CN105436475A - Modified manufacturing process for high-chromium cast iron composite roll through forged steel roll neck and equipment - Google Patents

Abstract

The invention discloses a modified manufacturing process for a high-chromium cast iron composite roll through a forged steel roll neck and equipment. The material comprises, by mass, 3.0%-3.6% of C, 0.60%-1.20% of Si, 0.30%-1.20% of Mn, 3.0%-5.0% of Ni, 1.0%-2.0% of Cr, 0.40%-1.2% of Mo, 0.1%-2% of W, 0.5%-1.0% of Cu, 0%-0.05% of P, 0%-0.03% of S, 0.04%-0.06% of Mg, 0.1%-0.3% of Nb, 0.1%-0.30% of Ti, 0.2%-0.6% of V, 0.05%-0.2% of B, 1.5%-2.5% of Ba, 1%-2% of Ca, 1%-3% of Sb, 0.02%-0.18% of N, 1.0%-2.0% of Y/RE and the balance Fe and inevitable microelements. Yttrium-based rare earth nodulizing and compound inoculating of Ba, Ca and silicon iron are adopted, and modification treatment is conducted by adding Nb, Ti, V, B, and Sb, so that the mechanical property of the roll is improved. The strength of the roll is improved through the forged steel roll neck. Overall in-mold heating and fusion casting are conducted on a core rod through an induction heater. Forming is conducted through a water cooled crystallizer. A composite layer interface can be dynamically controlled. The process is simple, the efficiency is high, power consumption is small, the cost is low, composition segregation is avoided, and the service life of the roll is long.

Description

A kind of modified forged steel roll neck rich chromium cast iron composite roll manufacturing process and equipment

Technical field

The invention belongs to metal-pressed machine technical field, particularly a kind of modified forged steel of one roll neck rich chromium cast iron composite roll Processes and apparatus, is applicable to the manufacture of composite roll in Steel-rolling Industry.

Background technology

Roll is described as " mothers of steel ", be steel, the rolling metal such as aluminium, copper makes metal material produce the instrument of plastic deformation in producing, it is the important large component determining milling train production efficiency and mill bar quality and economy, be the indispensable critical piece of mill milling and topmost large consumable part, its consuming cost is about 5% ~ 15% of Rolling production cost.If consider that the production brought because of roll consumption is shut down, fallen the factors such as product and plant maintenance increase, then the proportion of production cost shared by it can be higher.

Milling train is the visual plant during metal-pressed machine is produced, and is the distinctive marks of the national Iron & Steel Development technical merit of measurement one.And roll is the chief component of milling train, it is a large amount of critical component consumed in Rolling production, being the basic guarantee determining a national rolling technique development level, is the embodiment directly perceived of the basic industries comprehensive technical levels such as national metal material design, forming materials technology, processing and manufacturing and a heat treatment.In steel rolling industrial production, each stocking none be not rely on the rolling of roll and be shaped, in other words " good-for-nothing without roller ", so, the quality of roll and act on most important.

Roll quality is not only related to Rolling production cost and milling train production operational availability, also affects mill bar quality to a great extent.Along with the development of steel rolling technology, rolling mill speed and automaticity improve constantly, and the breaker roll quality particularly wearability of roll, intensity and toughness etc. is had higher requirement.Further raising roller performance, to adapt to the needs of milling train, realizes the energy-saving and cost-reducing production of iron and steel material shaped, is the fresh target that roll development person faces.

China's roll manufacturing industry is through the development of decades and growth, and become roll output big country of the world at present, there is very large development roll manufacturing technology and material kind aspect.In roll material, develop into present acicular constituent spheroidal graphite cast-iron, high alloy infinitely chilled ductile cast iron, rich chromium cast iron, carbide alloy, semi-high speed steel and high-speed steel etc. from spheroidal graphite cast-iron, alloy infinitely chilled ductile cast iron.In casting technique also from routine cast single material and press over system casting composite, develop into centrifugal compound casting process.Current domestic roll deliverability has reached more than 1,000,000 tons, manufactures and designs ability and can reach 120 ~ 1,500,000 tons.Along with the transformation of China's rolling equipment with constantly from the external milling train introducing advanced person, milling train is to automation, serialization, heavy-duty future development, and the structure and properties of breaker roll is had higher requirement.

But the metallurgical roller rolled steel mean consumption that China develops voluntarily still has larger gap compared with developed countries.From the recent statistics of China Steel association, within 2014, China's steel output has reached 1,125,570,000 tons, accounts for global output of steel more than 40%, calculates according to loss per ton steel roll 1.0 ~ 1.2kg/t steel, more than 110 ~ 130 ten thousand tons, year consumption roll, year consumes roll fund more than 20,000,000,000 yuan.In order to meet the actual needs of Rolling production, China all needs to spend a large amount of foreign exchange import roll every year, only about more than 3.0 ten thousand ton, import high-quality roll in 2010, consumes foreign exchange about more than 200,000,000 dollar.A large amount of consumption of China's roll, cause the huge waste of resource and the energy.In addition, external roll Year's consumption also more than 1,000,000 tons, the huge market demand.So large learies no matter from the rolling cost of steel rolling mill, or is all a huge waste from the viewpoint of the energy of China and resource consumption, exerts heavy pressures on to environment and resources.Therefore, improve roll quality, extend roll campaign, can not only save a large amount of foreign exchange, but also can save a large amount of roll materials, exploitation high-quality long-life roll material and forming technique thereof, not only can meet domestic demand, but also can realize foreign exchange earning.

For the requirement of satisfied modern steel rolling industry to high-performance roll, in recent years, have developed various new high-performance roll making technology both at home and abroad, wherein mainly contain in the technique of casting manufacture combination process aspect developing: centrifugally cast composite roll, continuous casting (CPC) compound car are shallow, electroslag remelting (ESR) composite roll, combined roll etc.

Centrifugally cast composite roll technique (CF) adopts the method for centrifugal casting to produce bimetallic composite roll.Rotation is mainly used to produce centrifugal force, molten metal is poured in the casting mold rotated, utilize centrifugal force that poured into a mould molten metal is got rid of outer rim to casting mold from pivot, the ecto-entad order of solidifying of molten metal is carried out, is frozen into the outer high abrasion resisting material for dense structure, internal layer is the composite roll of common material.The flowing of molten metal contributes to fragmentation and the refinement of dendritic crystal, and the resistance simultaneously overcoming intercrystalline " tunnel " carries out feeding, and the density of foundry goods is improved.After outer sphere molten metal solidifies, casting mold is sling and to assemble with bottom and top and rising head sand mold, by core and upper lower impressions with gravity-assist pouring filling, realize the compound of bi-material.Centrifugal roller casting manufactures the advantage that composite roll has Castingother technique not possess, specific as follows: (1) some parts do not need dead head, effectively improve the service efficiency of molten metal; (2) do not need to use core just can cast out the foundry goods of annular and empty tubular, can produce the length cast tube different with diameter, have good production efficiency, production cost is not high yet simultaneously yet; (3), under the influence of centrifugal force, after molten metal solidifies, quality is fine and smooth; (4) skin of the roll produced in this way has higher wearability, and the toughness material of internal layer can ensure that again roll has higher toughness, has the application prospect more wide than integral material roll and higher cost performance.

Although it is simple that this technique has equipment, equipment investment is little, and production efficiency is high, and cost is low, is suitable for the feature of production in enormous quantities.But there is following several deficiency in this technique:

1) when roll for the manufacture of high alloy material, owing to often containing the high alloy of large metric density in material, as tungsten, molybdenum, vanadium etc., during centrifugal casting, due to the effect of centrifugal force, the alloy that these density are high understands segregation in roller surface, roll inner alloy constituent content is reduced, make tissue and composition uneven thus worsen roller surface layer toughness, reduce the wearability of skin of the roll, affect the quality of roll.

2) when the fusing point of core material is higher than the fusing point of cladding material, during cast, fused layers is produced in the inner surface of the cladding material solidified.Therefore, when core material selects cast steel, good compound interface can not be obtained.

3) composite roll of forged steel core with high strength, high tenacity cannot be produced.

