CN111809105B - In-situ composite carbide particle reinforced wear-resistant roller and preparation method thereof - Google Patents
In-situ composite carbide particle reinforced wear-resistant roller and preparation method thereof Download PDFInfo
- Publication number
- CN111809105B CN111809105B CN202010715194.9A CN202010715194A CN111809105B CN 111809105 B CN111809105 B CN 111809105B CN 202010715194 A CN202010715194 A CN 202010715194A CN 111809105 B CN111809105 B CN 111809105B
- Authority
- CN
- China
- Prior art keywords
- roller
- molten iron
- furnace
- feti70
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C37/00—Cast-iron alloys
- C22C37/10—Cast-iron alloys containing aluminium or silicon
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/26—Methods of annealing
- C21D1/30—Stress-relieving
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/56—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering characterised by the quenching agents
- C21D1/607—Molten salts
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/08—Making cast-iron alloys
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C37/00—Cast-iron alloys
- C22C37/06—Cast-iron alloys containing chromium
- C22C37/08—Cast-iron alloys containing chromium with nickel
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/001—Austenite
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/008—Martensite
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Child & Adolescent Psychology (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
An in-situ composite carbide particle reinforced wear-resistant roller and a preparation method thereof belong to the technical field of steel rolling. In-situ generating (Nb, Ti) C composite carbide particles in a roller matrix, firstly smelting molten iron containing 3.44-3.78% of C, 12.06-12.39% of Cr, 2.74-2.90% of Nb, 0.77-0.95% of Si, 1.03-1.27% of Al, 2.55-2.79% of Co, 4.51-4.86% of Mn and 3.07-3.38% of Ni in a medium-frequency induction furnace, heating the molten iron to 1558-. The roller has excellent wear resistance and good use effect after casting, processing and heat treatment.
Description
Technical Field
The invention discloses a wear-resistant roller and a preparation method thereof, particularly relates to an in-situ composite carbide particle reinforced wear-resistant roller and a preparation method thereof, and belongs to the technical field of steel rolling.
Background
The roller is a key spare part in the production process of hot rolled plate strip steel, the roller types commonly used for the hot rolled plate strip steel are a nickel-chromium-molybdenum infinite chilled cast iron roller and a high-chromium cast iron roller, wherein in the nickel-chromium-molybdenum infinite chilled cast iron roller, because graphite is in a flat strip shape and carbide is in a net-shaped structure, the strength of a matrix is relatively low, the service life is short, and secondly, because the carbide is in a net-shaped structure and the boundary effect of graphite cavities, the heat crack resistance of the material is poor. The high-chromium cast iron roller for the front rolling section of the hot rolled strip steel continuous rolling mill has the advantages that a layer of oxide film with higher strength and wear resistance can be generated on the surface of the roller in the rolling process, and the roller surface is protected, so that the wear resistance of the roller surface of the roller is improved, and the wear is reduced. However, the existing high-chromium cast iron roll not only generates hot cracks on the high-chromium cast iron working layer, but also easily peels off an oxide film generated on the roll surface in the rolling process, so that the existing high-chromium cast iron roll has poor wear resistance and high roll consumption. In order to improve the performance of the roller, the Chinese invention patent CN108620560A discloses a processing method for strengthening the wear resistance of a cast iron roller by adding particles, which is characterized by comprising the following specific steps: (1) the method comprises the following steps of putting scrap iron, vanadium-titanium pig iron, nickel plates, ferrochrome, ferromolybdenum and ferrotungsten into a medium-sized induction electric frequency furnace after batching, heating and smelting until the scrap iron, the vanadium-titanium pig iron, the nickel plates, the ferrochrome, the ferromolybdenum and the ferrotungsten are completely molten, adding partial ferrosilicon after smelting for 20min, sampling and analyzing, and determining that chemical components are C: 2.8 to 3.6 percent; si: 0.7-1.1%; mn: 0.5-0.8%; cr: 1.6-2.5%; ni: 3 to 5 percent; mo: 0.2-0.70%; ti: 0.02-0.05%; v: 0.03-0.10%; w: 0.2 to 0.4 percent; p is less than or equal to 0.04 percent; s is less than or equal to 0.025 percent; the balance being Fe; (2) when the temperature of molten iron reaches 1500-; (3) removing scum after inoculation, adding a particle modifier to the surface of the molten iron, keeping the temperature for 10-12min, slightly pressing the modifier into the molten iron at a position with the depth of 150mm after 10-12min, and keeping the temperature for 3-5 min; (4) controlling the temperature of molten iron before tapping to 1380-1450 ℃ after modification, taking the part of molten iron as outer-layer casting liquid of the roller, selecting common grey cast iron liquid as the inner-layer casting liquid, ensuring that the casting speed is stable, casting the inner-layer grey cast iron liquid after the outer-layer casting liquid is solidified, and obtaining the wear-resistant roller at the casting temperature of 1360-1380 ℃; the nodulizer in the step (2) comprises the following components: 1.9-2.2% of rhenium, 1.1-1.4% of cerium, 6-6.2% of magnesium, 2.2-2.5% of calcium, 1.3-1.4% of barium, 42-44% of silicon and the balance of iron; the preparation method of the composite silicon carbide inoculated cored wire in the step (2) comprises the following steps: mixing 50nm silicon carbide and 10 μm silicon carbide according to a mass ratio of 1: 9, mixing 10-micron silicon carbide, 50-nm silicon carbide, composite nano silicon carbide, chromium carbide and iron silicon inoculant according to a mass ratio of 2: 3: 4: 4: 0.2, adding the mixture into a core-wrapping machine, and wrapping the mixture by using a cold-rolled low-carbon steel strip; the addition amount of the inoculant is 0.8 wt% of the mass of the molten iron; the modifier in the step (3) is that the NbC content in the NbC/Fe composite powder is 28-35 wt%, and the density of the niobium carbide powder is adjusted by adding iron powder, so that the niobium carbide powder floats on the surface of molten iron and fully undergoes modification reaction; the addition amount of the modifier NbC/Fe composite powder is 1.2 wt% of the mass of the molten iron. The Chinese invention patent CN 110184524A also discloses a Nb and V composite microalloying preparation method for improving the wear resistance of the high-chromium cast iron roller and the high-chromium cast iron roller with high wear resistance, wherein the preparation method comprises the following steps of controlling the total amount of Nb and V in the high-chromium cast iron roller according to the mass percent to be 0.8-1.8%, and the mass ratio of Nb to V is Nb: v is 4: 1-2: and 1, adjusting the total amount of Nb and V according to the content of Cr and C in the high-chromium cast iron roll component, so that eutectic MC type carbide containing Nb and V is formed in the high-chromium cast iron roll. The Nb and V composite microalloying preparation method can improve the wear resistance of the high-chromium cast iron roller by alloying a small amount of Nb and V.
