CN115122052A - Forming method of ultrahigh-strength steel automobile thin-wall structural member - Google Patents
Forming method of ultrahigh-strength steel automobile thin-wall structural member Download PDFInfo
- Publication number
- CN115122052A CN115122052A CN202210846851.2A CN202210846851A CN115122052A CN 115122052 A CN115122052 A CN 115122052A CN 202210846851 A CN202210846851 A CN 202210846851A CN 115122052 A CN115122052 A CN 115122052A
- Authority
- CN
- China
- Prior art keywords
- strength steel
- structural member
- forming
- ultra
- welding
- 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.)
- Pending
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
- B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/18—Hardening; Quenching with or without subsequent tempering
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D11/00—Process control or regulation for heat treatments
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/0068—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for particular articles not mentioned below
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
The invention relates to a forming method of an ultrahigh-strength steel automobile thin-wall structural member, which comprises the following steps: s1, preforming of the workpiece: bending the ultrahigh-strength steel material with the pressure of more than 1000MPa at normal temperature, and bending the plate into a shape corresponding to the structural member; s2, welding the plates: connecting the processed plates in the step S1 together through laser fuse welding, and shaping the workpiece through correction; the ratio between the wire feeding speed and the welding speed is represented by a forming coefficient K, the laser power is P, P is larger than 2400W and smaller than or equal to 2800W, the forming coefficient K is larger than or equal to 1.5 and smaller than or equal to 1.7, and the ratio n between the laser power and the forming coefficient is P/K in the welding process; and S3, quenching the formed workpiece, and controlling deformation by a pressure quenching mode. The invention can produce the ultra-high strength steel component in small batch without using a hot stamping die, accurately control the precision and the performance of the formed component and greatly save the cost in the production process of the structural component.
Description
Technical Field
The invention relates to the field of automobile part production, in particular to a method for forming an ultrahigh-strength steel automobile thin-wall structural member.
Background
With the topic of energy conservation and emission reduction being widely regarded, the application of the lightweight technology in various industries is more and more extensive. In order to adapt to the gradual advance of the light-weight technology, the production of various parts also needs to continuously improve the technology and ensure the performance and quality requirements of the parts. The ultra-high strength steel and the heat treatment process are selected, so that the strength of the material can be greatly improved, and the quality of the product can be effectively reduced.
For the ultrahigh-strength steel material with the pressure of more than 1000MPa, because the material needs a heat treatment quenching process in the forming process and the quenching process is easy to deform, the material is hot stamped on a special die by adopting a hot stamping mode aiming at the processing of the material at present, and the quenching and cooling process is carried out in the die. However, for some closed structures, no proprietary dies can be used for forming, so that hot stamping cannot be used for forming such structures. Furthermore, for hot stamping, corresponding dedicated dies have to be produced for the component, so that the costs of the entire process are greatly increased, and in particular for components produced in small quantities, the hot stamping process is not suitable for the production of such parts. For the ultrahigh-strength steel material, heat treatment is needed to ensure that the strength of the ultrahigh-strength steel material meets the requirement, but the heat treatment can cause large deformation of a component.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a method for forming an ultra-high strength steel automobile thin-wall structural member, which can be used for producing ultra-high strength steel structural members in small batches without using a hot stamping die, accurately controlling the precision and the performance of the formed structural members and greatly saving the cost in the production process of the structural members.
The technical scheme adopted by the invention for solving the technical problems is as follows: the forming method for constructing the ultra-high-strength steel automobile thin-wall structural member comprises the following steps of:
s1, preforming of the workpiece: bending the ultrahigh-strength steel material with the pressure of more than 1000MPa at normal temperature, and bending the plate into a shape corresponding to the structural member;
s2, welding the plates: connecting the processed plates in the step S1 together through laser fuse welding, and shaping the workpiece through correction; the ratio between the wire feeding speed and the welding speed is represented by a forming coefficient K, the laser power is P, P is larger than or equal to 2400W and smaller than or equal to 2800W, the forming coefficient is equal to or larger than 1.5 and smaller than or equal to 1.7, and the ratio n between the laser power and the forming coefficient is P/K in the welding process;
and S3, quenching the formed workpiece, and controlling deformation by a pressure quenching mode.