The outer forming process (CPC method) of continuous pouring, this technique is that Japanese Nippon Steel Corp and late 1980s input in research and development are produced.CPC method is logging material, technique, equipment, be automatically controlled in one new and high technology ^[10], only have Nippon Steel and Hitachi, Ltd to be used successfully to suitability for industrialized production at present in the world.Its operation principle makes roller core with forged steel, cast steel or waste or old roll, is coated with last layer silicon system glass protection film, prevents roller core surface oxidation on its surface.To the outer sphere molten metal of compound be needed to be poured between vertically arranged roller core and water mold, for the outer high-speed steel and roller core making casting fuses completely, adopt two cover electromagnetic induction heaters to carry out concurrent heating and preheating to molten steel and roller core respectively.Outer sphere molten metal order while fusing with roller core of melting is upwards solidified, and makes the interface of two kinds of materials reach metallurgical binding.By stripping equipment, the roll that compound is good is constantly extracted out from water mold, until composite roll casting complete.In cohesive process, roller core surface occurs micro-molten, makes roller core and outer high-speed steel metal realize firm metallurgical binding, improves bond strength.Tissue and the grain size of the high-speed steel roller stock of this method production are much thinner than centre spinning method, and the distribution of carbide even dispersion, the life-span, comparable centrifugal casting roll was high by 30%.

The formation of binder course affects the decrease speed of roll, also just determines the production efficiency of CPC method.The method has following features: 1. the outer material of roll can select multiple high alloy material, core material can with obdurability and the high steel based material of rigidity, avoids primary carbie segregation and tissue, composition segregation shortcoming that Centrifugal Cast High Speed Steel Roll occurs; 2. molten steel solidifies in water-cooled knot product device, and cooling velocity is fast, the features such as can obtain tiny, fine and close solidified structure, hot-cracking resistance is good, and roller performance is good; 3. consecutive solidification from bottom to top, keeps away the generation of having exerted oneself shrinkage cavity and the casting flaw such as loose; 4. both new roll can be manufactured, also reparation can be manufactured again to old roll.

The shortcoming of CPC is mainly: 1. owing to adopting two cover heating systems, equipment is more complicated, and technical difficulty is large; 2. owing to adopting stripping mode, production efficiency is lower, and the pure brilliant degree of the steel produced is poor; 3. need in production process to be incubated for a long time molten steel, power consumption is large, and require high to tundish refractory material, production cost is high; 4. require high to factory building and operator.Based on above reason, promote the use of scope at present very little, China is not yet invested in plantization production so far.

Liquid pouring of electroslag method (ESSLM), ESSLM invents in E.O. Ba Dun electric welding at beginning of the nineties in last century research institute.Its production technology puts into by the forging of compound in the middle of a copper water mold, casting or the waste and old roller core by mistake, again the slag melted in advance is poured in the gap between roller core and crystallizer, be energized between crystallizer and roller core, electric loop is formed by molten slag, the heat produced in slag is by the surface melting of roller core, melted liquid metal is poured in the gap between roller core and crystallizer with certain technique, slag floats by liquid metal, when passing through slag bath by electroslag refining, simultaneously by coated for roller core and with oneself through preheating roller core surface fuse, solidify under the cooling of crystallizer, form composite bed.In the process, constantly extract out from crystallizer by stripping device roller core, constantly pour into liquid metal, until predetermined length simultaneously.The material covering layer can be cast iron, high-speed steel and other metal, and made composite roll both can be used as cold roll, hot roll or Continuous Casting Rolls, can carry out casting clad again manufacture waste or old roll.But strictly to control melt cinder temperature and the time of roller core in melt cinder, prevent the fusing that core is too much, pollute working lining.

ESSLM technology allows composite diameter from 100mm to 1800mm, even larger diameter billet outer surface.Composite bed thickness 15 ~ 20mm to 100mm is even larger.This technique is compared with electroslag remelting process, and its efficiency is high, and poring rate is 200 ~ 800kg/h, and power consumption is close to 800kWh/t steel ^[10].

When the shortcoming of this technique is mainly that in recombination process, molten steel injects crystallizer in batches or continuously, due to poring rate slowly, molten steel needs insulation, molten steel storage facility is very complicated and expensive, the refractory material of holding furnace and steel ladle washes away for a long time by high-temperature liquid metal and causes a large amount of losses, and causing nonmetal inclusion to pollute, molten metal is strongly overheated all can cause alloying element and deoxidier oxidation to be accelerated with long-time preservation under high temperature.The energy ezpenditure of this process is larger, and owing to adopting stripping technique, slag temperature is mated and metal liquid level control technology complexity with stripping speed, and roller core surface fusion penetration layer control technology difficulty is large, and production efficiency is low.

Although CPC technique and ESSLM technique can manufacture the composite bed of heavy thickness, the problems referred to above existing for technology and equipment, at present only for the manufacture of high-end composite rolls such as the high-speed steel being less than 10 tons.

Combined roll is that roll is made several parts, mechanically combines.Roll internal layer uses toughness material, outer fieldly mostly makes carbide ring.This roll can save valuable carbide alloy, and cost performance is higher.Outer field carbide ring can ensure that roll has very high wearability.But because carbide ring and internal layer roller core are difficult to accomplish seamless combination, roll unbalance stress can be caused in the operation of rolling and chipping.

Although have developed numerous composite roller manufacturing process both at home and abroad, up to the present, still also there is not a composite roll manufacturing process that technique is simple, production cost is low, performance is good.Therefore, research and development composite roller manufacturing process and equipment, carries out low cost to various material roll and large-scale roller, high efficiency, high-performance manufacture is the current problem being badly in need of solving.It is the new direction of composite roll Manufacturing Technology Development.

Cast iron system roll refers to that phosphorus content is at the roll of 2.50 ~ 3.5%, can be divided into the large class of plain cast iron roll, nickel chromium triangle Infinite chilled complex cast iron roll, high Cr complex cast iron roll and alloy nodular cast iron roll four by main material.Alloy nodular cast iron roll has good heat shock resistance and abrasion resistance properties, is widely used and does large-scale blooming mill, shape rolling mill, bar materials on continuous rolling mill and large-scale seamless-tube rolling mill roller.Current domestic main employing can adopt the manufacture of centrifugal compound pouring technology, and by the restriction of manufacturing process, core adopts spheroidal graphite cast-iron, and because spheroidal graphite cast-iron intensity is low, in Rolling production, easily roll breakage occurs, serious have impact on Rolling production and product quality.

At present in rod product, cutting frame and plate sheet and strip, the centrifugal bainite roll of usual use, this roll has the following disadvantages in Long-Time Service process: 1, hardness drop is large, centrifugal bainite roll first time uses and uses for the last time, material structure changes greatly, hardness wearability declines very fast, and rolling tonnage can decline 50 ~ 70 tons; 2, thermal fatigue resistance is poor, and at high operating temperatures, low thermal fatigue resistance causes roll in use for some time in roll long-term work, easily cracks and the phenomenons such as block are fallen on top layer, has a strong impact on rolled piece quality; 3, the toughness of centrifugal bainite roll is low, fragility large, and roll breakage phenomenon happens occasionally.And this material due to graphite be flat strip shaped, carbide is network structure, so matrix strength is relatively low, therefore its wearability still feels not enough in actual use, and service life does not grow (millimeter amount of rolling is generally 2000 ~ 3000 tons); Secondly, because carbide is network structure, and the boundary effect in graphite hole; make the heat resistanceheat resistant crack performance of this material also not good enough, made roll in plate strip rolling process, along with the increase of amount of rolling can produce fire check; therefore need often to shut down to change roll, removed reparation.Production efficiency when not only affecting the class of milling train, increases replacement operation intensity, and repair amount; But also the surface quality of meeting influence of rolled strip, fire check produces the service life of repairing and also reducing roll, causes production cost higher.The problems referred to above cause centrifugal bainite roll whole service life shorter, can not meet the production requirement of high efficiency milling train.

Rich chromium cast iron is a kind of high-abrasive material of important abrasive wear resistant weld deposit, the performances such as amount of deflection is little when it has higher hardness, good wearability, a fracture, be widely used in production manufacturing the important wear member such as roll, show good combination property compared with other white cast-iron.But it still belongs to fragile material, being hit under larger service condition, often there is the failure phenomenon such as fragmentation, fracture, showing as toughness deficiency, cause its application to be restricted.

