CN1012826B - Continuous annealing method for deep drawable extra-low carbon steel - Google Patents
Continuous annealing method for deep drawable extra-low carbon steelInfo
- Publication number
- CN1012826B CN1012826B CN86105994A CN86105994A CN1012826B CN 1012826 B CN1012826 B CN 1012826B CN 86105994 A CN86105994 A CN 86105994A CN 86105994 A CN86105994 A CN 86105994A CN 1012826 B CN1012826 B CN 1012826B
- Authority
- CN
- China
- Prior art keywords
- temperature
- steel
- steel plate
- continuous annealing
- zone
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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-
- 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
- C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
- C21D9/54—Furnaces for treating strips or wire
- C21D9/56—Continuous furnaces for strip or wire
-
- 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
- C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
- C21D9/48—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals deep-drawing sheets
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Strip Materials And Filament Materials (AREA)
- Heat Treatment Of Sheet Steel (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
A method and an apparatus for continuously annealing extra-low carbon steels are disclosed. The apparatus for practising the method comprises a heating zone, a temperature regulating zone having a large heating capacity per unit length of steel sheet and a good response, a rapid cooling zone and a final cooling zone.
Description
The present invention relates to deep-drawing is carried out with ultra low-carbon steel the method for continuous annealing.More particularly, and compare as most important stove district with the cooling zone in the conventional oven minor structure, the present invention relates to heating can utilize the method for the fabulous mechanical property of ultra low-carbon steel to greatest extent as the most important structure of stove.
Before the present invention, disclose among the Japanese Patent Application Publication No.47-33409 by continuous annealing process for producing deep-drawing steel plate.Shown in symbol among Fig. 5 (a), this processing method be hot rolling and cold rolling after steel sheet volume is heated to comparatively high temps, one section specific time of soaking insulation under this temperature, quick cooling is to about 400 ℃, about 400 ℃, kept 1-3 minute, then cool to room temperature.In addition, also mention a kind of technology in the description of the Prior Art of above-mentioned patent documentation part, shown in symbol among Fig. 5 (b), it is after heating, soaking insulation, only utilizes cooling to come soft steel is carried out anneal.In any case, always very hard according to above-mentioned thermal cycling annealed steel plate, be not suitable as the deep-drawing steel plate.
At present, only soft steel is carried out annealed equipment and realized industrial applications according to this technological cycle of heating → soaking insulation → chilling → overaging.
As everyone knows, produce deep-drawing with in the routine techniques of steel plate in this soft steel continuous annealing, refrigerating work procedure is most important in the continuous annealing process.In other words, chilling and overaging condition must be controlled, preceding slow cooling conditions of chilling or the final cooling conditions after the overaging must be controlled in addition.Therefore, in the continuous annealing of soft steel, an important problem is how to realize a kind of like this ideal and very complicated refrigeration cycle effectively in actually operating, how to design the equipment that can produce this steel plate according to above-mentioned thermal cycling expeditiously in other words.Up to the present, people design and build according to above-mentioned technical conceive to produce deep-drawing with the continuous annealing apparatus of steel plate.With in continuous annealing apparatus of steel plate, the cooling zone has become the part of decision device productivity to the result at all existing production deep-drawings, so the operation of cooling zone and control method give design earlier, so that preferentially reach desired cooling conditions.This is the inevitable outcome that the viewpoint from the technical conceive of this routine draws.
On the other hand, people know, when using carbon content to be lower than 1/10th ultra low-carbon steel (C ≈ 0.002%) of ordinary low-carbon steel (C ≈ 0.04%), just there is no need to carry out overaging and have handled.Yet, it is also believed that soft steel and ultra low-carbon steel heat with the soaking operation on do not have essence difference.Thereby up to the present people are used for handling ultra low-carbon steel to the common annealing stove that designs for soft steel always.But in such stove, the fabulous mechanical property of ultra low-carbon steel may not obtain utilizing, and has but brought many troubles on the contrary.
When handling soft steel in the deep-drawing usefulness common continuous annealing apparatus of steel plate as shown in Figure 4, the control of chilling speed and overaging condition is very important.In order accurately to control these factors, the temperature during the beginning chilling, promptly the temperature in exit, soaking zone should be a constant.But because the variation of steel plate translational speed, steel plate thickness etc., as symbol (ⅰ) among Fig. 4 a, (ⅱ) with (ⅲ), different variations take place in the temperature in the heating zone.Under extreme case, in the heating zone, be heated to the steel plate of comparatively high temps, in cooling gradually shown in symbol (ⅰ) among Fig. 4 a in the soaking zone.
