The method of dispersion implanting fine heterogeneous particles and interpolation raw material in the metal solidification process
Technical field
The invention belongs to solidifying and the continuous casting field of metal, the disperse that specially refers to fine heterogeneous particles in a kind of metal solidification process is implanted.
Background technology
Along with the raising of machinery manufacturing industry ability and the continuous progress of level of processing, demand to high strength, high tenacity steel increases day by day, begin to be extensive use of high-intensity ferrous materials as automobile, engineering machinery, container, coal mine machinery etc., and for example the refinement of crystallization again of hull material has been proposed specific (special) requirements in the application of shipbuilding industry large-line energy solder technology.In conventional art, these materials generally adopt complicated high-alloying design to produce, and increased the manufacturing cost of material greatly, so the new technology path of active demand are realized the production of low cost, premium quality product.
The tiny heterogeneous particles that exists in the solidification of molten steel process with newly separate out (or claim second particle) mutually can be used for pinning crystal boundary, crystal grain thinning, improvement tissue, and these heterogeneous particles generally include titanium oxide, zirconia, magnesia, aluminium oxide, manganese oxide etc.
In recent years, because it is increasingly extensive that the solder technology of high power, large-line energy is used, welding temperature further raises, thereby need seek the austenite grain boundary of the second more stable phase particle with the pinning welding heat affected zone, metal structure after the refinement welding, the steel strength of raising welding heat affected zone.Common metal oxide free energy is very low, at high temperature also can stable existence, and utilize the full oxide particle that belongs to improve solidified structure, crystal grain thinning, this technology is called as " oxide metallurgy ", and it had become one of research focus of metallurgical material circle already.This good action of heterogeneous particles in steel mainly depends on its tinyization and disperse degree, and the more little disperse degree of heterogeneous particles is high more in the steel, and its refining effect to structure of steel is just strong more; Otherwise heterogeneous particles is big more in the steel, the disperse degree is poor more, has just become harmful field trash.
At present, the method that obtains the heterogeneous particles of small and dispersed in actual production in steel mainly contains two approach: the one, smelt and refining by control, and at first in molten steel, generate a large amount of tiny oxides.But need long period of time owing to from the steel ladle to the metal, solidify also entirely, generally be about 1 hour, the tiny oxide of part may grow up into harmful being mingled with in the meantime, also is because this growth process is inevitable, therefore seldom adopts this technology path.Another kind of approach is at the extremely low aluminium content of refining process control, adopt weak deoxidization technique, to keep molten steel after refining still to contain certain free oxygen content (as the free oxygen of 20~30ppm), these free oxygen will be separated out in process of setting, and with steel in reaction such as alloying element titanium generate stable oxide and (see Wang Minglin, Cheng Guoguang etc., " titaniferous mild steel process of setting titanium oxide forms thermodynamics ", the steel research journal, 2004,16 (3): 40-43).Because molten steel solidification time of clock in a measure only from the liquidus curve to the solidus, therefore formed oxide particle is minimum, the existence of the oxide particle that these are tiny just effectively refinement solidified structure, suppressed growing up of crystal grain.But the shortcoming that adopts this process route be exactly after the refining the free oxygen in the molten steel be difficult to control, free oxygen content is low can't to form a large amount of oxide particles, does not have thinning solidification structure, suppresses the effect of grain growth; Free oxygen content slightly height will cause a large amount of rimholes of strand, has a strong impact on slab quality.
Some metallargists have also carried out adding the method research work of alloying element in the casting process crystallizer in recent years, and these work mainly are divided into two classes: the one, and feeding is wrapped in the core-spun yarn of alloying element in crystallizer; The 2nd, by the directly molten steel winding-up or pour alloy in crystallizer of immersion discharge pipe.As Chinese utility model patent " rare earth the wire feeder " (patent No.: 91203718.0) proposed a kind of wire feeder that steel pouring process adds rare earth that is used for, mainly take turns, advance a velocity sensor, rare-earth wires inlet tube, regulator, compositions such as rotating disk, rocking arm, meter wheel by base plate, direct current generator, gear-box, reductor, wire leading pipe, wire leading pipe fixator, wire feed rolls, silk pressing.This device is difficult for card silk, fracture of wire, oil, wax for rare-earth wires can be removed automatically, can not produce and skid, it is true, accurate to survey silk speed, advancing a speed and casting speed can be synchronous, wear silk easily, the wire leading pipe convenient disassembly is rapid, wire leading pipe can be swung along with the vibration of crystallizer, and electric fault is low, take the operating platform area little, can report to the police flexible operation automatically.
