CN104625376B - The flash welding manufacturing process of aluminium alloy heavy in section ring - Google Patents

Abstract

The invention discloses the flash welding manufacturing process of a kind of aluminium alloy heavy in section ring, the steps include: first to be fixed on fixture by the aluminium alloy heavy in section ring base of band opening, switch on power, make electric current reach right-hand member from left end through back and form circulation, preheat；Drive right-hand member close to left end again, carry out weak flash of light；Improve feed speed again, adjust electric current, carry out intense flash, form temperature field；Further according to temperature field, calculate high temperature mushy zone and the length in high temperature microstructure roughening district, so that it is determined that upset distance, carry out upset；Pressurize a period of time again.The method can form stable, rational temperature field, and ensure that in compressing process, the metal of high temperature mushy zone can all be ejected matrix, the metal in high temperature microstructure roughening district can occur sufficient plastic deformation, by recovery and recrystallization crystal grain thinning, it is thus achieved that superior in quality flash welding ring.The method shapes for sectional area bigger ring flash welding.

Description

The flash welding manufacturing process of aluminium alloy heavy in section ring

Technical field

The present invention relates to a kind of welding method, the flash welding having particularly related to aluminium alloy heavy in section ring shapes Method.

Background technology

Flash welding is a kind of solid State Welding, forms certain temperature by flash of light in two welding end surface of workpiece , then by the effect of upset force, workpiece is welded.Therefore, temperature field and the Reasonable of upset parameter Conjunction is the key realizing high-quality welding, and suitable temperature field can provide suitable diffusion activation for metallic atom Can, the phase counterdiffusion of two ends atom during acceleration forge, meet compressing process plastic deformation simultaneously and become The demand of shape, and the foundation in temperature field is mainly determined by flash stage.The temperature formed by flash of light process , it is broadly divided into two parts: high temperature mushy zone and high temperature microstructure are roughened district.In compressing process, high temperature The metal of mushy zone is ejected matrix；Plasticity is there is in the metal in high temperature microstructure roughening district under the effect of upset force Deformation, forms the tissue that crystal grain is the most tiny.

Actually aluminium alloy is to be difficult to set up suitable temperature field when flash welding shapes, and closes especially for aluminum The flash welding of gold heavy in section ring shapes, normal for, the sectional area of the welding end surface of workpiece is the biggest, flash of light The required power provided of butt welding machine is the biggest.But when flash of light, the welding end surface spot temperature of workpiece is Height, is the position being consumed at first, and this part metals can be gone out along with flash of light is injected, takes away substantial amounts of Heat.So when power is the biggest, glistening the most violent, at this moment flash of light scaling loss speed is high, heat transfer rate is little, The thermograde formed on workpiece is big, and during upset, plastically deformable region is less, thus causes rosin joint occur Phenomenon (i.e. " is welded unreal "), and workpiece interface area is the biggest, and this phenomenon is the most obvious.Therefore, for Aluminium alloy heavy in section ring is it is generally required to use reduction flash intensity, prolongation flash time to set up suitable temperature Degree field.But flash intensity is the least, the oversize meeting of flash time cause set up temperature field shadow the mildest, hot Ring district wider, i.e. high temperature mushy zone and high temperature microstructure roughening district is wider.When upset, due to its upset row Journey is fixing, and the metal of these high temperature mushy zone can not all be ejected matrix in limited upset stroke, Thermal stress in the high temperature paste-like metallic that these are not ejected cooling procedure after having welded and follow-up Under bulging power effect during the shape of school, easily form crackle.High temperature microstructure roughening district metal as Can not get enough deformation, it is impossible to sufficiently recrystallization, and cause grain size defective, make workpiece scrap.

Disclosed in 20 days June in 2012, Chinese invention patent description CN 102500899 A discloses one Using the method that preheating flash butt welding produces bloster, the method includes clamping workpiece, pre-flash, preheats, dodges Light, upset, heating pressurize and the dismounting step such as workpiece, specifically by after good for clamping workpiece, switch on power Carry out pre-flash, after flashing allowance reaches preset value, then with the pre-thermal pulse set, workpiece preheated, Glistening it the most stage by stage, the flashing speed in each stage and flashing allowance are fixing, it After, upset immediately, and the pressure of workpiece applying setting is carried out pressurize electrified regulation, after a period of time, Take out workpiece.Although the flash welding that the method is capable of bloster shapes, but it is common to be also only limitted to Q345 etc. The flash welding of material, heat transfer rate this kind of for aluminium alloy is compared with slow, the fireballing material of scaling loss, it is not easy to shape Becoming suitable temperature field, institute is in this way and inapplicable.

