Gas turbine blower impeller isothermy die forging method
Technical field
What the present invention relates to is a kind of die forging method of technical field of forging, is specifically related to a kind of gas turbine blower impeller isothermy die forging method.
Background technology
Forging is one of fundamental technology of machine-building, is the engineering goods important key link.Whole FMT overall development trend is more smart more province, and reaching does not need machining or a little machining just can use.Realize the forging precise treatment, on forging, work hard.Can reduce financial cost, labour cost because finish forge spare is compared with common die forging, forging new technology is clean shape precision forging, and typical part is the automotive transmission part of profile of tooth forging and closed-die forging, and application development is very fast aspect the forged teeth wheel-class parts.Isothermal forging be meant mold heated to the identical or close temperature of blank deformation, in than the low velocity deformation process, the forging method that hot blank and mold temperature are remained unchanged substantially.Isothermal die forging process is the new technique for forging that grows up the end of the sixties, uses this new technology can produce the product of dead size.During the die forging forging, because the temperature of mould is lower, workpiece rib or horn gap position are easy to cooling on ordinary press or hammer, and it is higher to add rate of deformation again, and resistance of deformation obviously increases, and these all can hinder the filling of metal pair mold cavity.
Find through retrieval " isothermal forging process " prior art document, Chinese patent application number: 200510046984, publication number: 1907594, title: " recombination pressure container lining half casing blank die forging forming method ", this technology readme: adopt a former and at least two shapes, the different drift branch passage of diameter to carry out instead squeezing distortion, each passage drift is identical to the active area of blank, and in the capacity of equipment scope; First passage and second passage are carried out under the condition of blank isothermal; After the 3rd road, the processing of need lowering the temperature in advance to the bottom of blank.This technology adopts the not anti-extrusion method of isothermal of multi-pass, realizes that with the press of less tonnage big volume recombination pressure container lining half casing blank die forging is shaped.The die-forging forming that this technology is different from conventional hemispherical shell adopts the form of a former one drift, but adopt a former and a plurality of diameter, variform drift branch passage to carry out instead squeezing distortion, can realize that big volume recombination pressure container lining half casing blank die forging is shaped with the press of less tonnage, extrusion molding belongs to a kind of special case of die forging, during extruding, the direction of metal flow is parallel to the drift direction of motion; And die forging belongs to cubic deformation, and metal all has mobile on X, Y, Z direction.Therefore, in the isothermal die forging process of impeller, flowing of metal is more complicated than extruding far away, and the direction of controlling its metal streamline only misses one's aim with extrusion process.
Find through further retrieval " isothermal forging process " prior art document, Chinese patent application number: 200410064548, publication number: 1605429, title: a kind of die forging production technology for hard copper alloy explosion-proof instrument, this technology readme: it is according to the formulated component of beryllium-bronze, aluminium-bronze explosion-proof tool alloy material, the percentage composition that adapts to the fabrication tool material adds smelting furnace with this raw material according to production technology and carries out alloy melting.Smelting temperature reaches 1100 ℃ ± 20 ℃ beginning sand casting.The copper liquid that smelting temperature is qualified stirs and pours in sand mold or the steel tire cast gate that to form the foundry goods hair bad.The qualified blank of above-mentioned foundry goods takes out blank when passing through post bake to 780 ℃ ± 10 ℃ again, blank was delayed time for 5-10 seconds, when making its temperature reduce to 700 ℃ ± 10 ℃, this moment is mould and die preheating to 300 ℃ ± 20 ℃, puts into the forging equipment mould and is equipped with calendering and rolls.This technology can enough combination process for casting and forging manufacturings obtain the aluminium bronze and the explosion-proof spanner of beryllium-bronze of respective performances, but can not be used for the die forging of impeller.Because it is feasible making the inductile forging with casting forging method, the product strength after casting is forged is higher than foundry goods, but is lower than the forging that this material is made; Its percentage elongation is higher than foundry goods, but also is lower than its forging.Therefore, the performance that product is forged in this technology casting is better than foundry goods but is lower than forging, more has been lower than isothermal die forging process spare! This technology can't be finished and make the impeller of rotating speed up to 40300 rev/mins.
Above-mentioned two technology can not solve the isothermal die forging process base of the compressor impeller that gas turbine uses, because the gas compressor blade wheel speed that gas turbine is used is up to 40300 rev/mins, centrifugal force is too big, requires to form the complete metal streamline on the impeller blade.And above-mentioned two technology all can not satisfy the obdurability requirement of impeller, can not solve and easily cause the technical barrier of impeller in the place's fracture of vibration nodel line.
