CN103212950A - Technique of improving toughening and formability of automotive AHSS hot-stamping structural component - Google Patents
Technique of improving toughening and formability of automotive AHSS hot-stamping structural component Download PDFInfo
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- CN103212950A CN103212950A CN2013101457861A CN201310145786A CN103212950A CN 103212950 A CN103212950 A CN 103212950A CN 2013101457861 A CN2013101457861 A CN 2013101457861A CN 201310145786 A CN201310145786 A CN 201310145786A CN 103212950 A CN103212950 A CN 103212950A
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Abstract
The invention belongs to the field of hot-stamping forming, and discloses a technique of improving toughening and formability of an automotive AHSS hot-stamping structural component. The technique of improving the toughening and the formability of the automotive AHSS hot-stamping structural component is characterized by comprising the follow steps: step (1), pretreatment; step (2), warming treatment and heat insulation treatment of a heating furnace; step (3), splat cooling treatment; step (4), hot-pressing treatment and pressure-maintaining-quenching treatment; and step (5), after-treatment. The technique of improving the toughening and the formability of the automotive AHSS hot-stamping structural component effectively solves the problems that the AHSS hot-stamping structural component cracks and wrinkles easily and toughening is not evenly distributed due to the fact that each position is subjected to different modes of external stress, and has the advantages that a martensite novel structure with refined organization after hot forming is obtained, and the toughening and the formability of each position of a component are remarkably improved compared with an original technique.
Description
Technical field
The present invention relates to field of hot stamping forming, specifically a kind of process of improving automobile-used AHSS drop stamping structural member Strengthening and Toughening and formability.
Background technology
At present, the AHSS structural member with complicated shape becomes the first-selected object of present automobile lightweight, security because of possessing high strength, and preparing the most frequently used technology of these parts is the drop stamping technology, promptly is shaped under the high temperature austenite tissue morphology.And automobile-used structural member when being shaped suffered external carbuncle be not singly to draw or single mode of action of pressing, the parts that still unresolved drawing-compression exists jointly in original hot press-formed technology are the feature of formability, Strengthening and Toughening performance profile inequality everywhere, therefore, improving AHSS structural member Strengthening and Toughening, forming property everywhere is a key issue that needs solution.
AHSS sheet material is heated to after austenitizing insulation comes out of the stove, because of having the definite shape requirement, make its suffered external carbuncle difference in the drop stamping process everywhere, Yin La-compression is different with the effect degree again, the microcosmic of parts martensite phase transformation is influenced mechanism be there are differences, thereby cause parts easy to crack, wrinkling, phenomenons such as heterogeneous microstructure skewness occur, and this problem has become the bottleneck part of comprehensively improving AHSS structural member Strengthening and Toughening both at home and abroad, mainly start with at present from the angle of improvement steel plate, Thyssen company is by adding trace element when steel-making, as niobium etc., to improve steel plate compactness, satisfy drop stamping structural member compact texture demand, but its cost improves obviously also; In addition, component segregation appears in trace niobium easily in the production, and the improvement of AHSS obdurability is also limited to very much.
At publication number is 200510073917.5 to be the processing method that all discloses relevant heat-punch member in 200910067375.9 the patent with publication number.But all not mentionedly be subjected to different external carbuncle effects everywhere when how to take into account AHSS structural member drop stamping and improve its formability-avoid cracking and the method for improving its obdurability-compact structure with complicated shape.
Summary of the invention
According to the technical problem of above-mentioned proposition, and provide a kind of process of improving automobile-used AHSS drop stamping structural member Strengthening and Toughening and formability.The present invention mainly improves original processing technology, is considering that different external carbuncles act under the prerequisite structural member under the high temperature everywhere, has solved the problem of parts Strengthening and Toughening distributions everywhere.
