CN203502309U - TFLD (Temperature Forming Limit Diagram) testing device for high-temperature warm and hot forming limit of metal - Google Patents
TFLD (Temperature Forming Limit Diagram) testing device for high-temperature warm and hot forming limit of metal Download PDFInfo
- Publication number
- CN203502309U CN203502309U CN201320475508.8U CN201320475508U CN203502309U CN 203502309 U CN203502309 U CN 203502309U CN 201320475508 U CN201320475508 U CN 201320475508U CN 203502309 U CN203502309 U CN 203502309U
- Authority
- CN
- China
- Prior art keywords
- heating furnace
- mould
- sample
- temperature
- forming limit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Abstract
The utility model discloses a TFLD (Temperature Forming Limit Diagram) testing device for high-temperature warm and hot forming limit of metal. The TFLD testing device is characterized by comprising a hydraulic testing machine, a mould, a mould heating furnace, an automatic feeding mechanism, a plate material heating furnace, a plate material rapid cooling device, a heating control system and a strain measurement analyzing device. According to the device disclosed by the utility model, the mould can be heated uniformly and a forming temperature of a plate material is not changed; an isothermal or non-isothermal forming limit of the tested plate material under a testing temperature is ensured; the TFLD testing device has the advantages of simplicity in operation, high automation degree, high working efficiency, accurate and effective testing results and the like.
Description
Technical field
The utility model relates to metal sheet forming technical field, specifically a kind of metallic high temperature warm forming limit TFLD proving installation.
Background technology
In recent years, due to the aggravation of the energy and environmental problem, the problem that Automobile Design manufacture faces is automobile lightweight under the prerequisite that guarantees vehicle passive safety how, thereby improves automobile fuel ecomomy, reduces exhaust emissions.Optimizing structure design of automobile, using new material and corresponding advanced manufacturing technology is the main method addressing the above problem.The hot press-formed technology of high-strength steel sheet is a novel advanced manufacturing technology that is specifically designed to shaping high-strength steel sheet, can produce part thinner but that intensity is higher, and without resilience, shape precision is higher, be widely used in abroad producing the structural member on automobile, as the front/rear collision bumper of automobile, A, B, C post, door anti-collision joist etc.In addition, the Warm Forming Technology of the light-weight metal such as magnesium, aluminium alloy is also widely used in producing automobile body part.And the domestic research for temperature, thermoforming technology is just at the early-stage.
In temperature, thermoforming technology, all need sheet metal to be heated to uniform temperature, adopt subsequently special dies to carry out drawing to high temperature plate.Especially, in thermoforming technology, need be by high strength steel board heating to austenitic temperature, insulation certain hour, make its abundant austenitizing, then plate is quickly cooled to best forming temperature, and is transported to rapidly with carrying out drawing pressurize quenching in the mould of cooling system, obtain final part.
Formability is the ability that plate does not break in forming process, has reflected the maximum distortion degree that material can be obtained in forming process.In temperature, in thermoforming process, improper if forming parameters is selected, such as pressure-pad-force is excessive, start forming temperature improper, unlubricated etc., stamping formability variation, occurs that constriction even breaks, and causes formation of parts not meet request for utilization.Development along with computing machine and finite element technique, the normal CAE software that adopts is carried out numerical Simulation Prediction to the forming process of plate, and introduce corresponding forming limit decision criteria, whether the formability that judges part meets the demands, thereby instruct Design of Dies remodeling and process parameter optimization, shorten product development cycle.
In traditional cold stamping process, conventionally adopt shaping limit curve (FLC-Forming Limit Curve) as decision criteria, to describe the formability of plate.Yet thermoforming process is a non-isothermal process, in the process being shaped, plate temperature constantly changes according to contact situation and deformation condition, the formability of plate in this process is mainly subject to the impact of the factors such as temperature, shaping rate, and the formability that therefore adopts shaping limit curve under single temperature, shaping rate to evaluate plate in thermoforming process is inaccurate.
Consider thermoforming principle and forming limit and be subject to temperature, shaping rate impact, application number is 201110082554.7, 201210238542.3 patent has all been mentioned forming limit test device and how have been obtained forming limit diagram, but the device of the existing sheet material high temperature warm forming limit and method of testing are difficult to accurately obtain the high temperature warm forming Limit Surface figure (TFLD-Temperature Forming Limit Diagram) of high-strength steel sheet under warm forming technique, main deficiency is embodied in all can not simulate thermoforming real process, be that plate austenitizing lacks necessity afterwards and effective plate quickly cooling device is quickly cooled to probe temperature by plate, cause plate generation structural transformation.In addition, application number is that the method that 201220130204.3 patent proposes is to use inductive coil to heat plate, although use air nozzle to carry out cooling to plate before being shaped, but now plate contacts with the mould of preheating, mould can be lowered the temperature indirectly, thereby be difficult to guarantee that mold temperature keeps invariable, make the forming limit of mensuration inaccurate.In addition, while not containing the inoxidzable coating steel plate high temperature warm forming limit for mensuration, lack necessary oxidation in prior art, after causing being shaped, grid is invisible.And in prior art, also have no and propose a kind of effective ways that are applicable to evaluate the part forming in temperature, thermoforming isothermal or non-isothermal forming process.
Utility model content
According to the technical matters of above-mentioned proposition, provide a kind of metallic high temperature warm forming limit TFLD proving installation.