Chinese invention patent " alloy addition method and device thereof in a kind of metal liquid " (application number: 03116839.6) proposed the method that a kind of metal liquid alloy adds and for example, metal liquid is poured into crystallizer by the immersion discharge pipe from the metal liquid receptacle, in the immersion discharge pipe, adopt injection or line feeding mode in the molten metal beam, to add alloy material.Adding apparatus comprises immersion discharge pipe, gas-tight sealing, at least one conduit, induction heater; Wherein, immersion discharge pipe two ends are connected with metal liquid receptacle and crystallizer respectively, have at least one guide hole on it; Gas-tight sealing is arranged at the guide hole place, comprises body, which is provided with at least one tracheae; Conduit is communicated in the guide hole on the immersion discharge pipe; Induction heater is arranged on the conduit.Very fast fusing under the high temperature of alloy material molten metal beam in the immersion discharge pipe, and obtain powerful beam momentum, with fabulous the mixing of molten metal, the oxidation of having stopped alloying element; And improve the rare uniformity of element in steel that go up greatly, improve the rate of recovery of rare earth, eliminate the nozzle clogging phenomenon.
Above-mentioned two patents all are in order to add fusible alloy in the molten steel in crystallizer, if adopt such scheme to add metal oxide core-spun yarn or solid metal oxide in molten steel, must cause molten steel pollution, field trash to increase so.
At defective that exists in the above-mentioned technology and deficiency, the present invention proposes the disperse method for implantation of fine heterogeneous particles in a kind of metal solidification process and add raw material.
The invention technology contents
The object of the present invention is to provide the disperse method for implantation of fine heterogeneous particles in a kind of metal solidification process and add raw material, bring a large amount of forming core cores for solidifying of molten metal forms equiax crystal, grain growths such as the phase transformation in the process of metal working thereafter, heat treatment and welding are played effective inhibitory action.
In order to achieve the above object, the present invention is achieved in that
The invention provides the disperse method for implantation of the fine heterogeneous particles in a kind of metal solidification process, be that successively feeding a kind of in the molten metal 3 in process of setting is the interpolation raw material 4 that matrix and metal oxide are formed by metal or alloy, this interpolation raw material is rod or strip, contains percentage by weight 0.2%~6%, size is the metal oxide of 10nm~1000nm; And under the driving of vibration source 5, do the high frequency small amplitude motion, its part of inserting molten metal 3 is by continuous melting, metal oxide wherein under the mobile effect of vibration and fluid by even dispersion in whole liquid phase.
Contained metal oxide can be the one matter of titanium oxide, magnesia, zirconia, calcium oxide, aluminium oxide, manganese oxide etc. in the interpolation raw material 4, also can be the combination of multiple oxide.
Adding raw material 4 matrixes can be single metals such as metallic iron, copper, aluminium, also can be that these single metals and other several or a plurality of elements comprise the alloy that manganese, silicon, aluminium, carbon, titanium, chromium, nickel etc. are formed.
This interpolation raw material 4 is after being mixed according to a certain percentage by the powder of parent metal or alloy and metal-oxide powder, compacting, sinter molding.The purpose of sintering is for the metal or alloy powder is at high temperature spread, and then becomes as a whole, and processing and manufacturing becomes the required size specification then.
In order to prevent to feed the oxidation of interpolation raw material 4 in the sinter molding process in the molten metal, also can be with after metal or alloy powder and the metal-oxide powder compression moulding, wrap up the thick metal skin close of one deck 0.1~1.0mm earlier with the metallic matrix composition, as the metal skin of iron or copper or aluminium, and then carry out sintering.
Contained aggregate metal oxide is 0.2%~6% in the interpolation raw material 4, and size is 10nm~1000nm; The total amount of metal oxide is difficult for too much, and total amount is (〉 6% too much) time can make metal oxide in adding raw material 4, just connect into oarse-grained sheet or netted field trash.