The Chinese invention patent CN 108149132A discloses a casting method of a boron-containing roller, wherein the outer layer of the boron-containing roller is formed by a centrifugal casting method, the roller core is made of nodular cast iron and is cast by a top pouring method, the chemical components and the weight percentage of the outer layer are C3.2-3.5%, Si 0.2-0.4%, B1.2-1.6%, Cr6.3-7.0%, Mn 1.6-1.8%, V1.5-1.8%, Mo2.2-2.8%, W1.2-1.6%, Nb0.1-0.3%, Ce0.25-0.35%, Ti0.3-0.5%, S < 0.03%, P < 0.04%, and the balance Fe, the method comprises the following steps: mixing and heating common scrap steel, ferrochrome, pig iron, ferrotungsten, ferromolybdenum and ferroniobium for melting, adding ferrosilicon and ferromanganese after molten steel is melted down, and adding ferrovanadium before discharging; secondly, after the components are adjusted to be qualified in front of the furnace, the temperature is raised to 1580 ℃ plus material temperature, aluminum accounting for 0.15-0.20 percent of the mass of the molten steel is added for deoxidation, then ferrotitanium and ferroboron are sequentially added, and the molten steel is taken out of the furnace when the temperature of the molten steel reaches 1580 ℃ plus material temperature of 1600 ℃; thirdly, crushing the cerium-based rare earth into small blocks with the granularity of 5-7mm, drying at the temperature of 160 ℃ and 200 ℃, placing the small blocks at the bottom of a casting ladle, and carrying out composite modification treatment on the molten steel by using an in-ladle flushing method; fourthly, pouring the outer layer of the roller by using a centrifugal casting machine, wherein the pouring temperature of the molten steel of the outer layer is 1470-; pouring for 12-24 hours by using a roller, unpacking, placing in a slow cooling pit, cooling to room temperature, cutting a casting head, cleaning residual roots, flash and burrs, and then roughly processing; sixthly, performing heat treatment on the roller after rough machining, wherein the heat treatment comprises high-temperature quenching and tempering treatment, the quenching heating temperature is 1000-1050 ℃, and the heat preservation time is 2-4 hours. During quenching and cooling, firstly spray cooling for 10-20 minutes, then air cooling until the temperature of the roller surface is lower than 200 ℃, putting the roller surface into a heating furnace for first tempering treatment, tempering and heating the roller surface at 520-560 ℃, preserving heat for 5-8 hours, then air cooling, when the temperature of the roller surface is lower than 200 ℃, putting the roller surface into the heating furnace for second tempering treatment, tempering and heating the roller surface at 500-540 ℃, preserving heat for 8-12 hours, then furnace cooling, when the temperature of the roller surface is lower than 200 ℃, discharging the roller surface out of the furnace, and finish machining to the specified size. The Chinese invention patent CN 106676408A also discloses a preparation method of the high-carbon graphite steel roller, which is characterized by comprising the following steps: step one, determining chemical components: the high-carbon graphite steel roller comprises the following chemical components in pouring: c: 2.00-2.35%; si: 1.30-1.60%; mn: 0.50-1.00%; cr: 0.60-0.80%; ni: 2.50-3.50%; mo: 0.50-1.00%; p is less than or equal to 0.030 percent; s is less than or equal to 0.025 percent; v: 0.20-0.50%; nb: 0.20-0.50%; ba + Ca is more than or equal to 0.40 percent; re is more than or equal to 0.15 percent; the balance of Fe and inevitable impurities; step two, pouring: smelting in an electric arc furnace, and carburizing with carbon powder and ferrosilicon powder before tapping to ensure that the chemical components of the molten steel meet the requirements; then heating to 100-150 ℃ for tapping on the basis of the liquid phase temperature, simultaneously adding 0.20-0.40% of BaCa for spheroidizing, and adding 0.40-0.60% of CaSi alloy during inoculation; calming for 5-8 min, stirring for 0.5-1 min with an electromagnetic stirrer, and pouring; step three, heat treatment: cold unpacking the steel billet, carrying out special heat treatment, and detecting a roller to obtain a qualified finished product; and step two, assembling a set of high-temperature ceramic wire mesh screen beside a steel port of the steel ladle during casting, wherein a micro-fine-particle BaCa nodulizer and a CaSi inoculant are filled in the high-temperature ceramic wire mesh screen, and the nodulizer and the inoculant in the screen automatically flow into the molten steel under the action of a vibration power source generated along with the start of the steel port, and flow in while casting, so as to play a role in nodulizing and inoculating.