The key improving wear resistance of high-chromium iron is to improve its tissue morphology, namely destroys the carbide structure that it is continuous net-shaped, strengthens the continuity of its matrix and then improves the toughness plasticity of cast iron.Meanwhile, according to Principles of Metallography, the refinement of crystal grain contributes to the mechanical property improving material.Therefore, for high-nickel-chromium molybdenum cast iron, if can its crystal grain of refinement and improve its carbide network structure distribution, undoubtedly will to its wearability produce beneficial effect.

The automatic automation of the operation of rolling, serialization, heavy-duty are the developing direction of modern rolling technique.Due to the specific demand to rolled steel, the performance of the size of stocking, surface accuracy, stocking is all had higher requirement.In addition, along with the development of rolling technique, the working environment of roll is also more and more harsher.Therefore, for the problem existing for the roll used at present, the roll material of development of new, improves traditional production technology, makes roll meet milling train production requirement, is the important topic that insider pays close attention to and studies.The new problem that China's roll industry faces is become for present-day mill is equipped with high performance roll.

Summary of the invention

The object of the invention is to the deficiency having technology for oneself, propose that a kind of production technology is simple, equipment investment is little, production efficiency is high, cost is low, heat crack resistance is good, hardness drop is little, good toughness, a kind of modified forged steel roll neck rich chromium cast iron composite roll Processes and apparatus that wearability is good, solve centre spinning and easily component segregation occurs, CPC method, ESR method complex manufacturing, power consumption is large, cost is high, inefficient deficiency, adopt forged steel to do roll neck, solve a roll breakage difficult problem.

The equipment scheme solving its technical problem is: this equipment has a planer-type region directional solidification jacking equipment 16, planer-type region directional solidification jacking equipment 6 is provided with lifting platform 17, electromagnetic induction heater 8 is installed on lifting platform 17, rotating lifting screw 15 or hydraulic test by lifting motor 14 drives lifting platform 17 to move up and down with set speed, in the side of planer-type region directional solidification jacking equipment 16, electromagnetic induction electrical power control cabinet 19 is installed, two outputs of electromagnetic induction electrical power control cabinet 19 are connected by the two ends of water-cooled cable 20 with electromagnetic induction heating device 8, a base support is had in the bottom of planer-type region directional solidification jacking equipment 16, base support 13 is provided with support plinth 12, Water-cooled bottom water tank 11 is installed on support plinth 12, the center of end water tank 11 is manhole, the center that is provided with on end water tank 11 is the bottom board 10 of manhole, Combined water cooling crystallizer 7 is installed on bottom board 10, on the top of water mold 7, insulation ring 6 is installed, roll plug 5 is by support plinth 12, the center hole of end water tank 11 and bottom board 12 is fixed on the center of crystallizer 7, casting runner 3 is connected with in the side of bottom board 10, casting runner 3 to be arranged on base support 13 and to sit brick 4 with cast and is connected, cast is sat brick 4 and is provided with feed trumpet 2 above, at the top of feed trumpet, sprue cup 1 is installed, pouring ladle 18 is had on depositing funnel 1.

Water inlet pipe 23 and outlet pipe 24 is had respectively in the side of Water-cooled bottom water tank 11; Water mold 7 is made up of the fourplatemold arc water-cooled box assembly 7 at crystallizer circumferentially equally distributed 2 or 3 integral multiples, water inlet pipe 21 is connected with in the bottom of each arc water-cooled box assembly 7, be connected with outlet pipe 22 on the top of each arc water-cooled box assembly 7, by attachment bolt 9, arc water-cooled box assembly 7 connected into drum-shaped entirety; Insulation ring 6 is manufactured by refractory material or fiber reinforcement refractory material; Electromagnetic induction power supply is line-frequency induction power supply, medium frequency induction power supply, high frequency induction power supply, and frequency is 500Hz ~ 3000Hz.

The process technology scheme solving the employing of its technical problem is:

(1) mandrel preparation and preheating

First the roll mandrel surface of the required size manufactured is carried out oil removing, after processing of rust removing, one deck antioxidizing paint is applied at its surface uniform, put into after heating furnace carries out being preheating to 500 DEG C ~ 700 DEG C, pass through support plinth, the center hole of end water tank and bottom board is fixed on the center of crystallizer, starting region directional solidification lowering or hoisting gear, electromagnetic induction heater is dropped to the bottom of crystallizer, to fetch boiling water the water inlet pipe and water outlet pipe of cooling crystallizer and end water tank, start electromagnetic induction heating power supply, by the induction heater being arranged on water mold outside, surface heating is carried out to plug, to be heated to 840 DEG C ~ 1100 DEG C,

(2) Composition Design

The mass percent of improved High-Chromium Cast-Iron composite roller operational layer material composition is:

C:2.5 ~ 3.2%, Si:0.60 ~ 1.0%, Mn:0.50 ~ 1.20%, Ni:0.8 ~ 1.2%, Cr:13.0 ~ 20.0%, Mo:0.80 ~ 3.0%, W:0.5 ~ 1.0%, Cu:0.5 ~ 1.0%, A1:0.1 ~ 0.2%, P :≤0.05%, S :≤0.O3%, Mg:0.04 ~ 0.06%, Nb:0.1 ~ 0.3%, Ti:0.1 ~ 0.30%, V:0.2 ~ 0.6%, B:0.05 ~ 0.2%, Ba:1.5 ~ 2.5%, Ca:1 ~ 2%, Sb:1 ~ 3%, N:0.02 ~ 0.18%, Y:0.1 ~ 0.3%, surplus be Fe and inevitably trace element;

(3) molten metal melting

Base iron, foundry returns, ferrochrome, steel scrap, ferrotungsten, vanadium iron, ferro-molybdenum, nickel ingot, ferrocolumbium, ferro-titanium, red copper is taken by rich chromium cast iron composite roll predetermined material composition; be placed into melting in intermediate frequency furnace; carry out repeatedly slag making in fusion process to skim, ensure hot metal purifying degree; When molten iron temperature is 1450 ~ 1500 DEG C, sampling is chemically examined, and adjusts each constituent content until meet component requirements;

(4) breed, Metamorphism treatment

After ladle being toasted, the yttrium based heavy rare earths magnesium and 1/3 of weight needed for preheated is needed Ba, Ca of adding and silicon iron inoculator and Nb, Ti, V, B, Sb, Al, CrN, Si ₃n ₄alloy inoculant is imbedded in the pit in roasted ladle together, the roll iron filings of covering 0.5 ~ 1% on it compacting, first pour the molten iron of the good qualified composition of the fusing of total amount 2/3, after spheroidizing reacion terminates, add remaining 1/3 molten iron, and in iron notch, the ferrosilicon grain (breeding the 75SiFe of in total amount remaining 2/3) of preheating is poured into stream, skim after fully stirring, add coverture preparation cast;

(5) pour into a mould

By nodularization, breed, the skin of the roll molten metal that Metamorphism treatment is good is poured in pouring ladle, molten metal in pouring ladle is passed through depositing funnel according to predetermined cast program, feed trumpet, casting runner pours in the space in crystallizer and between plug, in casting process, pouring temperature should control 1350 ~ 1380 DEG C of scopes, start cast and need large stream, after 40 ~ 60s, start to subtract stream to water slowly, whole casting process must not be greater than 5min, electromagnetic induction heater does not stop heating, after pouring metal melt, induction heater proceeds heating 10 ~ 50 minutes, make poured into a mould molten metal within the regular hour, keep liquid, to increase the liquid-solid time, interface is made to form metallurgical binding, electromagnetic induction heater upwards promotes with certain speed by starting region directional solidification lowering or hoisting gear, the roll shaft composite bed progressively departing from electromagnetic induction heating successively consecutive solidification from bottom to top, and in different regions, control the different rates of climb according to quality requirement, forming region directional solidification, be raised to insulation ring place to stop through 5 ~ 15 minutes, continue to carry out heating 10 ~ 50 minutes to insulation ring, to postpone insulated feeder setting time, feeding is carried out to rising head, gas in composite-layer metal liquid and field trash are fully floated, eliminate composite-layer metal casting flaw, heating is stopped after reaching the scheduled time, continue water flowing and cool 30 minutes ~ 24 hours, the compound roll shaft cast is taken out in crystallizer.

