CN103698233A - Determination method for cupping value of metal material and die - Google Patents
Determination method for cupping value of metal material and die Download PDFInfo
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- CN103698233A CN103698233A CN201310689509.7A CN201310689509A CN103698233A CN 103698233 A CN103698233 A CN 103698233A CN 201310689509 A CN201310689509 A CN 201310689509A CN 103698233 A CN103698233 A CN 103698233A
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Abstract
The invention discloses a determination method for the cupping value of a metal material and a die. The method comprises the following steps: 1) tightly pressing a test sample, specifically, selecting a proper periphery-pressing force according to the tensile strength of a metal test sample, and tightly pressing the periphery of the test sample by the periphery-pressing force, so as to prevent the flowing of the periphery material of the test sample; 2) stamping the test sample, specifically, lubricating the central part of the test sample by bonding lubricating grease with a polyethylene film, and then stamping the central part by a plunger chip at stamping speed of 0.5-2.0 mm/s; 3) determining the cupping value, specifically, in the stamping process, when a stamping-driving force is reduced by 1-6 kN, stopping stamping, at the moment, a plunger chip displacement corresponding to the maximum stamping-driving force is the cupping value. The die is provided with mutually matched brake beads on a press die and a cushion die. According to the determination method and the die disclosed by the invention, the influence of the periphery-pressing force, the lubricating agent and the stamping speed on the test of the cupping value is adequately considered, quantitative control is performed on crack judgement, and the flowing of the periphery material of the test sample is further prevented by optimizing the structure of the die, thus improving the accuracy of the test result.
Description
Technical field
The present invention relates to metallurgical measuring technology, refer to particularly a kind of assay method and mould thereof of metal material Erichsen number.
Background technology
Erichsen test method (GB/T4156-2007) is a kind ofly to measure sheet metal and strip bears the test method of plastic deformation ability when draw forming, its principle is to be that spherical drift carries out punching press facing to a test button being clamped in pad mould and pressing mold by an end, form an indenture, until there is a penetrated crack, the indenture degree of depth now recording according to drift displacement is Erichsen number, then using this Erichsen number as a kind of performance index of passing judgment on metal limit deep drawability, Erichsen number is larger, represents that material deep drawability is more superior.Yet, with Erichsen test standard method, carrying out Erichsen number while measuring, exist Erichsen number test result precision differential, stability is differential, the shortcoming that comparability repeatability is differential, these shortcoming imbodies are as follows: when varying strength material is carried out to Erichsen number test, time and have a test result contrary with actual conditions, as: the Erichsen number of the dual phase steel recording with standard method is greater than the Erichsen number of IF steel, and this does not square with the fact; Adopt different lubricants larger on test result impact; The accuracy that penetrated crack is observed can not quantitatively be controlled, thereby causes the Erichsen number result recording to be disperseed, and by reducing later stage drawing velocity, observes penetrated crack, because having ignored the impact of drawing velocity on test structure, can cause equally result to be disperseed.Therefore, find a kind of method of energy Accurate Measurement metal Erichsen number, just become problem demanding prompt solution.
Summary of the invention
Object of the present invention is exactly assay method and the mould thereof that a kind of metal material Erichsen number will be provided, the method energy Accurate Measurement metal Erichsen number, and test result is stable, can accurately reflect the two-way draw forming performance of metal material.
For achieving the above object, the technical solution used in the present invention is: a kind of assay method of metal material Erichsen number, comprises the steps:
1) compress sample: according to the tensile strength of test button, select the pressure-pad-force of suitable size, with this pressure-pad-force, the periphery of sample is compressed, to stop sample limit portion material to flow;
2) punching press sample: the centre at sample is lubricated with railway grease sticking polyethylene film, then with drift, punching press is carried out in this centre, and drawing velocity is 0.5mm/s～2.0mm/s;
3) measure Erichsen number: in punching course, when rushing to summit power decline 1kN～6kN, stop punching press, now, maximum drift displacement corresponding to power of rushing to summit is Erichsen number.
Further, in described step 1), described test button is thickness 0.1～2.0mm and the sheet metal of tensile strength below 600MPa, and its pressure-pad-force of selecting is 100～200kN.
Further, in described step 1), described test button is thickness 0.1～2.0mm and the sheet metal of tensile strength more than 600MPa, pressure-pad-force >=200kN that it is selected.
Further, described metal is aluminium alloy or IF steel.
Further, described metal is dual phase steel.