The Chinese invention patent CN 106835124A discloses a composite laser toughening and strengthening process of intermetallic compounds on the surface of a roller, which is characterized by comprising the following process steps: adopting intermetallic compound Fe3Al and ZrO2The composite material participates in laser nano-reinforcement treatment; the composite material is an intermetallic compound Fe3Al and ZrO2Preparing micron-sized granular materials according to the same proportion; secondly, adopting nano-scale base carbide as a reinforcing phase, wherein the reinforcing phase comprises the following components in parts by weight: nano-scale 60-70 parts of Ti-based carbide, 4-6 parts of Si-based carbide, 1-2 parts of W-based carbide and 1-2 parts of Cr-based carbide; the method comprises the following specific steps: mixing 1-2 parts of composite material by mass and 10-15 parts of reinforcing phase to form a strengthening and toughening material with a composite structure, wherein the strengthening and toughening material is pre-coated on the surface of a hot roll working roll or is delivered to the surface of a roll body by adopting a coaxial powder delivery mode, and the pre-coating thickness is 0.2-0.3 mm; and carrying out laser composite strengthening treatment by using a laser processing unit to form a toughening and strengthening layer in the depth of 0.5-2.0mm on the surface of the roller. The chinese invention patent CN 105121043a also discloses a hot rolling roll outer layer material and a hot rolling composite roll which have excellent fatigue resistance of the roll surface layer and are difficult to generate fatigue scars and chipping. The roller outer layer material contains 500-2500 circle equivalent diameter 3-30 micron fine carbide/mm2And 20 coarse carbides having a circle equivalent diameter of 50 μm or more per mm2The following exist, preferably the roll shell material is of the following composition: contains, in mass%, C: 2.4-2.9%, Si: 0.2 to 1.0%, Mn: 0.2-1.0%, Cr: 4.0-7.5%, Mo: 4.0-6.5%, V: 5.3 to 7.0%, Nb: 0.5 to 3.0%, satisfies 1.5. ltoreq. Cr + Mo)/V.ltoreq.2.4, and further preferably contains Al: 0.001-0.05% or REM: 0.001 to 0.03%, and the balance of Fe and inevitable impurities. And a composite roll for hot rolling having an outer layer made of the outer layer material. The Chinese invention patent CN 106345980A also discloses a method for manufacturing a wear-resistant particle rolling roller sleeve, which comprises the following steps: 1) and (3) centrifugal casting of the outer layer:casting a high-carbon high-alloy steel outer layer by adopting a centrifugal casting method, firstly, pouring molten high-carbon high-alloy steel into a centrifugal casting machine, when the thickness of the outer layer is close to 10mm, adding wear-resistant particles along with the molten steel, wherein the adding amount of the wear-resistant particles is gradually increased along with the time until the outer layer is cast, and the wear-resistant particles account for 10% of the total weight of the outer layer; the added wear-resistant particles are titanium tungsten carbide solid solution; the specific gravity of the titanium tungsten carbide solid solution is 10g/cm3(ii) a The temperature at which the wear resistant particles are added is 500 ℃; the thickness of the outer layer after the casting is finished is 60 mm; 2) centrifugally casting the inner layer: and when the inner surface of the centrifugally cast outer layer is close to solidification, casting the inner layer of the medium-carbon low-alloy steel.
However, the wear-resistant particles are added directly into the molten metal, so that the agglomeration phenomenon of the wear-resistant particles is easy to occur, the reinforcing effect of the wear-resistant particles cannot be fully exerted, and the wear-resistant particles are expected to be uniformly distributed by means of electromagnetic stirring, mechanical vibration or ultrasonic vibration and the like. However, interfaces between the added wear-resistant particles and the metal matrix exist, the bonding strength between the wear-resistant particles and the metal matrix is low, the wear-resistant particles are easy to peel off in the using process, and the peeled particles are adhered to the surface of the roller, so that the abrasion of the roller is aggravated.
Disclosure of Invention
In order to overcome the defects of the added wear-resistant particles, the invention adopts an in-situ reaction method to generate (Nb, Ti) C composite carbide particles in a roller matrix in situ, and the (Nb, Ti) C composite carbide particles are uniformly distributed in the roller matrix, thereby promoting the remarkable improvement of the wear resistance of the roller.
A preparation method of an in-situ composite carbide particle reinforced wear-resistant roller comprises the following specific preparation process steps:
firstly, smelting molten iron containing elements such as niobium, chromium, cobalt, manganese, nickel and the like in a medium-frequency induction furnace, and controlling the chemical composition and the mass fraction of the molten iron in the furnace to be 3.44-3.78% of C, 4.51-4.86% of Mn, 2.55-2.79% of Co, 12.06-12.39% of Cr, 2.74-2.90% of Nb, 0.77-0.95% of Si, 1.03-1.27% of Al, 3.07-3.38% of Ni, less than 0.030% of S, less than 0.035% of P and the balance of Fe; heating the molten iron to 1558-1575 ℃, then adding FeTi70 accounting for 9-10% of the mass fraction of the molten iron in the furnace, baking FeTi70 at 650-700 ℃ for 2.5-3.0 hours before the molten iron is put into the furnace, and enabling the particle size of FeTi70 to be 15-22 mm; after FeTi70 is completely melted, preserving heat for 4-6 minutes, and then discharging molten iron to a ladle;
after slagging off and standing, pouring molten iron in the casting ladle into a casting mold when the temperature is reduced to 1447-; the adding amount of the silicon-calcium-barium alloy accounts for 0.75-0.90 percent of the mass fraction of the molten iron entering the casting mold; after the molten iron is completely solidified, opening the box, taking out the roller blank, and performing rough machining after sand removal and polishing;
heating the rough-machined roller to 1015 ℃ along with the furnace, preserving the heat for 2.0-2.5 hours, and then cooling the roller for 10-12 minutes in a 195 ℃ salt bath furnace at 180-; the salt bath is made of 50 wt.% NaNO3And 50 wt.% KNO3Melting to obtain the product;
and fourthly, immediately putting the roller cooled by the salt bath into a heat treatment heat preservation furnace with the temperature of 350-360 ℃, preserving the heat for 50-60 minutes, cooling the furnace to the temperature lower than 100 ℃, taking out the roller from the furnace, cooling the roller to the room temperature, and finally, finely processing the roller to the specified size and precision.
