CN106702295A - Method for improving structure and high-temperature smooth fatigue performance of GH4698 disk forge piece - Google Patents

Abstract

The invention relates to a method for improving the structure and high-temperature smooth fatigue performance of a GH4698 disk forge piece. Under normal conditions, production of the GH4698 disk forge piece needs the multiple procedures of upsetting cake blank making, die forging, secondary solid solution treatment and aging heat treatment, wherein the blank making and die forging procedures further comprise forging heating and deformation procedures. Formulation of all heating procedures shall follow the structure change characteristics of GH4698 materials during heating, and the internal relation between nominal deformation and real deformation of all areas shall also be fully understood during formulation of all deformation procedures. The method is started with setting of GH4698 heating parameters, deformation step distribution and other aspects emphatically, the structure of the GH4698 disk forge piece can be effectively refined and homogenized, and finally the high-temperature smooth fatigue performance of the GH4698 disk forge piece is improved.

Description

A kind of method of improvement GH4698 disk forging tissues and the smooth fatigue behaviour of high temperature

Technical field：

The invention belongs to the technical field of hot working of high temperature alloy, it is related to a kind of improvement GH4698 disk forging tissues and high temperature The method of smooth fatigue behaviour.

Background technology：

GH4698 is the nickel base superalloy strengthened with elements such as aluminium, titanium, molybdenum, niobiums, is mended on the basis of GH4033 alloys Alloying development is filled, there is enduring quality and good combination property high in the range of 500~800 DEG C.The alloy It is widely used in the important load parts such as the turbine disk, compressor disc, flow deflector, the force bearing ring of manufacture aero-engine.Operating temperature Up to 750~800 DEG C.

The aero-engine formulation of all heating processes of GH4698 products should follow group of the GH4698 materials in heating Knit Variation Features；The formulation of all deformation operations simultaneously should be also fully understood by between nominal deflection and each region true strain amount Internal association.Can otherwise cause GH4698 disks forging such as tissue odds, coarse grains, dynamic recrystallization crystal grain occur to subtract Less, shear twin crystal grain such as increases at the phenomenon.

Heating step temperature setting should according to GH4698 materials heating when tissue change feature：Original bar tissue It is single-phase γ matrixes+a small amount of primary carbide and boride；Bar heating and thermal insulation certain hour between 980~1010 DEG C, it is main Large-sized γ ＇ hardening constituents (main disperse is in austenitic matrix inside and crystal boundary) are separated out, 1000 DEG C is precipitation cutting edge of a knife or a sword；With heating Time increases, and separating out quantity increases, and crystal grain and intercrystalline strengthening effect are strengthened, and the limitation that crystal grain is grown up is strengthened simultaneously, grain growth Speed slows down；Bar dissolves in 1020 DEG C of temperatures above long-time heatings, various hardening constituents, is single-phase γ tissues；It is now brilliant Grain growth limitation weakens, and growth rate is accelerated.Therefore, the heating step of setting should be " 800 DEG C of preheating insulations, rise to 990 again~ 1000 DEG C of preheating insulations, finally rise to the insulation of 1100~1120 DEG C of high-temperature region ".A large amount of forging technologies are primary concern is that high-temperature region The setting of heating-up temperature and the scope of final forging temperature, and emphasis consider high-temperature region heating before it is not adjacent preheating step it is reasonable Temperature range.Preheating temperature is directly for example set as 1050~1070 DEG C or so, because in technology establishment person, preheating temperature The lower crystal grain of degree will not grow up, and the temperature spread shortened between high-temperature region and adjacent preheating step is conducive to metal first in preheating At a temperature of heat penetration to reduce high-temperature region soaking time, so as to reduce the amplitude that crystal grain is grown up in high-temperature region.But it is true really not so, Because GH4698 materials are more than 1020 DEG C under heating condition, almost single phase austenite tissue, a dispersion-strengtherning dissolved γ ＇ do not have the effect of limitation, and austenite crystal will rapidly start recovery and recrystallization, gradually coalescence.By this temperature platform Rank sets, and is preheated 3~4 hours first at a temperature of 1050~1070 DEG C per fire time blank, then in high-temperature region 1110~1120 DEG C insulation 2~3 hours, equivalent to the recovery and recrystallization that austenite structure time has occurred 5~7 hours per fire.If or else can protect Card has suitable deflection, and forging tissue and fatigue behaviour would become hard to reach requirement.

