CN104726762A - Warm-hot forming method for boron-free medium-manganese steel - Google Patents
Warm-hot forming method for boron-free medium-manganese steel Download PDFInfo
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- CN104726762A CN104726762A CN201510084352.4A CN201510084352A CN104726762A CN 104726762 A CN104726762 A CN 104726762A CN 201510084352 A CN201510084352 A CN 201510084352A CN 104726762 A CN104726762 A CN 104726762A
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Abstract
The invention discloses a warm-hot forming method for boron-free medium-manganese steel. The method is characterized by comprising the following steps: austenitizing pretreatment, namely heating a sheet to 750-820 DEG C at the heating rate of not lower than 10 DEG C/s, and carrying out heat preservation for 3-10 minutes; a sheet transferring process, namely cooling the sheet to a stamping temperature of 450-700 DEG C at the cooling rate of not lower than 5 DEG C/s, and transferring to a stamping mold; heat-resistant stamping and pressurizing-quenching treatment, namely transporting the sheet below the stamping mold, forming, and simultaneously carrying out heat-retaining quenching, wherein the quenching cooling rate is greater than 5 DEG/s; and the pressurizing time is 5-20s; and post-treatment, namely carrying out shot blasting on a formed sample piece, and anti-rust oil coating treatment. The warm-hot forming method provided by the invention conforms to industrial production of the boron-free medium-manganese steel, and has the advantages that the manufacture cost is reduced and the strength and plasticity of a steel part are improved; the new generation of automobile is promoted to reach a relatively high step in the aspects of light weight, fuel conservation and safety; and the warm-hot forming method is simple in technological process and convenient to operate.
Description
Technical field
The present invention relates to warm deep drawing molding field, specifically one sets up the mild hot formation method of automobile steel (without boron Medium Manganese Steel, i.e. TG steel) structural part.
Background technology
Energy saving standard has become the trend of Global Auto industry technology development.Therefore, high-strength steel structural part is adopted to be with one of most effective way realizing this target by " automotive light weight technology ".Along with going deep into of being familiar with vehicle safety, it is found that the intensity only improving steel can not meet the demand of design, the high strength and ductility steel construction piece of combine high strength and high-ductility significantly can improve the safety performance of vehicle, and therefore, its development and application becomes the advanced problems of research both at home and abroad.But the intensity of ferrous materials and plasticity are often difficult to coordinate.Along with the raising of hardness of steel level, its plasticity reduces usually, makes the strength and ductility product (Rm × A) of sign security be difficult to improve.Therefore, under the development trend of ferrous materials high strength, how improving the plasticity of steel, is the major issue that it faces.At present, develop mainly for thermoforming boron steel and study in the world, Germany Ben Tele (Arcelor) has released the world market that USIBOR1500 boron alloyed steel has captured tide of motorism shaping and punching part, but, the unit elongation (less than 8%) that thermoforming boron steel is lower, cause its strength and ductility product to be only about 12GPa%, limit the further lifting of automotive light weight technology and security.
Summary of the invention
According to the technical problem of above-mentioned proposition, and provide a kind of without boron Medium Manganese Steel mild hot formation method.The present invention mainly utilizes warm forming technology, preparation high strength, high-ductility without boron Medium Manganese Steel, thus reduction manufacturing cost, develop microtexture and the uniform high-strength steel structural part of mechanical property distribution.
The technique means that the present invention adopts is as follows:
A kind of without boron Medium Manganese Steel mild hot formation method, it is characterized in that comprising the steps:
S1, austenitizing pre-treatment: default structural part plate will be cut into without boron Medium Manganese Steel after rolling process, and be transferred in heat treatment furnace and be heated to 750 DEG C-820 DEG C, insulation 3min-10min, preferably, soaking time is at 3min-5min;
S2, plate transport process: according to the final performance requriements of steel part, cool to press temperature between 450 DEG C-700 DEG C by pretreated for austenitizing plate with the rate of cooling being greater than 5 DEG C/s, then be transported to the press tool with cooling water channel;
S3, warm deep drawing, pressurize-quench treatment: plate is shaped under being transported to press tool, is incubated quenching simultaneously, quenching cooling rate is greater than 5 DEG C/s, and the dwell time, preferably, warm forming temperature controlled at 450 DEG C-550 DEG C at 5s-20s;
S4, post-processed: the exemplar that is shaped is carried out trimming, shot-peening, the process of painting slushing oil, make the structural part meeting technical performance index requirement.
