CN102703679B - Method for improving corner flaw and heat-transfer flaw of niobium-containing steel casting blank by adopting low-voltage pulse current - Google Patents
Method for improving corner flaw and heat-transfer flaw of niobium-containing steel casting blank by adopting low-voltage pulse current Download PDFInfo
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Abstract
The invention discloses a method for improving a corner flaw and a heat-transfer flaw of a niobium-containing steel casting blank by adopting a low-voltage pulse current and belongs to the technical field of improvement for the corner flaw and the heat-transfer flaw of the casting blank. The method comprises the following steps: before the niobium-containing steel casting blank enters into a straightening area or after the casting blank is discharged from a continuous casting machine and is cut, applying a pulse current to the niobium-containing steel casting blank, wherein the parameters of the pulse current are as follows: pulse voltage is 2-20V, pulse current is 30-120A and pulse frequency is 15-40Hz; the niobium-containing steel is Omega [C] (0.25%) niobium-containing low-carbon steel; and Omega [Nb] is more than or equal to 0.01% but less than or equal to 0.40%. According to the method provided by the invention, the low-voltage pulse current is applied for changing a micro-structure of the niobium-containing steel casting blank and increasing the high-temperature mechanical property of the casting blank, so that the corner flaw and the heat-transfer (red) flaw of the casting blank are effectively reduced. The method provided by the invention is free from influence on the normal production; the present production technology need not be changed and alloy elements need not be added; the method is pollution-free for the casting blank and equipment and is harmless to human body; and the method is a new environment-friendly and safe technology for reducing the defects of the casting blank.
Description
Technical field
The invention belongs to and improve strand corner crack and the hot technical field of sending crackle, more particularly, relate to a kind of method that adopts the action of low-voltage pulse electric current to improve to contain niobium steel strand corner crack and heat to send crackle, improve and to contain niobium steel strand microtexture and mechanical behavior under high temperature by applying an action of low-voltage pulse electric current, the present invention is particularly useful for easily producing the steel grade that strand corner crack, heat send (red sending) crackle.
Background technology
In super-steel research project or Iron ﹠ Steel Material of New Generation research project that the nineties in 20th century, various countries implemented in succession, the carbonitride of microalloy element is widely used in regulating the behavior of deformation austenite recrystallization and stops grain growth, plays the effect that improves steel strength and toughness.Micro-alloying technology just is being used to field more widely now, as middle carbon non-hardened and tempered steel, Properties of Heavy Rail Steel By, tool steel etc.And along with the output of micro-alloyed steel significantly improve (Weng Yuqing, Yang Caifu, Shang Chengjia. low alloy steel is in current situation and the trend of China. iron and steel, 2011,46 (9): 1-10), the frequent defective that occurs of micro-alloyed steel continuous casting base more and more is concerned, especially microalloy steel with nb.
In recent years, both at home and abroad the metallargist focus of research is concentrated in the impact of NbCN on micro-alloyed steel strand High Temperature Ductility (Zhu Zhenghai. Second Phase Precipitation and solid solution behavioral study in continuous casting, conveying, heat-processed micro-alloyed steel. Beijing: Iron and Steel Research Geueral Inst, 2010).Although in the operation of rolling, the behavior of separating out of NbCN has to intensity and the toughness that improves steel the effect that is highly profitable.but, in casting process, when strand microtexture generation austenite γ → ferrite α phase transformation, due to NbCN at α the solubility product in mutually much smaller than γ mutually in, cause NbCN along separating out in a large number in the membranaceous pro-eutectoid α of γ crystal boundary, reduced the strand High Temperature Ductility, the oscillation mark place very easily produces corner crack (K.Toru in the strand bight, I.Yoshiki, K.Masayuki et al. Prevention of Slab Surface Transverse Cracking by Microstructure Control. ISIJ International, 2003, 43 (11): 1742-1750, I.Yoshiki, K.Toru, Y.Akihiro. Improvement of hot ductility in continuously cast strand by ferrite precipitation control. TETSU-TO-HAGANE, 2003,89 (10): 1023-1030, Zhu Guosen, Zhu Zhiyuan, Wang Yanfeng etc. the control of niobium-containing steel plate transverse corner crack line. iron and steel, 2006,41 (12): 30).People (the Xia Wenyong such as the summer literary composition is brave in addition, Zhu Zhenghai, Zhu Zhenghai, do brave. the red experimental study of sending crackle to form of micro-alloyed steel. iron and steel, 2011.46 (12): 29-32) studies show that, the heat of micro-alloyed steel send crackle also to separate out relevant with NbCN along the membranaceous pro-eutectoid α of γ crystal boundary.The root that these problems produce just is that the behavior of separating out of NbCN has been subject to the impact of γ → α phase transformation.If change so the behavior of separating out of NbCN and affect conversely γ → α phase transformation, just might improve the High Temperature Ductility of micro-alloyed steel strand.