In April, 2000 has issued one by Huang Huagang etc. in the 4th phase of volume 30 of Chinese Magazines " electric welding machine " The paper of entitled " great section workpiece preheating flash butt welding technical study " that people writes, the publication presents one The technique of great section workpiece preheating flash butt welding, workpiece is after dodging gentle preheating procedure, at workpiece end face along axle To setting up temperature field, by continuing with heat during flash of light, adjust temperature field.Although this method Temperature field can be formed, but do not disclose concrete technological parameter, and the method uses and passes through Temperature field is set up in preheating intermittently, and flash of light process adjusts temperature field, and therefore this process is discontinuous, The temperature field formed is unstable, can affect by welding quality.

Summary of the invention

The technical problem to be solved in the present invention be to provide a kind of set up during continuous print glistens one stable, Reasonably temperature field, it is ensured that in compressing process, the metal of high temperature mushy zone can all be ejected matrix, high temperature The metal in microstructure coarsening district can occur sufficient plastic deformation, by recovery and recrystallization crystal grain thinning, thus The flash welding realizing aluminium alloy heavy in section ring shapes, and the method can improve welding quality.

For solving above-mentioned technical problem, the flash welding manufacturing process of aluminium alloy heavy in section of the present invention ring, Its technical scheme comprises the following steps:

Being fixed on left fixture by the left end of the aluminium alloy heavy in section ring base of band opening, right-hand member is fixed on right fixture On；Set the operating power of flash welder as P=250KVA～750KVA, electric current I₀=45KA～55KA, Switching on power, at this moment there is bigger distance at both ends open, electric current can be from the left end of ring base through ring base Back reaches the right-hand member of ring base and forms circulation, and ring base has resistance, and ring base, through ring base, is carried out by electric current Heating, after a period of time, the left end of ring base and right-hand member are all heated to T₀=100～150 DEG C, after being conducive to Temperature field is formed during continuous flash of light；

Adjusting electric current is I=20KA～30KA, enables flash of light process to be maintained at low-intensity and persistently carries out, now, The flash of light scaling loss speed v of ring base₀=1.00mm/s～1.42mm/s；Drive right fixture make the right-hand member of ring base with and ring The flash of light scaling loss speed v of base₀Equal feed speed v is close to left end, when left and right two ends distance≤ During 5.00mm, electric current reaches right-hand member from left end through opening part, now, can produce substantial amounts of heat at opening part Amount, melts left and right both ends of the surface metal, the most outwards sprays to be formed and dodge after forming liquid lintel and explosion occurring Light, owing to the flash of light scaling loss speed of ring base is relatively low, is less than heat transmission speed, the heat energy that flash of light produces Enough fully along ring base transfers to far-end, and right-hand member is to the flash of light scaling loss speed of the feed speed of left end with ring base Spend equal, thus two ends remain at≤distance of 5.00mm is constant, flash of light process continues t=2s～4s；

Instantaneous feed speed is risen to 10.00mm/s～14.20mm/s, electric current is adjusted to simultaneously I₁=60KA～75KA, now, the flash of light scaling loss speed of ring base is 2.80mm/s～3.12mm/s, makes opening There is violent flash of light in place, produces substantial amounts of metallic vapour and form protective layer, protect follow-up compressing process, should Process reaction is violent, and the response time is shorter, and left and right two ends high temperature metallic material is burnt, and scaling loss is a length of d₀=1.26mm～2.18mm, and the heat produced that glistens has little time to transmit to far-end, and ultimately form top Temperature field needed for forging, left and right two ends temperature is higher than T₁The aluminium alloy of=550 DEG C of parts is high temperature pasty state, left, Right two ends temperature is at T₂=420 DEG C～T₁Time between=550 DEG C, aluminium alloy is that high temperature microstructure is roughened shape, process of glistening Complete；

The a length of of high temperature mushy zone is gone out according to the Temperature calculating that flash of light process is formed d₁=6.00mm～8.00mm, a length of d in high temperature microstructure roughening district₂=10.00mm～12.00mm, thus set Upset distance when determining upset is D=8.00mm～14.00mm；In the moment that flash of light process completes, with The upset force of 15KN～30KN carries out upset to the left and right two ends of ring base, makes the left and right two ends of ring base The complete upset of metal of high temperature mushy zone is gone out, and enables the metal in high temperature microstructure roughening district to occur The deformation of 20%～50%；

Described heavy in section ring takes apart after pressurize 15s～25s under the effect of upset force from welding machine.