Further, the chemical component weight per-cent without boron Medium Manganese Steel described in step S1 is: C:0.08-0.2%; Mn:4-6%; P≤0.015%; S≤0.02%; N≤0.005%; Surplus is Fe and inevitable impurity.
Further, the heat treatment furnace temperature rise rate in step S1 is greater than 10 DEG C/s.
Further, in step S2 to the plate after described austenitizing process carry out lower the temperature process to target press temperature can adopt normal temperature protect air cooling but, band cooling water channel mold cools down or cool in fore-cooling room.
The cooling of normal temperature shielding gas goes in the treatment chamber being full of the protection against oxidation such as room temperature under nitrogen or argon gas gas by the plate of austenitizing, and rate of cooling is greater than 5 DEG C/s, and cooled temperature controls at 450 ~ 700 DEG C.This kind of Pre-cooling Mode operating process is simple, simplifies production line.
Mold cools down with cooling water channel be the plate of austenitizing is transported to cooling water channel up and down between flat plate mold, carry out precompressed-precooling treatment, rate of cooling controls be greater than 5 DEG C/s, pressing, cooled temperature control between the forming temperature of plate, and temperature range is at 450 ~ 700 DEG C.This kind of type of cooling can solve the defect of plate warpage in punching course to a great extent.
In fore-cooling room, cooling is by the plate pressurized air of austenitizing, and compressed nitrogen, water smoke cools, and rate of cooling is greater than 5 DEG C/s, and cooled temperature controls at 450 ~ 700 DEG C.This kind of Pre-cooling Mode can improve the forming property of plate, not easily breaks and mechanical property is everywhere average when punching press.
Comparatively prior art is compared, the present invention adopt without boron Medium Manganese Steel, before punching press, metallographic structure is ultra-fine grained ferrite or ultra-fine grained ferrite and residual austenite, size is between 2 μm-3 μm, even hundreds of nanometer, the microstructure of its Ultra-fine Grained is beneficial to possesses high strength, high-ductility simultaneously, i.e. the realization of high strength and ductility performance.But when needs armor plate strength exceedes certain magnitude, be just difficult to the press finding the moulding stock supporting with it and suitable tonnage, production cost also cannot reduce.Warm forming technology has significant advantage for high-strength steel, and it can cool fast in deformation process, obtains the steel part at room temperature with even martensitic stucture.What the present invention proposed utilizes warm forming technology, and preparation high strength, high-elongation, performance are equally distributed without boron Medium Manganese Steel structural part, to promote lightweight and the security of automobile structure further.
The present invention has the following advantages:
1, compared with thermoforming boron steel, warm forming has lower austenitizing Heating temperature and lower press temperature without boron Medium Manganese Steel, is beneficial to reduction production cost.
What 2, warm forming was obtained has refinement, uniform microstructure without boron Medium Manganese Steel, is beneficial to the steel part obtaining and have high strength, high-ductility mechanical property.
Accompanying drawing explanation
Below in conjunction with the drawings and specific embodiments, the present invention is further detailed explanation.
Fig. 1 is the process flow sheet of the present invention without boron Medium Manganese Steel mild hot formation method.
Fig. 2 is the pictorial diagram of the warm forming prepared of the present invention without boron Medium Manganese Steel automobile B-column structural part.
Fig. 3 is the automobile B-column structural part string diagram of Fig. 2.
Fig. 4 the present invention is based on the microscopic appearance figure (5) in Fig. 2 put.
Fig. 5 the present invention is based on the microscopic appearance figure (1) in Fig. 2 put.
Fig. 6 the present invention is based on the microscopic appearance figure (8) in Fig. 2 put.