The chemical composition and mass fraction of FeTi70 are 70.36-70.95% Ti, 0.97-2.82% A1, < 0.5% Si, and the rest is Fe.
The chemical composition and the mass fraction of the silicon-calcium-barium alloy are 42.38-43.05% of Si, 11.26-11.53% of Ca, 10.62-10.97% of Ba, less than or equal to 0.8% of C, less than or equal to 0.04% of P, less than or equal to 0.06% of S and the balance of Fe.
In order to overcome the defects of easy agglomeration and easy peeling of the added wear-resistant particles, the invention provides a method for generating (Nb, Ti) C composite carbide particles in situ in a roller matrix by adopting an in-situ reaction method, and the (Nb, Ti) C composite carbide particles are uniformly distributed in the roller matrix to promote the remarkable improvement of the wear resistance of the roller. In order to realize one purpose, molten iron containing elements such as niobium, chromium, cobalt, manganese, nickel and the like is smelted in a medium-frequency induction electric furnace, and the chemical composition and the mass fraction of the molten iron in the furnace are controlled to be 3.44-3.78% of C, 4.51-4.86% of Mn, 2.55-2.79% of Co, 12.06-12.39% of Cr, 2.74-2.90% of Nb, 0.77-0.95% of Si, 1.03-1.27% of Al, 3.07-3.38% of Ni, less than 0.030% of S, less than 0.035% of P and the balance of Fe. The molten iron in the furnace contains 3.44-3.78% of C and 2.74-2.90% of Nb, mainly for ensuring that C is combined with Ti which is added later to generate fine TiC particles with high melting point and high hardness. In the solidification process, the Nb, Ti and C elements in the molten iron can generate an in-situ combination reaction:
wherein the content of the first and second substances,
gibbs free energy, T temperature, from each chemical reaction
As can be seen from the change curve of the temperature T, the Gibbs free energy of TiC is lower than that of NbC, but the difference between the two is changed along with the change of the Nb/Ti ratio in molten iron, and the change has an important influence on the growth process of (Ti, Nb) C particles. As the solidification proceeds, TiC particles in the molten iron increase and Ti content decreases, so that
And
the difference of NbC relative to TiC is reduced, the nucleation capability of NbC is gradually enhanced, and finally, composite carbide (Ti, Nb) C with the lattice constant approximate to that of TiC is formed. The growth conditions of the composite carbide (Ti, Nb) C not only depend on the thermodynamic difference of TiC and NbC, but also need to analyze the crystal plane matching of the TiC and the NbC, wherein the lattice constants of the TiC and the NbC are respectively 4.33 and 4.471. The surface energies of TiC, NbC (100), (210), (111), (211) and (110) are calculated by using a first principle based on the density functional theory, and the lower surface energy is preferentially selected as a matching crystal plane. The surface energy calculation formula is as follows:
wherein E isslabIs the system energy (eV), E of the surfacebulkIs the energy (eV) of the unit cell, N is the number of atoms, AsurfIs the surface area. The calculation result shows that the two carbides have more matching surfaces with low surface energy, which makes the attaching growth of TiC and NbC possible, and the composite carbide (Ti, Nb) C is easily obtained in the process of molten iron solidification.
In addition, 12.06-12.39% Cr is added into molten iron except for forming Cr7C3Besides increasing the quantity of wear-resistant phases of the roller, partial chromium enters the matrix, the high-temperature oxidation resistance of the roller is improved, and a compact oxidation film is generated on the surface of the roller in the use process of the roller, so that the friction coefficient of steel rolling is reduced, the rolling force is reduced, the surface quality of a rolled material is improved, and the service life of the roller is prolonged. 2.55-2.79% of Co and 1.03-1.27% of Al are added, and the Co and the Al are non-carbide forming elements, are dissolved in a matrix, can improve the high-temperature hardness of the matrix, and are beneficial to improving the high-temperature wear resistance of the roller. However, the addition of a large amount of Al can reduce the hardenability of the roller, so that the roller hardenability can be greatly improved by adding 4.51-4.86% of Mn and 3.07-3.38% of Ni while adding 2.55-2.79% of Co and 1.03-1.27% of Al. Particularly, 3.07-3.38 percent of Ni is added, so that the strength of the roller can be improved, the high-load rolling of the roller can be ensured, and the production efficiency of the rolling mill can be improved.
When the temperature of molten iron is raised to 1558-1575 ℃, FeTi70 accounting for 9-10% of the mass fraction of the molten iron in the furnace is added, FeTi70 is roasted at 650-700 ℃ for 2.5-3.0 hours before being put into the furnace, and the particle size of the FeTi70 is 15-22 mm; after FeTi70 is completely melted, preserving heat for 4-6 minutes, and then discharging molten iron to a ladle. The main purpose of adding FeTi70 is to combine C in molten iron with Ti in FeTi70 to generate fine TiC particles, and finally combine with niobium to synthesize the composite carbide (Ti, Nb) C with high hardness and good thermal stability in situ, thereby being beneficial to improving the wear resistance of the roller.