According to the scheme, in step S1, the thickness of the processed ultrahigh-strength steel plate is less than 6mm during bending, and the relation between the bending die gap h and the plate thickness t is that h is more than or equal to 1.1t and less than or equal to 1.5 t.
According to the scheme, in the step S1, the friction coefficient is between 0.1 and 0.2, and the stamping speed is 600-800 mm/S.
According to the above scheme, in step S1, the following relationship is satisfied between the bending fillet radius r and the plate thickness t during bending: for the ultrahigh-strength steel plate with the plate thickness of 3 mm-t 6mm, r is 2 t; r is 2.5t for the ultrahigh-strength steel plate with the plate thickness of 0-t 3 mm.
According to the scheme, in the step S3, the heat preservation temperature of the component during quenching is controlled to be 780-920 ℃.
According to the scheme, in step S3, the heat preservation time t during quenching is more than or equal to 5min and less than or equal to 15min, and the transfer time is less than 30S.
The method for forming the thin-wall structural member of the ultrahigh-strength steel automobile has the following beneficial effects:
1. the invention can produce the ultra-high strength steel components in small batch without using a hot stamping die, and can greatly save the cost in the production process of the structural components.
2. In the bending process of the part, the invention can realize the molding of the material in a cold state by taking the performance parameters of the ultrahigh-strength steel into consideration.
3. The welding process of the invention uses laser filler wire welding for the ultra-high strength steel, and strictly controls the laser power, so that the strength of the welding seam can still meet the requirements after quenching.
4. When the quenching heat treatment is carried out on the component, the deformation of the workpiece and the performance of the processed component are effectively controlled, so that the final product has the characteristics of high precision and good performance.
In conclusion, the method can firstly bend, weld and form the ultrahigh-strength steel material needing heat treatment, and then ensure the deformation of subsequent quenching by means of pressure quenching, temperature control and the like, thereby realizing the forming of the component. The method has the advantages of simple and effective forming process, no need of special mould in the production process, low production cost and good product quality.
Drawings
The invention will be further described with reference to the accompanying drawings and examples, in which:
FIG. 1 is a flow chart of the forming method of the thin-wall structural member of the ultrahigh-strength steel automobile.
Detailed Description
For a more clear understanding of the technical features, objects and effects of the present invention, embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
As shown in figure 1, the invention provides a method for forming an ultra-high-strength steel automobile thin-wall structural member, which comprises the following steps:
s1, preforming of the workpiece: and bending the ultrahigh-strength steel material at normal temperature, and bending the plate into a shape corresponding to the structural member. For structural members made of ultrahigh-strength steel materials, the plate thickness t is generally less than or equal to 6mm, and for bending of the workpieces in a cold state, the wrinkling phenomenon of parts caused by thinning of materials at the round corners in the bending process is controlled on one hand, and the springback of the bent plates is controlled on the other hand. These two issues can be effectively controlled, generally from controlling the die gap, coefficient of friction, press speed, and bend radius.
The die gap h is the distance between the upper bending die and the lower bending die after the final reduction is finished, and the ideal thickness t of the plate is required. However, the maximum thinning amount is gradually reduced along with the increase of the die clearance; but the rebound angle gradually increases as the die gap increases. When the relation between the die clearance and the plate thickness is h ═ 2t, the rebound angle reaches the maximum, which shows that an excessively large die clearance causes an excessively large rebound angle after the steel plate is bent. Therefore, the die clearance should be reasonably selected, and when the die clearance satisfies that h is more than or equal to 1.1t and less than or equal to 1.5t, the thinning phenomenon and the rebound phenomenon are both small, and the production requirement is satisfied.