The mathematic(al) representation in the temperature field that described flash of light process is formed is:

$T\left(x\right)=\frac{(1-\mathrm{\η})(P-I^2{\mathrm{\ρ}}_T\frac{L}{S})}{4CS\mathrm{\ρ}\mathrm{\π}\mathrm{\λ}}\exp \[-\frac{{(x-v_{0}t-d_0/2)}^2}{4\mathrm{\λ}t}\]+T_0$

Wherein, T (x) is the temperature at distance end face x；η is the heat ratio lost because of flash of light；P is Operating power during flash of light；I is operating current during flash of light；ρ_TFor resistivity；L is the girth of ring；S Cross-sectional area for ring；d₀For scaling loss length；v₀For flash of light scaling loss speed during weak flash of light；T is weak flash of light Time；λ is thermal conductivity；T₀For preheating temperature；C is thermal capacitance；ρ is density of material.

The computing formula of described upset distance is as follows:

D=d₁+ (0.2～0.5) d₂

In formula:

d₁Length for high temperature mushy zone；

d₂The length in high temperature microstructure roughening district.

Described aluminium alloy is preferably 2A70 alloy.

Compared with prior art, beneficial effects of the present invention is as follows:

The flash welding manufacturing process of aluminium alloy heavy in section of the present invention ring, by before flash of light, makes electric current Reach the right-hand member formation circulation of ring base, the left and right two ends to ring base through the back of ring base from the left end of ring base Preheating, this warm is stable, it is possible to ensure that follow-up flash of light process forms stable, rational temperature field.

Through first weak flash of light, then the flash model of intense flash, when weak flash of light, heat transmission speed is greater than The flash of light scaling loss speed of aluminium alloy, heat can be along the transfers of ring base to far-end, it is ensured that form temperature field. In this temperature field, when temperature is more than T₁When=550 DEG C, aluminium alloy is high temperature pasty state, this Temperature numerical is substituted into The mathematic(al) representation in temperature field, can calculate x₁Numerical value, and draw a length of of high temperature mushy zone d₁=6.00mm～8.00mm；When temperature is at T₂=420 DEG C～T₁Time between=550 DEG C, aluminium alloy is high temperature microstructure Roughening shape, this Temperature numerical substitutes into the mathematic(al) representation in temperature field, can calculate x₂Numerical value, and draw The a length of d in high temperature microstructure roughening district₂=10.00mm～12.00mm；Further according to formula D=d₁+ (0.2～0.5) d₂, may finally determine that the distance of upset is D=8.00mm～14.00mm；This upset distance ensure that ring The complete upset of metal of the high temperature mushy zone at the left and right two ends of base is gone out, and makes the gold in high temperature microstructure roughening district Genus can occur the deformation of 20%～50%, enables high temperature microstructure roughening district sufficiently recovery and recrystallization, it is thus achieved that Organize excellent welding junction, it is ensured that the flash welding quality of aluminium alloy heavy in section ring.

As a example by the trade mark aluminium alloy heavy in section ring as 2A70, after heat treatment detect this alloy heavy in section ring The room temperature tensile properties of part welding position, its tensile strength is that 389MPa (uses more than design and requires 358.2MPa), elongation after fracture is 7% (using 6% required more than design).

Accompanying drawing explanation

With detailed description of the invention, the present invention is described in further detail below in conjunction with the accompanying drawings.

Fig. 1 is that ring base preheats schematic diagram.

Fig. 2 is the flash stage schematic diagram of ring base.

Fig. 3 is the temperature field schematic diagram at the end of flash of light process.

Detailed description of the invention

The flash welding manufacturing process implementing aluminium alloy heavy in section of the present invention ring needs to provide flash butt welding The equipment such as machine, mechanical hand.The party is described in detail below as a example by China's material trademark aluminium alloy as 2A70 The detailed description of the invention of method:

The main chemical elements content (percentage by weight) of this alloy is: containing Cu amount 1.9%～2.5%, contain Mg amount 1.4%～1.8%, containing Fe amount 0.9%～1.5%, ni content 0.9%～1.5%, containing Ti measure 0.02%～0.10%, 0.20% is measured containing Mn, containing Zn amount 0.30%, si content 0.35%, other elements Single≤0.05% and summation≤0.10%, surplus be Al.

The flash welding shaping process step of this alloy heavy in section ring is as follows:

Step 1: preheating.The left end 121 of the aluminium alloy heavy in section ring base 100 of band opening is fixed on left fixture On 111, right-hand member 122 is fixed on right fixture 112；Set the operating power of flash welder as P=250KVA～750KVA, electric current I₀=45KA～55KA, switches on power, and at this moment exists at both ends open Distance relatively big, electric current can reach ring base from the left end 121 of ring base 100 through the back 101 of ring base 100 The right-hand member 122 of 100 forms circulation, as it is shown in figure 1, owing to there is resistance in ring base 100, can make ring base 100 heatings, after a period of time, left end 121 and the right-hand member 122 of ring base 100 are all heated to T₀=100～150 DEG C, during follow-up flash of light, form temperature field.