(6) Technology for Heating Processing

Rich chromium cast iron composite roll is directly carried out roughing under as cast condition, then slowly heat up 10 ~ 12h in heating furnace, quench be incubated 1h by the every 30mm of roller diameter at 1070 DEG C after, then in heating furnace with heat temperature raising heating rate to 520 ~ 560 DEG C of 15 ~ 25 DEG C/h, air-cooled after insulation 6 ~ l0h, carry out first time tempering, and then being heated to 450 ~ 480 DEG C with the programming rate of 25 ~ 35 DEG C/h, after insulation 12 ~ 15h, stove is chilled to less than 150 DEG C, air cooling, carries out second time tempering.

Described roll mandrel material is forging or cast low alloy steel, medium carbon steel or spheroidal graphite cast-iron.

Described 75SiFe innoculant adding quantity is 0.2 ~ 0.4%.

Described N source material is CrN and Si ₃n ₄.

Described fourplatemold both can realize the adjustment within the specific limits of fourplatemold inner diameter size by the arc water-cooled box assembly adding or reduce different size, meet the manufacture of different different-diameter size composite roll, thus reduce mould expense.

The composition of described mandrel surface antioxidizing paint is that Na2B407, Si02, Na20, K20, A1203, CaO one or more one-tenth are wherein grouped into.

Beneficial effect

The roll that the methods such as the inventive method and centre spinning, CPC method, ESLLM method are produced is very different, and its main feature is:

1, this invented technology is used to manufacture composite roll, because special casting method makes the metal of melting solidify from bottom to top, be conducive to the feeding of liquid metals, overcome the defect that centre spinning easily produces microstructure segregation, manufactured composite roll material does not have gravity segregation, crystalline structure is excellent, even tissue, and the tiny density of crystal grain is high.The range of choice of plug and composite material is wide, forging varying strength can being selected freely to require according to different instructions for uses or the composite material of rod cast thereby material and different performance, skin of the roll can adopt high alloy material, makes it have good red hardness and high temperature abrasion resistance.

2, electromagnetic induction heater breaker roll mandrel before cast is adopted directly to carry out preheating in crystallizer, after cast, breaker roll mandrel is incubated with the molten metal poured into a mould, decrease the temperature difference between roller core and outer sphere molten metal, be conducive to the good compound of bimetallic material, there is good mechanical performance.On the other hand in order to reduce casting flaw, metallic composite is allowed to realize to lower and upper consecutive solidification, molten metal flowing from top to bottom automatically, be conducive to molten metal feeding from top to bottom, thus shorten the length in feeding district, decrease casting flaw, form the fine and close composite roll without shrinkage cavity; Continue to carry out electromagnetic induction heating to composite in casting process, can reduce by the preheat temperature of composite, reduce the oxidation of composite, the liquid-solid time can be increased, impel the diffusion of two phase material more abundant, function composite by electromagnetic stirring can be utilized simultaneously, increase liquid metals to washing away by mandrel material surface, promote that the matter and energy between two phase material exchanges, composite bed interface is made to be easy to control, thus greatly improve the bond strength at interface, can realize good metallurgical bonding interface, product quality is easy to control.

3, the present invention adopt water mold replace sand mold and metal mold shaping, in roll forming process, because skin of the roll molten metal is cooled and solidified in water mold, cooling velocity is high, nucleation ability is strong, the solidified structure that crystal grain is tiny can be obtained, dense structure's degree is high, hardness is even, mechanical property is good, improve obdurability and the thermal fatigue resistance of roll, there is higher wearability and cold-resistant, the properties possessed needed for thermal fatigue and modern roll working layer, and there is excellent machinability, casting and forging can be realized, improve the service life of roll, thus meet the requirement of modern rolling steel industry to high-performance roll.Adopt water mold to replace sand mold and metal mold shaping, the technique recovery rate of foundry goods is high, and liquid metals consumption reduces, and comparable sand casting saves 15 ~ 30%; Using rate of metal is high.Product size precision, surface light Zhi Dugao, machinery adds remaining minimum, and cast(ing) surface is without viscosity sand layer simultaneously.And quality and dimensionally stable., decreased by very little allowance meanwhile, correspondingly improve using rate of metal, saved material.

4, the present invention adopts water mold to cast, and can not need molding sand completely, so decrease the operation of molding sand process.Again can pour into a mould after foundry goods removing from mould simultaneously, be thus convenient to do mechanization and automated production, and production efficiency be high.

5, owing to adopting water mold shaping, the mold use life-span even several ten thousand times up to several thousand times, save Modeling Material greatly, reduce die cost, due to without sand molding, when having saved a large amount of molding sand and moulder, improve efficiency.Save a large amount of manufacturing expenses, reduced manufacturing cost, decrease the waste of resource and the energy and the pollution of environment.

6, current domestic usual use centrifugal compound manufacture technics roll, this roll has the following disadvantages in Long-Time Service process: 1. hardness drop is large, the roll first time that centrifugal process manufactures uses and uses for the last time, material structure changes greatly, hardness wearability declines very fast, and rolling tonnage can decline 50-70 ton; 2. thermal fatigue resistance is poor, and at high operating temperatures, low thermal fatigue resistance causes roll in use for some time in roll long-term work, easily cracks and the phenomenons such as block are fallen on top layer, has a strong impact on rolled piece quality; 3. the toughness of centrifugal bainite roll is low, fragility large, and roll breakage phenomenon happens occasionally.The present invention adopts imbedding process to manufacture composite roll, in casting process, although mandrel has carried out the preheating of uniform temperature, but for poured into a mould high temperature fluent metal, in casting process, mandrel material is equivalent to chill effect, thus improve roll internal cooling effect, increase the cooling velocity of inside during roll cast, improve and enhance roll dense internal organization, make interface by fused layers, diffusion layer and Quench solidification layer composition, reduce the hardness drop of composite material radial direction, whole composite material hardness drop is minimum, further increase compound roll shaft performance, it is little that service life after manufactured composite roll is repaired in whole life cycle at every turn reduces amplitude.Simultaneously, the present invention adopts water mold shaping, and composite-layer metal liquid is subject to the quick cooling of crystallizer, changes composite bed crystalline structure, improve composite material performance, the composite roll single through this manufacture technics/manufacture again exceedes former material used new roll more than 20 ~ 30% service life.Comprehensive life improves more than 50%.

7, this technology and equipment is used to manufacture composite roll, due to preheating overall in employing type, Quick pouring is shaping, region directional solidification crystallization control tissue, solves CPC method, ESLLM method employing stripping explained hereafter production efficiency is low, power consumption is large, require high to factory building and operator; CPC method adopt two cover heating systems, equipment compared with complicated, technical difficulty is large, the pure brilliant degree of steel is poor; ESLLM method slag temperature is mated and metal liquid level control technology complexity with stripping speed, the drawbacks such as roller core surface fusion penetration layer control technology difficulty is large, there is the production efficiency higher than centrifuging process, and the component segregation overcome existing for Centrifugal compound foundry process and the drawback that cannot manufacture forged steel roll neck roll, controllable process parameters is few, production technology is simply easy to operation, production efficiency is high, power consumption is little, production cost is lower than electroslag remelting process by 1/2, lower than submerged arc bead welding method by 2/3, equipment is simply invested little, is applicable to batch production.Can not by the restriction of equipment and process, realization mini-plant manufactures large-sized multilayer laminar joint product or Gradient Composite Layer product, applied widely.

8, adopt composite nodulizer of yttrium based heavy rare earths magnesium and and Ba, Ca, ferrosilicon composite inoculant, enhance nodularization and pregnant effect, improve graphite form, improve the strength of materials and toughness.Mated by the reasonably optimizing of alloy element, adopt rotten inoculation, add appropriate Nb, Ti, V, B, Sb, Si simultaneously ₃n ₄improve the composition of roll, carbide morphology in roll is made to obtain remarkable improvement, by adding antimony, the network structure of carbide is made to obtain basic elimination, organize disperse more, reach the metallographic structure and performance that change material, the wearability of material and heat resistanceheat resistant crack performance are effectively combined.Above-mentioned resultant effect, improves the bending strength of roll, impact toughness, amount of deflection, the contraction percentage of area, elongation after fracture and yield strength, and solves the problem of peeling off precision rolling working roll body of roll hole slot endosexine, and improves the amount of rolling of milling train.