At present, the strand corner crack and the heat that produce in the actual production process of Steel Plant are sent crackle, the actual solution that adopts is: for corner crack, general the roll off the production line method in rear artificial flame cleaning or excision bight of strand that adopts, the method has not only reduced the efficient of producing, and has improved production cost; Send crackle for heat, generally adopt the method for sending again process furnace to heat after slab cooling, the method has not only affected the direct motion of producing, and the contained amount of heat of high temperature strand is wasted.
In existing research, thus people for interaction how to intervene the NbCN behavior of separating out and change itself and γ → α phase transformation, research considerably less.External (the K.Toru such as Toru, Yoshiki only, I.Yoshiki, K.Masayuki et al. Prevention of Slab Surface Transverse Cracking by Microstructure Control. ISIJ International, 2003,43 (11): 1742-1750; I.Yoshiki, K.Toru, Y.Akihiro. Improvement of hot ductility in continuously cast strand by ferrite precipitation control. TETSU-TO-HAGANE, 2003,89 (10): 1023-1030) carried out the research of this respect, they point out by research, and it (is mainly that the hot resume that change casting billet surface can improve the High Temperature Ductility of microalloyed steel containing Nb strand
The brittle zone).Detailed process is: casting blank surface temperature is cooled to γ → below the α transformation temperature from high-temperature area with the speed that is exceedingly fast, and due to the generation of crossing cold-peace α phase, NbCN separates out in mutually fast at γ+α.Again casting blank surface temperature is heated to the γ zone at the utmost point in the short period of time, then temperature descends again, during high temperature solid solution, the remaining NbCN of part will become the forming core point that α separates out mutually, suppress thus the membranaceous α γ phase crystal boundary that hands down and generate, and form plasticity microstructure preferably.
This method has obtained effect preferably, for the High Temperature Ductility that improves the microalloyed steel containing Nb strand provides new approaches, but because in the short period of time, temperature fluctuation is too violent, controllability is not good, implement difficulty larger, easily form new mass defect, so not yet can use by spread.
In recent years, scholars more both domestic and external attempt improving the tissue of solid metallic material under the pulsed current effect, and have obtained some achievements.Conrad.H finds (Conrad, H. Effects of electric current on solid state phase transformations in metals. Materials Science ﹠amp; Engineering A (Structural Materials:Properties, Microstructure and Processing), 2000) pulsed current has remarkably influenced to the behavior of separating out of the precipitated phase in solid metal, and main influence factor is material type, current density, power frequency.Yang Liu thinks (Yang Liu, Lei Wang, Yuchen Wang, et al. Effects of Electropulsing Treatment on the Precipitation Behaviour of Grain Boundary Carbides in GH3044 Alloy. Materials Science Forum, Switzerland:Trans Tech Publications Ltd, 2010) pulsed current is influential to Carbide Precipitation in the GH3044 alloy, burst process has changed the thermodynamics and kinetics condition of Carbide Precipitation, select suitable pulse parameter, be conducive to separating out of carbide, showing as the beginning Precipitation Temperature reduces, the total amount of precipitated phase increases.Wang Jianjun etc. (Wang Jianjun, Zhou Li, Li Qiang etc. the impact of Pulse Current on Solidification Structure of Steel. the steel research journal, 2007,19 (5): 49-53) research finds that the pulsed current processing can improve the equiax crystal nucleation rate, and crystal grain thinning has unusual effect to improving the continuously cast bloom solidified structure.