Step 2: weak flash of light.Adjust electric current be I=20KA～30KA, enable flash of light process be maintained at low by force Degree is persistently carried out, now, and the flash of light scaling loss speed v of ring base 100₀=1.00mm/s～1.42mm/s；Drive the right side Fixture 112 makes the right-hand member 122 of ring base 100 with the flash of light scaling loss speed v with ring base 100₀Equal feeding speed Degree v close to left end 121, as the distance≤5.00mm at left and right two ends, as in figure 2 it is shown, electric current from Left end 121 reaches right-hand member 122 at opening 120, now, can produce substantial amounts of heat at opening part, molten Changing left and right both ends of the surface metal, after forming liquid lintel and explosion occurring, the most outwards injection forms flash of light, by Relatively low in the flash of light scaling loss speed of ring base 100, it is less than heat transmission speed, the heat that flash of light produces can Fully along ring base 100 transfers to far-end, and right-hand member 122 is to the feed speed of left end 121 and ring base 100 Flash of light scaling loss speed equal, so two ends remain at≤distance of 5.00mm is constant, flash of light process is held Continuous t=2s～4s.

Step 3: intense flash.Instantaneous feed speed is risen to 10.00mm/s～14.20mm/s, will simultaneously Electric current is adjusted to I₁=60KA～75KA, now, the flash of light scaling loss speed of ring base 100 be 2.80mm/s～ 3.12mm/s, makes to occur at opening 120 violent flash of light, produces substantial amounts of metallic vapour, for follow-up upset Time form protective layer, this process reaction is violent, and the response time is shorter, and left and right two ends high-temperature part is burnt One segment length is d₀The metal material of=1.26mm～2.18mm, and glisten produce heat have little time to Far-end transmits, and ultimately forms the temperature field needed for upset, as it is shown on figure 3, when temperature is higher than T₁=550 DEG C Time, 2A70 alloy is high temperature pasty state, when temperature is at T₂=420 DEG C～T₁Time between=550 DEG C, 2A70 alloy Shape, i.e. 0～x it is roughened in high temperature microstructure₁Between be high temperature mushy zone, x₁～x₂It is roughened district, flash of light for high temperature microstructure Process completes.

Step 4: upset.The mathematic(al) representation in the temperature field according to the formation of flash of light process is:

$T\left(x\right)=\frac{(1-\mathrm{\η})(P-I^2{\mathrm{\ρ}}_T\frac{L}{S})}{4CS\mathrm{\ρ}\mathrm{\π}\mathrm{\λ}}\exp \[-\frac{{(x-v_{0}t-d_0/2)}^2}{4\mathrm{\λ}t}\]+T_0$

Wherein, T (x) is the temperature at distance end face x；η is the heat ratio lost because of flash of light；P is Operating power during flash of light；I is operating current during flash of light；ρ_TFor resistivity；L is the girth of ring；S Cross-sectional area for ring；d₀For scaling loss length；v₀For flash of light scaling loss speed during weak flash of light；T is weak flash of light Time；λ is thermal conductivity；T₀For preheating temperature；C is thermal capacitance；ρ is density of material.

When temperature is more than T₁When=550 DEG C, 2A70 alloy is high temperature pasty state, and this temperature substitutes into the number in temperature field Learn expression formula, x can be calculated₁Numerical value, and draw a length of of high temperature mushy zone d₁=6.00mm～8.00mm, when temperature is at T₂=420 DEG C～T₁Time between=550 DEG C, 2A70 alloy is high temperature Microstructure coarsening shape, substitutes into this temperature the mathematic(al) representation in temperature field, can calculate x₂Numerical value, and Go out a length of d in high temperature microstructure roughening district₂=10.00mm～12.00mm；Further according to formula D=d₁+ (0.2～0.5) d₂, upset distance during upset can be set as D=8.00mm～14.00mm；In flash of light The moment that process completes, with the upset force of 15KN～30KN, the left and right two ends of ring base 100 are carried out upset, The complete upset of metal making the high temperature mushy zone at left and right two ends is gone out, and makes the metal in high temperature microstructure roughening district The deformation of 20%～50% can occur.

Step 5: pressurize.The heavy in section ring of welding forming is kept under the effect of upset force 15s～25s, Just can take apart from flash butt welder after weld seam fully combines.

Using the 2A70 alloy heavy in section ring of said method welding forming, its axial cross section areal extent is 4500mm²Above.

