CN110195186A - A kind of special thick hot rolling high-alloy hot work mould steel and preparation method thereof - Google Patents

A kind of special thick hot rolling high-alloy hot work mould steel and preparation method thereof Download PDF

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CN110195186A
CN110195186A CN201910398547.4A CN201910398547A CN110195186A CN 110195186 A CN110195186 A CN 110195186A CN 201910398547 A CN201910398547 A CN 201910398547A CN 110195186 A CN110195186 A CN 110195186A
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steel
temperature
controlled
continuous casting
control
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CN110195186B (en
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赵坦
冯丹竹
范刘群
隋轶
尤晓明
李云
李广龙
***
金耀辉
石峰涛
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Angang Steel Co Ltd
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/18—Hardening; Quenching with or without subsequent tempering
    • 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
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Steel (AREA)

Abstract

The present invention provides a kind of special thick hot rolling high-alloy hot work mould steel and preparation method thereof, the ingredient of the mould steel is as follows by weight percentage: C:0.24%~0.30%, Si:0.36%~0.40%, P :≤0.010%, S :≤0.005%, Mn:0.45%~0.55%, Cr:0.90%~1.20%, Ni:0.55%~0.95%, Cu:0.50%~1.00%, W:0.30%~0.50%, Als:0.015%~0.030%, B:0.0005%~0.0035%, remaining is Fe and inevitable impurity.Preparation method includes that smelting-sheet slab continuous casting-blank pretreatment-vacuum assembly-weld seam partial modification-reheating-is high to module rolling-module post-processing-heat treatment；There is high polishing degree, high internal soundness, high equal orientation performance using hot die steel produced by the invention.

Description

A kind of special thick hot rolling high-alloy hot work mould steel and preparation method thereof
Technical field
The invention belongs to metal material production technical fields, more particularly to plant special thick hot rolling high-alloy hot work mould steel Preparation method.
Background technique
The trend in mold manufacturing industry future is will to develop to large size, precision, long-life, high efficiency direction, develops more tools There are excellent properties, the novel production model and mould steel of more efficient, more green short route become following important tackling key problem side To.
Die industry is referred to as the mother of manufacturing industry, it may be said that quality and technology of the promotion of manufacturing industry level with mould steel It reforms closely bound up.Countries in the world mainly use three kinds of modes to improve the quality of mould steel, first is that by optimization mould steel at Divide and develop new steel grade, second is that the production procedure and optimization technique technology of mould steel are improved, third is that being directed to the dress of special-purpose Standby technological transformation and comprehensive utilization.Such as, application number 201611205030.1 applies for a patent the " system of high-alloy hot work mould steel Standby technique ", application number 201710203441.5 apply for a patent " a kind of manufacturing process of hot-work die steel forgings " etc..
Domestic and international precision die mainly carries out forging method production using large-scale ingot casting, ESR ingot with steel product at present, Such as the patent " a kind of high tenacity, the production method of the big section hot die steel of high tropism " of application number 201510689315.6, It using the steel ingot twice homogenization after electroslag remelting, forges twice, for eliminating Aliquation carbide and dendritic segregation in steel billet Generated banded structure, complex process, energy consumption are high.A kind of patent " Forming Die of application number 201610459770.1 Tool steel plate and preparation method thereof " propose using static ingot-rolling a solution, but from production form and Aspect of performance do not find out the intrinsic segregation tissue of the material that rolling mill practice determines molding mode, come into being it is facies-controlled effectively Means are only simplified in process, and are equally designed using the high cost ingredients of high Mo.Further, since steel The solidification mode of ingot, the defects of solidification end often generates a large amount of shrinkage cavity, segregation, solidification end generates a large amount of total Brilliant low melting point and impurity product, and large-scale ingot mould defect is difficult to control, and has pole further for homogenizing to tissue For the mould product of high request, the defect distribution of static ingot once showed V-type distribution, this is inclined with the center of continuous casting billet regularity Analysis is different, is difficult to carry out regular type control.Metallargist uses different riser form and forging method, often can only The degree and erratic behavior trend for mitigating this segregation, cannot be inherently eliminated.On the other hand the life of riser feeding is used Production mode itself determines that the lumber recovery of blank can only be 80% hereinafter, bringing huge material loss.Therefore it is sent out from material From the aspect of exhibition and effective use two, the blank and mould steel production technology of Development of Novel become necessary.