9, the present invention owing to adding appropriate tungsten, vanadium, nitrogen and aluminium in rich chromium cast iron working lining; thus the roll working lining that smelting is obtained; not only heat resistanceheat resistant crack performance is significantly improved; and roll surface can form good heat stability, Cr203 and the A1203 complex oxide film that incrust, wearability is good in the operation of rolling; available protecting roll surface, significantly improves the service life of roll.Roll working lining, after heat treatment it organizes metallographic to be mainly the retained austenite of the high tempered martensite+carbide of case hardness+a small amount of, effectively reduce working lining hardness inhomogeneities, roll working lining hardness inhomogeneities is less than 3HSD, working lining tensile strength is greater than 800-850Mpa, thus roll can be made to work under large bending stress.

The more original rich chromium cast iron working lining of roll working lining of the present invention, wearability improves more than 50%, and millimeter amount of rolling improves more than 30%, service life and rolling yield are all enhanced about more than once, and roller consumption reduces greatly, each coping roller amount can reduce about one times, only needs 0.1 ~ 0.2mm.

10, low-alloy steel, medium carbon steel forged steel or cast steel is adopted to do roll plug, improve roller neck intensity, during Rolling production, core does not have the danger of roll breakage, improve security, fundamentally solve roll breakage accident, improve production efficiency, meet the requirement of modern steel industry to high strength roller core composite roll.May be used for large-scale top load and HI high impact load roll, as Wide and Thick Slab Heat Working Rolls, high roll-force when meeting wide and heavy plate mill rolling and the large requirement of impact load, substantially increase working roll service life.

Accompanying drawing explanation

Fig. 1 is present device installation diagram, wherein 1 is depositing funnel, 2 is feed trumpet, 3 is cast runner, 4 is cast seat brick, 5 is roll plug, 6 is insulation ring, 7 is fourplatemold, 8 is electromagnetic induction heater, 9 is attachment bolt, 10 is bottom board, 11 is end water tank, 12 is support plinth, 13 is base support, 14 is lifting motor, 15 is lifting screw, 16 is planer-type region directional solidification jacking equipment, 17 is lifting platform, 18 is pouring ladle, 19 electromagnetic induction electrical power control cabinets, 20 is water-cooled cable, 23 is end tank inlet pipe, 24 is end radiator drain.

Fig. 2 is fourplatemold structure chart of the present invention, and wherein 7 is fourplatemold.

Fig. 3 is fourplatemold arc water-cooled casing modular construction top view of the present invention, and wherein 21 is fourplatemold water inlet pipe, and 22 is fourplatemold outlet pipe, and 7 is crystallizer arc water-cooled box assembly.

Fig. 4 is end cisten mechanism figure of the present invention, and wherein 11 is end water tank.

Fig. 5 is the end of the present invention cisten mechanism top view, and wherein 11 is end water tank, and 23 is end tank inlet pipe, and 24 is end radiator drain.

Fig. 6 is that the present invention repairs roller structure figure, and wherein 25 is roll working lining, and 26 is roll mandrel.

Detailed description of the invention

By reference to the accompanying drawings, embodiments of the invention are provided as follows:

Embodiment 1: at Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, in Fig. 6, this equipment has a planer-type region directional solidification jacking equipment 16, planer-type region directional solidification jacking equipment 6 is provided with lifting platform 17, electromagnetic induction heater 8 is installed on lifting platform 17, rotating lifting screw 15 or hydraulic test by lifting motor 14 drives lifting platform 17 to move up and down with set speed, in the side of planer-type region directional solidification jacking equipment 16, electromagnetic induction electrical power control cabinet 19 is installed, two outputs of electromagnetic induction electrical power control cabinet 19 are connected by the two ends of water-cooled cable 20 with electromagnetic induction heating device 8, a base support is had in the bottom of planer-type region directional solidification jacking equipment 16, base support 13 is provided with support plinth 12, Water-cooled bottom water tank 11 is installed on support plinth 12, the center of end water tank 11 is manhole, the center that is provided with on end water tank 11 is the bottom board 10 of manhole, Combined water cooling crystallizer 7 is installed on bottom board 10, on the top of water mold 7, insulation ring 6 is installed, roll plug 5 is by support plinth 12, the center hole of end water tank 11 and bottom board 12 is fixed on the center of crystallizer 7, casting runner 3 is connected with in the side of bottom board 10, casting runner 3 to be arranged on base support 13 and to sit brick 4 with cast and is connected, cast is sat brick 4 and is provided with feed trumpet 2 above, at the top of feed trumpet, sprue cup 1 is installed, pouring ladle 18 is had on depositing funnel 1.

Water inlet pipe 23 and outlet pipe 24 is had respectively in the side of Water-cooled bottom water tank 11; Water mold 7 by crystallizer circumferentially equally distributed 2 fourplatemold arc water-cooled box assemblies 7 form, water inlet pipe 21 is connected with in the bottom of each arc water-cooled box assembly 7, be connected with outlet pipe 22 on the top of each arc water-cooled box assembly 7, by attachment bolt 9, arc water-cooled box assembly 7 connected into drum-shaped entirety; Insulation ring 6 is manufactured by refractory material or fiber reinforcement refractory material; Electromagnetic induction power supply is line-frequency induction power supply, medium frequency induction power supply, high frequency induction power supply, and frequency is 1000Hz.

Roll manufacture adopts following processing step:

(1) mandrel preparation and preheating

First the roll mandrel surface of the required size manufactured is carried out oil removing, after processing of rust removing, one deck antioxidizing paint is applied at its surface uniform, put into after heating furnace carries out being preheating to 560 DEG C, pass through support plinth, the center hole of end water tank and bottom board is fixed on the center of crystallizer, starting region directional solidification lowering or hoisting gear, electromagnetic induction heater is dropped to the bottom of crystallizer, to fetch boiling water the water inlet pipe and water outlet pipe of cooling crystallizer and end water tank, start electromagnetic induction heating power supply, by the induction heater being arranged on water mold outside, surface heating is carried out to plug, to be heated to 860 DEG C,

(2) Composition Design

The mass percent of improved High-Chromium Cast-Iron composite roller operational layer material composition is:

C:2.8%, Si:0.70%, Mn:0.70%, Ni:0.9%, Cr:16%, Mo:1.3%, W:0.6%, Cu:0.5%, A1:0.1%, P :≤0.05%, S :≤0.O3%, Mg:0.04%, Nb:0.1%, Ti:0.1%, V:0.2%, B:0.08%, Ba:1.5%, Ca:1%, Sb:1%, N:0.026%, Y:0.1, surplus be Fe and inevitably trace element;

(3) molten metal melting

Base iron, foundry returns, ferrochrome, steel scrap, ferrotungsten, vanadium iron, ferro-molybdenum, nickel ingot, ferrocolumbium, ferro-titanium, red copper is taken by rich chromium cast iron composite roll predetermined material composition; be placed into melting in intermediate frequency furnace; carry out repeatedly slag making in fusion process to skim, ensure hot metal purifying degree; When molten iron temperature is 1460 DEG C, sampling is chemically examined, and adjusts each constituent content until meet component requirements;

(4) nodularization and breed, Metamorphism treatment

After ladle being toasted, the composite nodulizer of yttrium based heavy rare earths magnesium and 1/3 of weight needed for preheated is needed Ba, Ca of adding and silicon iron inoculator and Nb, Ti, V, B, Sb, Al, CrN, Si ₃n ₄alloy inoculant is imbedded in the pit in roasted ladle together, the roll iron filings of covering 0.5 ~ 1% on it compacting, first pour the molten iron of the good qualified composition of the fusing of total amount 2/3, after spheroidizing reacion terminates, add remaining 1/3 molten iron, and in iron notch, the ferrosilicon grain (breeding the 75SiFe of in total amount remaining 2/3) of preheating is poured into stream, skim after fully stirring, add coverture preparation cast;

(5) pour into a mould

By nodularization, breed, the skin of the roll molten metal that Metamorphism treatment is good is poured in pouring ladle, molten metal in pouring ladle is passed through depositing funnel according to predetermined cast program, feed trumpet, casting runner pours in the space in crystallizer and between plug, in casting process, pouring temperature should control 1350 DEG C of scopes, start cast and need large stream, after 45s, start to subtract stream to water slowly, whole casting process must not be greater than 5min, electromagnetic induction heater does not stop heating, after pouring metal melt, induction heater proceeds heating 15 minutes, make poured into a mould molten metal within the regular hour, keep liquid, to increase the liquid-solid time, interface is made to form metallurgical binding, electromagnetic induction heater upwards promotes with certain speed by starting region directional solidification lowering or hoisting gear, the roll shaft composite bed progressively departing from electromagnetic induction heating successively consecutive solidification from bottom to top, and in different regions, control the different rates of climb according to quality requirement, forming region directional solidification, be raised to insulation ring place to stop through 8 minutes, continue to carry out heating 15 minutes to insulation ring, to postpone insulated feeder setting time, feeding is carried out to rising head, gas in composite-layer metal liquid and field trash are fully floated, eliminate composite-layer metal casting flaw, heating is stopped after reaching the scheduled time, continue water flowing and cool 40 minutes, the compound roll shaft cast is taken out in crystallizer.