Reasonable distribution upsetting cake, die forging the work step secondary deflection per fire, it is ensured that (should not mistake by per the deformation of fire time 25%~35% Greatly), fire is made by oneself, is come out of the stove using alumina silicate heat-preservation cotton Soft Roll set after predetermined high temperature area soaking time is reached during heating.Especially , it is emphasized that the setting per fire time deflection can not only consider overall large deformation, should also consider small deformation area, be unlikely to deform area Deformation state.As upsetting cake overall deformation amount sets excessive (being set as that the fire of 50% deflection one is completed), even if having taken bag Set Insulation, it is also difficult to which, by serious situation, its maximum distortion region is certainly to avoid the local temperature in prolonged deformation process Deflection that so can be more than 50%, but small deformation area or deformation dead band be also bound to exist.So tissue is exacerbated first not Uniformity, next to that result in the original big crystal grain of a large amount of non-occurrence dynamics recrystallizations and be short of power because of dynamic recrystallization, directly Connected the chaotic distribution of the feather organization of shear formation.

Reasonable set solution heat temperature first：, with reference to temperature setting in Forge Heating, high-temperature region temperature should for preheating step Selection lower limit temperature (usual 1100~1120 DEG C of scopes) as far as possible.Solid solution soaking time is to fix 8 hours first, under the conditions of being somebody's turn to do, Crystal grain can further occur recovery and recrystallization, and stock size can increase by 1~1.5 times, if do not carried out very to blank during forging Good improvement, basis is poor, then (although having certain homogenization) tissue may proceed to be deteriorated after by solid solution, special Be not super large crystal grain (more than 2.0mm) presence can cause have children outside the state plan the performance severe exacerbation such as wave inspection and the smooth fatigue of high temperature.

Emphasis of the present invention is set from GH4698 heating parameters, start with terms of deformation work step distribution etc., can effectively be refined, uniformly Change GH4698 disk forging tissues, finally improve the smooth fatigue behaviour of its high temperature.

The content of the invention：

The technical problems to be solved by the invention are：In order to solve, GH4698 disk forging structural homogenities are poor, coarse grains And the unstable problem of the smooth fatigue behaviour of high temperature.

The technical scheme is that：

A kind of forging method of GH4698 alloy discs forging is provided, is comprised the following steps：

Step 1, bar is heated, be heated to 800 DEG C, heat insulating coefficient be 0.8mm/min, afterwards with 50~70 DEG C/ The firing rate of min be warming up to 990~1000 DEG C, heat insulating coefficient be 0.8mm/min, be warming up to afterwards 1100~1120 DEG C, protect Warm coefficient is 0.8mm/min；The bar after heating is used into alumina silicate heat-preservation cotton Soft Roll set afterwards, is protected at 1100~1120 DEG C Warm 30min；

Step 2, many fire time upsetting cakes are carried out to jacket bar, obtain waste base, it is ensured that per fire time deflection be 25%~35%；

Step 3, the die forgings of many fire time are carried out to waste base, obtain forging and air cooling, it is ensured that be 25% per fire time deflection~ 35%；

Step 4, solution treatment first is carried out to forging, first by forging be heated to 800 DEG C, heat insulating coefficient be 0.8mm/min, Afterwards with the firing rate of 50~70 DEG C/min be warming up to 990~1000 DEG C, heat insulating coefficient be 0.8mm/min, be warming up to afterwards 1100 DEG C, insulation 8 hours after air cooling；

Step 5, Secondary Solid Solution Treatment is carried out to forging, first by forging be heated to 800 DEG C, heat insulating coefficient be 0.8mm/min, Air cooling after being warming up to 990~1000 DEG C, be incubated 4 hours with the firing rate of 50~70 DEG C/min afterwards；

Step 6, Ageing Treatment is carried out to forging, forging is sent directly into 700 DEG C of electric furnace air cooling after insulation 16 hours.