A kind of production method of special thick carbon mold steel plate of the patent of application number 201510789402.9, uses more Pure, the stronger continuous casting material of organization rule, this method are used to produce 45#, 50# steel of carbon content 0.4-0.5% or so, It is unable to satisfy the assembly of high alloy product.A kind of 150-400mm Steel for Plastic Die of the patent of application number 201210264180.5 The production method of plate, describes a kind of compound assembly, the technology of a variety of welding method Combination Weldings, complex procedures, but still It is unable to satisfy the mould steel assembly of more high-carbon more high alloy.
Carbon alloy mold steel plate in a kind of thick high flaw detection requirement of 200-350mm of the patent of application number 201711079372.8 And its manufacturing method, it is provided with using compound assembly but not combination process, and manufacturing method is the same as 201210264180.5 phases Seemingly, it is only applicable to the medium carbon alloy steel, and the heated compounded method used, easily causes billet oxidization, this is for wanting It is unfavorable for asking for the mould product of high homogenieity.
Furthermore above-mentioned several patents require the flaw detection matter that preferred blank improves product plus the mode for increasing compression ratio Amount, but on the one hand this method is not easy to implement for continuous production, because for compound blank often substance It is larger, and it is multifarious for different continuous casting stage continuous casting billet internal soundnesses, furthermore using the steel of the above compression ratio production of three times Plate, it is horizontal that flaw detection is only capable of reaching φ 3mm, this be for accurate mould it is far from being enough, be simply possible to use in general mould bases plus Work, and risk the defects of there are sand holes.In addition, there is no solution using complex technique for the material for thering is high tropism to require Scheme.
A kind of continuous casting steel billet forging high-quality plastic mould steel forgings of the patent of application number 201711299296.1 Method carries out the production method of the special thick mould steel of plastics by the way of the forging of 400mm continuous casting billet, but for more high alloy Precision die steel continuous casting-production, and with high equal orientation performance continuous casting billet production lack solution.
To sum up, develop in face of the precision die steel of enlargement, prior art cost is high, can be solved using continuous casting process The certainly above problem, but the characteristics of due to material high-carbon high-alloy, limit the development of sheet slab.Furthermore domestic and international mould steel The problems such as generally existing high cost, long process, complex process, and influenced by original solidified structures such as molding materials, reliable performance Property, stability are bad, and existing complex technique there is no very good solution means for high-carbon high-alloy material, furthermore existing Composite die internal soundness is only capable of reaching φ 3mm level, and the requirement away from precision die differs greatly, and raw for composite blank The special think gauge high alloy product of production, there is no the high technical solution to material at present.
Summary of the invention
The thick hot rolling of spy of a kind of process, efficient green is provided it is an object of the invention to overcome the above problem and deficiency High-alloy hot work mould steel and preparation method thereof has high polishing degree, high internal matter using hot die steel produced by the invention Amount, high equal orientation performance.
What the object of the invention was realized in:
A kind of special thick hot rolling high-alloy hot work mould steel, the ingredient of the mould steel are as follows by weight percentage: C: 0.24%~0.30%, Si:0.36%~0.40%, P :≤0.010%, S :≤0.005%, Mn:0.45%~0.55%, Cr:0.90%~1.20%, Ni:0.55%~0.95%, Cu:0.50%~1.00%, W:0.30%~0.50%, Als: 0.015%~0.030%, B:0.0005%~0.0035%, remaining is Fe and inevitable impurity.
The steel plate of die steel finished product thickness is 200-610mm.
The WC of rich Cu nanometers of phases and 10-80nm inside the steel plate of die steel containing 20-60nm.
C: the carbon content in hot die steel is the main element for determining its hardness, and C is most economical to a certain extent Alloy element.Carbon content is too low, will be unfavorable for the acquisition of martensitic structure, and the hardness of steel will not be able to guarantee, carbon content When excessively high, carbide inhomogeneities can be made to increase, the structural state after seriously affecting its toughness and annealing.Present invention selection It is 0.24%~0.30% that carbon content, which is added,.
Si: excessively high Si adversely affect not only for the segregation (banded structure etc.) in hot die steel (cause etc. to The decline of performance), also there is harmful effect further for continuous casting process autstenitic grain size and easily generates coarse column Crystal grain leads to the generation of surface billet surface and underbead crack, this is unfavorable for continuously casting.Comprehensively consider this hair Bright control Si is in 0.36%-0.40%.
Mn: it for the effect of solution strengthening and stable austenite, selects that Mn content is added to be 0.45%~0.55%.