The technological means that the utility model adopts is as follows:
A metallic high temperature warm forming limit TFLD proving installation, is characterized in that: comprise hydraulic dynamometer, mould, mould heating furnace, automatic feed mechanism, plate heating furnace, plate quickly cooling device, heating control system and strain measurement analytical equipment;
Described hydraulic dynamometer is for controlling described mould motion mounted thereto, and described mould is for carrying out flanging and drawing to sample;
Described mould heating furnace is placed on described hydraulic dynamometer for described mould/described mould and sample are heated, refer to that described mould heating furnace both can be used for independent heating mould, guarantee that in forming process, mold temperature keeps invariable, simultaneously heating mould and sample while also can be used for studying the alloy in lightweight warm working limit such as magnesium, aluminium, and guarantee that in forming process, mould and specimen temperature are invariable;
Described automatic feed mechanism, for sample is transported to described mould, sets gradually to be useful on and heats and be incubated the plate heating furnace of sample and the described plate quickly cooling device to probe temperature for fast reducing specimen temperature in the delivery section of described automatic feed mechanism;
Above-mentioned plate heating furnace is plate shaped heating furnace, and type of heating can adopt radiation heating and two kinds of modes of induction heating, and two ends are provided with fire door, can open up and down, and can provide sufficient nitrogen in this heating furnace, while guaranteeing heating steel plate, is not oxidized.Above-mentioned plate quickly cooling device is for when studying the high-strength steel sheet warm forming limit, in transmitting sample process, fast reducing specimen temperature, to probe temperature, is shaped sample and pearlite or bainite transformation (martensite conversion ratio is greater than 95%) does not occur or occur in right amount under austenitic state;
Described heating control system is for controlling described mould heating furnace and described plate heating furnace;
Described strain measurement analytical equipment is for obtaining the data of sample deformation, and sample deformation data analysis and calculating to acquisition, obtains plate warm forming Limit Surface figure at high temperature.
Test unit provided by the utility model comprises two jacket heating systems, and mould heating furnace and plate heating furnace, all control its temperature by heating control system.At research high-strength steel sheet at high temperature during forming limit, must simulation actual heat forming technology process: by plate heating furnace heating sample to austenitic temperature, and insulation realizes complete austenitizing, then by automatic feed mechanism, high temperature sample is delivered to plate quickly cooling device and be quickly cooled to probe temperature, then deliver to the mould being heated by mould heating furnace and carry out drawing; During forming limit at high temperature of the alloy in lightweight such as research magnesium, aluminium, sample and mould can be heated at mould heating furnace simultaneously, carry out again drawing after arriving probe temperature.
Above-mentioned hydraulic dynamometer is two dynamic compressors, and flanging speed is that 0.1～50mm/s is adjustable, and drawing velocity is that 0.1～100mm/s is adjustable, and maximum load is 300KN.And hydraulic dynamometer and mould and mould heating furnace are combined into one.
Above-mentioned strain measurement analytical equipment comprises image capture device and Measurement and analysis equipment; Image capture device, for gathering the image of the sample after distortion, obtains the data of circular grill distortion on sample; Measurement and analysis equipment will be measured the upper circular grill distortion of test, and the line number of going forward side by side calculates the first principal strain and second principal strain of distortion sample according to one's analysis.
As preferably, described mould comprises hemispheric punch, die and with the blank holder of bead, described punch is placed in described blank holder, and the bulb diameter of described punch is less than the internal diameter of described die and described blank holder; Described punch, described die and described blank holder are coaxially arranged on described hydraulic dynamometer, described die is fixed on top shoe subordinate's the central shaft of described hydraulic dynamometer, described blank holder is fixed on the base of described hydraulic dynamometer, on taking blame for others in the bottom that described punch is fixed on described hydraulic dynamometer.
Above-mentioned punch, die and blank holder are made by refractory metal material, and the internal diameter that bulb diameter is less than die and blank holder for example refers to that it is example that bulb diameter is chosen 100mm, and the internal diameter of die and blank holder can be chosen 110mm; The shape of bead can adopt the form of rounding off, as circular arc or triangle (drift angle is arc transition), is mainly to guarantee that sample does not slide in forming process.In real work stroke, punch, die and blank holder centerline deviation are not more than 0.15mm.
As preferably, described punch, described die and described blank holder inside are equipped with for sample and fire box temperature in Real-Time Monitoring mould and feed back to the temperature sensor of described heating control system.
As preferably, described mould heating furnace comprises heating furnace and lower heating furnace, described upper heating furnace and lower heating furnace are configured for holding the spatial accommodation of described mould, and the inwall of described upper heating furnace and described lower heating furnace is equipped with for heating the loop type inductive coil of described mould; The outside of described upper heating furnace and described lower heating furnace is provided with for preventing the annular cooling water pipe of heating furnace outer side surface excess Temperature.
Above-mentioned upper heating furnace heats for die, and lower heating furnace heats for punch and blank holder, and die and upper heating furnace can be with the motion campaigns of hydraulic dynamometer top shoe, and blank holder and lower heating furnace maintain static, and takes blame for others and control punch motion in bottom.Upper heating furnace is connected on hydraulic dynamometer top shoe by cable wire, and in the time of can guaranteeing that upper and lower heating furnace is closed, die still can move downward and carry out flanging.
As preferably, on described upper heating furnace and described lower heating furnace, be equipped with nitrogen tube, can, toward in liberal supply nitrogen in stove, while guaranteeing shaping high-temperature steel plate, not be oxidized.