The impact of the stamping speed and the friction coefficient on the thinning phenomenon of the plate is small, but with the increase of the stamping speed and the reduction of the friction coefficient, the rebound angle after bending can be correspondingly reduced, the forming difficulty in the bending process is comprehensively considered, the friction coefficient is selected to be 0.1-0.2, and the stamping speed is selected to be 600 plus 800 mm/s.
Along with the increase of the fillet radius of the upper die and the lower die, the thinning amount is gradually reduced, the resilience value of the plate bending is gradually increased, and the increasing amplitude is large. However, the rebound angle is reduced along with the increase of the plate thickness, so that the thinning amount and the rebound value of the plate material can be reasonably controlled by selecting a reasonable relation between the fillet radius and the plate thickness. For ultrahigh strength steel sheet materials having a thickness of less than 6mm, the formability can be controlled appropriately by selecting r to be about 2 t.
S2, welding the plates: and connecting the plates processed in the steps together through welding treatment, and forming the workpiece through certain correction. In order to ensure that the strength of the welding seam can still be ensured after the subsequent heat treatment process, the selected welding mode is laser fuse welding. If the traditional gas shielded welding is used for the ultrahigh-strength steel, the strength of the welding seam after welding is higher than that of the base metal, the test sample is subjected to a tensile test after quenching, the test sample is broken at the welding seam, and the strength of the welding seam in the welding mode cannot meet the requirement for a stressed structural member. The problem can be effectively solved by adopting the laser wire-filling welding process, and the laser power, the wire feeding speed and the welding speed have great influence on the welding quality of the ultrahigh-strength steel. When the laser power is too low, the heat input per unit time is small, the base material is not melted with enough energy, and the defects of incomplete penetration, incomplete fusion of the side wall and the like can occur. When the laser power is high enough, the weld joint is well formed, and the tensile strength of the weld joint is higher than that of the base metal. The ratio between the wire feeding speed and the welding speed is represented by a forming coefficient K, the laser power is P, when the value of P is 2400W or more and P or less than 2800W, and the forming coefficient is 1.5 or more and K or less than 1.7, the quality of a welding seam is optimal, so the ratio n between the laser power and the forming coefficient in the welding process is about 1600, and n is P/K.
And S3, quenching the formed workpiece. In the process of quenching the parts, in order to ensure the requirements of shape, size and precision and strength performance of the parts, on one hand, the heat preservation time of the workpiece needs to be reasonably controlled, and on the other hand, the workpiece transfer speed needs to be increased as much as possible. For the ultra-high strength steel structural member with the pressure of more than 1000MPa, the larger the size of the structural member is, the slower the temperature rising speed is, and the longer the required heating time is, so that the heat preservation time t is enabled to be more than or equal to 5min and less than or equal to 15min according to the size of the structural member. On the other hand, the transfer speed needs to be improved in the quenching process, for general thin-wall parts, due to the fact that the wall thickness is thin, the temperature can be rapidly reduced after the parts are discharged from a furnace, due to the fact that the size of the parts is large, clamping and quenching transfer are difficult after the parts are discharged from the furnace, and compared with small-size samples, large-size components need longer quenching transfer time. The temperature of the component when the component is discharged is 900 ℃, the large-scale operation arm component is contacted with air in the quenching transfer process, the temperature is reduced, and the temperature of the component is continuously reduced along with the increase of the quenching transfer time. When the transfer time is 30s, the temperature at two ends of the component is reduced to the maximum, the temperature is reduced to about 720 ℃ at the minimum, and A in a CCT curve of general heat-treated steel c1 Is 7The temperature is about 20 ℃, so the transferring time is controlled within 30s, and the components are transferred by adopting special tools and transferring devices. In addition, because the quenching process of the component is not carried out in a special hot stamping die, the quenching process is easy to cause the component to be greatly deformed, and a press mounting device is used on a long side which is easy to deform to prevent the deformation of the component.