Cr: chromium can increase the harden ability of steel, improve temper resistance, and generate post-curing phenomenon；Chromium be in strong carbon Compound formation element can form carbide with carbon in steel, also dissolve in solid solution and Fe3In C, chromium is to the wear-resistant of steel Property, elevated temperature strength, hot hardness, toughness have a favorable influence, the present invention select to be added Cr content for 0.90%~ 1.20%.
Cu: the toughness for helping to promote steel is precipitated in the nanometer of micro Cu of the present invention, and addition content is 0.50-1.00%.
P, S: excessively will affect the homogenieity and degree of purity of steel, but consider production cost, and present invention selection addition P≤ 0.015%, S≤0.015%.
Whole harden ability can be improved in the addition of B:B, controls 0.0005%~0.0035%.
The High-Temperature Strengthening effect of W:W is obvious, under alloy system of the present invention, with M2The form of C exists, relative to M6C、 M7C3、M23C6Etc. forms alloy utilization rate it is higher, it is more efficient for the formation of carbide.Alloy carbon in hot work tool steel Compound structure, stability are related with the electron deficiency degree of corresponding alloying element d electron shell and S electron shell.With The decline of electron deficiency degree, metallic atomic radius reduces therewith, the atomic radius of carbon and metallic element is than increase, alloy gap The trend of mutually oriented alloy interstitial compound conversion, and corresponding carbide stability weakens, and dissolves in corresponding austenite Temperature reduces, corresponding lowered hardness.W2C with having stronger secondary precipitation effect in relatively wide process window, This is not only the usual range of such hot-work steel hardening and tempering process window, and such as traditional steel grade of the far excellent traditional material of the temperature window Common use environment temperature.For above-mentioned consideration and discovery, the present invention selects that W content is added are as follows: 0.30%-0.55%.
Als: the content of dissolved aluminum is controlled in 0.015%-0.030% in steel in the present invention, is on the one hand used as smelting process Deoxidation core element is added, and on the other hand plays the role of high-temperature control autstenitic grain size.
Ni: for controlling Cu bring continuous casting process crackle tendency, and improving the whole harden ability of steel, and control exists 0.55%-0.95%
The steel plate of die steel finished product thickness is 200-610mm.
A kind of preparation method of special thick hot rolling high-alloy hot work mould steel, including smelting-sheet slab continuous casting-blank are located in advance Reason-vacuum assembly-weld seam partial modification-reheating-is high to module rolling-module post-processing-heat treatment；
(1) sheet slab continuous casting:
The low overheat casting that continuous casting uses, the low overheat are 10-15 DEG C；Continuous casting billet by the way of weak cold into Row production, the control of weak cold cooling rate are not more than 1min in 5-15 DEG C/s, duration, and cold control temperature range exists weak cold eventually 700-900 DEG C, the slab pressure is divided into two sections of front and back, and the control of leading portion drafts exists in 3-8mm, the control of back segment drafts 1-5mm；
To guarantee that continuous casting billet is drawn successfully, and good continuous casting billet quality is obtained, the generous long-pending X (m of sheet slab specification2) need Meet 0.20≤X≤0.38, slab thickness H is controlled in 100mm≤H≤400mm, and sheet slab width W control range exists 1200mm≤W≤2000mm。
(2) continuous casting billet pre-processes: the continuous casting material is offline to be pre-processed, and the steel billet must not be to temperature, must be in steel 600 DEG C of base temperature or more are pre-processed, and 850-1000 DEG C of pretreatment temperature, 50-120 DEG C of heating rate/h, blank is kept the temperature only Time is 2.5-3.5min/mm, makes full use of and match billet residual heat and red temperature, guarantees that billet surface to inside occurs The W of 100-220nm2C carbide tissue and 80-120nm rich nanometer Cu phase, 5-10 μm of average headway.