The inventor has found following situation from the test-results of being done in this respect.Melting contains 0.0025%C, 0.08%Mn, 0.01%Si, 0.010%P0.005%S, 0.04%Al, 0.002%N and 0.035%Ti(% meter by weight) ultra low-carbon steel and it is continuously cast into slab through hot rolling with cold rollingly obtain the steel plate that final thickness is 0.8mm.Steel plate is heated under different temperature, and soaking is incubated 0-120 second, carries out skin rolling then.Measure the unit elongation through the steel plate of handling so subsequently, obtain the result shown in Fig. 2, the numerical value among the figure in the circle of garden is unit elongation value (%).As can see from Figure 2, unit elongation increases with the rising of Heating temperature, but under 750 ℃ lesser temps,, and be higher than influence that can't see the soaking soaking time under 800 ℃ the Heating temperature basically even it is still very small to be incubated the increase of unit elongation for a long time.Also observe similar trend for other performances such as resembling yield strength, tensile strength.
Subsequent check obtains the result shown in Fig. 2 at 850 ℃ of annealed secondary processing brittleness, and symbol O represents there is not fragility among the figure, and symbol * expression produces fragility.From the result of Fig. 2 as can be seen, when the soaking soaking time was 0, even also do not ftracture under-80 ℃ temperature, and the soaking insulation was when being no less than 30 seconds, and-50 ℃ are brought up to and be not less than to embrittlement temperature.Confirmed preferably to make the soaking soaking time to shorten as far as possible according to this fact.
Subsequent the steel plate that through cold rolling final thickness is 0.8mm is heated to different temperature with 35 ℃/second rate of heating, then with 30 ℃/second speed of cooling quick cooling, measures its r value (Lankford value), the result who obtains as shown in Figure 3.As seen from Figure 3, under the situation of soft steel, the r value trends towards along with the annealing temperature rising and increases, but the variation of r value is not too big.On the contrary, when annealing temperature reached 850 ℃, the ratio increase of austenite phase had stoped grain growth, thereby the r value trends towards reducing.Otherwise under the situation of ultra low-carbon steel, the r value trends towards raising and significantly increase with annealing temperature.
According to these results, the inventor finds, for the product that is obtained by ultra low-carbon steel to determine, it is essential control maximum heating temperature rather than control soaking soaking time.
Consider in common continuous annealing apparatus ultra low-carbon steel annealed situation according to above-mentioned knowledge, steel plate in foregoing heating zone by symbol (ⅰ) among Fig. 4 a, (ⅱ) and the thermal cycling (ⅲ) change and anneal, even the temperature in exit, result soaking zone is a constant, because maximum heating temperature difference in the heating zone has still produced the problem that mechanical property changes.
Because ultra low-carbon steel at high temperature becomes very soft, along with hold-time prolongation at high temperature, the danger that produces surface imperfection and generation coil breaks has increased, therefore necessary SC.
The objective of the invention is, solve the above-mentioned all problems in the ultra low carbon steel slab production and the continuous annealing method that can accurately control the regulation Heating temperature is provided
According to the present invention, the continuous annealing method of a kind of deep-drawing with ultra low-carbon steel proposed, this method may further comprise the steps:
The sheet material of above-mentioned steel is heated to it more than brilliant again temperature by room temperature;
By being heated rapidly to the temperature of the steel plate that the adjustment of regulation maximum heating temperature heated, precision at least ± ℃ in, said regulation maximum heating temperature is according to giving selected earlier steel composition, the relation of working condition and product performance is determined;
Without just cooling fast of soaking insulation, be cooled to room temperature then.
The present invention is described with reference to the accompanying drawings, in the accompanying drawings:
Fig. 1 a represents according to the present invention a thermal cycling in equipment;
Fig. 1 b is the synoptic diagram of a concrete equipment of the method according to this invention;
Fig. 2 represents the influence to unit elongation of soaking time and Heating temperature;
Fig. 3 is the graphic representation of annealing temperature to the influence of r value;
Fig. 4 a is illustrated in a thermal cycling in the common continuous annealing apparatus;
Fig. 4 b is common continuous annealing apparatus synoptic diagram;
Fig. 5 is illustrated in a thermal cycling in the common annealing process;
Fig. 6 is a graphic representation, the changes of properties when translational speed that it is illustrated in uncoiling steel plate in the continuous annealing process changes.
The method according to this invention has been omitted the overaging district and has been provided with the temperature adjustment district that replaces the soaking zone in annealing device. The intent of the present invention is, controls reliably temperature when heating steel plate in temperature adjustment district, therefore requires to have sizable thermal capacity and good sensitivity. In this case, the thermal capacity of per unit length steel plate must or be given the hot-zone greater than the thermal treatment zone in the temperature adjustment district. In addition, even also must reach at least at inhomogeneous district temperature accuracy ± 10 ℃. For this purpose, adopted in temperature adjustment district to steel plate directly jet through the device of the non-oxidizing gas of high-temperature heating, energising directly the heating steel plate device, be higher than the radiation pipe apparatus that uses under the typical temperature etc. In addition, temperature adjustment district has the effect that changes by annealing temperature control mechanical performance and compensating component, perhaps have compensation owing to the variation of steel plate translational speed or steel plate thickness causes the effect of steel billet temperature variation, thereby can control accurately the regulation maximum heating temperature of steel plate. In addition, the characteristics at heating process light plate Local cooling also are effective for realization purpose of the present invention.
With steel plate in temperature adjustment district by Fig. 1 a in symbol (ⅰ), (ⅱ), (ⅲ) or (ⅳ) shown in be heated to the regulation maximum heating temperature after, make its rapid cooling without the overaging district. In this case, it is the type of cooling that suits that jet cooling, rolling cooling or these two kinds of types of cooling combine. In addition, from the viewpoint of mechanical performance, almost do not need to limit cooling velocity, because do not need this specially treated of chilling one overaging, therefore from device and behaviour It can mainly according to circumstances determine the angle of doing.
The reason of after temperature reaches the regulation maximum heating temperature steel plate being cooled off rapidly is, as shown in Figure 2, when increasing, the soaking temperature retention time no longer looks to improving the fact of mechanical performance, on the contrary, resemble unusual grain growth, these danger of hydraulic performance decline have increased, the number of times of warpage takes place, pecking the production problem such as seal has also increased.
In order further to improve the thermal efficiency, can arrange one in the front of the thermal treatment zone and give the hot-zone, perhaps can be divided into several bodies of heater to the thermal treatment zone, do not do so and can damage effect of the present invention. In addition, in order to improve cooling effectiveness the way that the cooling zone is divided into two or more cooling bodies of heater can not damaged effect of the present invention yet.
According to the present invention, when using ultra-low-carbon steel to make sheet material, can obtain different mechanical performances by same sheet material, perhaps when processing, continuous annealing only just can make mechanical performance homogenising inhomogeneous in the sheet material by accurately controlling the annealing heating temperature. Specifically, the present invention can realize following truth expediently:
(1) according to the variation of chemical composition, by the control heating-up temperature, can obtain very uniformly steel plate of mechanical performance;
(2), can compensate the outside of the steel sheet volume after hot rolling and inner mechanical property and descend by localized hyperthermia's heating;
(3) steel billet temperature that can avoid the variation owing to plate size or steel plate translational speed to cause changes;
(4) has the product of specified mechanical property by same material production.
For example as shown in Figure 6, when the steel plate translational speed of ultra low-carbon steel in the figure annealing process (C:0.0015%, Ti:0.055%) changes, the r value, hot rolling gets temperature and Heating temperature can keep uniformity substantially on whole steel plate length.
Embodiment
Steel plate thickness (mm) and steel plate translational speed (meter per second) long-pending be that the thermal capacity of heating zone (burner capacity) is 40 * 10 in the common continuous annealing apparatus of about 400 throughput
6About kilocalorie/hour.On the contrary, the heat of the only enough compensation of the thermal capacity of soaking zone loss from body of heater, its burner capacity is 1/10th of heating zone.
Otherwise owing to used a ultrahigh-temperature radiator tube and the high-temperature gas blowing device with furnace temperature more than 1100 ℃, its thermal capacity is the twice of common soaking zone at least according to temperature adjustment of the present invention district, and this is equivalent to 10～20 * 10
6Kilocalorie/hour.If particularly consider the thermal capacity of per unit length steel plate, then the thermal capacity in temperature adjustment district is higher than the thermal capacity of heating zone.
As mentioned above, can accurately control the regulation Heating temperature of deep-drawing according to the present invention, thereby obtain not having the steel plate of mechanical property variation with ultra low carbon steel slab.In addition, owing to be provided with in the front, heating zone and give the hot-zone and can improve thermo-efficiency.These improvement effects are very outstanding.
Claims (2)
1, a kind of to deep-drawing with the method that ultra low-carbon steel carries out continuous annealing, may further comprise the steps:
(1) sheet material with above-mentioned steel plate is heated to it more than recrystallization temperature by room temperature,
(2) by quickly heating up to the regulation maximum heating temperature, adjust the steel billet temperature that has heated, in ± 10 ℃, described regulation maximum heating temperature is to determine according to the relation of giving selected earlier steel product ingredient, working condition and product performance to precision at least,
(3) without just cooling fast of soaking insulation, be cooled to room temperature then.
2, in accordance with the method for claim 1, wherein in order to adjust maximum heating temperature, in heat-processed, make the local cooling of said steel.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP176,817/85 | 1985-08-13 | ||
| JP17681785 | 1985-08-13 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN86105994A CN86105994A (en) | 1987-04-01 |
| CN1012826B true CN1012826B (en) | 1991-06-12 |
Family
ID=16020362
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN86105994A Expired CN1012826B (en) | 1985-08-13 | 1986-08-12 | Continuous annealing method for deep drawable extra-low carbon steel |
Country Status (11)
| Country | Link |
|---|---|
| EP (1) | EP0211681B1 (en) |
| JP (1) | JPS62124233A (en) |
| KR (1) | KR910001607B1 (en) |
| CN (1) | CN1012826B (en) |
| AT (1) | ATE103011T1 (en) |
| BE (1) | BE905254A (en) |
| CA (1) | CA1274157A (en) |
| DE (1) | DE3689714T2 (en) |
| ES (1) | ES2000607A6 (en) |
| FR (1) | FR2586257B1 (en) |
| IT (1) | IT1197864B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19860472A1 (en) * | 1998-12-28 | 2000-07-06 | Bosch Gmbh Robert | Process for tempering steel strips |
| CN101921949B (en) * | 2010-07-22 | 2012-01-25 | 首钢总公司 | Continuous annealing production method of cold-rolled sheet No.45 steel |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3385946A (en) * | 1965-04-16 | 1968-05-28 | Westinghouse Electric Corp | Continuous annealing method and apparatus |
| DE2056313B2 (en) * | 1969-11-14 | 1972-11-09 | Nippon Kokan K.K., Tokio | Continuous tempering process for cold-rolled, deep-drawable strip |
| JPS6044376B2 (en) * | 1978-10-21 | 1985-10-03 | 新日本製鐵株式会社 | A method for manufacturing cold rolled steel sheets using continuous heat treatment that is non-aging and has excellent deep drawing workability. |
| JPS5794524A (en) * | 1980-12-04 | 1982-06-12 | Nippon Kokan Kk <Nkk> | Method for continuous annealing |
| JPS5989727A (en) * | 1982-11-12 | 1984-05-24 | Kawasaki Steel Corp | Manufacture of cold rolled steel sheet for extremely deep drawing with superior press formability |
| JPS60106919A (en) * | 1983-11-15 | 1985-06-12 | Kawasaki Steel Corp | Method for continuously annealing cold rolled dead soft steel sheet |
-
1986
- 1986-08-08 BE BE0/217032A patent/BE905254A/en not_active IP Right Cessation
- 1986-08-12 FR FR868611642A patent/FR2586257B1/en not_active Expired - Lifetime
- 1986-08-12 JP JP61187922A patent/JPS62124233A/en not_active Withdrawn
- 1986-08-12 KR KR1019860006610A patent/KR910001607B1/en not_active IP Right Cessation
- 1986-08-12 CA CA000515759A patent/CA1274157A/en not_active Expired - Lifetime
- 1986-08-12 ES ES8601043A patent/ES2000607A6/en not_active Expired
- 1986-08-12 DE DE3689714T patent/DE3689714T2/en not_active Expired - Fee Related
- 1986-08-12 EP EP86306234A patent/EP0211681B1/en not_active Expired - Lifetime
- 1986-08-12 CN CN86105994A patent/CN1012826B/en not_active Expired
- 1986-08-12 AT AT86306234T patent/ATE103011T1/en not_active IP Right Cessation
- 1986-08-12 IT IT21475/86A patent/IT1197864B/en active
Also Published As
| Publication number | Publication date |
|---|---|
| EP0211681A2 (en) | 1987-02-25 |
| IT8621475A0 (en) | 1986-08-12 |
| ATE103011T1 (en) | 1994-04-15 |
| KR870002288A (en) | 1987-03-30 |
| EP0211681A3 (en) | 1990-06-06 |
| BE905254A (en) | 1986-12-01 |
| IT8621475A1 (en) | 1988-02-12 |
| CA1274157A (en) | 1990-09-18 |
| ES2000607A6 (en) | 1988-03-01 |
| FR2586257B1 (en) | 1991-03-01 |
| JPS62124233A (en) | 1987-06-05 |
| IT1197864B (en) | 1988-12-21 |
| FR2586257A1 (en) | 1987-02-20 |
| DE3689714D1 (en) | 1994-04-21 |
| DE3689714T2 (en) | 1994-09-29 |
| KR910001607B1 (en) | 1991-03-16 |
| CN86105994A (en) | 1987-04-01 |
| EP0211681B1 (en) | 1994-03-16 |
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