The technological means that the present invention adopts is as follows:
A kind of process of improving automobile-used AHSS drop stamping structural member Strengthening and Toughening and formability is characterized in that comprising the steps:
1. preliminary treatment: rolling high strength steel plate is cut into default structural member plate through plate shearing machine, carries out inoxidzable coating then and handle, described antioxidation coating is treated in the structural member panel surface and brushes antioxidizing paint;
2. heating furnace heats up, is incubated and handles: the structural member plate is transported in the heating furnace heats, heating and temperature control is at 850-1150 ℃, and temperature retention time is at 3-5min;
3. chilling is handled: the structural member plate is taken out transhipment, in transport process thermal structure spare plate being carried out rapid quench handles, cooldown rate is greater than 40 ℃/s, and cooled temperature is controlled between the forming temperature of structural member plate, and forming temperature is 700 ℃～800 ℃;
4. hot pressing, pressurize-Quenching Treatment: the structural member plate after chilling is handled is transported to the high-speed hydraulic stamping machine drawing that has cooling water channel, and the pressurize quenching, cooldown rate 40-70 ℃/s, the dwell time is controlled at 10～20s;
5. post-processed: will pass through side cut, shot-peening, oiling again through the structural member plate after hot pressing, pressurize are handled, and make the structural member that meets the technical performance index requirement.
As preferably, described step 2. in the heating rate of heating furnace greater than 10 ℃/s.
As preferably, the chilling processing mode of described step in 3. comprises compressed air cooling, nitrogen cooling or water smoke cooling.
As preferably, described high strength steel plate is the AHSS steel plate with non-diffused martensite phase transformation feature, comprises the boron alloy steel plate.
As preferably, when described high strength steel plate was the boron alloy steel plate, the heating and temperature control in the 2. middle heating furnace of step was at 890 ℃～930 ℃.
The AHSS structural member is when drop stamping, and it is subjected to the different external carbuncle modes of action everywhere, promptly draws-compression.The mode of improving the Strengthening and Toughening of AHSS structural member and formability is generally on the one hand and promotes structural member martensite inversion quantity everywhere, remedies the different and phase content skewness problem brought of external carbuncle; Perhaps make plate before punching press, arrive best press temperature, improve the plate hardenability value, optimize the performance of sheet metal forming.
The present invention is improved original drop stamping technology, after structural member heating and austenitizing insulation, before the drop stamping its chilling that carries out certain rate of temperature fall is handled.Both guaranteed that the tension loading zone had higher hardenability value n value, improved formability; Satisfy the toughness reinforcing purpose of the increase of compression loading zone forming core number, compact structure again.Experiment shows: based on the loading zone of tension, the hardenability value n value in the time of 700 ℃ is higher than 900 ℃ and 600 ℃ (as shown in Figure 1) respectively on the parts, and the former has better formability, is shaped near this temperature, is beneficial to avoid cracking, problem such as wrinkling to take place; Based on the loading zone of compression, it is very few to its cenotype effect on microstructure to reach forming temperature before the phase transformation, still can ignore; Before the punching press, satisfy the preliminary treatment of certain chilling rate of temperature fall, be beneficial to the microstructure that obtains cenotype dense structure, purpose that can implementation structure spare Strengthening and Toughening.(be the CCT curve, as shown in Figure 2,1 is traditional temperature lowering curve to the chilling rate of temperature fall among the figure, directly punching press after promptly exemplar is come out of the stove, quenching with the overcooling austenite continuous cooling transformation (CCT) curve; 2 for when the cooling rate of chilling processing is hanged down, and will cause the two-phase of bainite grade in an imperial examination to generate; 3 methods that propose for the present invention, promptly exemplar come out of the stove the back with suitable rate of temperature fall greater than 40 ℃/s, carry out chilling and handle, and then punching press, quench) be restriction on the parameters, can avoid tissues such as bainite, ferrite to produce.And satisfy the most direct method of above-mentioned purpose simultaneously is the preliminary treatment that before the drop stamping AHSS structural member is not less than 40 ℃/s cooldown rate, and punching press in 800 ℃～700 ℃ temperature ranges, too high or too low for temperature, all can not get the better Strengthening and Toughening of expecting and the institutional framework of formability.