(3) vacuum assembly:
It is produced using 400-1500mm composite billet, is prepared using multilayered structure；
2 layers of composite blank asymmetrical design, H are used for finished product thickness 200-410mm steel plate of die steelIt is thick/HIt is thin>=2, Middle HIt is thickFor thick sotck thinkness, HIt is thinFor thin sotck thinkness；Steel billet can effectively be solved due to biting impact, operation of rolling upper and lower surface Blank deformation unevenness problem above and below caused by the temperature difference is big, and weak compound interface can be shifted near surface position, so that deformation Compound interface just can be more effectively transmitted at rolling initial stage.For finished product thickness 410-610mm steel plate of die steel use > 2 layer Composite blank；
The mould steel mother base controls in 2.2 >=L/W >=1.2 longer side and a shorter side ratio；L is throwing direction length, mm；
Continuous casting billet welding surface and contact surface are subjected to milling, guarantee the control of compound interface surface roughness in Ra=10-20 μm；Prepare to weld into vacuum chamber；Welding procedure is weldingvoltage 20-100kV, welding current 400-1000mA, Speed of welding 300-500mm/min, fusion penetration 60-100mm；
The welding sequence is successively to carry out spot welding, sequential welding.The spot welding and sequential welding should be true at 350-500 DEG C It is carried out under dummy status, guarantees that hot gas does not influence seam organization and performance.
Welding for multiple groups base, is then carried out by the way of " first outside and then inside " using carrying out by the way of " first long after short ", Specific step is as follows
1. carrying out equidistant 3-5 point spot welding along a long side (being denoted as the side B1) according to charge length；Edge (is denoted as edge-to-edge The side B2) carry out equidistant 3-5 point spot welding；
2. carrying out equidistant 3-5 point spot welding along a short side (being denoted as the side C1)；Carried out along another short side (being denoted as the side C2) etc. Away from 3-5 point spot welding.
3. being intermittently welded along the side B1 according to length 200-400mm, the direction being intermittently welded every time is the same as overall welding direction phase Instead；Along carrying out discontinuous welding in the way of B2 is while by B1；
4. short side repeats the sequence of above-mentioned 1-3 and mode is welded, wherein the last item side can once weld completion.
(4) weld seam partial modification: cannot directly be carried out hot-working after the steel billet welding, be heated using quick electromagnetic, right Seam organization is carried out carrying out weld seam partial modification processing, modified depth 30-120mm, and 200-400 DEG C of temperature, when modified Between method 1-1.5min/cm3.Steel billet can be placed to be rolled for a long time after baking, and the whole cracking resistance of steel billet both can be improved Property, improve the equal orientation performance of welding position, while also meeting the needs of continuous production.
(5) reheat: total heating was divided into for three stages, and soaking time controlled within 10-25 hours.First stage: first For the control of bringing-up section temperature at 600-700 DEG C, soaking time 4-8h, the second bringing-up section temperature controls the heating at 1100-1200 DEG C Rate >=150 DEG C/h, to warm soaking time 2-6h, the control of third bringing-up section temperature is at 1230-1290 DEG C, soaking time 8- 12h reduces nearly 100% compared with traditional heating.Heating cycle effect has three, reduces the crack sensitivity and gradually of composite blank Subtract the thermal stress in lower thickness x cross sectional direction, reduce segregation tissue the heredity of subsequent material integrative organization performance is influenced and As-cast structure is pre-processed, is that hot-working and the disperse of annealing process tissue are analysed to reach ideal initial tissu state It lays the foundation out.
(6) high to roll to module: control roller speed 8-15 turns/min.Control open rolling billet surface temperature is 1200-1220 DEG C, first reduction in pass should be greater than 100mm, guarantee that each mating surface once combines.Overall process be averaged reduction in pass control exist 30mm or more, it is therefore an objective to utilize the big pressure of high temperature, promote material sufficiently to recrystallize, refine austenite grain sufficiently, and after being Continuous organizational controls lays the foundation.Modular surface carries out surface layer hardening by cooling, cooling rate by the way of water cooling after first passes ≥20℃/s.Module surface temperature >=950 DEG C after the hardening by cooling of surface layer；Finishing temperature control is at 870-930 DEG C.
Produced simultaneously using the method for large scale boradside rolling in the operation of rolling, be rolled down to target distortion rate and Before goal standard, deformed using horizontal-vertical tandem rolling mode；Throwing Direction distortion rate Kl: 65%-170%, width Direction distortion rate Kw: 40%-90%, comprehensive deformation rate K:1.4-3.9；K=KL/Kw, Kw: the deformation of composite blank width direction Rate, %； KL: composite blank length direction deformation rate, %；
After rolling, cooling control, 2.5 >=time upper water ratio >=1.5 are carried out into DQ cooling device.Cooling rate control In 5-10 DEG C/s, final cooling temperature is controlled at 400-500 DEG C system, too fast to be easy to cause localized cracks, is unfavorable for tissue control slowly excessively System.Material red temperature is utilized after air-cooled, it is comprehensive to reach refinement crystal grain, the hardness gradient of surface and center portion is reduced, analysis is promoted Out, so improve mould steel composite billet comprehensive performance.
