4738 ring forgings should be formally approved for theoretical analysis,simulation and on-site trial production to seek a more reasonable forging and forming process and heat treatment process to ensure that Parts can get higher performance and better organization.In this paper,hot compression test was used to study the high temperature deformation behavior of GH4738 alloy.The constitutive relationship model of GH4738 was established.The hot working diagram was drawn and the micro-structure evolution of the alloy was analyzed.Meanwhile,the forming temperature and deformation of GH4738 alloy were studied,Deformation rate of the forming quality,in order to obtain the best forging process parameters: The best deformation temperature is between 1120?~1140?,the forging rate is between 5s-1~20s-1,the deformation control is between 40% ~ 60%.Before the production of seal ring of GH4738 alloy,the process of blank and ring rolling was simulated by Deform-3d software to verify the rationality of the process route.In forging upsetting process,the method of upsetting insulation blanket was proposed to solve forging Surface temperature drop too fast.In the process of research trials,the choice of imports ? 200 mm,imports ? 250 mm,made ? 200 mm bar three kinds of production contrast and found for the forging a fire ring rolling process forging produced more evenly,made ? 200 mm bar and ? 200 mm imports of bar material Production of forgings,performance quite,are better than the use of imported ? 250 mm bar forgings production indicators,verified GH4738 alloy sealing ring high temperature forming process can be used 3t free forging billet and ring rolling machine ring.Finally,the test pieces were heat-treated to study the influence of different heat treatment parameters on the forgings.It is found that the grain size of GH4738 alloy after solution treatment is more easily obtained than that of water cooling.The grain sizes of different positions in oil-forged afterglow are more similar,but the grain sizes in different positions after water cooling are more discrete and easy to have Some large grains and twins exist.With the decrease of solution temperature,the grain size of forgings generally shows the corresponding decreasing rule.Finally,the best heat treatment system is obtained when the temperature in the furnace is kept at 1020? to 1040?.and the holding time is 240 min,then coll in oil.The aging is maintained at a temperature of 845?.in the furnace for 240 minutes,then coll in the air.The second aging in the furnace heating temperature of 760?,insulation 960 min,then coll in the air.