Embodiment
A kind of without boron Medium Manganese Steel mild hot formation method, comprise the steps (as shown in Figure 1):
S1, austenitizing pre-treatment: default structural part plate will be cut into without boron Medium Manganese Steel after rolling process, and be transferred in heat treatment furnace and be heated to 750 DEG C-820 DEG C, insulation 3min-10min, heat treatment furnace temperature rise rate is greater than 10 DEG C/s; The described chemical component weight per-cent without boron Medium Manganese Steel is: C:0.08-0.2%; Mn:4-6%; P≤0.015%; S≤0.02%; N≤0.005%; Surplus is Fe and inevitable impurity;
S2, plate transport process: according to the final performance requriements of steel part, pretreated for austenitizing plate is cooled to press temperature between 450 DEG C-700 DEG C with the rate of cooling being greater than 5 DEG C/s, be transported to the press tool with cooling water channel again, the pretreated plate of described austenitizing carry out lower the temperature process can adopt normal temperature protect air cooling but, band cooling water channel mold cools down or cool in fore-cooling room;
S3, warm deep drawing, pressurize-quench treatment: plate is shaped under being transported to press tool, is incubated quenching simultaneously, quenching cooling rate is greater than 5 DEG C/s, and the dwell time is at 5s-20s;
S4, post-processed: the exemplar that is shaped is carried out trimming, shot-peening, the process of painting slushing oil.
Embodiment 1
Will (its chemical component weight per-cent be: C:0.1% without boron Medium Manganese Steel plate; Mn:5%; P:0.015%; S:0.015%; N:0.005%; Surplus is Fe and inevitable impurity) be warming up to 800 DEG C, insulation 3min, be transported to press tool, press temperature is 500 DEG C, and with the rate of cooling quench treatment of 10 DEG C/s, pressurize 10s.Above-mentioned processing parameter is adopted to make automobile B-column, as shown in Figure 2 and Figure 3, and from choosing 11 representative points (as the point that plane or structural part edges at two ends place etc. in the sidewall edge of B-pillar structure part or structural part is representative) above, and survey relevant mechanical property as table 1.
Each mechanical property parameters value of table 1 corresponding point position of the present invention
As can be seen from the mechanical property recorded, even without the exemplar performance profile that boron Medium Manganese Steel is obtaining, hardness is at about 450HV, meet the safety performance standard of automobile steel sheet, its unit elongation is also apparently higher than boron steel (about 8%) the exemplar unit elongation that traditional hot stamping technique is made, this means that there is better energy-absorbing effect, navigating mate can be avoided in car collision to be subject to grievous injury.
Choose (5) point and survey metallographic (as shown in Figure 4), drawn by microscopic sdIBM-2+2q.p.approach, microtexture of the present invention is obviously than boron steel part microcosmic refinement prepared by hot stamping traditional technology, be Ultra-fine Grained martensite without the martensite obtained after boron Medium Manganese Steel warm forming, size is less than ten microns, the martensite (tens microns) formed after general boron steel hot stamping, this also just warm forming Medium Manganese Steel have the reason of better mechanical property; And from (1) point chosen and (8) point (as shown in Figure 5, Figure 6), different positions microstructure sizes provided by the invention is put similar with compactness extent to (5), thus the macro property demonstrating structural part is evenly distributed, distribution gap is less.
The above; be only the present invention's preferably embodiment; 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 according to technical scheme of the present invention and inventive concept thereof and replace or change, all should be encompassed within protection scope of the present invention.
Claims (4)
1., without a boron Medium Manganese Steel mild hot formation method, it is characterized in that comprising the steps:
S1, austenitizing pre-treatment: default structural part plate will be cut into without boron Medium Manganese Steel after rolling process, and be transferred in heat treatment furnace and be heated to 750 DEG C-820 DEG C, insulation 3min-10min;
S2, plate transport process: according to the final performance requriements of steel part, cool to press temperature between 450 DEG C-700 DEG C by pretreated for austenitizing plate with the rate of cooling being greater than 5 DEG C/s, then be transported to the press tool with cooling water channel;
S3, warm deep drawing, pressurize-quench treatment: plate is shaped under being transported to press tool, is incubated quenching simultaneously, quenching cooling rate is greater than 5 DEG C/s, and the dwell time is at 5s-20s;
S4, post-processed: the exemplar that is shaped carried out shot-peening, be coated with slushing oil process.
2. according to claim 1 without boron Medium Manganese Steel mild hot formation method, it is characterized in that: the chemical component weight per-cent without boron Medium Manganese Steel described in step S1 is: C:0.08-0.2%; Mn:4-6%; P≤0.015%; S≤0.02%; N≤0.005%; Surplus is Fe and inevitable impurity.
3. according to claim 1 without boron Medium Manganese Steel mild hot formation method, it is characterized in that: the heat treatment furnace temperature rise rate in step S1 is greater than 10 DEG C/s.