While the present invention has been described with reference to the particular illustrative embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but is intended to cover various modifications, equivalent arrangements, and equivalents thereof, which may be made by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (6)
1. A forming method of an ultra-high-strength steel automobile thin-wall structural member is characterized by comprising the following steps:
s1, preforming of the workpiece: bending the ultrahigh-strength steel material with the pressure of more than 1000MPa at normal temperature, and bending the plate into a shape corresponding to the structural member;
s2, welding the plates: connecting the processed plates in the step S1 together through laser fuse welding, and shaping the workpiece through correction; the ratio between the wire feeding speed and the welding speed is represented by a forming coefficient K, the laser power is P, P is larger than 2400W and smaller than or equal to 2800W, the forming coefficient K is larger than or equal to 1.5 and smaller than or equal to 1.7, and the ratio n between the laser power and the forming coefficient is P/K in the welding process;
and S3, quenching the formed workpiece, and controlling deformation by a pressure quenching mode.
2. The method for forming an ultra-high strength steel automobile thin-walled structure member according to claim 1, wherein in step S1, the thickness of the ultra-high strength steel plate processed during bending is less than 6mm, and the relation between the bending die clearance h and the plate thickness t is 1.1 t-h 1.5 t.
3. The method for molding the thin-walled structural member of the ultra-high strength steel automobile as claimed in claim 1, wherein in step S1, the friction coefficient is between 0.1 and 0.2, and the stamping speed is 600-800 mm/S.
4. The method for forming an ultra-high strength steel thin-walled automotive structural member as claimed in claim 1, wherein in step S1, the following relationship is satisfied between the bend fillet radius r and the plate thickness t during bending: for the ultrahigh-strength steel plate with the plate thickness of 3 mm-t 6mm, r is 2 t; for the ultra-high strength steel plate with the plate thickness of 0-t 3mm, r is 2.5 t.
5. The method for forming the ultra-high strength steel thin-walled automotive structural member as claimed in claim 1, wherein in step S3, the holding temperature of the member during quenching is controlled to be between 780 ℃ and 920 ℃.
6. The forming method of the ultra-high strength steel automobile thin-wall structural member as claimed in claim 1, wherein in step S3, the heat preservation time t during quenching is 5min or more and t or less than 15min, and the transfer time is less than 30S.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210846851.2A CN115122052A (en) | 2022-07-05 | 2022-07-05 | Forming method of ultrahigh-strength steel automobile thin-wall structural member |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210846851.2A CN115122052A (en) | 2022-07-05 | 2022-07-05 | Forming method of ultrahigh-strength steel automobile thin-wall structural member |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115122052A true CN115122052A (en) | 2022-09-30 |
Family
ID=83384807
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210846851.2A Pending CN115122052A (en) | 2022-07-05 | 2022-07-05 | Forming method of ultrahigh-strength steel automobile thin-wall structural member |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115122052A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101284334A (en) * | 2008-06-06 | 2008-10-15 | 贵州大学 | Application of laser weld in ultra-high tensile steel welding and welding method |
| CN103233112A (en) * | 2013-04-25 | 2013-08-07 | 北京机电研究所 | Quenching and tempering heat treatment equipment and method for 4-6mm high-strength sheet |
| CN107557538A (en) * | 2017-09-20 | 2018-01-09 | 北京星航机电装备有限公司 | A kind of thin-wall part process for quenching |