Compare than prior art, the AHSS structural member of process of the present invention preparation obdurability and formability and mechanical characteristic everywhere improves, the frequency that cracking, problem such as wrinkling occur when especially having reduced punching press, and by obtaining the microcosmic compact texture, make the parts obdurability be improved, both satisfy the security requirement that parts have expectation, improved product qualified rate again.Simultaneously, process of the present invention does not influence the operation of other operations.In addition, the parts by the chilling processing procedure have reduced the water-cooled energy and have discharged when being shaped, and then have reduced the power consumption of electrical equipment such as water pump.After the structural member drop stamping that process of the present invention obtains is quenched, its yield strength 〉=1100MPa everywhere, tensile strength 〉=1600MPa, percentage elongation is more than 7%.
Description of drawings
The present invention is further detailed explanation below in conjunction with the drawings and specific embodiments.
Fig. 1 is the relation curve of temperature and alloy hardenability value.
Fig. 2 is the overcooling austenite continuous cooling transformation (CCT) curve.
Fig. 3 is by the schematic diagram of the collision prevention girders of AHSS structural member drawing and the metallic phase image of diverse location thereof:
Wherein: Fig. 3 a is the schematic diagram by the collision prevention girders of AHSS structural member drawing;
Fig. 3 b is the metallic phase image after (1) some employing traditional handicraft is handled among Fig. 3 a;
Fig. 3 c is the metallic phase image after (3) some employing traditional handicraft is handled among Fig. 3 a;
Fig. 3 d is the metallic phase image after (1) some employing PROCESS FOR TREATMENT of the present invention among Fig. 3 a;
Fig. 3 e is the metallic phase image after (3) some employing PROCESS FOR TREATMENT of the present invention among Fig. 3 a.
Fig. 4 is the schematic diagram by the automobile B-column of AHSS structural member drawing.
The specific embodiment
A kind of process of improving automobile-used AHSS drop stamping structural member Strengthening and Toughening and formability comprises the steps:
1. preliminary treatment: rolling high strength steel plate is cut into default structural member plate through plate shearing machine, carries out inoxidzable coating then and handle; Described high strength steel plate is the AHSS steel plate with non-diffused martensite phase transformation feature, comprises boron alloy steel plate (22MnB5);
2. heating furnace heats up, is incubated and handles: the structural member plate is transported in the heating furnace heats, heating and temperature control is at 850-1150 ℃, and temperature retention time is at 3-5min; Wherein, the heating rate of heating furnace is greater than 10 ℃/s; Preferably, the heating and temperature control in the heating furnace is at 890 ℃～930 ℃;
3. chilling is handled: the structural member plate is taken out transhipment, in transport process thermal structure spare plate being carried out rapid quench handles, cooldown rate is greater than 40 ℃/s, and cooled temperature is controlled between the forming temperature of structural member plate, and forming temperature is 700 ℃～800 ℃; The chilling processing mode comprises compressed air cooling, nitrogen cooling or water smoke cooling;
4. hot pressing, pressurize-Quenching Treatment: the structural member plate after chilling is handled is transported to the high-speed hydraulic stamping machine drawing that has cooling water channel, and the pressurize quenching, cooldown rate 40-70 ℃/s, the dwell time is controlled at 10～20s;
5. post-processed: will pass through side cut, shot-peening, oiling again through the structural member plate after hot pressing, pressurize are handled, and make the structural member that meets the technical performance index requirement.
Shown in Fig. 3 a, be example with the hot forming collision prevention girders, 6 different points of chosen position are made sample and are carried out the hardness test analysis thereon, see Table 1.