4. according to claim 3 without boron Medium Manganese Steel mild hot formation method, it is characterized in that: in step S2 to the plate after described austenitizing process carry out lower the temperature process to target press temperature can adopt normal temperature protect air cooling but, band cooling water channel mold cools down or cool in fore-cooling room.
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| CN106086648A (en) * | 2016-07-22 | 2016-11-09 | 大连理工大学 | A kind of method realizing there is the medium managese steel part capability gradient distribution of TRIP effect |
| CN106191676A (en) * | 2016-08-15 | 2016-12-07 | 大连理工大学 | A kind of Varying-thickness method customizing warm forming medium managese steel part |
| CN106282878A (en) * | 2016-08-31 | 2017-01-04 | 大连理工大学 | A kind of preparation method of galvanizing warm working high intensity medium managese steel part |
| CN106636905A (en) * | 2016-12-27 | 2017-05-10 | 大连理工大学 | Method for improving deformation capability of medium manganese steel with TRIP (Transformation-Induced Plasticity) effect |
| CN107083475A (en) * | 2017-04-10 | 2017-08-22 | 钢铁研究总院淮安有限公司 | A kind of production method of hot press-formed shellproof part |
| WO2017157770A1 (en) * | 2016-03-15 | 2017-09-21 | Salzgitter Flachstahl Gmbh | Method for producing a hot-formed steel component, and hot-formed steel component |
| CN107309273A (en) * | 2017-07-28 | 2017-11-03 | 哈尔滨工业大学（威海） | A kind of low cost, the regulation and control method of flexibility hot forming super-high strength steel structural member |
| 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 |
| CN110465573A (en) * | 2019-08-23 | 2019-11-19 | 帝国理工创新有限公司 | A method of lightweight thin-walled sheet metal part is manufactured with data for guiding |
| CN114309069A (en) * | 2022-01-07 | 2022-04-12 | 太原科技大学 | Medium manganese steel sub-temperature forming method, medium manganese steel prepared by same and application of medium manganese steel |
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| CN106191676A (en) * | 2016-08-15 | 2016-12-07 | 大连理工大学 | A kind of Varying-thickness method customizing warm forming medium managese steel part |
| CN106191676B (en) * | 2016-08-15 | 2017-11-10 | 大连理工大学 | A kind of Varying-thickness method for customizing warm forming medium managese steel part |
| CN106282878B (en) * | 2016-08-31 | 2018-09-04 | 大连理工大学 | A kind of preparation method of galvanizing warm working high intensity medium managese steel part |
| CN106282878A (en) * | 2016-08-31 | 2017-01-04 | 大连理工大学 | A kind of preparation method of galvanizing warm working high intensity medium managese steel part |
| CN106636905A (en) * | 2016-12-27 | 2017-05-10 | 大连理工大学 | Method for improving deformation capability of medium manganese steel with TRIP (Transformation-Induced Plasticity) effect |
| CN106636905B (en) * | 2016-12-27 | 2018-05-15 | 大连理工大学 | A kind of method for improving the medium managese steel deformability with TRIP effects |
| CN107083475A (en) * | 2017-04-10 | 2017-08-22 | 钢铁研究总院淮安有限公司 | A kind of production method of hot press-formed shellproof part |
| 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 |
| CN107309273B (en) * | 2017-07-28 | 2019-04-12 | 哈尔滨工业大学（威海） | A kind of inexpensive, flexibility hot forming super-high strength steel structural member regulation method |
| CN107309273A (en) * | 2017-07-28 | 2017-11-03 | 哈尔滨工业大学（威海） | A kind of low cost, the regulation and control method of flexibility hot forming super-high strength steel structural member |
| CN110465573A (en) * | 2019-08-23 | 2019-11-19 | 帝国理工创新有限公司 | A method of lightweight thin-walled sheet metal part is manufactured with data for guiding |
| CN114309069A (en) * | 2022-01-07 | 2022-04-12 | 太原科技大学 | Medium manganese steel sub-temperature forming method, medium manganese steel prepared by same and application of medium manganese steel |
| CN114309069B (en) * | 2022-01-07 | 2023-12-01 | 太原科技大学 | Sub-temperature forming method of medium manganese steel, medium manganese steel prepared by sub-temperature forming method and application of medium manganese steel |
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