A kind of for realizing the mensuration mould of the metal material Erichsen number that said method designs, comprise the annular press mold that is pressed on metal material top and the ring gasket mould that is padded on metal material below, it is spherical drift that the centre of described pad mould is provided with end, the bottom surface of described pressing mold is provided with annular convex rib, and the end face of described pad mould is provided with the concave bar matching with described convex tendon.
Compared with prior art, tool of the present invention has the following advantages:
One, in standard method, for all metal materials, all adopt the pressure-pad-force of 10KN, and the present invention has taken into full account the impact of pressure-pad-force size on Erichsen number test result, for the metal of varying strength, select the pressure-pad-force of suitable size, thereby thoroughly stop the limit portion material of test button to flow to sample centre, and then improve the accuracy of Erichsen number data.
They are two years old, the present invention has taken into full account the impact of lubricant on Erichsen number test result, the centre that sample is contacted with drift is lubricated with railway grease sticking polyethylene film, in comparison with standard method, be only coated with a small amount of railway grease, the lubricant effect of the lubricating system in the inventive method is more abundant, polyethylene film is lubricated has reliable stability, can guarantee that crack initiation is in the centre of sample, is conducive to improve the degree of accuracy of Erichsen number test.
They are three years old, when in standard method, regulation crackle demonstrates the whole thickness through sample, stop immediately drift, using the displacement of drift now as Erichsen number, because the time point that occurs crackle judges by observing, error is larger, thereby Erichsen number result is disperseed, if reduce later stage drawing velocity, observe penetrated crack, because having ignored the impact of drawing velocity, can cause equally result to be disperseed, and in the present invention, utilize sample when being about to ftracture, to there will be this feature of power value decay, when the power of rushing to summit declines 1～6kN, stop punching press, realized the quantitative control of crack penetration time judgement, thereby further improved the degree of accuracy of Erichsen number test result.
Its four, the present invention does not produce under the prerequisite of obvious effect of rate of strain at drawing velocity, selects the Erichsen number test drawing velocity of 0.5mm/s～2.0mm/s, has improved test speed.
They are five years old, the present invention is by improving mould structure, on pressing mold and pad mould, the bead cooperatively interacting is set, further stops the limit portion material of test button to flow to sample centre, make Erichsen number test result can more truly reflect the two-way draw forming performance of metal material; The present invention is simple to operation, practical, is applicable to the evaluation of the two-way draw forming performance of metal material, and its test result can be used as the guidance target that sheet metal is produced and applied, and has application value.
Accompanying drawing explanation
Fig. 1 is the cross-sectional view that a kind of metal material Erichsen number is measured mould.
Fig. 2 is the cross-sectional view of pressing mold in Fig. 1.
Fig. 3 pads the cross-sectional view of mould in Fig. 1.
Fig. 4 is the force-displacement curve of rushing to summit of dual phase steel.
Fig. 5 is the force-displacement curve of rushing to summit of IF steel.
Fig. 6 is the position view of crackle on sample after employing grease lubrication.
Fig. 7 is the position view of crackle on sample after the film lubrication of employing railway grease sticking polyethylene.
Fig. 8 is drawing velocity-Erichsen number histogram.
Embodiment
Below in conjunction with drawings and Examples, the present invention is described in further detail, be convenient to more clearly understand the present invention, but they do not form restriction to the present invention.
As shown in Figure 1, a kind of mensuration mould of metal material Erichsen number, comprise the annular press mold 1 that is pressed on metal material top and the ring gasket mould 2 that is padded on metal material below, it is spherical drift 3 that the centre of described pad mould 2 is provided with end, the bottom surface of described pressing mold 1 is provided with annular convex rib 4(as shown in Figure 2), the end face of described pad mould 2 is provided with the concave bar 5(that matches with described convex tendon 4 as shown in Figure 3), this drift 3, pressing mold 1 and pad mould 2 are all assemblied on existing punching tester.
An assay method for metal material Erichsen number, comprises the steps:
1) compress sample: the mould in Fig. 1 is arranged on punching tester, test button 6 is placed between pressing mold 1 and pad mould 2, then according to the tensile strength of test button 6, select the pressure-pad-force of suitable size, with this pressure-pad-force, the periphery of test button 6 is compressed, to stop sample limit portion material to flow, wherein, when this test button 6 is sheet metal below 600MPa of thickness 0.1～2.0mm and tensile strength, pressure-pad-force is 100～200kN preferably, when this test button 6 is sheet metal more than 600MPa of thickness 0.1～2.0mm and tensile strength, its preferred pressure-pad-force >=200kN,
2) punching press sample: the centre at sample 6 is lubricated with railway grease sticking polyethylene film, then carries out punching press with 3 pairs of these centres of drift, and drawing velocity is 0.5mm/s～2.0mm/s;
3) measure Erichsen number: in punching course, the punching tester record force-displacement curve of rushing to summit, when rushing to summit power decline 1kN～6kN, stops punching press, now, the maximum recording on the force-displacement curve of rushing to summit drift displacement corresponding to power of rushing to summit is Erichsen number.
Embodiment 1:
Choose the dual phase steel 600DP sample that 1.5mm is thick, the tensile strength of this dual phase steel is 630MPa, and extensibility is 23.1%, and this sample is placed between pressing mold and pad mould, with the pressure-pad-force of 250kN, the periphery of sample is compressed, to stop sample limit portion material to flow; , in the centre of sample, with railway grease sticking polyethylene film, be lubricated meanwhile, then with drift, punching press carried out in this centre, drawing velocity is 1.0mm/s; In punching course, punching tester records the force-displacement curve of rushing to summit, as shown in Figure 4, when rushing to summit power decline 5kN, stop punching press, now read the maximum recording on the force-displacement curve of rushing to summit drift displacement corresponding to power of rushing to summit and be Erichsen number, the Erichsen number that obtains this steel plate is 10.30mm, wherein, and pressure-pad-force, drawing velocity, crackle judges that these parameters of power of rushing to summit all set before starting characteristics test machine.
Choose the high-strength IF steel HC260Y that 1.5mm is thick, the tensile strength of this high-strength IF steel is 400MPa, and extensibility is 36.2%, and this sample is placed between pressing mold and pad mould, with the pressure-pad-force of 150kN, the periphery of sample is compressed, to stop sample limit portion material to flow; , in the centre of sample, with railway grease sticking polyethylene film, be lubricated meanwhile, then with drift, punching press carried out in this centre, drawing velocity is 2.0mm/s; In punching course, punching tester records the force-displacement curve of rushing to summit, as shown in Figure 5, when rushing to summit power decline 6kN, stop punching press, now read the maximum recording on the force-displacement curve of rushing to summit drift displacement corresponding to power of rushing to summit and be Erichsen number, the Erichsen number that obtains this steel plate is 10.05mm.
For the superiority of checking the inventive method, below for the correlation parameter in the inventive method, carry out contrast test:
1) the affect contrast test of pressure-pad-force on Erichsen number
Choose the dual phase steel 600DP sample that 1.5mm is thick, the tensile strength of this dual phase steel is 630MPa, extensibility is 23.1%, alternative is got the high-strength IF steel HC260Y that 1.5mm is thick, the tensile strength of this high-strength IF steel is 400MPa, extensibility is 36.2%, from these performances, the drawing performance of high-strength IF steel is better than dual phase steel, then the steel of these two kinds of varying strengths is carried out to Erichsen number test respectively in different pressure-pad-force situations, wherein, mould is existing standard mould, drawing velocity is 1.0mm/s, all adopt railway grease and polyethylene film lubricated, crackle automatic decision is set to 5kN, under different pressure-pad-forces, record Erichsen number and see following table 1:
Table 1
As known from Table 1, when pressure-pad-force is 10kN, the Erichsen number of dual phase steel is much larger than the Erichsen number of high-strength IF steel, increase along with pressure-pad-force, Erichsen number is reducing, that is to say the continuous increase along with pressure-pad-force, limit portion material reduces gradually to center flow, limit portion material is more to center flow, Erichsen number is larger, when pressure-pad-force is increased to 80kN when above, increase along with pressure-pad-force, the Erichsen number of high-strength IF steel is tending towards certain value 10.5mm, and the Erichsen number of dual phase steel is still being in line decline, hence one can see that, same pressure-pad-force value is different to the influence degree of varying strength material, the pressure-pad-force of 150kN has stoped the limit portion material of high-strength IF steel to center flow completely, but do not stop the limit portion material of dual phase steel to center flow completely, the pressure-pad-force of 10kN has partly stoped the limit portion material of high-strength IF steel to center flow, but do not stop the limit portion material of dual phase steel to center flow, concerning dual phase steel, the pressure-pad-force of 10kN just prevents that in punching course, limit portion material is wrinkling.