As preferably, described automatic feed mechanism adopts chain structure driven, line slideway guiding, variable-frequency motor stepless time adjustment, guarantees sample presentation accurately and fast, steadily, and motion parts is equipped with safty shield, prevents operating personnel to damage; The delivery section of described automatic feed mechanism is equipped with safty shield; The leading portion of described delivery section is provided with the sample clamp device of pneumatic control, on described automatic feed mechanism, be also provided with transmission distance adjusting means, can transmit respectively sample that size is different to accurate location: sample center line and mold center's line deviation are not more than 0.15mm.
As preferably, in described plate quickly cooling device, be provided with the gases at high pressure blowoff that can spray compressed nitrogen, both can fast cooling board material to probe temperature, also can prevent that steel plate is oxidized.
The method that the metallic high temperature warm forming limit TFLD proving installation that application the utility model provides obtains high temperature warm forming Limit Surface figure is as follows:
Described method comprises to be obtained high-strength steel sheet thermoforming process high temperature warm forming Limit Surface figure and obtains the alloy in lightweight warm working process high temperature warm forming Limit Surface figure such as magnesium, aluminium;
The described method of obtaining high-strength steel sheet thermoforming high temperature warm forming Limit Surface figure comprises the steps:
First, smear lubricant lubricated on the punch of mould, adopt mould heating furnace that the punch of described mould, die and blank holder are heated to the predetermined temperature of shaping and remain unchanged, shaping predetermined temperature is between 600～800 ℃; Described lubricant is the potpourri of graphite and molybdenum disulfide, and both mix for 2:1 by volume, smears a little and can reduce the friction between sample and punch in forming process;
Then, plate heating furnace is warming up to after 900～950 ℃, sample is placed on automatic feed mechanism and by automatic feed mechanism, sample is sent in plate heating furnace, sample is heated to 900～950 ℃, and insulation 1～5min, obtains uniform austenite structure;
Then, automatic feed mechanism takes out sample from plate heating furnace, cooling fast by adopting high pressure nitrogen to carry out sample in sample fast transfer plate quickly cooling device, cooling velocity is greater than 50 ℃/s(according to actual needs, when cooling velocity is greater than 80 ℃/s, effect is better), guarantee that sample is not oxidized, avoid sample generation bainite or perlitic transformation, adopt infrared thermometer monitoring specimen temperature feedback control system simultaneously, when specimen temperature will reach probe temperature, rapidly sample is transferred on mould, within temperature while making sample arrive mould remains on experimental test temperature ± 10 ℃ scope,
Then, when sample arrives mould, die moves downward sample is carried out to quick flanging, flanging speed is 25～30mm/s, and punch starts to move upward subsequently, and movement velocity is that 10～100mm/s is adjustable, sample deforms under temperature constant state, the etched circular grill of specimen surface deforms, and when sample occurs constriction or breaks, stops test;
Finally, repeat above-mentioned steps, by strain measurement analytical equipment, obtain various sample deformation data and analyze, calculate the first principal strain and second principal strain of distortion sample, finally strain result is carried out to matching and obtain metallic high temperature warm forming Limit Surface figure;
The described method of obtaining the alloy in lightweight warm working process high temperature warm forming Limit Surface figure such as magnesium, aluminium comprises the steps:
First, on the punch of mould, smear lubricant lubricated, sample is put into mould heating furnace, the punch of sample and mould, die and blank holder are heated to test predetermined temperature simultaneously and remain unchanged, predetermined temperature, between 200～400 ℃, is incubated 1～5min;
Then, die moves downward, sample is carried out to flanging, flanging speed is 25～30mm/s, and punch starts to move upward subsequently, and movement velocity is 10～100mm/s, sample deforms under temperature constant state, the etched circular grill of specimen surface deforms, and when sample occurs constriction or breaks, stops test;
Finally, repeat above-mentioned steps, by strain measurement analytical equipment, obtain various sample deformation data and analyze, calculate the first principal strain and second principal strain of distortion sample, finally strain result is carried out to matching and obtain metallic high temperature warm forming Limit Surface figure.
Further, described strain measurement analytical equipment is taken sample constriction or burst region by optics and infrared image acquisition, the major axis and the minor axis length that adopt strain measurement system to measure circular grill change, the long and short shaft length variation of circular grill is mainly divided into three kinds, as shown in Figure 3, the circular grill of breaking, the circular grill of constriction and near the uncracked circular grill of constriction, then adopt following formula to calculate the first principal strain and the second principal strain that changes grid
Wherein, ε
1be the first principal strain, ε
2be the second principal strain, d
1for the long axis length of measured circular grill, d
2for the minor axis length of measured circular grill, d
0initial diameter for circular grill.
Further, the described test method of obtaining high-strength steel sheet thermoforming process high temperature warm forming Limit Surface figure can complete different size sample in the test of 500～800 ℃ of temperature ranges, and arbitrary temp interval, interval is carried out test of many times and obtained corresponding metallic high temperature warm forming Limit Surface figure; The described test method of obtaining the alloy in lightweight warm working high temperature warm forming Limit Surface figure such as magnesium, aluminium can complete different size sample in the test of 200～400 ℃ of temperature ranges, and arbitrary temp interval, interval is carried out test of many times and obtained corresponding metallic high temperature warm forming Limit Surface figure.Generally, carry out a test and be advisable in 50 ℃, interval.