φ 1- φ 2mm can achieve using the clad steel plate flaw detection of the rolling technique production.
(7) module post-processes: it is kept the temperature immediately after after Modular surface temperature returns red to 500-600 DEG C, soaking time >= 24h；
Steel plate stacking is post-processed using the technique that " upper cover lower berth " can be used, 500-600 DEG C of bedding steel billet temperature, Bedding steel plate thickness should be 3 times of clad steel plate or more, i.e. thickness proportion are as follows: HPaving, lid≥3×HIt is compound。
(8) it is heat-treated: tempering+quenching+tempering；
The tempering: module carries out tempering after module post-processing, and charging temperature should be controlled at 200-400 DEG C.It returns Fiery temperature control enters furnace steel plate needs and is quickly raised to target temperature, heating rate should be controlled in 1-2min/mm at 850-910 DEG C Within the scope of, it is air-cooled to be cooled to 650-700 DEG C or less stacking of coming out of the stove by net soaking time 6-10min/mm.
The quenching: hardening heat is controlled in 1000-1120 ± 10 DEG C, and heating rate should be controlled in 1.5-2.5min/mm Within the scope of, soaking time 3-6min/mm,
The tempering: being tempered immediately after quenching, and tempering charging temperature answers >=250 DEG C, and tempering temperature control exists 610-750 keeps the temperature 2-4h, the rich nanometer Cu phase of 20-60nm and the WC of 10-80nm is precipitated inside steel plate.
Further, in the step (2), after blank pre-processes, away from there is 100- within the scope of the 50mm of surface inside steel plate The carbide tissue of 220nm and the rich Cu nanometers of phases of 20-80nm, the carbide W2C。
Further, in the step (3), composite blank is continuous casting billet or electroslag base, and the electroslag blank uses above-mentioned company Slab does electrode and is prepared.
The blank is intercepted on continuous casting material using cold working mode, length of the width as composite blank, long The width as composite blank is spent, the electroslag blank does electrode using above-mentioned continuous casting billet and is prepared.
Further, in the step (3), the finish-milling be to steel billet welding surface and contact surface carries out milling and slightly After milling goes out fresh metal, it is still to continue milling 1-2mm.
The beneficial effects of the present invention are:
(1) preparation method of special thick hot rolling high-alloy hot work mould steel provided by the invention is large-scale in face of manufacturing industry, smart Close, long-life, high efficiency direction are developed.
(2) special thick high alloy die steel short route, greenization, efficiently production are solved the problems, such as；
(3) it solves under high alloy die steel traditional mode of production mode, high temperature heating time is greatly reduced to 30h hereinafter, not It is only greatly reduced production cost, improves production efficiency, and solve the skin decarburization under the conditions of long-time at elevated temperature and ask Topic；
(4) assemblies such as material at high temperature drag is larger, interface binding power is bad are solved the problems, such as；
(5) present invention provides a kind of Novel control milling method, passes through blank pre-treatment-assembly-controlled rolling-cooling- Post-processing-heat treatment process composite design realizes the tropisms such as material high three-dimensional, high polishing degree, high internal soundness and Gao Jun Matter.Product properties are excellent, reach electroslag Product Level, great popularization.
Specific embodiment
Below by embodiment, the present invention is further illustrated.