Vickers (HV) hardness number of table 1 traditional handicraft and technology of the present invention corresponding position
| Number in the figure | 1 | 2 | 3 | 4 | 5 | 6 |
| Traditional handicraft | 415 | 428 | 457 | 469 | 432 | 424 |
| Technology of the present invention | 470 | 480 | 498 | 495 | 500 | 487 |
From mechanical characteristic relatively, the hardness number of traditional handicraft is lower than the present invention, its hardness skewness everywhere especially, and the hardness number distribution gap that the present invention obtains obviously diminishes than the former.
Contrast from metallographic, choose that two places are comparison other among Fig. 3 a, i.e. (1) and (3) point (shown in Fig. 3 b-Fig. 3 e), draw by micro-analysis, microstructure size in the traditional handicraft there are differences, can obviously find out the tissue (3) located (1) refinement some, thereby proved to macromechanics characteristic what and there are differences; And microscopic appearance provided by the invention can be found out from two figure, and its microstructure size, compactness extent are similar, and with traditional handicraft relatively, have tangible refined structure.
As shown in Figure 4, be example with the automobile B-column, choose 4 points, promptly among the figure shown in P1, P2, P3 and the P4, (comprise yield strength σ s and tensile strength sigma b, MPa) the distributing homogeneity degree sees Table 2 to survey its mechanical characteristic.
The automobile B-column each several part yield strength σ s of table 2 PROCESS FOR TREATMENT of the present invention and tensile strength sigma b value (unit: MPa)
| ? | σs | σb |
| P1 | 1112 | 1613 |
| P2 | 1131 | 1660 |
| P3 | 1115 | 1635 |
| P4 | 1107 | 1624 |
From mechanical characteristic relatively, the present invention's mechanical characteristic everywhere is evenly distributed, and the distribution gap is less.
The above; only be the preferable specific embodiment of the present invention; but protection scope of the present invention is not limited thereto; anyly be familiar with those skilled in the art in the technical scope that the present invention discloses; be equal to replacement or change according to technical scheme of the present invention and inventive concept thereof, all should be encompassed within protection scope of the present invention.
Claims (5)
1. a process of improving automobile-used AHSS drop stamping structural member Strengthening and Toughening and formability is characterized in that comprising the steps:
1. preliminary treatment: rolling high strength steel plate is cut into default structural member plate through plate shearing machine, carries out inoxidzable coating then and handle;
2. heating furnace heats up, is incubated and handles: the structural member plate is transported in the heating furnace heats, heating and temperature control is at 850-1150 ℃, and temperature retention time is at 3-5min;
3. chilling is handled: the structural member plate is taken out transhipment, in transport process thermal structure spare plate being carried out rapid quench handles, cooldown rate is greater than 40 ℃/s, and cooled temperature is controlled between the forming temperature of structural member plate, and forming temperature is 700 ℃～800 ℃;
4. hot pressing, pressurize-Quenching Treatment: the structural member plate after chilling is handled is transported to the high-speed hydraulic stamping machine drawing that has cooling water channel, and the pressurize quenching, cooldown rate 40-70 ℃/s, the dwell time is controlled at 10～20s;
5. post-processed: will pass through side cut, shot-peening, oiling again through the structural member plate after hot pressing, pressurize are handled, and make the structural member that meets the technical performance index requirement.
2. a kind of process of improving automobile-used AHSS drop stamping structural member Strengthening and Toughening and formability according to claim 1 is characterized in that: described step 2. in the heating rate of heating furnace greater than 10 ℃/s.
3. a kind of process of improving automobile-used AHSS drop stamping structural member Strengthening and Toughening and formability according to claim 1 is characterized in that: the chilling processing mode of described step in 3. comprises compressed air cooling, nitrogen cooling or water smoke cooling.
4. a kind of process of improving automobile-used AHSS drop stamping structural member Strengthening and Toughening and formability according to claim 1, it is characterized in that: described high strength steel plate is the AHSS steel plate with non-diffused martensite phase transformation feature, comprises the boron alloy steel plate.