After the molten iron in the casting ladle is subjected to slag skimming and standing, the molten iron is cast into a casting mold when the temperature is reduced to 1447-Adding silicon-calcium-barium alloy with the particle size of 2-4 mm. The silicon-calcium-barium alloy comprises 42.38-43.05% of Si, 11.26-11.53% of Ca, 10.62-10.97% of Ba, less than or equal to 0.8% of C, less than or equal to 0.04% of P, less than or equal to 0.06% of S and the balance of Fe, wherein the adding amount of the silicon-calcium-barium alloy accounts for 0.75-0.90% of the mass fraction of molten iron entering a casting mold. 0.75-0.90% of silicon-calcium-barium alloy is added along with the flow, and the silicon in the silicon-calcium-barium alloy is mainly used for inoculating molten iron, so that the solidification core is further increased, the nucleation rate of the molten iron is favorably improved, and the refinement of the solidification structure is promoted. The combined action of calcium and barium in the silicon-calcium-barium alloy is utilized to improve the form and distribution of inclusions and improve the fatigue performance of the roller. And after the molten iron is completely solidified, opening the box, taking out the roller blank, and performing rough machining after sand removal and polishing. The rough-processed roller is heated to 1015 ℃ along with the furnace, and the heat preservation is carried out for 2.0-2.5 hours, so that the roller material finishes the high-temperature austenitization, part of carbide enters the matrix, the quantity of carbon and alloy elements in the matrix is increased, and the hardenability of the roller is favorably improved. After the high-temperature austenitizing is finished, the roller is cooled for 10 to 12 minutes in a salt bath furnace with the temperature of 180-195 ℃, wherein the salt bath is composed of 50 wt.% of NaNO3And 50 wt.% KNO3And melting to obtain the product. The aim is to obtain more martensite cores, which is beneficial to obtaining fine martensite + austenite matrix structure. The cooling time should not be too long, otherwise the amount of martensite is too high and the roll may crack. And (3) immediately putting the roller cooled by the salt bath into a heat treatment heat preservation furnace with the temperature of 350-360 ℃, preserving the heat for 50-60 minutes, and promoting further carbide precipitation in austenite, thereby improving the wear resistance of the roller. Finally, the furnace is cooled to the temperature lower than 100 ℃, and the roller is taken out of the furnace and cooled to the room temperature by air, mainly in order to eliminate the internal stress of the roller and ensure that the roller has good comprehensive performance.
Compared with the prior art, the invention has the following characteristics:
1) according to the invention, due to the large precipitation of in-situ composite carbide (Ti, Nb) C, the surface of the roller has excellent wear resistance, a comparative wear test is carried out on an MM200 type high-speed ring block wear tester, the friction pair is a GCr15 steel ring (with the hardness of 61.4HRC), the normal load is 900N, the sliding speed is 240r/min, the continuous wear time is 1800s, and the wear resistance of the roller is improved by more than 2 times compared with Cr15Mo3 high-chromium cast iron (with the hardness of 62HRC) under the same wear condition;
2) the hardness of the surface of the roller is high and is more than 86HSD, the hardness uniformity is good, the hardness difference of the surface of the roller is less than 1.5HSD, the service life of the roller is improved by 260 percent compared with that of a high-chromium cast iron roller when the roller is used at the front section of a hot-rolled strip steel finishing mill, and the service life of the roller is improved by 330 percent compared with that of a high-nickel-chromium infinite chilled cast iron roller when the roller is used at the rear;
3) the roller of the invention is safe and reliable, has no roller breaking and slipping during the use, can be used for the front section and the rear section of a hot-rolled strip steel finishing mill, has strong universality, can improve the operation rate of the mill, lightens the labor intensity of workers, and has good economic and social benefits when being popularized and used.
Detailed Description
The present invention will be further illustrated with reference to the following examples, but the present invention is not limited to the following examples.
Example 1:
an in-situ composite carbide particle reinforced wear-resistant roller and a preparation method thereof are characterized in that (Nb, Ti) C composite carbide particles are generated in a roller matrix in situ and are uniformly distributed in the roller matrix to promote the remarkable improvement of the wear resistance of the roller, and the specific preparation process comprises the following steps:
firstly, smelting molten iron containing elements such as niobium, chromium, cobalt, manganese, nickel and the like in a 1000 kg medium-frequency induction furnace, and controlling the chemical composition and the mass fraction of the molten iron in the furnace to be 3.63% of C, 4.74% of Mn, 2.69% of Co, 12.27% of Cr, 2.83% of Nb, 0.86% of Si, 1.16% of Al, 3.29% of Ni, 0.027% of S, 0.030% of P and the balance of Fe; heating the molten iron to 1569 ℃, adding FeTi70 (the chemical composition and the mass fraction of FeTi70 are 70.82% of Ti, 1.95% of A1, 0.25% of Si and the balance of Fe) accounting for 9.5% of the mass fraction of the molten iron in the furnace, baking FeTi70 for 2.5 hours at 680 ℃ before the molten iron is put into the furnace, wherein the particle size of FeTi70 is 15-22 mm; after FeTi70 is completely melted, preserving heat for 5 minutes, and then discharging molten iron to a ladle;
secondly, after slagging off and standing, pouring molten iron in a casting ladle into a casting mold when the temperature is reduced to 1452 ℃, and adding silicon-calcium-barium alloy (the chemical composition and the mass fraction of the silicon-calcium-barium alloy are 42.76% of Si, 11.48% of Ca, 10.84% of Ba, 0.57% of C, 0.036% of P, 0.047% of S and the balance of Fe) with the particle size of 2-4mm along with the molten iron flow in the process of pouring the molten iron; the adding amount of the silicon-calcium-barium alloy accounts for 0.80 percent of the mass fraction of the molten iron entering the casting mold; after the molten iron is completely solidified, opening the box, taking out the roller blank, and performing rough machining after sand removal and polishing;
thirdly, heating the rough-machined roller to 1010 ℃ along with a furnace, preserving heat for 2.0 hours, and then cooling in a salt bath furnace at the temperature of 185 ℃ for 11 minutes; the salt bath is made of 50 wt.% NaNO3And 50 wt.% KNO3Melting to obtain the product;
and fourthly, immediately putting the roller cooled by the salt bath into a heat treatment heat preservation furnace with the temperature of 355 ℃, preserving heat for 55 minutes, cooling the furnace to the temperature lower than 100 ℃, taking out of the furnace, air cooling to room temperature, and finally finishing to the specified size and precision. The mechanical properties of the rolls are shown in Table 1.