The embodiment of the present invention carries out smelting-sheet slab continuous casting-blank pretreatment-very according to the component proportion of technical solution Empty assembly-weld seam partial modification-reheating-is high to module rolling-module post-processing-heat treatment；
(1) sheet slab continuous casting: the low overheat casting that continuous casting uses, the low overheat are 10-15 DEG C；
Continuous casting billet is produced by the way of weak cold, and weak cold cooling rate is controlled in 5-15 DEG C/s, and the duration is little In 1min, weak cold eventually cold control temperature range at 700-900 DEG C；
The slab pressure is divided into two sections of front and back, and the control of leading portion drafts is controlled in 3-8mm, back segment drafts in 1- 5mm；
Sheet slab thickness H control in 100mm≤H≤400mm, sheet slab width W control range 1200mm≤W≤ 2000mm；The generous long-pending X of sheet slab specification needs to meet 0.200m2≤X≤0.38m2；
(2) continuous casting billet pre-processes: being pre-processed at 600 DEG C or more, 850-1000 DEG C of pretreatment temperature, heating rate 50-120 DEG C/h, the net soaking time of blank is 2.5-3.5min/mm, guarantees that billet surface to inside occurs 100-220nm's W2C carbide tissue and Cu nanometers of phases of richness, 5-10 μm of average headway；
(3) vacuum assembly:
It is produced using 400-1500mm composite billet, is prepared using multilayered structure；
2 layers of composite blank asymmetrical design, H are used for finished product thickness 200-410mm steel plate of die steelIt is thick/HIt is thin>=2, Middle HIt is thickFor thick sotck thinkness, HIt is thinFor thin sotck thinkness；It is compound for finished product thickness 410-610mm steel plate of die steel use > 2 layer Blank；
Sheet slab 2.2 >=L/W >=1.2；L is throwing direction length, mm；
Continuous casting billet welding surface and contact surface are subjected to milling, guarantee the control of compound interface surface roughness in Ra=10-20 μm；Prepare to weld into vacuum chamber；Welding procedure is weldingvoltage 20-100kV, welding current 400-1000mA, Speed of welding 300-500mm/min, fusion penetration 60-100mm；
(4) weld seam partial modification: the composite billet after welding is heated using quick electromagnetic, carries out seam organization to weld seam Progress partial modification processing, modified depth 30-120mm, 200-400 DEG C of temperature, modification time method 1-1.5min/cm3；
(5) reheat: total heating was divided into for three stages, and soaking time was controlled at 10-25 hours；First stage: the first heating At 600-700 DEG C, soaking time 4-8h, the second bringing-up section surface of steel plate temperature is controlled in 1100- the control of section surface of steel plate temperature 1200 DEG C, heating rate >=150 DEG C/h, to warm soaking time 2-6h, third bringing-up section surface of steel plate temperature is controlled in 1230- 1290 DEG C, soaking time 8-12h；
(6) high to roll to module: control roller speed 8-15 turns/min；Controlling start rolling temperature is 1200-1220 DEG C, first road Secondary drafts should be greater than 100mm, and Modular surface carries out surface layer hardening by cooling, cooling rate >=20 DEG C/s after first passes；Surface layer is cold But module surface temperature >=950 DEG C after hardening；Finishing temperature control average reduction in pass in 870-930 DEG C, the operation of rolling Control is in 30mm or more；
Produced simultaneously using the method for large scale boradside rolling in the operation of rolling, be rolled down to target distortion rate and Before goal standard, deformed using horizontal-vertical tandem rolling mode；Throwing Direction distortion rate Kl: 65%-170%, width Direction distortion rate Kw: 40%-90%, comprehensive deformation rate K:1.4-3.9；K=KL/Kw, Kw: the deformation of composite blank width direction Rate, %； KL: composite blank length direction deformation rate, %；
Roller repairing, cooling rate control are controlled in 5-10 DEG C/s, final cooling temperature at 400-500 DEG C；
(7) module post-processes: it is kept the temperature immediately after Modular surface temperature returns red to 500-600 DEG C, soaking time >=for 24 hours；
(8) it is heat-treated: tempering+quenching+tempering；
The tempering: module carries out tempering after module post-processing, and charging temperature should be controlled at 200-400 DEG C, be returned Fiery temperature control enters furnace steel plate needs and is quickly raised to target temperature, heating rate should be controlled in 1-2min/mm at 850-910 DEG C Within the scope of, it is air-cooled to be cooled to 650-700 DEG C or less stacking of coming out of the stove by net soaking time 6-10min/mm；
The quenching: hardening heat is controlled at 1000-1120 DEG C, and heating rate should be controlled in 1.5-2.5min/mm range Within, soaking time 3-6min/mm,
The tempering: being tempered immediately after quenching, and tempering charging temperature answers >=250 DEG C, and tempering temperature control exists 610-750 DEG C, 2-4h is kept the temperature, the rich Cu nanometers of phases of 20-60nm and the WC of 10-80nm are precipitated inside steel plate.
Further, in the step (2), after blank pre-processes, away from there is 100- within the scope of the 50mm of surface inside steel plate The W of 220nm2Cu nanometers of phases of C carbide and 80-120nm richness.
Further, in the step (3), composite blank is continuous casting billet or electroslag base, and the electroslag blank uses above-mentioned company Slab does electrode and is prepared.
Further, in the step (3), the finish-milling is to carry out milling 1- to steel billet welding surface and contact surface 2mm。
The ingredient of steel of the embodiment of the present invention is shown in Table 1.The main casting parameters of steel of the embodiment of the present invention are shown in Table 2.This hair The continuous casting billet pretreating process and organizational controls parameter of bright embodiment steel are shown in Table 3.The assembly technological parameter of steel of the embodiment of the present invention It is shown in Table 4.The steel billet postwelding modification process parameter of steel of the embodiment of the present invention is shown in Table 5.The heating process of steel of the embodiment of the present invention Parameter is shown in Table 6.The rolling technological parameter of steel of the embodiment of the present invention is shown in Table 7.After steel of embodiment of the present invention roller repairing and module Treatment process parameter is shown in Table 8.Heat-Treatment of Steel technique of the embodiment of the present invention is shown in Table 9.Steel Rockwell hardness of the embodiment of the present invention is shown in Table 10.Steel of embodiment of the present invention equal orientation performance and polishing degree are shown in Table 11.
The ingredient of 1 steel of the embodiment of the present invention of table
The main casting parameters of 2 steel of the embodiment of the present invention of table
3 steel continuous casting billet of embodiment of the present invention pretreating process of table and organizational controls parameter
The assembly technological parameter of 4 steel of the embodiment of the present invention of table
The steel billet postwelding modification process parameter of 5 steel of the embodiment of the present invention of table
Embodiment Modified depth (mm) Modification temperature (DEG C) Modification time (min/cm3)
1 35 250 1.1
2 70 220 1.15
3 110 315 1.32
4 80 370 1.25
The heating technique parameter of 6 inventive embodiments steel of table
The rolling technological parameter of 7 steel of the embodiment of the present invention of table
8 steel of embodiment of the present invention roller repairing of table and module aftertreatment technology parameter
9 steel heat treatment process of the embodiment of the present invention of table
10 steel Rockwell hardness of the embodiment of the present invention of table
11 steel of embodiment of the present invention equal orientation performance of table and polishing degree
In order to state the present invention, explanation appropriately and is being sufficiently carried out to the present invention by embodiment among the above, it is above Embodiment is merely to illustrate the present invention, and not limitation of the present invention, those of ordinary skill in related technical field, In the case where not departing from the spirit and scope of the present invention, it can also make a variety of changes and modification, made any modification, etc. With replacement, improvement etc., should all be included in the protection scope of the present invention, scope of patent protection of the invention should be wanted by right Ask restriction.

Claims (7)

1. a kind of special thick hot rolling high-alloy hot work mould steel, which is characterized in that the ingredient of the mould steel is by weight percentage such as Under: C:0.24%~0.30%, Si:0.36%~0.40%, P :≤0.010%, S :≤0.005%, Mn:0.45%~ 0.55%, Cr:0.90%~1.20%, Ni:0.55%~0.95%, Cu:0.50%~1.00%, W:0.30%~ 0.50%, Als:0.015%~0.030%, B:0.0005%~0.0035%, remaining is Fe and inevitable impurity.
2. a kind of special thick hot rolling high-alloy hot work mould steel according to claim 1, which is characterized in that the mould steel steel Board finished product is with a thickness of 200-610mm.
3. a kind of special thick hot rolling high-alloy hot work mould steel according to claim 1, which is characterized in that the mould steel steel Intralamellar part contains the rich Cu nanometers of phases of 20-60nm and the WC of 10-80nm.