The particle size of each element of the powder of parent metal or alloy (comprising: iron, manganese, silicon, aluminium, carbon, titanium, chromium, nickel etc.) is 0.1~100 μ m.The excellent diameter that is pressed into is φ 10mm~φ 35mm, and the thickness of strip is that 2mm~10mm, width are 20mm~150mm.The metal or alloy matrix fusing point of this rod or strip is close with the fusing point of handled molten metal 3, promptly is lower than the temperature of the molten metal of handling; The fusing point of metal or alloy matrix can be adjusted by adding alloying elements such as manganese, silicon, aluminium, carbon, titanium, chromium, nickel in rod or the strip manufacturing process.
Interpolation raw material 4 in the feeding molten metal is done the high frequency small amplitude motion under the driving of vibration source 5, its vibration frequency is 20~3000Hz, and amplitude is 0.05~0.3mm.
Above-mentioned interpolation raw material 4 can be in casting process crystallizer 1, fed, also above-mentioned interpolation raw material 4 can be in casting process tundish 8, fed.
The speed of feeding interpolation raw material 4 is 0.2~2 meter/minute in molten metal.
When raw material 4 is added in feeding in molten metal, can adopt the mode of vibration feeding, also can not adopt the mode of vibration feeding.
Description of drawings
Fig. 1 carries out the schematic diagram that disperse is implanted in crystallizer.
Fig. 2 adds raw material 4 to insert the schematic diagram of fusing in the molten metal 3.
Fig. 3 carries out the schematic diagram that disperse is implanted in tundish.
Reference numeral:
1 crystallizer, 2 submersed nozzles, 3 molten metals
4 add raw material 5 vibration sources
6 support guide rollers, 7 uncoilers, 8 tundish, 9 big bag long nozzles
10 add the oxide particle that enters after raw material 4 melts in the molten metal
The specific embodiment
Introduce embodiments of the invention below in conjunction with accompanying drawing.
Embodiment 1 is applied in the crystallizer
When reality is used, interpolation raw material 4 is fed to the molten metal 3 interior (see figure 1)s of crystallizer by uncoiler 7, support guide roller 6, add raw material 4 simultaneously and do the high frequency small amplitude motion under the driving of vibration source 5, its vibration frequency is 20~3000Hz, and amplitude is 0.05~0.3mm.The purpose that applies vibration is to quicken to add the fusing of raw material 4, and the remaining metal oxide particle in matrix fusing back is launched in the metal solution fast.Insert in the molten metal 3 when adding raw material 4, because parent metal or alloy melting point are low, parent metal or alloy will be melted, high-melting point metal oxide then is saved in it, and is distributed to even dispersion (see figure 2) in the whole molten metal under the acting in conjunction of metal flow and vibration.All solidified and also just have only a few minutes to tens minute owing to launch the molten metal molten metal from metal oxide, thus metal oxide to collide the probability and the degree of growing up in molten metal all very little; The particle that adds metal oxide is very little again, can not float, can only be along with metal fluid flows, thus can obtain in the metal structure after solidifying a large amount of fine size (0.1 μ m~2.0 μ m), can play thinning microstructure, suppress the out-phase fine particle of grain growth.
Adding feeding molten metal 3 speed of raw material 4 can adjust the demand of heterogeneous particles according to metal solidification texture, and require to guarantee to add all fusings in 10~50mm scope under the raw material 4 insertion metal bath surfaces, calculating simulation and experimental study result show: suitable feeding speed is 0.2~2 meter/minute.
The purpose that the interpolation raw material 4 that feeds molten metal 3 is applied with vibration is in order to quicken to add the fusing of raw material 4, promote that metal oxide disperse in molten metal distributes in it, therefore in metal solidification texture to also can not adopting mode of vibration under the little situation of metal oxide demand.
Embodiment 2 is applied to tundish
Another embodiment is a (see figure 3) in the interpolation raw material 4 feeding tundish that will be made up of metal or alloy matrix and metal oxide.Because the tundish molten steel also has only tens minutes to solidifying entirely, also can obtain the fine heterogeneous particles of a large amount of disperses in the metal solidification texture after therefore handling.