Example 2:
an in-situ composite carbide particle reinforced wear-resistant roller and a preparation method thereof are characterized in that (Nb, Ti) C composite carbide particles are generated in a roller matrix in situ and are uniformly distributed in the roller matrix to promote the remarkable improvement of the wear resistance of the roller, and the specific preparation process comprises the following steps:
firstly, smelting molten iron containing elements such as niobium, chromium, cobalt, manganese, nickel and the like in a 1500 kg medium-frequency induction furnace, and controlling the chemical composition and the mass fraction of the molten iron in the furnace to be 3.78% of C, 4.51% of Mn, 2.79% of Co, 12.06% of Cr, 2.90% of Nb, 0.77% of Si, 1.27% of Al, 3.07% of Ni, 0.025% of S, 0.032% of P and the balance of Fe; heating the molten iron to 1575 ℃, then adding FeTi70 (the chemical composition and the mass fraction of FeTi70 are 70.95% of Ti, 0.97% of A1, 0.28% of Si and the balance of Fe) accounting for 10% of the mass fraction of the molten iron in the furnace, baking FeTi70 for 2.50 hours at 700 ℃ before the molten iron is put into the furnace, wherein the particle size of FeTi70 is 15-22 mm; after FeTi70 is completely melted, preserving heat for 6 minutes, and then discharging molten iron to a ladle;
secondly, after slagging off and standing, pouring molten iron in the ladle into a casting mold when the temperature is reduced to 1466 ℃, and adding silicon-calcium-barium alloy (the chemical composition and the mass fraction of the silicon-calcium-barium alloy are 43.05 percent of Si,11.26 percent of Ca, 10.97 percent of Ba, 0.57 percent of C, 0.031 percent of P, 0.044 percent of S and the balance of Fe) with the particle size of 2-4mm along with the molten iron flow in the process of pouring the molten iron; the adding amount of the silicon-calcium-barium alloy accounts for 0.90 percent of the mass fraction of the molten iron entering the casting mold; after the molten iron is completely solidified, opening the box, taking out the roller blank, and performing rough machining after sand removal and polishing;
thirdly, heating the rough-machined roller to 1015 ℃ along with a furnace, preserving heat for 2.0 hours, and then cooling in a salt bath furnace at the temperature of 195 ℃ for 12 minutes; the salt bath is made of 50 wt.% NaNO3And 50 wt.% KNO3Melting to obtain the product;
and fourthly, immediately putting the roller cooled by the salt bath into a heat treatment heat preservation furnace with the temperature of 360 ℃, preserving the heat for 50 minutes, cooling the furnace to the temperature lower than 100 ℃, taking out of the furnace, air-cooling to the room temperature, and finally, finely processing to the specified size and precision. The mechanical properties of the rolls are shown in Table 1.
Example 3:
an in-situ composite carbide particle reinforced wear-resistant roller and a preparation method thereof are characterized in that (Nb, Ti) C composite carbide particles are generated in a roller matrix in situ and are uniformly distributed in the roller matrix to promote the remarkable improvement of the wear resistance of the roller, and the specific preparation process comprises the following steps:
firstly, smelting molten iron containing elements such as niobium, chromium, cobalt, manganese, nickel and the like in a 1000 kg medium-frequency induction furnace, and controlling the chemical composition and the mass fraction of the molten iron in the furnace to be 3.44% of C, 4.86% of Mn, 2.55% of Co, 12.39% of Cr, 2.74% of Nb, 0.95% of Si, 1.27% of Al, 3.07% of Ni, 0.028% of S, 0.031% of P and the balance of Fe; heating the molten iron to 1558 ℃, adding FeTi70 (the chemical composition and the mass fraction of FeTi70 are 70.36% of Ti, 2.82% of A1, 0.27% of Si and the balance of Fe) accounting for 9% of the mass fraction of the molten iron in the furnace, baking FeTi70 at 650 ℃ for 3.0 hours before the molten iron is put into the furnace, wherein the particle size of FeTi70 is 15-22 mm; after FeTi70 is completely melted, preserving heat for 4 minutes, and then discharging molten iron to a ladle;
secondly, after slagging off and standing, pouring molten iron in a casting ladle into a casting mold when the temperature is reduced to 1447 ℃, and adding silicon-calcium-barium alloy (the chemical composition and the mass fraction of the silicon-calcium-barium alloy are 42.38% of Si, 11.53% of Ca, 10.62% of Ba, 0.41% of C, 0.033% of P, 0.039% of S and the balance of Fe) with the particle size of 2-4mm along with the molten iron flow in the process of pouring the molten iron; the adding amount of the silicon-calcium-barium alloy accounts for 0.75 percent of the mass fraction of the molten iron entering the casting mold; after the molten iron is completely solidified, opening the box, taking out the roller blank, and performing rough machining after sand removal and polishing;
thirdly, heating the rough-machined roller to 1000 ℃ along with the furnace, preserving heat for 2.5 hours, and then cooling in a salt bath furnace at the temperature of 180 ℃ for 10 minutes; the salt bath is made of 50 wt.% NaNO3And 50 wt.% KNO3Melting to obtain the product;
and fourthly, immediately putting the roller cooled by the salt bath into a heat treatment heat preservation furnace with the temperature of 350 ℃, preserving the heat for 60 minutes, cooling the furnace to the temperature lower than 100 ℃, taking out of the furnace, cooling the roller to the room temperature by air, and finally finishing the roller to the specified size and precision. The mechanical properties of the rolls are shown in Table 1.