In addition, China Patent No. ZL200810151116.X, Granted publication day is on October 27th, 2010, invention and created name is: a kind of method that adopts high electric field pulse to improve the carbon steel solidification tissue, the method of this application case is in the crystallizer of the tundish of continuous casting steel machine and continuous casting steel machine or in the casting mold of die casting, apply a selected high electric field pulse to the carbon steel solidification process or before solidifying, the parameter of described high-voltage pulse is: pulsed voltage 1000V ~ 3900V, pulse-repetition 0.50Hz ~ 1.50Hz, pulsed capacitance 100 μ F ~ 500 μ F.The method especially is adapted to improve coarse grains in solidified structure, and dentrite is flourishing, easily produces the steel grade of component segregation, to increase the nucleation rate of metal freezing, reduce dentrite, increase equiax crystal, reduce internal fissure, the shrinkage cavity and loose of solidified structure, improve the composition segregation.Aforesaid method is to adopt pulsed current to improve solidified structure, its alleged solidified structure refers to: macrostructure's patterns such as the dentrite that molten steel forms in process of setting, equiax crystal, loose and segregation namely can be observed by acid etching under low power (＜10 times) state.And the pulsed voltage that adopts in this application case is the high electric field pulse of 1000V ~ 3900V, and power consumption is larger.
But so far, not yet there is the investigator pulsed current to be processed the microtexture that is applied to improve the metallurgical process continuously cast bloom, microtexture alleged in the present invention refers to: temperature variant solid phase microtexture after molten steel solidification, the sosoloid that the carbon of namely observing when magnification is more than 50 times at microscopically forms in α-Fe or γ → Fe is commonly referred to ferrite (α), austenite (γ).What particularly point out is: the microtexture of strand and the solidified structure of strand are diverse two concepts.In addition, contain niobium steel strand corner crack and heat in prior art and send the problem of crackle to be badly in need of solving, contain niobium steel slab quality with raising.
Summary of the invention
1. invent the technical problem that will solve
The object of the invention is to overcome niobium-containing low-carbon steel of the prior art and very easily produce corner crack at oscillation mark place, strand bight, and heat is sent the deficiency of (red sending) crackle, providing a kind of adopts the improvement of action of low-voltage pulse electric current to contain niobium steel strand corner crack and the hot method of sending crackle, the present invention by inhibition contain niobium steel strand in process of cooling the proeutectoid ferrite nethike embrane in the formation of austenite grain boundary, improve the mechanical property of strand, reduce casting blank defect.
2. technical scheme
For achieving the above object, technical scheme provided by the invention is:
A kind of method that adopts the action of low-voltage pulse electric current to improve to contain niobium steel strand corner crack and heat to send crackle of the present invention, before containing niobium steel strand to enter aligning district or after strand goes out continuous caster and be cut, the above-mentioned niobium steel strand that contains is applied a pulsed current, described pulsed current parameter is: pulsed voltage 2～20V, pulsed current 30～120A, pulse-repetition 15～40 Hz.
Further, when containing niobium steel strand and applying pulsed current, the temperature that contains niobium steel strand is 1000～750 ℃ to described.