5. according to claim 1 or 4 described a kind of processes of improving automobile-used AHSS drop stamping structural member Strengthening and Toughening and formability, it is characterized in that: when described high strength steel plate was the boron alloy steel plate, the heating and temperature control in the 2. middle heating furnace of step was at 890 ℃～930 ℃.
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Cited By (10)
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| 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 |
| CN103409613A (en) * | 2013-08-30 | 2013-11-27 | 上海交通大学 | Method for realizing gradient property distribution of hot stamping workpiece |
| CN104726762A (en) * | 2015-02-16 | 2015-06-24 | 大连理工大学 | Warm-hot forming method for boron-free medium-manganese steel |
| CN104762460A (en) * | 2015-03-12 | 2015-07-08 | 燕山大学 | Rolling and deep-processing short-process integrated manufacturing method of high-strength steel automobile sheet |
| CN105251685A (en) * | 2015-10-29 | 2016-01-20 | 桂林创研科技有限公司 | Hot punch forming technology |
| CN106391850A (en) * | 2016-08-31 | 2017-02-15 | 天津圣金特汽车配件有限公司 | High-strength steel plate hot-stamping and in-mold quenching process |
| CN107321832A (en) * | 2017-07-10 | 2017-11-07 | 山东钢铁集团日照有限公司 | A kind of process of steady decrease thermoforming temperatures |
| CN107354278A (en) * | 2017-08-22 | 2017-11-17 | 大连理工大学 | A kind of aerosol Quenching Production Line and its production technology for obtaining intensity adjustable automobile structure |
| CN109434384A (en) * | 2018-11-16 | 2019-03-08 | 苏州普热斯勒先进成型技术有限公司 | A kind of preparation method and device, hot stamping method of coated steel sheet |
| CN109622706A (en) * | 2018-12-11 | 2019-04-16 | 吉林省正轩车架有限公司 | The process of auto parts is manufactured with middle thick boron alloyed steel plate heat stamping and shaping |
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Cited By (12)
| 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 |
| CN103409613A (en) * | 2013-08-30 | 2013-11-27 | 上海交通大学 | Method for realizing gradient property distribution of hot stamping workpiece |
| CN104726762A (en) * | 2015-02-16 | 2015-06-24 | 大连理工大学 | Warm-hot forming method for boron-free medium-manganese steel |
| CN104762460A (en) * | 2015-03-12 | 2015-07-08 | 燕山大学 | Rolling and deep-processing short-process integrated manufacturing method of high-strength steel automobile sheet |
| CN105251685A (en) * | 2015-10-29 | 2016-01-20 | 桂林创研科技有限公司 | Hot punch forming technology |
| CN106391850A (en) * | 2016-08-31 | 2017-02-15 | 天津圣金特汽车配件有限公司 | High-strength steel plate hot-stamping and in-mold quenching process |
| CN107321832A (en) * | 2017-07-10 | 2017-11-07 | 山东钢铁集团日照有限公司 | A kind of process of steady decrease thermoforming temperatures |
| CN107354278A (en) * | 2017-08-22 | 2017-11-17 | 大连理工大学 | A kind of aerosol Quenching Production Line and its production technology for obtaining intensity adjustable automobile structure |
| CN107354278B (en) * | 2017-08-22 | 2018-11-09 | 大连理工大学 | A kind of aerosol Quenching Production Line and its production technology obtaining intensity adjustable automobile structure |
| CN109434384A (en) * | 2018-11-16 | 2019-03-08 | 苏州普热斯勒先进成型技术有限公司 | A kind of preparation method and device, hot stamping method of coated steel sheet |
| CN109622706A (en) * | 2018-12-11 | 2019-04-16 | 吉林省正轩车架有限公司 | The process of auto parts is manufactured with middle thick boron alloyed steel plate heat stamping and shaping |
| CN109622706B (en) * | 2018-12-11 | 2020-08-25 | 吉林省正轩车架有限公司 | Process method for manufacturing automobile parts by hot stamping and forming medium-thickness boron alloy steel plate |
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Application publication date: 20130724 |