TABLE 1 mechanical Properties of the rolls
The roller contains more niobium and titanium elements, a large amount of composite carbide (Ti, Nb) C is precipitated in situ, the surface of the roller has excellent wear resistance, a comparative wear test is carried out on an MM200 type high-speed ring block wear tester, a friction pair is a GCr15 steel ring (the hardness is 61.4HRC), the normal load is 900N, the sliding speed is 240r/min, the wear duration is 1800s, and the wear resistance is improved by more than 2 times compared with Cr15Mo3 high-chromium cast iron (the hardness is 62HRC) under the same wear condition. The hardness of the surface of the roller is high and is more than 86HSD, the hardness uniformity is good, the hardness difference of the surface of the roller is less than 1.5HSD, the service life of the roller is improved by 260 percent compared with that of a high-chromium cast iron roller when the roller is used at the front section of a hot-rolled strip steel finishing mill, and the service life of the roller is improved by 330 percent compared with that of a high-nickel-chromium infinite chilled cast iron roller when the roller is used at the rear. The invention has safe and reliable use of the roller, has no roller breaking and slipping during the use of the roller, can be used for the front section and the rear section of a hot-rolled strip steel finishing mill, has strong universality, can improve the operation rate of the mill, lightens the labor intensity of workers, and has good economic and social benefits when being popularized and used.
Claims (2)
1. The preparation method of the in-situ composite carbide particle reinforced wear-resistant roller is characterized by comprising the following specific preparation process steps:
firstly, smelting molten iron containing niobium, chromium, cobalt, manganese and nickel in a medium-frequency induction furnace, and controlling the chemical composition and the mass fraction of the molten iron in the furnace to be 3.44-3.78% of C, 4.51-4.86% of Mn, 2.55-2.79% of Co, 12.06-12.39% of Cr, 2.74-2.90% of Nb, 0.77-0.95% of Si, 1.03-1.27% of Al, 3.07-3.38% of Ni, less than 0.030% of S, less than 0.035% of P and the balance of Fe; heating the molten iron to 1558-1575 ℃, then adding FeTi70 accounting for 9-10% of the mass fraction of the molten iron in the furnace, baking FeTi70 at 650-700 ℃ for 2.5-3.0 hours before the molten iron is put into the furnace, and enabling the particle size of FeTi70 to be 15-22 mm; after FeTi70 is completely melted, preserving heat for 4-6 minutes, and then discharging molten iron to a ladle;
after slagging off and standing, pouring molten iron in the casting ladle into a casting mold when the temperature is reduced to 1447-; the adding amount of the silicon-calcium-barium alloy accounts for 0.75-0.90 percent of the mass fraction of the molten iron entering the casting mold; after the molten iron is completely solidified, opening the box, taking out the roller blank, and performing rough machining after sand removal and polishing;
heating the rough-machined roller to 1015 ℃ along with the furnace, preserving the heat for 2.0-2.5 hours, and then cooling the roller for 10-12 minutes in a 195 ℃ salt bath furnace at 180-; the salt bath is made of 50 wt.% NaNO3And 50 wt.% KNO3Melting to obtain the product;
fourthly, the roller cooled by the salt bath is immediately placed into a heat treatment heat preservation furnace with the temperature of 350-;
the chemical composition and the mass fraction of the FeTi70 are 70.36-70.95% of Ti, 0.97-2.82% of A1, < 0.5% of Si and the balance of Fe;
the silicon-calcium-barium alloy comprises, by mass, 42.38-43.05% of Si, 11.26-11.53% of Ca, 10.62-10.97% of Ba, less than or equal to 0.8% of C, less than or equal to 0.04% of P, less than or equal to 0.06% of S and the balance of Fe.
2. The in-situ composite carbide particle reinforced wear-resistant roller prepared according to the method of claim 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010715194.9A CN111809105B (en) | 2020-07-22 | 2020-07-22 | In-situ composite carbide particle reinforced wear-resistant roller and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010715194.9A CN111809105B (en) | 2020-07-22 | 2020-07-22 | In-situ composite carbide particle reinforced wear-resistant roller and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111809105A CN111809105A (en) | 2020-10-23 |
| CN111809105B true CN111809105B (en) | 2021-06-25 |
Family
ID=72862351
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010715194.9A Active CN111809105B (en) | 2020-07-22 | 2020-07-22 | In-situ composite carbide particle reinforced wear-resistant roller and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111809105B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006257507A (en) * | 2005-03-17 | 2006-09-28 | Hitachi Metals Ltd | Alloy for nonferrous molten metal |
| JP2006291286A (en) * | 2005-04-11 | 2006-10-26 | Hitachi Metals Ltd | Erosion-resistant member for nonferrous molten metal |
| JP2006291285A (en) * | 2005-04-11 | 2006-10-26 | Hitachi Metals Ltd | Erosion-resistant member for nonferrous molten metal |
| CN103624084A (en) * | 2013-11-20 | 2014-03-12 | 枣庄瑞兴机械制造有限公司 | Resource-saving type high-boron high-speed steel composite roll and manufacturing method thereof |
| CN104593663A (en) * | 2015-01-26 | 2015-05-06 | 郑州航空工业管理学院 | Wear-resisting white cast iron and preparation method thereof |
| CN105364029A (en) * | 2015-12-08 | 2016-03-02 | 北京工业大学 | Thick-wall steel casting solidification structure refining and purifying method |
| CN106834888A (en) * | 2017-02-09 | 2017-06-13 | 北京工业大学 | A kind of high-strength abrasion-proof cast steel lining board and preparation method thereof |
| CN107034411A (en) * | 2017-03-23 | 2017-08-11 | 北京工业大学 | A kind of abrasion-resistant roller and preparation method thereof |
| CN108660361A (en) * | 2018-05-31 | 2018-10-16 | 安徽环渤湾高速钢轧辊有限公司 | Hot rolled seamless steel tube high speed steel roll collar and preparation method thereof |
| CN109482654A (en) * | 2018-11-23 | 2019-03-19 | 枣庄瑞兴机械制造有限公司 | For Kocks milling train composite ring and its manufacturing method |
-
2020
- 2020-07-22 CN CN202010715194.9A patent/CN111809105B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006257507A (en) * | 2005-03-17 | 2006-09-28 | Hitachi Metals Ltd | Alloy for nonferrous molten metal |
| JP2006291286A (en) * | 2005-04-11 | 2006-10-26 | Hitachi Metals Ltd | Erosion-resistant member for nonferrous molten metal |
| JP2006291285A (en) * | 2005-04-11 | 2006-10-26 | Hitachi Metals Ltd | Erosion-resistant member for nonferrous molten metal |
| CN103624084A (en) * | 2013-11-20 | 2014-03-12 | 枣庄瑞兴机械制造有限公司 | Resource-saving type high-boron high-speed steel composite roll and manufacturing method thereof |
| CN104593663A (en) * | 2015-01-26 | 2015-05-06 | 郑州航空工业管理学院 | Wear-resisting white cast iron and preparation method thereof |
| CN105364029A (en) * | 2015-12-08 | 2016-03-02 | 北京工业大学 | Thick-wall steel casting solidification structure refining and purifying method |
| CN106834888A (en) * | 2017-02-09 | 2017-06-13 | 北京工业大学 | A kind of high-strength abrasion-proof cast steel lining board and preparation method thereof |
| CN107034411A (en) * | 2017-03-23 | 2017-08-11 | 北京工业大学 | A kind of abrasion-resistant roller and preparation method thereof |
| CN108660361A (en) * | 2018-05-31 | 2018-10-16 | 安徽环渤湾高速钢轧辊有限公司 | Hot rolled seamless steel tube high speed steel roll collar and preparation method thereof |
| CN109482654A (en) * | 2018-11-23 | 2019-03-19 | 枣庄瑞兴机械制造有限公司 | For Kocks milling train composite ring and its manufacturing method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111809105A (en) | 2020-10-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100369681C (en) | Compound high speed steel roll and its making process | |
| CN103624084B (en) | Resource-saving type high-boron high-speed steel composite roll and manufacturing method thereof | |
| CN106756448B (en) | Junked-auto components, iron filings recycle production High-Strength Low-Alloy brake drum | |
| CN100574910C (en) | Centrifugal casting half steel/steel/graphite steel composite roll collar and preparation method thereof | |
| CN100532619C (en) | High-boron low-carbon abrasion resistant cast steel and heat treatment method thereof | |
| CN102107215B (en) | Resource-saving boron-containing high-speed steel composite roll and preparation method thereof | |
| CN101407891B (en) | Boron-containing semi-high speed steel cold roller and manufacturing method thereof | |
| CN105750529A (en) | High-tungsten high-abrasion-resistant high-speed steel composite roller and preparation method thereof | |
| CN111945053B (en) | Method for preparing high-speed steel roller by composite modification treatment | |
| CN110000362B (en) | High-tungsten-vanadium high-speed steel wear-resistant roller and manufacturing method thereof | |
| CN102990031B (en) | Centrifugal compound casting method of high-boron high-speed steel roller | |
| CN110184548B (en) | Method for refining solidification structure of high manganese steel continuous casting billet | |
| CN1803339A (en) | Low crack type high speed steel roll and its centrifugal casting method | |
| CN102676946B (en) | Segmented hardness low-alloy steel hammer head and manufacturing method thereof | |
| CN101857941B (en) | Manufacturing method of medium-carbon alloy cast steel shots | |
| CN106544596B (en) | A kind of aluminium alloying high-boron high-speed steel composite roller and preparation method thereof | |
| CN114959431A (en) | Large-scale semi-autogenous mill lining plate and manufacturing method thereof | |
| CN104593663B (en) | A kind of wear-resistant white cast iron and preparation method thereof | |
| CN111001792B (en) | High-nickel high-chromium steel roller and preparation method thereof | |
| CN111809105B (en) | In-situ composite carbide particle reinforced wear-resistant roller and preparation method thereof | |
| CN114059059B (en) | High-boron high-speed steel composite roller and preparation method thereof | |
| CN106521294B (en) | A kind of preparation method of Si-Mn alloyings abrasion resistant cast steel | |
| CN111218540A (en) | High-boron iron-based wear-resistant alloy, preparation method and part thereof | |
| CN105908065B (en) | A kind of VCpManganese wear resistant alloy material, preparation method and wear-resisting spare part in enhancing | |
| CN111996436B (en) | Bucket tooth of large excavator and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20220818 Address after: South side of Dalian Road, Zhangfan Street, High-tech Zone, Zaozhuang City, Shandong Province, 277300 Patentee after: ZAOZHUANG XUECHENG RUIXING MACHINERY MANUFACTURE CO.,LTD. Address before: No. 606, private industrial park, Zhangfan sub district office, high tech Zone, Zaozhuang City, Shandong Province, 277300 Patentee before: Zaozhuang Guangyan Industrial Technology Co.,Ltd. |
|
| TR01 | Transfer of patent right |