The beneficial effects of the invention are as follows：Follow tissue change feature of the GH4698 materials in heating, rational heating Technological parameter；The strict relation distinguished between overall deformation amount and local true strain amount, reasonable, optimal design-aside forging deformation fire The secondary and secondary deflection per fire, can effectively solve GH4698 disk forging tissue odds, coarse grains, the smooth fatigue behaviour shakiness of high temperature (0.5mm~0.6mm that forging state body crystallite dimension is, crystallite dimension is in below 1.2mm, and tissue after heat treatment for the problems such as determining Uniformly).

Specific embodiment：

The manufacture of aviation type machine turbine disk forging is chosen below, and the process step of the invention is carried out specifically It is bright.

A kind of forging method of GH4698 alloy discs forging is provided, is comprised the following steps：

Step 1, bar is heated, be heated to 800 DEG C, heat insulating coefficient be 0.8mm/min, afterwards with 50~70 DEG C/ The firing rate of min be warming up to 990~1000 DEG C, heat insulating coefficient be 0.8mm/min, be warming up to afterwards 1100~1120 DEG C, protect Warm coefficient is 0.8mm/min；The bar after heating is used into alumina silicate heat-preservation cotton Soft Roll set afterwards, is protected at 1100~1120 DEG C Warm 30min；

Step 2, many fire time upsetting cakes are carried out to jacket bar, obtain waste base, it is ensured that per fire time deflection be 25%~35%； Step 3, the die forgings of many fire time are carried out to waste base, obtain forging and air cooling, it is ensured that per fire time deflection be 25%~35%；

Step 4, solution treatment first is carried out to forging, first by forging be heated to 800 DEG C, heat insulating coefficient be 0.8mm/min, Afterwards with the firing rate of 50~70 DEG C/min be warming up to 990~1000 DEG C, heat insulating coefficient be 0.8mm/min, be warming up to afterwards 1100 DEG C, insulation 8 hours after air cooling；

Step 5, Secondary Solid Solution Treatment is carried out to forging, first by forging be heated to 800 DEG C, heat insulating coefficient be 0.8mm/min, Air cooling after being warming up to 990~1000 DEG C, be incubated 4 hours with the firing rate of 50~70 DEG C/min afterwards；

Step 6, Ageing Treatment is carried out to forging, forging is sent directly into 700 DEG C of electric furnace air cooling after insulation 16 hours.

In sum, through the GH4698 disk forging even tissue, tiny of present invention production, every mechanical property is (particularly The smooth fatigue behaviour of high temperature) meet technical requirements, Project R＆D task needs can be met.

Claims (1)

1. a kind of forging method of GH4698 alloy discs forging, comprises the following steps：

Step 1, bar is heated, be heated to 800 DEG C, heat insulating coefficient be 0.8mm/min, afterwards with 50~70 DEG C/min's Firing rate be warming up to 990~1000 DEG C, heat insulating coefficient be 0.8mm/min, 1100~1120 DEG C, heat insulating coefficient are warming up to afterwards It is 0.8mm/min；The bar after heating is used into alumina silicate heat-preservation cotton Soft Roll set afterwards, is incubated at 1100~1120 DEG C 30min；

Step 2, many fire time upsetting cakes are carried out to jacket bar, obtain waste base, it is ensured that per fire time deflection be 25%~35%；

Step 3, the die forgings of many fire time are carried out to waste base, obtain forging and air cooling, it is ensured that per fire time deflection be 25%~35%；

Step 4, solution treatment first is carried out to forging, first by forging be heated to 800 DEG C, heat insulating coefficient be 0.8mm/min, afterwards With the firing rate of 50~70 DEG C/min be warming up to 990~1000 DEG C, heat insulating coefficient be 0.8mm/min, 1100 are warming up to afterwards DEG C, insulation 8 hours after air cooling；

Step 5, Secondary Solid Solution Treatment is carried out to forging, first by forging be heated to 800 DEG C, heat insulating coefficient be 0.8mm/min, afterwards Air cooling after being warming up to 990~1000 DEG C, be incubated 4 hours with the firing rate of 50~70 DEG C/min；

Step 6, Ageing Treatment is carried out to forging, forging is sent directly into 700 DEG C of electric furnace air cooling after insulation 16 hours.