Sample in above-mentioned test comprises to be needed in covering metal high temperature warm forming limiting figure from unilateral stretching strain regime to plane strain state, then to the scope of pair stretching strain states of grade.Based on GB/T15825.8-2008, specimen length is preferentially elected 180mm as, width can hank respectively decline trend 180,160,140,120,100,80,60,40,20mm totally 9 kinds of width.For preventing that rectangular specimen from rupturing at mould bead place, imitate tensile sample that its shape is revised as to the dumbbell shape that middle part is slightly narrow, two ends are widened.Before test, adopt laser marking machine to carry out circular grill drafting to sample, circular grill diameter is 2.5mm.
The process of metallic high temperature warm forming Limit Surface figure deal with data is as follows: first the first principal strain of three kinds of grids of the lower 9 kinds of samples of same design temperature and the second principal strain are all plotted in coordinate system, the necking point that connects 9 kinds of samples with smooth curve, thus the shaping limit curve set at forming speed and temperature (high-strength steel sheet that the test that being illustrated in figure 4 the utility model provides obtains is the shaping limit curve at 10mm/s, 800 ℃ in forming speed) obtained.Then the shaping limit curve based under same forming speed, different temperatures is drawn shaping Limit Surface in three-dimensional system of coordinate, take X-axis as the second principal strain, and Y-axis is temperature, and Z axis is the first principal strain.Be illustrated in figure 5 high-strength boron steel that the utility model the provides metallic high temperature warm forming Limit Surface figure under 10mm/s forming speed, three kinds of strain regimes and temperature history are plotted in figure, dotted line is through forming limit curved surface, and respective regions breaks; Fine rule just reaches curved surface, respective regions generation constriction; Thick line is positioned at curved surface below, respective regions safety.The metallic high temperature warm forming Limit Surface obtaining can be in temperature, thermoforming numerical simulation, prediction plate forming property at high temperature.The high-strength steel sheet high temperature warm forming Limit Surface that the utility model is provided is incorporated in CAE software, thermoforming process under two of certain automobile B-column kinds of operating modes is carried out to numerical simulation (operating mode 1: starting forming temperature is 800 ℃, pressure-pad-force is 100KN, and forming speed is 100mm/s; Operating mode 2: starting forming temperature is 800 ℃, and pressure-pad-force is 30KN, and forming speed is 100mm/s).Figure 6 shows that the second principal strain, temperature and the first principal strain distribution plan of all unit on 1 time B post of operating mode, can see that some distributed points have passed high temperature warm forming Limit Surface, therefore part breaks, and rupture location part middle part approaches the position of upper fillet.Figure 7 shows that the second principal strain, temperature and the first principal strain distribution plan of all unit on 2 times B posts of operating mode, can see that all distributed points are all positioned under high temperature warm forming Limit Surface, so the safe crack-free of part.For the reliability of checking numerical simulation result and high temperature warm forming Limit Surface, carried out actual B post thermoforming test, the B post part after 1 time thermoforming of operating mode, has occurred to break, and rupture location is consistent with numerical simulation result.B post part after 2 times thermoformings of operating mode, safe crack-free, consistent with numerical simulation result.Therefore the consistance situation of numerical simulation and actual tests has proved validity of the present utility model.
Compared with prior art, compare, the utlity model has following advantage:
1, plate heating furnace of the present utility model can select to adopt induced electricity heating or electric radiation heating and complex method thereof, and fast to the plate even speed of heating, efficiency is high;
2, mould heating furnace of the present utility model can quickly heat up to probe temperature by mould, and mould is heated evenly, and while guaranteeing sheet forming, temperature remains unchanged, and guarantees that tested is the isothermal/non-isothermal forming limit of plate under probe temperature;
3, automatic feed mechanism of the present utility model, adopts chain structure driven, line slideway guiding, and variable-frequency motor stepless time adjustment, guarantees sample presentation accurately and fast, steadily, motion parts is equipped with safty shield, prevents operating personnel to damage;
4, in plate heating furnace of the present utility model, plate quickly cooling device and mould heating furnace, be equipped with oxidation, can make high-temperature steel plate not be oxidized;
5, the proving installation that the utility model provides can be tested for the high temperature warm forming limit of the alloy in lightweight such as magnesium, aluminium and high-strength steel sheet respectively, distinguishingly, also can consider actual thermoforming actual process flow process;
6, proving installation is simple to operate, and automaticity is high, and work efficiency is high, test result accurate and effective.
In addition, thermoforming process is different from traditional cold forming, it is a non-isothermal process, stamping formability is mainly subject to the impact of the factors such as temperature, if adopt the shaping limit curve (FLC) at traditional single temperature to describe the formability at high temperature of plate as decision criteria, by inaccurate.The three-dimensional Limit Surface of the consideration temperature history that employing the utility model is set up, as limit criterion, come the formability of evaluating parts in thermoforming process more accurate, meanwhile, this proving installation also can obtain common metal steel plate and light-weight metal ausforming curve and three-dimensional curved surface.
The utility model can extensively be promoted in metal sheet forming field under hot conditions for the foregoing reasons.
Accompanying drawing explanation
Below in conjunction with the drawings and specific embodiments, the utility model is described in further detail.
Fig. 1 is the structural representation of the utility model test unit.
Fig. 2 is the structural representation of the utility model mould heating furnace and mould.
Fig. 3 is the burst region schematic diagram of the sample after the high-strength steel sheet high temperature warm forming marginal test that provides of the utility model.
Fig. 4 is the high-strength steel sheet that obtains of the test that provides of the utility model is the metallic high temperature warm forming limit curve figure at 10mm/s, 800 ℃ in forming speed.
Fig. 5 is the metallic high temperature warm forming Limit Surface figure of the high-strength boron steel that provides of the utility model under 10mm/s forming speed.
Fig. 6 is the second principal strain, temperature and the first principal strain distribution plan of all unit on the B post of 1 time numerical simulation of operating mode of providing of the utility model.
Fig. 7 is the second principal strain, temperature and the first principal strain distribution plan of all unit on the B post of 2 times numerical simulations of operating mode of providing of the utility model.
In figure: 1, the circular grill 103 of heating furnace 32, lower heating furnace 33, inductive coil 4, automatic feed mechanism 5, plate heating furnace 6, plate quickly cooling device 7, heating control system 8, strain measurement analytical equipment 9, computer control system 10, sample 101, the circular grill 102 of breaking, constriction on hydraulic dynamometer 2, mould 21, punch 22, die 23, blank holder 3, mould heating furnace 31, near the uncracked circular grill of constriction
Embodiment
As shown in Figure 1 and Figure 2, a metallic high temperature warm forming limit TFLD proving installation, comprises hydraulic dynamometer 1, mould 2, mould heating furnace 3, automatic feed mechanism 4, plate heating furnace 5, plate quickly cooling device 6, heating control system 7 and strain measurement analytical equipment 8;
Described hydraulic dynamometer 1 is for controlling described mould mounted thereto 2 motions, and described mould 2 is for carrying out flanging and stamping to sample 10; Described mould 2 comprises hemispheric punch 21, die 22 and with the blank holder 23 of bead, described punch 21 is placed in described blank holder 23, and the bulb diameter of described punch 21 is less than the internal diameter of described die 22 and described blank holder 23; Described punch 21, described die 22 and described blank holder 23 are coaxially arranged on described hydraulic dynamometer 1, described die 22 is fixed on top shoe subordinate's the central shaft of described hydraulic dynamometer 1, described blank holder 23 is fixed on the base of described hydraulic dynamometer 1, on taking blame for others in the bottom that described punch 21 is fixed on described hydraulic dynamometer 1; Described punch 21, described die 22 and described blank holder 23 inside are equipped with for sample 10 and fire box temperature in Real-Time Monitoring mould and feed back to the temperature sensor of described heating control system 7.
Described mould heating furnace 3 is placed on described hydraulic dynamometer 1 for mould 2 described in described mould 2/ and sample 10 are heated; Described mould heating furnace 3 comprises heating furnace 31 and lower heating furnace 32, described upper heating furnace 31 and lower heating furnace 32 are configured for holding the spatial accommodation of described mould 2, and the inwall of described upper heating furnace 31 and described lower heating furnace 32 is equipped with for heating the loop type inductive coil 33 of described mould 2; The outside of described upper heating furnace 31 and described lower heating furnace 32 is provided with for preventing the annular cooling water pipe of heating furnace outer side surface excess Temperature.Described die 22 can be with the motion campaign of hydraulic dynamometer 1 top shoe with upper heating furnace 31, and blank holder 23 maintains static with lower heating furnace 32, takes blame for others and control punch 21 motions in bottom.Upper heating furnace 31 is connected on hydraulic dynamometer 1 top shoe by cable wire, and in the time of can guaranteeing that upper and lower heating furnace is closed, die 22 still can move downward and carry out flanging.On described upper heating furnace 31 and described lower heating furnace 32, be equipped with nitrogen tube, can, toward in liberal supply nitrogen in stove, while guaranteeing shaping high-temperature steel plate, be oxidized.
Described automatic feed mechanism 4 heats and is incubated the plate heating furnace 5 of sample 10 and the described plate quickly cooling device 6 to probe temperature for fast reducing sample 10 temperature for sample 10 being transported to described mould 2, setting gradually in the delivery section of described automatic feed mechanism 4 to be useful on; Described automatic feed mechanism 4 adopts chain structure driven, line slideway guiding, variable-frequency motor stepless time adjustment, and the delivery section of described automatic feed mechanism 4 is equipped with safty shield; The leading portion of described delivery section is provided with the sample clamp device of pneumatic control, on described automatic feed mechanism 4, is also provided with transmission distance adjusting means; Described plate heating furnace 5 is plate shaped heating furnace, and type of heating can adopt radiation heating and two kinds of modes of induction heating, and two ends are provided with fire door, can open up and down, and can provide sufficient nitrogen in this heating furnace, while guaranteeing heating steel plate, is not oxidized; In described plate quickly cooling device 6, be provided with the gases at high pressure blowoff that can spray compressed nitrogen.
Described heating control system 7 is for controlling described mould heating furnace 3 and described plate heating furnace 5;
The data that described strain measurement analytical equipment 8 is out of shape for obtaining sample 10, and controlled by computer control system 9, sample 10 deformation datas that obtain are carried out to analysis and calculation, obtain plate warm forming limiting figure at high temperature.Described strain measurement analytical equipment 8 comprises image capture device and Measurement and analysis equipment; Described image capture device, for gathering the image of the sample after distortion, obtains the data of circular grill distortion on sample; Described Measurement and analysis equipment will be measured the upper circular grill distortion of test, and the line number of going forward side by side calculates the first principal strain and second principal strain of distortion sample according to one's analysis.
Apply the method that above-mentioned metallic high temperature forming limit TFLD proving installation obtains metallic high temperature warm forming Limit Surface figure, comprise and obtain high-strength steel sheet thermoforming process high temperature warm forming Limit Surface figure and obtain the alloy in lightweight warm working high temperature warm forming Limit Surface figure such as magnesium, aluminium;
The choosing of sample 10 needs in drape forming limiting figure from unilateral stretching strain regime to plane strain state, then to the scope of pair stretching strain states of grade.Based on GB/T15825.8-2008, choosing sample 10 length is 180mm, and width is respectively 180,160,140,120,100,80,60,40, totally 9 kinds of 20mm.For preventing that rectangular specimen from rupturing at mould bead place, imitate tensile sample that its shape is revised as to the dumbbell shape that middle part is slightly narrow, two ends are widened.Before test, adopt laser marking machine to carry out circular grill drafting to sample 10, circular grill diameter is 2.5mm.
The method of obtaining high-strength steel sheet thermoforming process high temperature warm forming Limit Surface figure comprises the steps:
First, the potpourri of smearing a little graphite of profit and molybdenum disulfide on the punch 21 of mould 2 is lubricated as lubrication prescription, and graphite is that 2:1 mixes with the volume ratio of molybdenum disulfide; Adopt mould heating furnace 3 that the punch of described mould 2 21, die 22 and blank holder 23 are heated to the predetermined temperature of shaping and remain unchanged, shaping predetermined temperature is between 600～800 ℃;
Then, plate heating furnace 5 is warming up to after 900～920 ℃, sample 10 is placed on automatic feed mechanism 4 and by automatic feed mechanism 4, sample 10 is sent in plate heating furnace 5, sample 10 is heated to 900～920 ℃, insulation 1～5min;
Then, automatic feed mechanism 4 takes out sample 10 from plate heating furnace 5, to in sample 10 fast transfer plate quickly cooling devices 6, adopt high pressure nitrogen to carry out cooling fast to sample 10, cooling velocity is greater than 80 ℃/s, adopt infrared thermometer monitoring sample 10 temperature feedback control system simultaneously, when sample 10 temperature will reach probe temperature, rapidly sample 10 is transferred on mould 2, within the temperature while making sample 10 arrive mould 2 remains on experimental test temperature ± 10 ℃ scope;
Then, when sample 10 arrives mould 2, die 22 moves downward sample 10 is carried out to quick flanging, flanging speed is 25～30mm/s, and punch 21 starts to move upward subsequently, and movement velocity is 10～100mm/s, sample 10 deforms under temperature constant state, the circular grill of sample 10 surface etchings deforms, and when sample 10 occurs constriction or breaks, stops test;
Finally, repeat above-mentioned steps, complete 9 kinds of different size samples in the test of 600～800 ℃ of temperature ranges, carry out a test in 50 ℃, interval, by strain measurement analytical equipment 8, obtaining various sample deformation data analyzes, calculate the first principal strain and second principal strain of distortion sample, finally strain result is carried out to matching and obtain metallic high temperature warm forming Limit Surface figure.
The method of obtaining the alloy in lightweight warm working process high temperature warm forming Limit Surface figure such as magnesium, aluminium comprises the steps:
First, on the punch 21 of mould 2, smear a little FUCHS ease al278 lubricated as lubricant, sample 10 is put into mould heating furnace 3, the punch 21 of sample 10 and mould 2, die 22 and blank holder 23 are heated to test 10 predetermined temperatures simultaneously and remain unchanged, predetermined temperature, between 200～400 ℃, is incubated 1～5min;
Then, die 22 moves downward, sample 10 is carried out to flanging, flanging speed is 25～30mm/s, and punch 22 starts to move upward subsequently, and movement velocity is 10～100mm/s, sample 10 deforms under temperature constant state, the circular grill of sample 10 surface etchings deforms, and when sample 10 occurs constriction or breaks, stops test;
Finally, repeating above-mentioned steps, complete 9 kinds of different size samples in the test of 200～400 ℃ of temperature ranges, carries out a test in 50 ℃, interval.By strain measurement analytical equipment 8, obtain various sample deformation data and analyze, calculate the first principal strain and second principal strain of distortion sample, finally strain result is carried out to matching and obtain metallic high temperature warm forming Limit Surface figure.
In above-mentioned two kinds of test methods, strain measurement analytical equipment 8 is taken sample 10 constriction or burst region by optics and infrared image acquisition, the major axis and the minor axis length that adopt strain measurement system to measure three kinds of circular grill (circular grill 101 of breaking, the circular grill 102 of constriction and near the uncracked circular grill 103 tightening) change, then adopt following formula to calculate the first principal strain and the second principal strain that changes grid
Wherein, ε
1the first principal strain, ε
2be the second principal strain, d
1for the long axis length of measured circular grill, d
2for the minor axis length of measured circular grill, d
0initial diameter for circular grill.
The first principal strain of three kinds of grids of the lower 9 kinds of samples of same design temperature and the second principal strain are all plotted in coordinate system, with smooth curve, connect the necking point of 9 kinds of samples, thereby obtain the shaping limit curve of setting at forming speed and temperature.Being illustrated in figure 4 high-strength steel sheet that test method that the utility model provides obtains is the metallic high temperature warm forming limit curve figure at 10mm/s, 800 ℃ in forming speed; Shaping limit curve based under same forming speed, different temperatures is drawn shaping Limit Surface in three-dimensional system of coordinate, take X-axis as the second principal strain, and Y-axis is temperature, and Z axis is the first principal strain.Be illustrated in figure 5 high-strength boron steel that the utility model the provides metallic high temperature warm forming Limit Surface figure under 10mm/s forming speed.The metallic high temperature warm forming Limit Surface obtaining can be in temperature, thermoforming numerical simulation, prediction plate forming property at high temperature.High-strength steel sheet metallic high temperature warm forming Limit Surface is introduced in CAE software, to the numerical simulation result of automobile B-column and verification experimental verification, result demonstration metallic high temperature warm forming Limit Surface can be predicted the forming property of plate in thermoforming process exactly, thereby instruct hot stamping die design development and process parameter optimization, shorten product development cycle.
The above; it is only preferably embodiment of the utility model; but protection domain of the present utility model is not limited to this; anyly be familiar with those skilled in the art in the technical scope that the utility model discloses; according to the technical solution of the utility model and utility model design thereof, be equal to replacement or changed, within all should being encompassed in protection domain of the present utility model.
Claims (7)
1. a metallic high temperature warm forming limit TFLD proving installation, is characterized in that: comprise hydraulic dynamometer (1), mould (2), mould heating furnace (3), automatic feed mechanism (4), plate heating furnace (5), plate quickly cooling device (6), heating control system (7) and strain measurement analytical equipment (8);
Described hydraulic dynamometer (1) is for controlling described mould (2) motion mounted thereto, and described mould (2) is for carrying out flanging and drawing to sample (10);
It is upper for described mould (2)/described mould (2) and sample (10) are heated that described mould heating furnace (3) is placed in described hydraulic dynamometer (1);
Described automatic feed mechanism (4), for sample (10) is transported to described mould (2), sets gradually to be useful on and heats and be incubated the plate heating furnace (5) of sample (10) and the described plate quickly cooling device (6) to probe temperature for fast reducing sample (10) temperature in the delivery section of described automatic feed mechanism (4);
Described heating control system (7) is for controlling described mould heating furnace (3) and described plate heating furnace (5);
The data that described strain measurement analytical equipment (8) is out of shape for obtaining sample (10), and sample (10) deformation data obtaining is carried out to analysis and calculation, obtain plate warm forming Limit Surface figure at high temperature.
2. metallic high temperature warm forming limit TFLD proving installation according to claim 1, it is characterized in that: described mould (2) comprises hemispheric punch (21), die (22) and with the blank holder (23) of bead, described punch (21) is placed in described blank holder (23), and the bulb diameter of described punch (21) is less than the internal diameter of described die (22) and described blank holder (23); Described punch (21), described die (22) and described blank holder (23) are coaxially arranged on described hydraulic dynamometer (1), described die (22) is fixed on top shoe subordinate's the central shaft of described hydraulic dynamometer (1), described blank holder (23) is fixed on the base of described hydraulic dynamometer (1), on taking blame for others in the bottom that described punch (21) is fixed on described hydraulic dynamometer (1).
3. metallic high temperature warm forming limit TFLD proving installation according to claim 2, is characterized in that: described punch (21), described die (22) and described blank holder (23) inside are equipped with for sample (10) and fire box temperature in Real-Time Monitoring mould and feed back to the temperature sensor of described heating control system (7).
4. metallic high temperature warm forming limit TFLD proving installation according to claim 2, it is characterized in that: described mould heating furnace (3) comprises heating furnace (31) and lower heating furnace (32), described upper heating furnace (31) and lower heating furnace (32) are configured for holding the spatial accommodation of described mould (2), and the inwall of described upper heating furnace (31) and described lower heating furnace (32) is equipped with for heating the loop type inductive coil (33) of described mould (2); The outside of described upper heating furnace (31) and described lower heating furnace (32) is provided with for preventing the annular cooling water pipe of heating furnace outer side surface excess Temperature.
5. metallic high temperature warm forming limit TFLD proving installation according to claim 4, is characterized in that: on described upper heating furnace (31) and described lower heating furnace (32), be equipped with nitrogen tube.
6. metallic high temperature warm forming limit TFLD proving installation according to claim 1, it is characterized in that: described automatic feed mechanism (4) adopts chain structure driven, line slideway guiding, variable-frequency motor stepless time adjustment, and the delivery section of described automatic feed mechanism (4) is equipped with safty shield; The leading portion of described delivery section is provided with the sample clamp device of pneumatic control, and described automatic feed mechanism is also provided with transmission distance adjusting means on (4).