Further, the described niobium-containing low-carbon steel that the niobium steel is ω [C]＜0.25%, the wherein 0.01%≤ω [Nb]≤0.40% of containing.
adopt method of the present invention to after containing niobium steel strand and applying the action of low-voltage pulse electric current, phase transition process concrete in strand is presumed as follows: after strand is carried out the pulsed current processing, promoted separating out of precipitated phase NbCN in the strand, when the strand temperature is down to below A3 point (austenite/ferritic phase height), microtexture in strand begins austenite γ → ferrite α phase transformation, the NbCN that before separates out can provide a large amount of forming core particles to ferritic forming core in austenite crystal, make ferrite to separate out at austenite crystal intragranular forming core, change the characteristics that ferrite is only separated out at the austenite grain boundary forming core, thereby suppress the membranaceous ferritic generation of austenite grain boundary.Can change the microtexture of niobium-containing low-carbon steel strand by this method, improve the strand mechanical behavior under high temperature, reduce corner crack and the heat of strand and send (red sending) crackle.
3. beneficial effect
Adopt technical scheme provided by the invention, compare with existing known technology, have following unusual effect:
(1) the present invention is by before containing niobium steel strand to enter aligning district or after strand goes out continuous caster and be cut, strand is applied a pulsed current, changed the microtexture of strand, improved the mechanical property of strand, the corner crack at oscillation mark place, strand bight reduces more than 80%, heat send crackle to reduce more than 90%, has effectively reduced casting blank defect;
(2) the present invention is reasonable in the position of implementing the pulsed current processing, does not affect normal production, and does not need to change existing production technique, does not need to add alloying element, and is pollution-free to strand and equipment, is the new technology of the minimizing casting blank defect of an Environmental Safety;
(3) the present invention be used for to improve and to contain niobium steel strand corner crack and heat to send the pulsed voltage of crackle be the action of low-voltage pulse of 2～20V, and pulsed voltage is less than 36V, and is safe and reliable, and power consumption is little;
(4) in method of the present invention, apply pulsed current when the temperature that contains niobium steel strand is 1000～750 ℃, the most suitable, strand corner crack and heat send the removal effect of crackle best;
(5) the present invention's improvement contains niobium steel strand corner crack and the hot method of sending crackle, and equipment is simple, less investment, and technique is simple, and easy to operate.
Description of drawings
Fig. 1 is without the Q345 microtexture picture of extra pulse current processing in embodiment 1;
Fig. 2 is the Q345 microtexture picture that adopts pulsed current of the present invention to process in embodiment 1.
Embodiment
For further understanding content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings and embodiments.Be below the embodiment that the contriver provides, need to prove, the invention is not restricted to these embodiment, method of the present invention is suitable for steel grade: niobium-containing low-carbon steel (ω [C]＜0.25%), wherein 0.01%≤ω [Nb]≤0.40%.Use method of the present invention to suppress the formation of austenite grain boundary proeutectoid ferrite film, change the microtexture of strand, improve mechanical behavior under high temperature, thereby reduce the strand corner crack, heat is sent crackle.Gordian technique main points of the present invention are the position of pulsed current processing and the parameter designing of pulsed current.
Embodiment 1
The material of the present embodiment is Q345 steel (its main chemical compositions is: 0.099%C, 0.181%Si, 1.339%Mn, 0.011%P, 0.003%S, 0.024%Nb, 0.0048%N), at first use intermediate frequency vacuum induction furnace smelting and casting to obtain the strand of Q345 composition, then strand is cut into 15 * 15 * 15mm
3Pat, be connected to Pulased power supply unit by wire, then sample put into chamber type electric resistance furnace, after 1200 ℃ of insulation 1h, speed cooling with 6 ℃/min, begin pulsed current and process when specimen temperature is down to 950 ℃, design parameter is: pulsed voltage 5V, pulsed current 60A, pulse-repetition 30Hz, when specimen temperature is down to 750 ℃, the stop pulse current processing, and take out sample and quench in the aqueous solution of NaCl concentration 10%.Its microtexture as shown in Figure 2.