| CN107900518A (en) * | 2017-11-23 | 2018-04-13 | 中南大学 | A kind of high-rate laser silk filling penetration fustion welding method of high strength dual phase steel thick plate |
| CN111203686A (en) * | 2018-11-21 | 2020-05-29 | 郑州宇通客车股份有限公司 | Preparation process of ultrahigh-strength vehicle framework section bar |
| CN111411211A (en) * | 2020-03-02 | 2020-07-14 | 武汉理工大学 | Method for forming vehicle arm of overhead working vehicle |
| CN111673392A (en) * | 2020-06-22 | 2020-09-18 | 辽宁衡业高科新材股份有限公司 | Continuous production process for ultra-high-strength lightweight automobile chassis longitudinal beam |
-
2022
- 2022-07-05 CN CN202210846851.2A patent/CN115122052A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101284334A (en) * | 2008-06-06 | 2008-10-15 | 贵州大学 | Application of laser weld in ultra-high tensile steel welding and welding method |
| CN103233112A (en) * | 2013-04-25 | 2013-08-07 | 北京机电研究所 | Quenching and tempering heat treatment equipment and method for 4-6mm high-strength sheet |
| CN107557538A (en) * | 2017-09-20 | 2018-01-09 | 北京星航机电装备有限公司 | A kind of thin-wall part process for quenching |
| CN107900518A (en) * | 2017-11-23 | 2018-04-13 | 中南大学 | A kind of high-rate laser silk filling penetration fustion welding method of high strength dual phase steel thick plate |
| CN111203686A (en) * | 2018-11-21 | 2020-05-29 | 郑州宇通客车股份有限公司 | Preparation process of ultrahigh-strength vehicle framework section bar |
| CN111411211A (en) * | 2020-03-02 | 2020-07-14 | 武汉理工大学 | Method for forming vehicle arm of overhead working vehicle |
| CN111673392A (en) * | 2020-06-22 | 2020-09-18 | 辽宁衡业高科新材股份有限公司 | Continuous production process for ultra-high-strength lightweight automobile chassis longitudinal beam |
Non-Patent Citations (1)
| Title |
|---|
| 吴信涛: "DP800双相高强钢折弯及回弹研究", 精密成形工程, vol. 8, no. 4, pages 38 - 42 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7240532B2 (en) | Hybrid metal forming system | |
| US8434231B2 (en) | Method for producing a metal component from a hot-stamped raw material | |
| US7389665B1 (en) | Sheet metal forming process | |
| EP1943034B1 (en) | Method for press forming of a panel part having a bent portion and press forming device | |
| CN108787904B (en) | Stamping and riveting integrated process and die for patch reinforcing structure | |
| JP2007326112A (en) | Press forming method | |
| WO2012011224A1 (en) | Method for forming steel plate by hot press | |
| CN112118922B (en) | Conductive preheating of sheet material for thermoforming | |
| JP2008055511A (en) | Method of manufacturing metallic sheet member for automotive use from blank | |
| US20230311185A1 (en) | Press methods for coated steels and uses of steels | |
| CN111565863A (en) | Method for producing press-molded article | |
| US8631675B2 (en) | Method and apparatus for forming flanges during hot-forming | |
| JP2008248342A (en) | Respective manufacturing methods of aluminum-alloy sheet material, sheet and formed member | |
| JP7087568B2 (en) | Hot press working method and processing equipment | |
| CN112572615B (en) | Hot forming component integrating tailor welded blank and patch panel and preparation method thereof | |
| CN115122052A (en) | Forming method of ultrahigh-strength steel automobile thin-wall structural member | |
| CN106077276A (en) | Method for forming stamping part with multiple strengths and hot stamping forming device | |
| JP5429849B2 (en) | Steel sheet bending method | |
| US20120174406A1 (en) | Method and production plant for making components for a motor vehicle | |
| CN114770048A (en) | One-time drawing thermal forming method for large-scale alloy aluminum plate | |
| CN115397578A (en) | Hot press line and method for manufacturing hot press molded article | |
| CN109047430A (en) | A kind of drop stamping technique and heating punching press all-in-one oven | |
| CN105772584B (en) | Improve the thermoforming process and molding machine of forming parts performance | |
| JP2006142905A (en) | Energy absorbing member and manufacturing method thereof | |
| CN117604201A (en) | Method for softening hot forming part riveting area by utilizing laser |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |