The production method of the nickeliferous ring forging of large thick-wall
The invention belongs to the production technical field of ferrous materials, it is related to a kind of production method of annular forging piece, particularly relates to
And the production method of the nickeliferous ring forging of large thick-wall a kind of.
Ring rolling is also known as rolling or reaming, and it makes ring billet by footpath, the compatible deformation repeatedly of axial co-deflection area material
Sufficiently plastic deformation and volume transfer are produced in growth process, in conjunction with rational temperature control, the material of optimization can be obtained
Expect microstructure, so as to form high performance high-quality ring, looping mill rolling technique is in middle or small rings such as production bearing ring, gear blanks
Occupy critical role in part part.With developing rapidly for industry, either electric power, offshore oil platform, ship for civil use, still
Especially big heavy-duty machinery, military project, Aero-Space etc. increasingly increase to the demand of large thick-wall ring forging.
The roll forming of large thick-wall ring forging is usually using horizontal machine for rolling ring, and it shapes sketch as shown in figure 1, ring blank
It is placed horizontally between the driven roller of radial-axial ring rolling mill and core roller, driven roller rotates, core roller makees feed motion, ring
Roll gap is iterated through under driven roller and the effect of core roller and produces continuous and local deformation, and a pair of guide rollers (also known as embracing roller) are symmetrical
In deformed area entrance and exit both sides, ring rolling is play the guiding role, ring often rolls one turn, its radial direction (X by roll gap
To) wall thickness reduction, axial direction (Y-direction) can then increase accordingly.Upper cone roller and lower cone roller are taper, respectively in the level of ring
End face and lower surface are processed.
Because nickeliferous (1.6-3.75%Ni) the ring forging build of large thick-wall is huge, and hot procedure is in high temperature,
High pressure and unstable shaped state, influence factor is more, it is difficult to be controlled, its production technology has the following disadvantages：
(1) the nickeliferous ring forging blank weight of large thick-wall is often beyond 5t, and blank volume is big, final ring forging blank dimension
It is difficult to reasonable distribution footpath, axial deflection during ring is rolled over, causes ring forging upper surface generation groove or upper surface inner circle to be collapsed
Fall into.By increasing the production surplus of ring forging height and internal diameter direction, so as to which the defect turning such as groove is fallen, but ring lumber recovery
It is low；
(2) by improving the heating-up temperature of ring forging, the hot-workability of steel is increased, although this method eliminates large-scale ring
The groove defect of forging upper surface, but because ring rolles over temperature height eventually, make finished product ring forging coarse grains, tissue odds；
(3) the nickeliferous ring forging dimensions of large thick-wall is big, and hot procedure is in high temperature, high pressure and unstable forming shape
State, finished product ring forging ovality is big.
(4) the ring later stage is being rolled over because the growth rate of ring diameter is fast, and embracing roller active force and be not adjusted in time, most
Ring ovality can be caused big eventually, but ring size is big, ring wall is thick, and ovality is difficult to be corrected；
(5) the nickeliferous ring forging of large thick-wall in cooling procedure surface and core due to different, the cooling of cooldown rate
During ring can from outward appearance to inner essence obtain different tissues and make ring uneven microstructure.
The content of the invention
For the defect of prior art, it is an object of the invention to provide a kind of producer of the nickeliferous ring forging of large thick-wall
Method, the inventive method solves the problems of the prior art, and thus obtained ring forging lumber recovery is high, steel structure property is obtained
Improve, requirement can be met.
To achieve these goals, the present invention is adopted the following technical scheme that：
A kind of production method of the nickeliferous ring forging of large thick-wall, comprises the following steps：
Base step, annular blank is made by cylinder material；
Ring step is rolled over, many fire time of progress on the axial ring rolling machine of footpath are placed in after the annular blank is heated and roll over ring, so as to obtain
To ring forging base；
Heat treatment step, multiple ring forging bases are spread out and are air-cooled to 250-350 DEG C, are made annealing treatment afterwards.
Machining steps, finished product ring forging is processed into by the ring forging base after the heat treatment.
In aforementioned production method, as a kind of preferred embodiment, in the base step, the cylinder material
Ratio of height to diameter (H/D) is 1.6≤H/D≤2.5, and wherein H is the height of cylinder material, and D is the diameter of cylinder material.It is highly preferred that
The diameter D of the cylinder material is 850-900mm.
In aforementioned production method, as a kind of preferred embodiment, in the base step, the cylinder material is first
Deformation temperature is first heated to, the annular blank is made in then forged and punching；It is highly preferred that the beginning forging temperature of the forging
Spend for >=1100 DEG C, final forging temperature is >=800 DEG C；The forging is followed successively by：Upset for the first time, chamfered edge, second of upset, rolling
Circle, upset, the slight rolling of third time, the 4th time it is upset.It is highly preferred that the deformation temperature is 1160-1260 DEG C.
In aforementioned production method, a kind of preferred embodiment, in the base step, the obtained annular are used as
The size of blank is as follows：External diameter is 1000-2000mm, and internal diameter is 200-500mm, is highly 200-700mm.
In aforementioned production method, as a kind of preferred embodiment, in the rolling ring step, the shaping of ring process is being rolled over
In the stage, ring ovality is measured by measurement bar, if ovality exceedes setting, pass through the cone roller up and down of the Ring Rolling Machine
Clamping stretches in the ring upper and lower end face for rolling over ring process and radially ring to realize ring full circle using core roller as fulcrum.It is preferred that
Ground, the setting of the ovality is≤8mm.
In aforementioned production method, as a kind of preferred embodiment, in the rolling ring step, the temperature of the heating is
In aforementioned production method, as a kind of preferred embodiment, in the rolling ring step, many fire time roll over rings
Fiery time is 2-4 times.The start temperature that each fire time rolles over ring is >=1150 DEG C, and final temperature is >=800 DEG C.It is highly preferred that when described
When the fire time that many fire time roll over rings is 2, the 1st fire time roll over the external diameter of blank after ring for the finished product ring forging and the annular blank outside
The half of footpath size sum.
In aforementioned production method, as a kind of preferred embodiment, in the heat treatment step, the annealing
Temperature be 650-710 DEG C, annealing time can be determined according to finished product ring forging wall thickness.
In aforementioned production method, as a kind of preferred embodiment, the specification of the finished product ring forging is as follows：External diameter OD
For 3000-5000mm；Wall thickness is 100-500mm；High H is 200-500mm.
In aforementioned production method, as a kind of preferred embodiment, in the finished product ring forging, nickel content is 1.6-
Compared with prior art, the present invention has the advantages that：
(1) method of the invention is mainly recessed by the nickeliferous ring forging upper surface of the effective prevention large thick-wall of following three aspects
The generation that groove or upper surface inner circle are collapsed：
1. it is appropriate to increase the height of making blank of ring blank.
2. many fire of fire such as two are formulated and roll over ring, such as fire of regulation one rolles over ring outside dimension, and a fire melts down the heat time.
3. the amount of feeding of cone roller is increased during ring is rolled over, two fire roll over ring and easily produce upper end planar defect, and this is accomplished by increasing
The pressure of big cone roller, increases the deformation of ring short transverse.
(2) method of the invention solves the not corrigibility problem of large thick-wall ring forging ovality；
(3) method flaw detection qualification rate of the invention is improved, and the structure property of steel is improved；
(4) method of the invention realizes large thick-wall ring forging footpath, axially mutually coordinated deformation, obtains accurate shape chi
Very little and good tissue, performance.
Brief description of the drawings
Fig. 1 is ring parts rolling forming sketch；
Wherein, 1, radial direction frame；2nd, axial rack；3rd, home roll；4th, core roller；5th, roller is embraced；6th, cone roller；7th, locating piece；8th, ring
Part Z-direction draw direction is radial drawing direction (correction ring)
Fig. 2 is the nickeliferous ring forging micro-organization chart (× 100) of large thick-wall；
Fig. 3 is the nickeliferous ring forging micro-organization chart (× 1000) of large thick-wall；
Fig. 4 be the nickeliferous ring forging of G20Cr2Ni4A large thick-walls that existing Technology for Heating Processing is obtained micro-organization chart (×
Below by specific embodiment, the present invention is described in detail, but the present invention is not limited thereto.
The production method for the nickeliferous ring forging of large thick-wall that the present invention is provided comprises the following steps：
(1) base：First by cylindrical material section heating to deformation temperature, upset → chamfered edge → for the first time is carried out successively afterwards
Secondary upset → round as a ball → upset → slight rolling → four time of third time be upset → punching, finally annular blank processed (i.e. ring
First, by regulation blanking, and the cylinder material after blanking is heated to deformation temperature, the deformation temperature is preferably
1160-1260 DEG C (such as：1165 DEG C, 1180 DEG C, 1200 DEG C, 1220 DEG C, 1240 DEG C, 1250 DEG C, 1255 DEG C), the heat time is
3-7h is (such as：3.5h, 5h, 6h, 6.5h), the ratio of height to diameter (H/D) of the cylinder material is 1.6≤H/D≤2.5 (such as H/D=
1.7th, H/D=2.0, H/D=2.2, H/D=2.4), wherein H is the height of cylinder material, and D is the diameter of cylinder material, preferably
Ground, the diameter D of the cylinder material is 850-900mm.
Then, annular blank is made in forged and punching；The forging is followed successively by：Upset for the first time, chamfered edge, second of pier
Slightly, round as a ball, upset, the slight rolling of third time, the 4th time it is upset, the initial forging temperature of the forging is >=1100 DEG C (such as 1102
DEG C, 1110 DEG C, 1120 DEG C, 1150 DEG C, 1180 DEG C, 1200 DEG C, 1240 DEG C), final forging temperature be >=800 DEG C (such as 810 DEG C, 850
℃、880℃、900℃、950℃、1000℃)；The size that annular blank is obtained after punching is as follows：External diameter is 1000-2000mm,
Internal diameter is 200-500mm, is highly 200-700mm.
(2) ring is rolled over：It is placed in after annular blank is heated on the axial ring rolling machine of footpath and carries out many fire time rolling rings, so as to obtains ring forging
Part base (i.e. blank ring)；
First, annular blank is heated, the temperature of heating for 1160-1260 DEG C (such as：1165℃、1180℃、1200
DEG C, 1220 DEG C, 1240 DEG C, 1250 DEG C, 1255 DEG C), soaking time is according to blank specification, and general soaking time is 0.5h/
100mm；Preferably, the heat time be 1-5h (such as：2h、3h、4h、4.5h).
Then, the annular blank after heating is placed on the axial ring rolling machine of footpath and carries out many heated roller rings, it is preferable that many fire roll over ring
Fire time be 2-4 times.It is each fire time roll over ring start temperature for >=1150 DEG C (such as：1165℃、1180℃、1200℃、1220
DEG C, 1240 DEG C, 1250 DEG C, 1255 DEG C), final temperature be >=800 DEG C (such as 810 DEG C, 850 DEG C, 880 DEG C, 900 DEG C, 950 DEG C,
1000℃).Illustrated below by taking 2 fire as an example, the 1st fire time rolles over ring：Annular blank after heating is placed in footpath axial ring rolling machine
Upper the 1st fire that carries out rolles over ring, start temperature >=1150 DEG C, and final temperature is >=800 DEG C, and the blank external diameter that the 1st fire time is rolled over after ring is
The half of finished product ring forging and annular blank outside dimension sum；2nd fire time rolles over ring：1st fire time is rolled over to the blank heating after ring
To 1160-1260 DEG C (such as：1165 DEG C, 1180 DEG C, 1200 DEG C, 1220 DEG C, 1240 DEG C, 1250 DEG C, 1255 DEG C), the heat time
For 1-5h, the blank for then again rolling over the 1st fire time after heating after ring is placed in the fire of progress the 2nd on the axial ring rolling machine of footpath and rolles over ring, opens
Beginning temperature >=1150 DEG C, final temperature is >=800 DEG C, until rolling ring has more 20-50mm to than the dimensions of finished product ring forging
The specification of surplus.The later stage that ring is rolled in the 2nd fire is truing phase, and the ring for carrying out rolling over ring is measured by measurement bar
Ovality, if ovality exceedes setting, ring upper and lower end face is clamped and with core by the cone roller up and down of the Ring Rolling Machine
Roller is that fulcrum radially stretches ring to realize the effect of ring full circle and correction ring ovality greatly.The regulation of the ovality
It is worth for≤8mm (such as 2mm, 3mm, 4mm, 5mm, 6mm, 7mm).Increase the amount of feeding and pressure of cone roller, energy during ring is rolled over
The effective upper surface inner circle that avoids collapses generation with upper surface groove.It is exactly to increase in fact to increase the cone roller amount of feeding and pressure
The pressure of cone roller, increases the deformation of ring short transverse, because different manufacturers Ring Rolling Machine model is different, power is also different, because
This, the occurrence of the amount of feeding of cone roller will be determined according to Ring Rolling Machine model.It may also be said that being annular blank preparing to roll over ring billet material
When, the normal many 30-50mm of the height ratio to be designed of annular blank, so during rolling, the feeding of short transverse
Measure nature and become big.
The method of the present invention is not on the premise of ring blank i.e. annular blank heating-up temperature is improved, and ring fire time is rolled in increase,
Prevent because temperature reduction reduces material plasticity, be 2 times when rolling over ring fire time, a fire roll over ring external diameter can according to factory's heating furnace and
Finished product ring size is determined, usually the half of blank external diameter and finished product ring external diameter sum.
Cone roller and core roller need to be only controlled, ring is bigger during rolling over ring, the possibility for ellipse occur is bigger, roll over the ring later stage such as
Fruit ovality is big, can be corrected by cone roller and core roller.
Roll over ring truing phase and ring ovality is measured by measurement bar, once find that ovality is excessive, by pushing cone roller
The small one end of ring diameter is clamped, then ring (such as Fig. 1) is stretched along Z-direction, so as to play the purpose of correction ovality.
In the present invention, by understanding the metal flow principle in the ring forging operation of rolling, on large thick-wall ring forging
Facing groove or upper surface inner circle collapse Producing reason and analyzed, when ring is in rolling, although metal is main
Along the circumferential direction flow, but simultaneously also can above and below flow, when ring wall thickness Direction distortion amount is larger, what is flowed above and below metal becomes
Gesture is also more obvious, and in particular for large thick-wall ring forging, " wall thickness reduction, height reduce, the deformation pattern of enlarged-diameter, such as
Not enough, the deflection of short transverse is limited when rolling over ring for fruit blank height of making blank, is easy for producing the defects such as sunken end face, increases ring
The height and cone roller volume under pressure of forging blank have good improvement result to plate defectses.
(3) it is heat-treated：Ring forging base be after blank ring is rolled over mustn't heap it is cold, it is necessary to spread out (each blank ring and ring it
Between distance preferably >=1m) air cooling, ring forging is air-cooled to the laggard furnace annealing of certain temperature, so that the tissue of steel, performance etc.
Meet and require.
In the heat treatment step, the type of cooling and annealing charging temperature of ring blank are controlled, suppresses tissue odds
Phenomenon.As a kind of preferred embodiment, be air-cooled to 250-350 DEG C (such as 260 DEG C, 280 DEG C, 300 DEG C, 320 DEG C, 330
DEG C, 340 DEG C), annealing temperature be 650-710 DEG C (such as 660 DEG C, 680 DEG C, 690 DEG C, 700 DEG C, 708 DEG C), annealing time can root
According to finished product ring wall thickness, it is preferable that annealing time is 5-20h (such as 5h, 7h, 9h, 11h).
(4) machine：Ring forging base after heat treatment is processed into finished product ring forging.
The wall thickness of the nickeliferous ring forging of finished product heavy wall produced by the invention is 100-500mm, 4-10 tons of weight, and nickel content is
1.6-3.75%.The material of heretofore described nickeliferous ring forging can be G20Cr2Ni4A.
The size for the blank that each stage obtains in exemplary explanation the inventive method：If pre-acquired finished product ring forging
Size is：3558mm (OD) × 3017mm (ID) × 262mm (H), weight：5744Kg；The blank ring i.e. ring forging then produced
Base needs to add 30mm production surplus, i.e. the size of ring forging base is：3588mm × 2987mm × 292mm, weight 7112Kg；With
It is in the size that the ring blank of production ring forging base is annular blank：1690mm(OD)×300mm(ID)×430mm(H)；By
When cylinder material is to produce blank ring i.e. ring forging base, there is scaling loss, have punching clout, therefore the material of these wastes is united
System is counted in, and it is that weight 7341Kg, H that the cylinder that ring forging base needs is expected are 1470mm to roll over a blank ring, and D is 900mm.
The method of the present invention is illustrated below by embodiment.
The material of the ring forging of rolling is G20Cr2Ni4A, it is desirable to which the specification of the ring forging rolled out is：External diameter is 3.6m,
Wall thickness is 300mm, is highly 250mm, gross weight is 6104Kg.Its production method is as follows：
(1) base：By Billet cutting into cylinder material section, the length H of material section is 1590mm, and material section diameter D is
900mm, by material section heating to 1200 DEG C or so, is incubated 5h, initial forging temperature is 1000 DEG C or so, and final forging temperature is 800 DEG C or so,
Carry out upset → chamfered edge → upset → round as a ball for the second time → upset → slight rolling of third time for the first time successively in the temperature range
Side → four time be upset → punching, annular blank is finally made, the blank dimension external diameter forged is 1366mm, and internal diameter is 434mm,
Highly it is 400mm.
(2) ring is rolled over：Annular blank is put into heating furnace and is heated to 1200 DEG C or so, 3h is incubated, is then placed rolling
A fire is carried out in ring machine and rolles over ring, start temperature is 1200 DEG C or so when a fire rolles over ring, and final temperature is 800 DEG C, radial feed speed
Degree is that 1.2A, pressure are 1.4A, and axial feed velocity is that 1.0A, pressure are 1.4A, and the external diameter that a fire rolles over blank after ring is 2.5m,
Wall thickness is 400mm, is highly 330mm；Then two fire are carried out again and roll over ring, and the same fire of Parameter Conditions that two fire roll over ring is rolled over ring, rolled over
The ring later stage carries out the correction of forging ovality, when oval angle value is more than 8mm, and cone roller clamps the small one end of the ring diameter up and down
And ring is radially stretched using core roller as fulcrum to realize the effect of ring full circle and correction ring ovality greatly, two fire are rolled over after ring
Obtain being expected the ring forging base of wall thickness, its external diameter is 3634mm, and wall thickness is 334mm, is highly 284mm.
Wherein, Ring Rolling Machine model：D53K-5000-400/315, during ring is rolled over, footpath/axial feed velocity, pressure
Represented with current flow.
(3) it is heat-treated：Ring forging base roll over after mustn't heap it is cold, it is necessary to spread (the distance between ring and ring >=1m) out empty
Cold, ring forging is cooled to 300 DEG C or so and enters furnace annealing, and annealing temperature is 700 DEG C or so, and annealing time is 10h, with stove after annealing
(4) the ring forging base after heat treatment is machined, finally gives the finished product ring forging for meeting size requirement.Using
The ring forging upper surface groove and upper surface inner circle of the present embodiment method production reach 90% without generation, stock utilization is collapsed
The ring forging micro-organization chart of the present embodiment production is referring to Fig. 2 and Fig. 3, it can be seen that the ring forging
Microstructure is uniform, grain size >=6；In addition, the turning ability of the ring forging is good, hardness≤225HBW.
In addition to heat treatment step and the difference of embodiment 1, other production processes are same as Example 1.Wherein, the comparative example
Technology for Heating Processing it is as follows：Ring is air-cooled to 650 DEG C or so rear direct shove charges and annealed after having rolled over, annealing temperature is 700 DEG C
Left and right, annealing time is 10h.
Heterogeneous microstructure such as Fig. 4 for the G20Cr2Ni4A ring forgings that the comparative example is obtained, it will be apparent from this figure that ring
Uneven microstructure in forging, grain size is thick.