Contain niobium steel strand corner crack and the hot unusual effect that send crackle for comparative illustration the present invention is used for improving, once do not adopt the simultaneous test of pulsed current processing.The material of this Comparative Examples is Q345 steel (its main chemical compositions is: 0.099%C, 0.181%Si, 1.339%Mn, 0.011%P, 0.003%S, 0.024%Nb, 0.0048%N), at first use intermediate frequency vacuum induction furnace smelting and casting to obtain the strand of Q345 composition, again strand is cut into pat, then sample is put into chamber type electric resistance furnace, after 1200 ℃ of insulation 1h, with the speed cooling of 6 ℃/min, take out sample and quench in the aqueous solution of NaCl concentration 10% when temperature is down to 750 ℃.Its microtexture as shown in Figure 1.
Can clearly be found out by Fig. 1 and Fig. 2, when processing without pulsed current, white proeutectoid ferrite is present in austenite grain boundary with membranaceous form, austenite crystal intragranular iron-free element body; After the pulse current processing, most ferrite is separated out at the austenite crystal intragranular, and is the disperse distribution.Can find from both contrasts, pulsed current is processed the nucleation site that has effectively changed most proeutectoid ferrites, suppressed the formation of the membranaceous proeutectoid ferrite of austenite grain boundary, change the microtexture of strand, contained niobium steel strand corner crack and heat is sent crackle thereby can effectively improve.
Embodiment 2
The material of the present embodiment is Q345 steel (its main chemical compositions is: 0.12%C, 0.185%Si, 1.37%Mn, 0.009%P, 0.004%S, 0.035%Nb, 0.0052%N), casting blank section is 210mm * 1800mm, teeming temperature is 1535 ℃, and pulling rate is 1.1m/min.The pulsed current device is arranged on the casting machine east side, before the strand aligning, along the throwing direction, six places has been installed, and pulsed current is carried out in the strand bight process, and extends 150mm in wide direction of strand, and the leptoprosopy direction is extended 100mm.Pulsed voltage 20V in the present embodiment, pulsed current 100A, pulse-repetition 20Hz.When pulsed current begins to process, 1002 ℃ of actual measurement strand bight temperature, during end treatment, strand bight temperature is 765 ℃.After strand cutting, with bight, strand east side (having pulsed current to process) and (no pulse current processing) cutting, the pickling of bight, west side and compare.Result shows: the crackle in bight, east side relative west side minimizing 82%, pulsed current is processed and has effectively been reduced the strand corner crack, has improved slab quality.
Embodiment 3
The base conditioning method of the present embodiment is with embodiment 2, and difference is: the pulsed voltage in the present embodiment is 2V, pulsed current 120A, and pulse-repetition 40 Hz, the effect of processing has unusual effect substantially with embodiment 2 to improving the strand corner crack.
Embodiment 4
The material of the present embodiment is Q345 steel (its main chemical compositions is: 0.12%C, 0.185%Si, 1.37%Mn, 0.009%P, 0.004%S, 0.035%Nb, 0.0052%N), casting blank section is 210mm * 1800mm, teeming temperature is 1535 ℃, and pulling rate is 1.1m/min.The pulsed current device is arranged on the rollgang both sides after the strand cutting, from after the strand cutting, along the roller-way throughput direction, eight places has been installed, and the wide face of strand is carried out pulsed current process.Pulsed voltage 3V in the present embodiment, pulsed current 70A, pulse-repetition 40Hz.When pulsed current begins to process, 860 ℃ of wide core temperatures of actual measurement strand, during end treatment, wide core temperature of strand is 755 ℃.Strand is rolled after roller-way heat is fed into process furnace, roll rear surface of steel plate after testing and the statistics, result shows: send strand rolling steel plate contrast with the heat that no pulse is processed, the surface of steel plate crackle reduces 94%, the pulsed current processing has effectively reduced casting billet surface heat and has sent (red sending) crackle, has improved strand and plate quality.
Embodiment 5
The base conditioning method of the present embodiment is with embodiment 4, difference is: the pulsed voltage in the present embodiment is 20V, pulsed current 30A, pulse-repetition 15Hz, the effect of processing send (red sending) crackle to have unusual effect substantially with embodiment 4 to improving strand heat.