The inventive method by designing the method for bead and choose reasonable pressure-pad-force size on mould, dual prevention limit portion material is to center flow, guarantee that Pressing Deformation spots localization take center that mould bead is circumference fixedly within the area of a circle, in Erichsen number test process, stop limit portion material to center flow completely, the result that so test obtains is more true and reliable, unlikelyly occurs that the Erichsen number of high strength dual phase steel is greater than the phenomenon of IF steel Erichsen number.
2) the impact test of lubricating system on Erichsen number
Choose the high-strength IF steel HC260Y that 1.5mm is thick, the tensile strength of this high-strength IF steel is 400MPa, extensibility is 36.2%, and this steel plate is lubricated by the mode of railway grease sticking polyethylene film in the railway grease in standard method and the present invention respectively, then measures Erichsen number, wherein, mould all adopts primary standard mould, and drawing velocity is 1.0mm/s, and pressure-pad-force is 10kN, crackle automatic decision is all set to 5kN, and test result is shown in Fig. 6 and Fig. 7:
Fig. 6 is for adopting the steel plate sample after grease lubrication punching press is broken, sample cracking is at drift and cylinder phase junction, rather than drift top center position, Fig. 7 is for adopting the steel plate sample after railway grease sticking polyethylene film lubrication punching press is broken, sample cracking is in drift top center position, therefore the lubricating system that, the inventive method is taked is more conducive to improve the degree of accuracy of Erichsen number test result.
3) the impact test of drawing velocity on Erichsen number
Choose the high-strength IF steel that 0.7mm is thick, the tensile strength of this high-strength IF steel is 410MPa, extensibility is 37.0%, under different drawing velocities, measure respectively Erichsen number, wherein, mould adopts primary standard mould, pressure-pad-force is 10kN, adopt the film lubrication of railway grease sticking polyethylene, crackle automatic decision is set to 5kN, drawing velocity is as the criterion not produce obvious effect of rate of strain, under different drawing velocities, the Erichsen number test result of this steel plate as shown in Figure 8, horizontal ordinate is drawing velocity, ordinate is Erichsen number, reduction along with drawing velocity, Erichsen number reduces gradually, when drawing velocity is less than 2mm/s, Erichsen number is tending towards certain value 8.22mm, a little less than now Erichsen number is subject to the impact extremely of drawing velocity, under the drawing velocity of 2mm/s, gained Erichsen number equals the 0.2mm/s in Fig. 8 with the 12mm/min(stipulating in GB) descend gained Erichsen number to equate.
Therefore, the drawing velocity scope 0.5～2.0mm/s of the present invention's regulation is scientific and reasonable, is greater than the drawing velocity of stipulating in standard, has improved the efficiency of test.
4) the impact test of sample crackle judgement on Erichsen number
As shown in Figure 4 and Figure 5, when sample is carried out to punching press, when sample is about to cracking, strong value relaxation phenomenon occurs, so the present invention utilizes this characteristic to realize the automatic decision in AEG-process crack, the power of rushing to summit declines after reaching maximal value immediately, when the power of rushing to summit starts to decline, there is penetrated crack, therefore maximum drift displacement corresponding to power of rushing to summit be Erichsen number, according to this characteristic, can be according to the force-displacement curve automatic decision initial breakthrough crackle of rushing to summit, and automatically draw Erichsen number, without by people for observing after penetrated crack, stop test, read again drift displacement, so both loaded down with trivial details, degree of accuracy is not high again.Dual phase steel 600DP is carried out to contrast test, the crackle automatic decision power decline 5kN that is set to rush to summit, other test conditions and test findings see the following form 2:
Table 2
By the Erichsen number data in table 2, can be found out, the data that obtain with the power decline judgement crackle of rushing to summit are more stable, and the data that eye-observation penetrated crack obtains are disperseed.
Claims (6)
1. an assay method for metal material Erichsen number, comprises the steps:
1) compress sample: according to the tensile strength of test button, select the pressure-pad-force of suitable size, with this pressure-pad-force, the periphery of sample is compressed, to stop sample limit portion material to flow;
2) punching press sample: the centre at sample is lubricated with railway grease sticking polyethylene film, then with drift, punching press is carried out in this centre, and drawing velocity is 0.5mm/s～2.0mm/s;
3) measure Erichsen number: in punching course, when rushing to summit power decline 1kN～6kN, stop punching press, now, maximum drift displacement corresponding to power of rushing to summit is Erichsen number.