Summary of the invention
The objective of the invention is to overcome deficiency of the prior art, a kind of gas turbine blower impeller isothermy die forging method is provided.The more common forging part of isothermal die forging process spare intensity of the present invention improves 19.7%, and percentage elongation increases by 76.6%, the working life of satisfying specified 100h fully.
The present invention is achieved by the following technical solutions, the present invention includes following concrete steps:
1., the impeller blank is heated to 190 ℃-210 ℃ for the first time, take out, spray lubricant, place again in the stove and be heated to 470 ℃-490 ℃ for the second time, be incubated 80-100 minutes;
2., will be installed in the mold heated to 470 ℃-490 ℃ on the press, the spraying lubricant places mould with the impeller blank that heats, samming is 20-40 seconds again;
3., start press, the time of pressing down is for the first time: 50-70 seconds, afterwards, during the also surplus 8mm of mould internal lobe wheel blank~10mm, press was slowly depressed with pressing down for the second time 4 minutes~5 minutes time, up to mould closure fully;
4., the press moved cross beam is up, mould is opened, and with water-cooled impeller forging, ejects the impeller forging by lower push rod.
The first time heating of step described in 1., heating-up temperature is preferably: 200 ℃.
The second time heating of step described in 1., heating-up temperature is preferably: 480 ℃.
The insulation of step described in 1. 80-100 minutes, temperature retention time is preferably: 90 minutes.
The once more heating of step described in 2., heating-up temperature is preferably: 480 ℃.
The samming of step described in 2. 20-40 seconds, the samming time is preferably: 30 seconds.
Step presses down the first time described in 3., and the time that presses down is preferred: 60 seconds.
Step presses down the second time described in 3., and the time that presses down is preferred: 5 minutes.
Described press adopts more than or equal to the 3000kN hydraulic press.
Described lubricant, the present invention selects one of following two kinds of lubricants for use: first kind, its component and percentage by weight are: flaky graphite 25-30%, talcum powder 4-8%, surplus is a cylinder oil; Second kind, its component and percentage by weight are: graphite 15-25%, water surplus.
From actual effect of the present invention as can be known, first kind of lubricant is better than second kind.Under similarity condition, one group of 6 sample of first kind of lubricant all are full of, and any surface finish, easily cleaning.And be inferior to first kind of lubricant at horn gap place full level with 6 samples of second kind of lubricant.
The present invention reaches 12:1 for the blade depth-width ratio of compressor impeller, and (blade depth-width ratio<8 are forged in common die forging, the depth of blade that forges does not reach the vibration node line position), shown the outstanding effect that the present invention obtained especially, the more common forging part intensity of the present invention improves more than 19%, percentage elongation increases more than 76%, satisfies the working life of specified 100h fully.The lubricant that the present invention correctly selects isothermal die forging process to use can reduce coefficient of contact friction, die forging power, unhomogeneity of deformation, the forging knockout press of blank and die surface widely and can improve the precision and the quality of die life, forging.
Description of drawings
Fig. 1 adopts the gas turbine blower impeller photo of isothermal die forging process of the present invention.
Fig. 2 gas turbine blower impeller isothermy die forging mould schematic diagram.
The specific embodiment
Below embodiments of the invention are elaborated: present embodiment has provided detailed embodiment being to implement under the prerequisite with the technical solution of the present invention, but protection scope of the present invention is not limited to following embodiment.
Embodiment 1
Present embodiment is at first determined 2A50 aluminum alloy mould and impeller blank isothermal temperature, make standard specimen with 2A50 forging aluminium alloy material, on 1-5-2 type high-temperature material testing machine, imitate actual isothermal rate of deformation and make high temperature tension test, make this alloy plasticity and resistance of deformation figure, thereby find mould and the best isothermal temperature of impeller blank to be: 480 ℃; Creep rate is: 5 * 3.4 * 10
-4s
-1, at the first-class warm deformation of YA32-500 type 5000kN hydraulic press.The blank external diameter that to get on the bus at lathe
43 are heated to 200 ℃ in KO-11 molding box formula resistance furnace, take out, and spray first kind of lubricant, place to be heated to 480 ℃ in the stove again, are incubated 80 minutes.