(6) Technology for Heating Processing

Rich chromium cast iron composite roll is directly carried out roughing under as cast condition, then slowly heat up 10h in heating furnace, quench be incubated 1h by the every 30mm of roller diameter at 1070 DEG C after, then in heating furnace with the heat temperature raising heating rate to 520 DEG C of 15 DEG C/h, air-cooled after insulation 6h, carry out first time tempering, and then being heated to 450 DEG C with the programming rate of 25 DEG C/h, after insulation 12h, stove is chilled to less than 150 DEG C, air cooling, carries out second time tempering.

Described roll mandrel material is forging or cast low alloy steel, medium carbon steel or spheroidal graphite cast-iron.

Described 75SiFe innoculant adding quantity is 0.2%.

Described N source material is CrN, Si ₃n ₄.

The composition of described mandrel surface antioxidizing paint is that Na2B407, Si02, Na20, K20, A1203, CaO one or more one-tenth are wherein grouped into.

Embodiment 2: at Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, in Fig. 6, this equipment has a planer-type region directional solidification jacking equipment 16, planer-type region directional solidification jacking equipment 6 is provided with lifting platform 17, electromagnetic induction heater 8 is installed on lifting platform 17, rotating lifting screw 15 or hydraulic test by lifting motor 14 drives lifting platform 17 to move up and down with set speed, in the side of planer-type region directional solidification jacking equipment 16, electromagnetic induction electrical power control cabinet 19 is installed, two outputs of electromagnetic induction electrical power control cabinet 19 are connected by the two ends of water-cooled cable 20 with electromagnetic induction heating device 8, a base support is had in the bottom of planer-type region directional solidification jacking equipment 16, base support 13 is provided with support plinth 12, Water-cooled bottom water tank 11 is installed on support plinth 12, the center of end water tank 11 is manhole, the center that is provided with on end water tank 11 is the bottom board 10 of manhole, Combined water cooling crystallizer 7 is installed on bottom board 10, on the top of water mold 7, insulation ring 6 is installed, roll shaft plug 5 is by support plinth 12, the center hole of end water tank 11 and bottom board 12 is fixed on the center of crystallizer 7, casting runner 3 is connected with in the side of bottom board 10, casting runner 3 to be arranged on base support 13 and to sit brick 4 with cast and is connected, cast is sat brick 4 and is provided with feed trumpet 2 above, at the top of feed trumpet, sprue cup 1 is installed, pouring ladle 18 is had on depositing funnel 1.

Water inlet pipe 23 and outlet pipe 24 is had respectively in the side of Water-cooled bottom water tank 11; Water mold 7 by crystallizer circumferentially equally distributed 3 fourplatemold arc water-cooled box assemblies 7 form, water inlet pipe 21 is connected with in the bottom of each arc water-cooled box assembly 7, be connected with outlet pipe 22 on the top of each arc water-cooled box assembly 7, by attachment bolt 9, arc water-cooled box assembly 7 connected into drum-shaped entirety; Insulation ring 6 is manufactured by refractory material or fiber reinforcement refractory material; Electromagnetic induction power supply is line-frequency induction power supply, medium frequency induction power supply, high frequency induction power supply, and frequency is 500Hz.

Roll manufacture adopts following processing step:

(1) mandrel preparation and preheating

First the roll mandrel surface of the required size manufactured is carried out oil removing, after processing of rust removing, one deck antioxidizing paint is applied at its surface uniform, put into after heating furnace carries out being preheating to 500 DEG C ~ 700 DEG C, pass through support plinth, the center hole of end water tank and bottom board is fixed on the center of crystallizer, starting region directional solidification lowering or hoisting gear, electromagnetic induction heater is dropped to the bottom of crystallizer, to fetch boiling water the water inlet pipe and water outlet pipe of cooling crystallizer and end water tank, start electromagnetic induction heating power supply, by the induction heater being arranged on water mold outside, surface heating is carried out to plug, to be heated to 890 DEG C,

(2) Composition Design

The mass percent of improved High-Chromium Cast-Iron composite roller operational layer material composition is:

C:3.0%, Si:0.8%, Mn:0.9%, Ni:1.0%, Cr:18.0%, Mo:2.0%, W:0.9%, Cu:0.90%, A1:0.2%, P :≤0.05%, S :≤0.O3%, Mg:0.05%, Nb:0.2%, Ti:0.2%, V:0.4%, B:0.15%, Ba:2.0%, Ca:1.5%, Sb:2%, N:0.10%, Y:0.2%, surplus be Fe and inevitably trace element;

(3) molten metal melting

Base iron, foundry returns, ferrochrome, steel scrap, ferrotungsten, vanadium iron, ferro-molybdenum, nickel ingot, ferrocolumbium, ferro-titanium, red copper is taken by rich chromium cast iron composite roll predetermined material composition; be placed into melting in intermediate frequency furnace; carry out repeatedly slag making in fusion process to skim, ensure hot metal purifying degree; When molten iron temperature is 1490 DEG C, sampling is chemically examined, and adjusts each constituent content until meet component requirements;

(4) nodularization and breed, Metamorphism treatment

After ladle being toasted, the composite nodulizer of yttrium based heavy rare earths magnesium and 1/3 of weight needed for preheated is needed Ba, Ca of adding and silicon iron inoculator and Nb, Ti, V, B, Sb, Al, CrN, Si ₃n ₄alloy inoculant is imbedded in the pit in roasted ladle together, the roll iron filings of covering 0.8% on it compacting, first pour the molten iron of the good qualified composition of the fusing of total amount 2/3, after spheroidizing reacion terminates, add remaining 1/3 molten iron, and in iron notch, the ferrosilicon grain (breeding the 75SiFe of in total amount remaining 2/3) of preheating is poured into stream, skim after fully stirring, add coverture preparation cast;

(5) pour into a mould

By nodularization, breed, the skin of the roll molten metal that Metamorphism treatment is good is poured in pouring ladle, molten metal in pouring ladle is passed through depositing funnel according to predetermined cast program, feed trumpet, casting runner pours in the space in crystallizer and between plug, in casting process, pouring temperature should control 1340 DEG C of scopes, start cast and need large stream, after 50s, start to subtract stream to water slowly, whole casting process must not be greater than 5min, electromagnetic induction heater does not stop heating, after pouring metal melt, induction heater proceeds heating 18 minutes, make poured into a mould molten metal within the regular hour, keep liquid, to increase the liquid-solid time, interface is made to form metallurgical binding, electromagnetic induction heater upwards promotes with certain speed by starting region directional solidification lowering or hoisting gear, the roll shaft composite bed progressively departing from electromagnetic induction heating successively consecutive solidification from bottom to top, and in different regions, control the different rates of climb according to quality requirement, forming region directional solidification, be raised to insulation ring place to stop through 10 minutes, continue to carry out heating 10 minutes to insulation ring, to postpone insulated feeder setting time, feeding is carried out to rising head, gas in composite-layer metal liquid and field trash are fully floated, eliminate composite-layer metal casting flaw, heating is stopped after reaching the scheduled time, continue water flowing and cool 60 minutes, the compound roll shaft cast is taken out in crystallizer.