A kind of method that adopts the action of low-voltage pulse electric current to improve to contain niobium steel strand corner crack and heat to send crackle of the present invention, by applying the action of low-voltage pulse electric current, change the microtexture of niobium-containing low-carbon steel strand, improve the strand mechanical behavior under high temperature, thereby the corner crack and the heat that have effectively reduced strand are sent (red sending) crackle, and method of the present invention does not affect normal production, and do not need to change existing production technique, do not need to add alloying element, pollution-free to strand and equipment, without harm, be the new technology of the minimizing casting blank defect of an Environmental Safety to personnel.
Below schematically the present invention and embodiment thereof are described, this description does not have restricted.So, if those of ordinary skill in the art is enlightened by it, in the situation that do not break away from the invention aim, without the creationary technical approach similar to this technical scheme and the embodiment of designing, all should belong to protection scope of the present invention.
Claims (2)
1. one kind is adopted the improvement of action of low-voltage pulse electric current to contain niobium steel strand corner crack and the hot method of sending crackle, it is characterized in that: before containing niobium steel strand to enter aligning district or after strand goes out continuous caster and be cut, the above-mentioned niobium steel strand that contains is applied a pulsed current, described pulsed current parameter is: pulsed voltage 2～20V, pulsed current 30～120A, pulse-repetition 15～40 Hz, wherein to described when containing niobium steel strand and applying pulsed current, the temperature that contains niobium steel strand is 1000～750 ℃.
2. employing action of low-voltage pulse electric current improvement according to claim 1 contains niobium steel strand corner crack and the hot method of sending crackle, it is characterized in that: the described niobium-containing low-carbon steel that the niobium steel is ω [C]＜0.25%, the wherein 0.01%≤ω [Nb]≤0.40% of containing.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006117111A1 (en) * | 2005-05-04 | 2006-11-09 | Evgenij Sterling | Method for the production of pigs, and pigs |
| JP2008168341A (en) * | 2006-12-04 | 2008-07-24 | Heraeus Inc | Method of forming cast ferromagnetic alloy, and cast ferromagnetic alloy produced by the method |
| CN101275180A (en) * | 2008-05-16 | 2008-10-01 | 昆明理工大学 | Method for eliminating defective structure in structural alloy steel and tool steel substrate by using impulse current |
| CN101358280A (en) * | 2008-09-26 | 2009-02-04 | 西安建筑科技大学 | Method for improving carbon steel solidification structure using high voltage electropulse |
| CN101705340A (en) * | 2009-11-03 | 2010-05-12 | 上海大学 | Method and device for thermally treating pulse current |
| CN101713009A (en) * | 2009-11-27 | 2010-05-26 | 天津钢铁集团有限公司 | Method for improving pass percent of medium plate flaw detection |
-
2012
- 2012-06-19 CN CN 201210203022 patent/CN102703679B/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006117111A1 (en) * | 2005-05-04 | 2006-11-09 | Evgenij Sterling | Method for the production of pigs, and pigs |
| JP2008168341A (en) * | 2006-12-04 | 2008-07-24 | Heraeus Inc | Method of forming cast ferromagnetic alloy, and cast ferromagnetic alloy produced by the method |
| CN101275180A (en) * | 2008-05-16 | 2008-10-01 | 昆明理工大学 | Method for eliminating defective structure in structural alloy steel and tool steel substrate by using impulse current |
| CN101358280A (en) * | 2008-09-26 | 2009-02-04 | 西安建筑科技大学 | Method for improving carbon steel solidification structure using high voltage electropulse |
| CN101705340A (en) * | 2009-11-03 | 2010-05-12 | 上海大学 | Method and device for thermally treating pulse current |
| CN101713009A (en) * | 2009-11-27 | 2010-05-26 | 天津钢铁集团有限公司 | Method for improving pass percent of medium plate flaw detection |
Non-Patent Citations (1)
| Title |
|---|
| 张伟强 著.材料电磁工艺.《金属电磁凝固原理与技术》.冶金工业出版社,2004,第2-4页. * |
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