7. metallic high temperature warm forming limit TFLD proving installation according to claim 1, is characterized in that: in described plate quickly cooling device (6), be provided with the gases at high pressure blowoff that can spray compressed nitrogen.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320475508.8U CN203502309U (en) | 2013-08-05 | 2013-08-05 | TFLD (Temperature Forming Limit Diagram) testing device for high-temperature warm and hot forming limit of metal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320475508.8U CN203502309U (en) | 2013-08-05 | 2013-08-05 | TFLD (Temperature Forming Limit Diagram) testing device for high-temperature warm and hot forming limit of metal |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203502309U true CN203502309U (en) | 2014-03-26 |
Family
ID=50333279
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201320475508.8U Expired - Fee Related CN203502309U (en) | 2013-08-05 | 2013-08-05 | TFLD (Temperature Forming Limit Diagram) testing device for high-temperature warm and hot forming limit of metal |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203502309U (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103398909A (en) * | 2013-08-05 | 2013-11-20 | 大连理工大学 | Method for acquiring metal temperature forming limit diagram (TFLD) and testing device therefor |
| CN103995551A (en) * | 2014-05-29 | 2014-08-20 | 江苏大学 | Device and method for assisting in achieving hot forming testing and variable-rate cooling of metal sheet |
| CN107831061A (en) * | 2017-11-18 | 2018-03-23 | 北京科技大学 | A kind of creep and stress rupture test machine sample Quick cooling equipment |
| CN108007791A (en) * | 2017-08-08 | 2018-05-08 | 南方科技大学 | A kind of multistation creep test device and method |
| CN108279177A (en) * | 2018-03-13 | 2018-07-13 | 大连理工大学 | A kind of hot press-formed go-no-go test equipment of high temperature and high speed sheet metal and test method |
| CN108279175A (en) * | 2018-03-13 | 2018-07-13 | 大连理工大学 | A kind of experimental rig and method obtaining the intensity adjustable steel plate temperature-differential forming limit |
| CN110394392A (en) * | 2019-06-12 | 2019-11-01 | 北京机科国创轻量化科学研究院有限公司 | It is a kind of based on heat-stream multi- scenarios method Forming Limit of Sheet Metals research method |
| CN111487186A (en) * | 2019-01-25 | 2020-08-04 | 宝山钢铁股份有限公司 | Heatable metal plate friction coefficient testing device and method |
-
2013
- 2013-08-05 CN CN201320475508.8U patent/CN203502309U/en not_active Expired - Fee Related
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103398909A (en) * | 2013-08-05 | 2013-11-20 | 大连理工大学 | Method for acquiring metal temperature forming limit diagram (TFLD) and testing device therefor |
| CN103995551A (en) * | 2014-05-29 | 2014-08-20 | 江苏大学 | Device and method for assisting in achieving hot forming testing and variable-rate cooling of metal sheet |
| CN103995551B (en) * | 2014-05-29 | 2016-04-27 | 江苏大学 | The auxiliary device and method realizing metal sheet hot forming test and variable Rate cooling |
| CN108007791A (en) * | 2017-08-08 | 2018-05-08 | 南方科技大学 | A kind of multistation creep test device and method |
| CN107831061A (en) * | 2017-11-18 | 2018-03-23 | 北京科技大学 | A kind of creep and stress rupture test machine sample Quick cooling equipment |
| CN108279177A (en) * | 2018-03-13 | 2018-07-13 | 大连理工大学 | A kind of hot press-formed go-no-go test equipment of high temperature and high speed sheet metal and test method |
| CN108279175A (en) * | 2018-03-13 | 2018-07-13 | 大连理工大学 | A kind of experimental rig and method obtaining the intensity adjustable steel plate temperature-differential forming limit |
| CN108279175B (en) * | 2018-03-13 | 2020-02-18 | 大连理工大学 | Test device and method for obtaining differential temperature forming limit of variable-strength steel plate |
| CN108279177B (en) * | 2018-03-13 | 2024-04-05 | 大连理工大学 | High-temperature high-speed sheet metal hot stamping forming limit testing device and testing method |
| CN111487186A (en) * | 2019-01-25 | 2020-08-04 | 宝山钢铁股份有限公司 | Heatable metal plate friction coefficient testing device and method |
| CN110394392A (en) * | 2019-06-12 | 2019-11-01 | 北京机科国创轻量化科学研究院有限公司 | It is a kind of based on heat-stream multi- scenarios method Forming Limit of Sheet Metals research method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103398909A (en) | Method for acquiring metal temperature forming limit diagram (TFLD) and testing device therefor | |
| CN203502309U (en) | TFLD (Temperature Forming Limit Diagram) testing device for high-temperature warm and hot forming limit of metal | |
| Liu et al. | Investigation of the hot-stamping process for advanced high-strength steel sheet by numerical simulation | |
| CN103852388B (en) | A kind of metal sheet hot forming limit experimental provision and method of testing | |
| CN102749253B (en) | Testing system and method of plate high temperature forming limit diagram | |
| RU2598065C2 (en) | Method for metal forming and a device for plastic working | |
| CN104515707A (en) | Temperature measurement method for electrified tensile test piece and tensile test device | |
| CN103852382B (en) | A kind of method for building up of high strength steel plate thermoforming limiting figure | |
| CN102172719A (en) | Hot stamping mould with temperature measuring system | |
| CN105181574B (en) | Hot press-formed process single-sided friction coefficient testing device and method of testing | |
| CN106503389A (en) | A kind of numerical method of quick determination drop stamping production line process parameter | |
| Shi et al. | Experimental and numerical determination of thermal forming limit diagrams (TFLD) of high strength steel 22MnB5 | |
| Zhang et al. | Hot stamping forming and finite element simulation of USIBOR1500 high-strength steel | |
| CN105195623A (en) | Temperature control type stamping die for high-strength steel plate and method | |
| CN109060552A (en) | A kind of thermal environment rebound test equipment and test method | |
| CN108279177B (en) | High-temperature high-speed sheet metal hot stamping forming limit testing device and testing method | |
| Quan et al. | Parameter optimization of cooling system in U-shape hot stamping mold for high strength steel sheet based on MOPSO | |
| Li et al. | Phase transformation testing and modeling for hot stamping of boron steel considering the effect of the prior austenite deformation | |
| CN113976683A (en) | High-strength steel plate warm bending forming device and method for online local contact heating | |
| CN104294020A (en) | Heat stamping apparatus used for quenching control | |
| CN109916735A (en) | A kind of test device and test method of sheet metal thermal transient forming limit | |
| CN108279175B (en) | Test device and method for obtaining differential temperature forming limit of variable-strength steel plate | |
| Meng et al. | Drawability and frictional behavior of pure molybdenum sheet in deep-drawing process at elevated temperature | |
| CN101599094A (en) | A kind of model method of setting up forming limit diagram of transformation induced plasticity steel plate | |
| Bay et al. | Off-line testing of tribo-systems for sheet metal forming production |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20140326 Termination date: 20160805 |