2. the assay method of metal material Erichsen number according to claim 1, it is characterized in that: in described step 1), described test button is thickness 0.1～2.0mm and the sheet metal of tensile strength below 600MPa, and its pressure-pad-force of selecting is 100～200kN.
3. the assay method of metal material Erichsen number according to claim 1, is characterized in that: in described step 1), described test button is thickness 0.1～2.0mm and the sheet metal of tensile strength more than 600MPa, pressure-pad-force >=200kN that it is selected.
4. the assay method of metal material Erichsen number according to claim 1 and 2, is characterized in that: described metal is aluminium alloy or IF steel.
5. according to the assay method of the metal material Erichsen number described in claim 1 or 3, it is characterized in that: described metal is dual phase steel.
6. one kind for realizing the mensuration mould of the metal material Erichsen number that method designs described in claim 1, comprise the annular press mold (1) that is pressed on metal material top and the ring gasket mould (2) that is padded on metal material below, it is spherical drift (3) that the centre of described pad mould (2) is provided with end, it is characterized in that: the bottom surface of described pressing mold (1) is provided with annular convex rib (4), the end face of described pad mould (2) is provided with the concave bar (5) matching with described convex tendon (4).
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104034298A (en) * | 2014-05-28 | 2014-09-10 | 武汉钢铁(集团)公司 | Method for accurate determination of metal material hole expansion rate |
| CN106198179A (en) * | 2016-08-01 | 2016-12-07 | 湖南大学 | A kind of assay device measuring complex diversion systen lower thin sheet forming limit and method |
| CN108956277A (en) * | 2018-08-29 | 2018-12-07 | 广州文冲船厂有限责任公司 | A kind of centering tooling and its working method for Charpy-type test |
| CN109211662A (en) * | 2017-07-04 | 2019-01-15 | 上海宝钢高强钢加工配送有限公司 | A kind of convex pilot system of cup and its test method detecting welded tube welding seam quality |
| CN109425698A (en) * | 2017-08-23 | 2019-03-05 | 宝山钢铁股份有限公司 | The quick pre-judging method of coating presentation quality after a kind of steel formability |
| CN111665188A (en) * | 2019-03-06 | 2020-09-15 | 科思创德国股份有限公司 | Method for testing chemical resistance of material |
| CN111855559A (en) * | 2020-07-01 | 2020-10-30 | 江苏省沙钢钢铁研究院有限公司 | Cold-rolled sheet forming performance rapid detection die and use method thereof |
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| CN202256074U (en) * | 2011-10-14 | 2012-05-30 | 上海工程技术大学 | Mould for carrying out steel metal cup drawing test on servo press |
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| CN202256074U (en) * | 2011-10-14 | 2012-05-30 | 上海工程技术大学 | Mould for carrying out steel metal cup drawing test on servo press |
Non-Patent Citations (1)
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| ISO: "Metallic-Sheet and strip-Erichsen cupping test", 《INTERNATIONAL STANDARD》 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104034298A (en) * | 2014-05-28 | 2014-09-10 | 武汉钢铁(集团)公司 | Method for accurate determination of metal material hole expansion rate |
| CN106198179A (en) * | 2016-08-01 | 2016-12-07 | 湖南大学 | A kind of assay device measuring complex diversion systen lower thin sheet forming limit and method |
| CN109211662A (en) * | 2017-07-04 | 2019-01-15 | 上海宝钢高强钢加工配送有限公司 | A kind of convex pilot system of cup and its test method detecting welded tube welding seam quality |
| CN109425698A (en) * | 2017-08-23 | 2019-03-05 | 宝山钢铁股份有限公司 | The quick pre-judging method of coating presentation quality after a kind of steel formability |
| CN108956277A (en) * | 2018-08-29 | 2018-12-07 | 广州文冲船厂有限责任公司 | A kind of centering tooling and its working method for Charpy-type test |
| CN111665188A (en) * | 2019-03-06 | 2020-09-15 | 科思创德国股份有限公司 | Method for testing chemical resistance of material |
| CN111855559A (en) * | 2020-07-01 | 2020-10-30 | 江苏省沙钢钢铁研究院有限公司 | Cold-rolled sheet forming performance rapid detection die and use method thereof |
| CN111855559B (en) * | 2020-07-01 | 2023-08-18 | 江苏省沙钢钢铁研究院有限公司 | Cold-rolled sheet forming property rapid detection die and application method thereof |
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Application publication date: 20140402 |