Claims (4)

1. the flash welding manufacturing process of an aluminium alloy heavy in section ring, it is characterised in that include following step Rapid:

Being fixed on left fixture by the left end of the aluminium alloy heavy in section ring base of band opening, right-hand member is fixed on right fixture On；Set the operating power of flash welder as P=250KVA～750KVA, electric current I₀=45KA～55KA, Switching on power, electric current can reach the right-hand member formation circulation of ring base from the left end of ring base through the back of ring base, right Ring base heats, and after a period of time, the left end of ring base and right-hand member are all heated to T₀=100～150 DEG C；

Adjusting electric current is I=20KA～30KA, enables flash of light process to be maintained at low-intensity and persistently carries out, this Time, the flash of light scaling loss speed v of ring base₀=1.00mm/s～1.42mm/s；Right fixture is driven to make the right-hand member of ring base With the flash of light scaling loss speed v with ring base₀Equal feed speed v is close to left end, when left and right two ends During distance≤5.00mm, electric current reaches right-hand member from left end through opening part, and can produce greatly at opening part The heat of amount, melts left and right both ends of the surface metal, the most outwards injection after forming liquid lintel and explosion occurring Forming flash of light, now, the flash of light scaling loss speed of ring base is relatively low, is less than heat transmission speed, and flash of light produces Heat can be fully along ring base transfers to far-end, and right-hand member is to the sudden strain of a muscle of the feed speed of left end Yu ring base Light scaling loss speed is equal, make two ends remain at≤distance of 5.00mm is constant, flash of light process continues T=2s～4s；

Instantaneous feed speed is risen to 10.00mm/s～14.20mm/s, electric current is adjusted to simultaneously I₁=60KA～75KA, now, the flash of light scaling loss speed of ring base is 2.80mm/s～3.12mm/s, makes opening There is violent flash of light in place, produces substantial amounts of metallic vapour and form protective layer, protect follow-up compressing process, should Process reaction is violent, and the response time is shorter, and left and right two ends high temperature metallic material is burnt, and scaling loss is a length of d₀=1.26mm～2.18mm, and the heat produced that glistens has little time to transmit to far-end, and ultimately form Temperature field needed for upset, left and right two ends temperature is high temperature pasty state higher than the aluminium alloy of 550 DEG C of parts, left, When right two ends temperature is between 420 DEG C～550 DEG C, aluminium alloy is that high temperature microstructure is roughened shape, and flash of light process completes；

The a length of of high temperature mushy zone is gone out according to the Temperature calculating that flash of light process is formed d₁=6.00mm～8.00mm, a length of d in high temperature microstructure roughening district₂=10.00mm～12.00mm, thus Upset distance when setting upset is as D=8.00mm～14.00mm；In the moment that flash of light process completes, with The upset force of 15KN～30KN carries out upset to the left and right two ends of ring base, makes the left and right two ends of ring base The complete upset of metal of high temperature mushy zone go out, and enable the metal in high temperature microstructure roughening district to occur The deformation of 20%～50%；

Described heavy in section ring takes apart after pressurize 15s～25s under the effect of upset force from welding machine.

The flash welding manufacturing process of aluminium alloy heavy in section the most according to claim 1 ring, its feature Being, described aluminium alloy is 2A70 alloy.

The flash welding manufacturing process of aluminium alloy heavy in section the most according to claim 1 and 2 ring, its Being characterised by, the mathematic(al) representation in the temperature field that described flash of light process is formed is:

$T\left(x\right)=\frac{(1-\mathrm{\η})(P-I^2{\mathrm{\ρ}}_T\frac{L}{S})}{4CS\mathrm{\ρ}\mathrm{\π}\mathrm{\λ}}\exp \[-\frac{{(x-v_{0}t-d_0/2)}^2}{4\mathrm{\λ}t}\]+T_0$

Wherein, T (x) is the temperature at distance end face x；η is the heat ratio lost because of flash of light；P For operating power during flash of light；I is operating current during flash of light；ρ_TFor resistivity；L is the girth of ring； S is the cross-sectional area of ring；d₀For scaling loss length；v₀For flash of light scaling loss speed during weak flash of light；T is weak The time of flash of light；λ is thermal conductivity；T₀For preheating temperature；C is thermal capacitance；ρ is density of material.

The flash welding manufacturing process of aluminium alloy heavy in section the most according to claim 1 and 2 ring, its Being characterised by, the computing formula of described upset distance is as follows:

D=d₁+ (0.2～0.5) d₂

In formula:

d₁Length for high temperature mushy zone；

d₂Length for high temperature microstructure roughening district.