(6) Technology for Heating Processing

Rich chromium cast iron composite roll is directly carried out roughing under as cast condition, then slowly heat up 11h in heating furnace, quench be incubated 1h by the every 30mm of roller diameter at 1070 DEG C after, then in heating furnace with the heat temperature raising heating rate to 540 DEG C of 20 DEG C/h, air-cooled after insulation 8h, carry out first time tempering, and then being heated to 470 DEG C with the programming rate of 30 DEG C/h, after insulation 13h, stove is chilled to less than 150 DEG C, air cooling, carries out second time tempering.

Described roll mandrel material is forging or cast low alloy steel, medium carbon steel or spheroidal graphite cast-iron.

Described 75SiFe innoculant adding quantity is 0.3%.

Described N source material is CrN, Si ₃n ₄.

Embodiment 3: at Fig. 1, Fig. 2, Fig. 3, Fig. 4, in Fig. 5, this equipment has a planer-type region directional solidification jacking equipment 16, planer-type region directional solidification jacking equipment 6 is provided with lifting platform 17, electromagnetic induction heater 8 is installed on lifting platform 17, rotating lifting screw 15 or hydraulic test by lifting motor 14 drives lifting platform 17 to move up and down with set speed, in the side of planer-type region directional solidification jacking equipment 16, electromagnetic induction electrical power control cabinet 19 is installed, two outputs of electromagnetic induction electrical power control cabinet 19 are connected by the two ends of water-cooled cable 20 with electromagnetic induction heating device 8, a base support is had in the bottom of planer-type region directional solidification jacking equipment 16, base support 13 is provided with support plinth 12, Water-cooled bottom water tank 11 is installed on support plinth 12, the center of end water tank 11 is manhole, the center that is provided with on end water tank 11 is the bottom board 10 of manhole, Combined water cooling crystallizer 7 is installed on bottom board 10, on the top of water mold 7, insulation ring 6 is installed, roll shaft plug 5 is by support plinth 12, the center hole of end water tank 11 and bottom board 12 is fixed on the center of crystallizer 7, casting runner 3 is connected with in the side of bottom board 10, casting runner 3 to be arranged on base support 13 and to sit brick 4 with cast and is connected, cast is sat brick 4 and is provided with feed trumpet 2 above, at the top of feed trumpet, sprue cup 1 is installed, pouring ladle 18 is had on depositing funnel 1.

Water inlet pipe 23 and outlet pipe 24 is had respectively in the side of Water-cooled bottom water tank 11; Water mold 7 by crystallizer circumferentially equally distributed 6 fourplatemold arc water-cooled box assemblies 7 form, water inlet pipe 21 is connected with in the bottom of each arc water-cooled box assembly 7, be connected with outlet pipe 22 on the top of each arc water-cooled box assembly 7, by attachment bolt 9, arc water-cooled box assembly 7 connected into drum-shaped entirety; Insulation ring 6 is manufactured by refractory material or fiber reinforcement refractory material; Electromagnetic induction power supply is line-frequency induction power supply, medium frequency induction power supply, high frequency induction power supply, and frequency is 2000Hz.

Roll manufacture adopts following processing step:

(1) mandrel preparation and preheating

First the roll mandrel surface of the required size manufactured is carried out oil removing, after processing of rust removing, one deck antioxidizing paint is applied at its surface uniform, put into after heating furnace carries out being preheating to 650 DEG C, pass through support plinth, the center hole of end water tank and bottom board is fixed on the center of crystallizer, starting region directional solidification lowering or hoisting gear, electromagnetic induction heater is dropped to the bottom of crystallizer, to fetch boiling water the water inlet pipe and water outlet pipe of cooling crystallizer and end water tank, start electromagnetic induction heating power supply, by the induction heater being arranged on water mold outside, surface heating is carried out to plug, to be heated to 900 DEG C,

(2) Composition Design

The mass percent of improved High-Chromium Cast-Iron composite roller operational layer material composition is: C:3.1%, Si:1.0%, Mn:1.20%, Ni:1.2%, Cr:20.0%, Mo:2.5%, W:1.0%, Cu:1.0%, A1:0.2%, P :≤0.05%, S :≤0.O3%, Mg:0.06%, Nb:0.3%, Ti:0.30%, V:0.6%, B:0.2%, Ba:2.5%, Ca:2%, Sb:3%, N:0.18%, Y:0.3%, surplus be Fe and inevitably trace element;

(3) molten metal melting

Base iron, foundry returns, ferrochrome, steel scrap, ferrotungsten, vanadium iron, ferro-molybdenum, nickel ingot, ferrocolumbium, ferro-titanium, red copper is taken by rich chromium cast iron composite roll predetermined material composition; be placed into melting in intermediate frequency furnace; carry out repeatedly slag making in fusion process to skim, ensure hot metal purifying degree; When molten iron temperature is 1500 DEG C, sampling is chemically examined, and adjusts each constituent content until meet component requirements;

(4) nodularization and breed, Metamorphism treatment

After ladle being toasted, the composite nodulizer of yttrium based heavy rare earths magnesium and 1/3 of weight needed for preheated is needed Ba, Ca of adding and silicon iron inoculator and Nb, Ti, V, B, Sb, Al, CrN, Si ₃n ₄alloy inoculant is imbedded in the pit in roasted ladle together, the roll iron filings of covering 1% on it compacting, first pour the molten iron of the good qualified composition of the fusing of total amount 2/3, after spheroidizing reacion terminates, add remaining 1/3 molten iron, and in iron notch, the ferrosilicon grain (breeding the 75SiFe of in total amount remaining 2/3) of preheating is poured into stream, skim after fully stirring, add coverture preparation cast;

(5) pour into a mould

By nodularization, breed, the skin of the roll molten metal that Metamorphism treatment is good is poured in pouring ladle, molten metal in pouring ladle is passed through depositing funnel according to predetermined cast program, feed trumpet, casting runner pours in the space in crystallizer and between plug, in casting process, pouring temperature should control 1350 DEG C of scopes, start cast and need large stream, after 60s, start to subtract stream to water slowly, whole casting process must not be greater than 5min, electromagnetic induction heater does not stop heating, after pouring metal melt, induction heater proceeds heating 30 minutes, make poured into a mould molten metal within the regular hour, keep liquid, to increase the liquid-solid time, interface is made to form metallurgical binding, electromagnetic induction heater upwards promotes with certain speed by starting region directional solidification lowering or hoisting gear, the roll shaft composite bed progressively departing from electromagnetic induction heating successively consecutive solidification from bottom to top, and in different regions, control the different rates of climb according to quality requirement, forming region directional solidification, be raised to insulation ring place to stop through 15 minutes, continue to carry out heating 30 minutes to insulation ring, to postpone insulated feeder setting time, feeding is carried out to rising head, gas in composite-layer metal liquid and field trash are fully floated, eliminate composite-layer metal casting flaw, heating is stopped after reaching the scheduled time, continue water flowing and cool 60 minutes, the compound roll shaft cast is taken out in crystallizer.

(6) Technology for Heating Processing

Rich chromium cast iron composite roll is directly carried out roughing under as cast condition, then slowly heat up 12h in heating furnace, quench be incubated 1h by the every 30mm of roller diameter at 1070 DEG C after, then in heating furnace with heat temperature raising heating rate to 520 ~ 560 DEG C of 25 DEG C/h, air-cooled after insulation 10h, carry out first time tempering, and then being heated to 480 DEG C with the programming rate of 35 DEG C/h, after insulation 15h, stove is chilled to less than 150 DEG C, air cooling, carries out second time tempering.

Described roll mandrel material is forging or cast low alloy steel, medium carbon steel or spheroidal graphite cast-iron.

Described 75SiFe innoculant adding quantity is 0.4%.

Described N source material is CrN, Si ₃n ₄.

The composition of described mandrel surface antioxidizing paint is that Na2B407, Si02, Na20, K20, A1203, CaO one or more one-tenth are wherein grouped into.

More than show and describe general principle of the present invention, principal character and advantage of the present invention.The technical staff of the industry should understand; the present invention is not by the restriction of step embodiment; the just principle of the present invention described in step embodiment and description; without departing from the spirit and scope of the present invention; design of the present invention can be implemented to use by other various forms; also have various changes and modifications, these changes and improvements equally all fall in the claimed scope of the invention.Application claims protection domain is defined by appending claims and equivalent thereof.

Claims (9)

1. a modified forged steel roll neck rich chromium cast iron composite roll Processes and apparatus, is characterized in that: roll manufacture adopts following processing step:

(1) mandrel preparation and preheating

First the roll mandrel surface of the required size manufactured is carried out oil removing, after processing of rust removing, one deck antioxidizing paint is applied at its surface uniform, put into after heating furnace carries out being preheating to 500 DEG C ~ 700 DEG C, pass through support plinth, the center hole of end water tank and bottom board is fixed on the center of crystallizer, starting region directional solidification lowering or hoisting gear, electromagnetic induction heater is dropped to the bottom of crystallizer, to fetch boiling water the water inlet pipe and water outlet pipe of cooling crystallizer and end water tank, start electromagnetic induction heating power supply, by the induction heater being arranged on water mold outside, surface heating is carried out to plug, to be heated to 840 DEG C ~ 1100 DEG C,

(2) Composition Design

The mass percent of improved High-Chromium Cast-Iron composite roller operational layer material composition is:

C:2.5 ~ 3.2%, Si:0.60 ~ 1.0%, Mn:0.50 ~ 1.20%, Ni:0.8 ~ 1.2%, Cr:13.0 ~ 20.0%, Mo:0.80 ~ 3.0%, W:0.5 ~ 1.0%, Cu:0.5 ~ 1.0%, A1:0.1 ~ 0.2%, P :≤0.05%, S :≤0.O3%, Mg:0.04 ~ 0.06%, Nb:0.1 ~ 0.3%, Ti:0.1 ~ 0.30%, V:0.2 ~ 0.6%, B:0.05 ~ 0.2%, Ba:1.5 ~ 2.5%, Ca:1 ~ 2%, Sb:1 ~ 3%, N:0.02 ~ 0.18%, Y:0.1 ~ 0.3%, surplus be Fe and inevitably trace element;

(3) molten metal melting

Base iron, foundry returns, ferrochrome, steel scrap, ferrotungsten, vanadium iron, ferro-molybdenum, nickel ingot, ferrocolumbium, ferro-titanium, red copper is taken by rich chromium cast iron composite roll predetermined material composition; be placed into melting in intermediate frequency furnace; carry out repeatedly slag making in fusion process to skim, ensure hot metal purifying degree; When molten iron temperature is 1450 ~ 1500 DEG C, sampling is chemically examined, and adjusts each constituent content until meet component requirements;

(4) breed, Metamorphism treatment

After ladle being toasted, the yttrium based heavy rare earths magnesium and 1/3 of weight needed for preheated is needed Ba, Ca of adding and silicon iron inoculator and Nb, Ti, V, B, Sb, Al, CrN, Si ₃n ₄alloy inoculant is imbedded in the pit in roasted ladle together, the roll iron filings of covering 0.5 ~ 1% on it compacting, first pour the molten iron of the good qualified composition of the fusing of total amount 2/3, after spheroidizing reacion terminates, add remaining 1/3 molten iron, and in iron notch, the ferrosilicon grain (breeding the 75SiFe of in total amount remaining 2/3) of preheating is poured into stream, skim after fully stirring, add coverture preparation cast;

(5) pour into a mould

By nodularization, breed, the skin of the roll molten metal that Metamorphism treatment is good is poured in pouring ladle, molten metal in pouring ladle is passed through depositing funnel according to predetermined cast program, feed trumpet, casting runner pours in the space in crystallizer and between plug, in casting process, pouring temperature should control 1350 ~ 1380 DEG C of scopes, start cast and need large stream, after 40 ~ 60s, start to subtract stream to water slowly, whole casting process must not be greater than 5min, electromagnetic induction heater does not stop heating, after pouring metal melt, induction heater proceeds heating 10 ~ 50 minutes, make poured into a mould molten metal within the regular hour, keep liquid, to increase the liquid-solid time, interface is made to form metallurgical binding, electromagnetic induction heater upwards promotes with certain speed by starting region directional solidification lowering or hoisting gear, the roll shaft composite bed progressively departing from electromagnetic induction heating successively consecutive solidification from bottom to top, and in different regions, control the different rates of climb according to quality requirement, forming region directional solidification, be raised to insulation ring place to stop through 5 ~ 15 minutes, continue to carry out heating 10 ~ 50 minutes to insulation ring, to postpone insulated feeder setting time, feeding is carried out to rising head, gas in composite-layer metal liquid and field trash are fully floated, eliminate composite-layer metal casting flaw, heating is stopped after reaching the scheduled time, continue water flowing and cool 30 minutes ~ 24 hours, the compound roll shaft cast is taken out in crystallizer,

(6) Technology for Heating Processing

Rich chromium cast iron composite roll is directly carried out roughing under as cast condition, then slowly heat up 10 ~ 12h in heating furnace, quench be incubated 1h by the every 30mm of roller diameter at 1070 DEG C after, then in heating furnace with heat temperature raising heating rate to 520 ~ 560 DEG C of 15 ~ 25 DEG C/h, air-cooled after insulation 6 ~ l0h, carry out first time tempering, and then being heated to 450 ~ 480 DEG C with the programming rate of 25 ~ 35 DEG C/h, after insulation 12 ~ 15h, stove is chilled to less than 150 DEG C, air cooling, carries out second time tempering.

2. the roll mandrel material described in is forging or cast low alloy steel, medium carbon steel or spheroidal graphite cast-iron;

Described 75SiFe innoculant adding quantity is 0.2 ~ 0.4%;

Described N source material is CrN and Si ₃n ₄.

3. one kind realizes the equipment of modified forged steel roll neck rich chromium cast iron composite roll technique, it is characterized in that: this equipment has a planer-type region directional solidification jacking equipment, planer-type region directional solidification jacking equipment is provided with lifting platform, on lifting platform, electromagnetic induction heater is installed, lifting platform is driven to move up and down with set speed by lifting motor rotation lifting screw or hydraulic test, in the side of planer-type region directional solidification jacking equipment, electromagnetic induction electrical power control cabinet is installed, two outputs of electromagnetic induction electrical power control cabinet are connected by the two ends of water-cooled cable with electromagnetic induction heating device, a base support is had in the bottom of planer-type region directional solidification jacking equipment, base support is provided with support plinth, Water-cooled bottom water tank is installed on support plinth, the center of end water tank is manhole, the bottom board that center is manhole is installed on end water tank, Combined water cooling crystallizer is installed on bottom board, on the top of water mold, insulation ring is installed, roll shaft plug passes through support plinth, the center hole of end water tank and bottom board is fixed on the center of crystallizer, casting runner is connected with in the side of bottom board, casting runner 3 to be arranged on base support and to sit brick with cast and is connected, cast is sat above brick and is provided with feed trumpet, at the top of feed trumpet, sprue cup is installed, pouring ladle is had on depositing funnel.

4. the equipment of a kind of modified forged steel roll neck rich chromium cast iron composite roll technique according to claim 2, it is characterized in that: water mold is made up of the fourplatemold arc water-cooled box assembly at crystallizer circumferentially equally distributed 2 or 3 integral multiples, water inlet pipe is connected with in the bottom of each arc water-cooled box assembly, be connected with outlet pipe on the top of each arc water-cooled box assembly, by attachment bolt, arc water-cooled box assembly connected into drum-shaped entirety.

5. the equipment of a kind of modified forged steel roll neck rich chromium cast iron composite roll technique according to claim 2, it is characterized in that: electromagnetic induction power supply is line-frequency induction power supply, medium frequency induction power supply, high frequency induction power supply, frequency is 500Hz ~ 3000Hz.

6. the equipment of a kind of modified forged steel roll neck rich chromium cast iron composite roll technique according to claim 2, is characterized in that: insulation ring is manufactured by refractory material or fiber reinforcement refractory material.

7. the equipment of a kind of modified forged steel roll neck rich chromium cast iron composite roll technique according to claim 2, is characterized in that: described fourplatemold both can realize the adjustment of fourplatemold inner diameter size by the arc water-cooled box assembly adding or reduce different size.

8. the equipment of a kind of modified forged steel roller rich chromium cast iron composite roll technique according to claim 2, is characterized in that: have water inlet pipe and outlet pipe respectively in the side of Water-cooled bottom water tank.

9. modified forged steel roll neck rich chromium cast iron composite roll technique according to claim 1, is characterized in that: the composition of described mandrel surface antioxidizing paint is that Na2B407, Si02, Na20, K20, A1203, CaO one or more one-tenth are wherein grouped into.