Design the mould of isothermal die forging process then, mould structure as shown in Figure 2.Die 5 is fixed on the lower bolster 1 by lower connecting block 2; Patrix 7 is fixed on the upper padding plate 10 by last contiguous block 8; Last lower bolster is individually fixed on the moved cross beam and workbench of forcing press by pressing plate.This mould structure can not only guarantee that impeller blade horn gap place is full of, and makes the metal streamline at this place vertical with the vibration nodel line, to strengthen the obdurability of impeller at vibration nodel line place.
For guaranteeing the obdurability at vibration nodel line place, outside guaranteeing this place's metal streamline and the vibration nodel line is vertical, also to guarantee the compactness of this place's forging material structure simultaneously, for this reason, mould with Frequency Induction Heating to 480 ℃, is sprayed first kind of lubricant, the blank that heats is placed die 5, samming is 40 seconds again, press begins to press down, after 70 seconds, when also remaining 8mm, press was slowly depressed with 4 minutes, and is closed fully up to mould.The press moved cross beam is up, and mould is opened, and with water-cooled impeller forging (it is yielding that Yin Gaowen ejects forging), lower push rod 3 ejects the impeller forging.
As shown in Figure 1, present embodiment obtains more common forging part intensity and improves 19.5%, and percentage elongation increases by 76.2%.
Embodiment 2.
During enforcement, with existing YA32-500 type 5000kN hydraulic press.The impeller blank external diameter that to get on the bus at lathe
43 are heated to 210 ℃ in KO-11 molding box formula resistance furnace, take out, and spray first kind of lubricant, place to be heated to 490 ℃ in the stove again, are incubated 80 minutes; Mould with Frequency Induction Heating to 470 ℃, is sprayed first kind of lubricant, the impeller blank that heats is placed mould, samming is 30 seconds again, and press begins to press down, after about 1 minute, when also remaining 9mm, press was slowly depressed with 4.5 minutes approximately, and is closed fully up to mould.The press moved cross beam is up, and mould is opened, and with water-cooled impeller forging (to eject the impeller forging yielding because of heat), lower push rod 3 ejects the impeller forging.
Present embodiment obtains more common forging part intensity and improves 19.3%, and percentage elongation increases by 76.4%.
Embodiment 3.
During enforcement, with YA32-630 type 6300kN hydraulic press.The impeller blank external diameter that to get on the bus at lathe
In KO-11 molding box formula resistance furnace, be heated to 190 ℃, take out, spray first kind of lubricant, place again to be heated to 470 ℃ in the stove, be incubated 100 minutes; Mould with Frequency Induction Heating to 490 ℃, is sprayed first kind of lubricant, the impeller blank that heats is placed mould, samming is 20 seconds again, and press begins to press down, and after 50 seconds, during also surplus 10mm, press was slowly depressed with 4 minutes approximately, up to mould closure fully.The press moved cross beam is up, and mould is opened, and with water-cooled impeller forging (to eject the impeller forging yielding because of heat), lower push rod ejects the impeller forging.Because press is bigger than embodiment 2 tonnages, therefore on blank temperature, can reduce by 10 ℃.
Present embodiment obtains more common forging part intensity and improves 19.1%, and percentage elongation increases by 76.1%.
Embodiment 4.
During enforcement, with YA32-300 type 3000kN hydraulic press.The impeller blank external diameter that to get on the bus at lathe
![Figure C200710045885D00083](https://patentimages.storage.***apis.com/28/fe/82/c852a4b159bec6/C200710045885D00083.png)
45 are heated to 200 ℃ in KO-11 molding box formula resistance furnace, take out, and spray first kind of lubricant, place to be heated to 480 ℃ in the stove again, are incubated 100 minutes; Mould with Frequency Induction Heating to 490 ℃, is sprayed first kind of lubricant, the impeller blank that heats is placed mould, samming is 40 seconds again, press begins to press down, after 70 seconds, when also remaining 8mm, sufficient strength left by press, pressed down after 5 minutes matched moulds, and following program such as embodiment 1,2 or 3 carry out; If matched moulds not, the press moved cross beam is up, and mould is opened, and behind the water cold forging spare, ejects the impeller forging with push rod 3, takes out the impeller forging.With cooled forging sandblast, deburring places resistance furnace to be heated to 200 ℃ again, takes out, and sprays first kind of lubricant, places to be heated to 480 ℃ in the stove again, is incubated 50 minutes (because of repeating heating, temperature retention time can reduce by half); Because press tonnage is less relatively, can press once again, obtains qualified forging equally.
Present embodiment obtains more common forging part intensity and improves 19.1%, and percentage elongation increases by 76.1%.