4. a kind of preparation method of special thick hot rolling high-alloy hot work mould steel as described in any one of claims 1-3, feature It is, including reheating-is high rolls to module for smelting-sheet slab continuous casting-blank pretreatment-vacuum assembly-weld seam partial modification- System-module post-processing-heat treatment；
(1) sheet slab continuous casting: the low overheat casting that continuous casting uses, the low overheat are 10-15 DEG C；
Continuous casting billet is produced by the way of weak cold, and weak cold cooling rate is controlled in 5-15 DEG C/s, and the duration is not more than 1min, weak cold eventually cold control temperature range at 700-900 DEG C；
The slab pressure is divided into two sections of front and back, and the control of leading portion drafts is controlled in 3-8mm, back segment drafts in 1-5mm；
Sheet slab thickness H is controlled in 100mm≤H≤400mm, and sheet slab width W control range is in 1200mm≤W≤2000mm； The generous long-pending X of sheet slab specification needs to meet 0.200m2≤X≤0.38m2；
(2) continuous casting billet pre-processes: being pre-processed at 600 DEG C or more, 850-1000 DEG C of pretreatment temperature, heating rate 50-120 DEG C/h, the net soaking time of blank is 2.5-3.5min/mm, guarantees that the W of 100-220nm occurs in billet surface to inside2C carbide Tissue and Cu nanometers of phases of richness, 5-10 μm of average headway；
(3) vacuum assembly:
It is produced using 400-1500mm composite billet, is prepared using multilayered structure；
2 layers of composite blank asymmetrical design, H are used for finished product thickness 200-410mm steel plate of die steelIt is thick/HIt is thin>=2, wherein HIt is thick For thick sotck thinkness, HIt is thinFor thin sotck thinkness；For finished product thickness 410-610mm steel plate of die steel use > 2 layer composite blank；
Sheet slab 2.2 >=L/W >=1.2；L is throwing direction length, mm；
Continuous casting billet welding surface and contact surface are subjected to milling, guarantee the control of compound interface surface roughness at Ra=10-20 μm；Into Enter vacuum chamber and prepares welding；Welding procedure is weldingvoltage 20-100kV, welding current 400-1000mA, welding speed Spend 300-500mm/min, fusion penetration 60-100mm；
(4) weld seam partial modification: the composite billet after welding is heated using quick electromagnetic, carries out seam organization to weld seam carry out office Portion's modification, modified depth 30-120mm, 200-400 DEG C of temperature, modification time method 1-1.5min/cm3；
(5) reheat: total heating was divided into for three stages, and soaking time was controlled at 10-25 hours；First stage: the first bringing-up section steel At 600-700 DEG C, soaking time 4-8h, the second bringing-up section surface of steel plate temperature is controlled in 1100-1200 the control of plate surface temperature DEG C, heating rate >=150 DEG C/h, to warm soaking time 2-6h, third bringing-up section surface of steel plate temperature is controlled in 1230-1290 DEG C, soaking time 8-12h；
(6) high to roll to module: control roller speed 8-15 turns/min；Controlling start rolling temperature is 1200-1220 DEG C, first passage pressure Amount should be greater than 100mm, and Modular surface carries out surface layer hardening by cooling, cooling rate >=20 DEG C/s after first passes；Surface layer hardening by cooling Module surface temperature >=950 DEG C afterwards；Finishing temperature control average reduction in pass control in 870-930 DEG C, the operation of rolling exists 30mm or more；
It is produced in the operation of rolling using the method for large scale boradside rolling simultaneously, is being rolled down to target distortion rate and target rule Before lattice, deformed using horizontal-vertical tandem rolling mode；Throwing Direction distortion rate Kl: 65%-170%, width direction deformation Rate Kw: 40%-90%, comprehensive deformation rate K:1.4-3.9；K=KL/Kw, Kw: composite blank width direction deformation rate, %；KL: it is multiple Close charge length Direction distortion rate, %；
Roller repairing, cooling rate control are controlled in 5-10 DEG C/s, final cooling temperature at 400-500 DEG C；
(7) module post-processes: it is kept the temperature immediately after Modular surface temperature returns red to 500-600 DEG C, soaking time >=for 24 hours；
(8) it is heat-treated: tempering+quenching+tempering；
The tempering: module carries out tempering after module post-processing, and charging temperature should be controlled at 200-400 DEG C, tempering temperature Degree control enters furnace steel plate needs and is quickly raised to target temperature, heating rate should be controlled in 1-2min/mm range at 850-910 DEG C Within, it is air-cooled to be cooled to 650-700 DEG C or less stacking of coming out of the stove by net soaking time 6-10min/mm；
The quenching: hardening heat is controlled at 1000-1120 DEG C, and heating rate should control within the scope of 1.5-2.5min/mm, Soaking time 3-6min/mm,
The tempering: being tempered immediately after quenching, and tempering charging temperature answers >=250 DEG C, and tempering temperature is controlled in 610-750 DEG C, 2-4h is kept the temperature, the rich Cu nanometers of phases of 20-60nm and the WC of 10-80nm are precipitated inside steel plate.
5. a kind of preparation method of special thick hot rolling high-alloy hot work mould steel according to claim 4, which is characterized in that institute It states in step (2), after blank pre-processes, away from there is the W of 100-220nm within the scope of the 50mm of surface inside steel plate2C carbide and Cu nanometers of phases of 80-120nm richness.
6. a kind of preparation method of special thick hot rolling high-alloy hot work mould steel according to claim 4, which is characterized in that institute State in step (3), composite blank be continuous casting billet or electroslag base, the electroslag blank using above-mentioned continuous casting billet do electrode preparation and At.
7. a kind of preparation method of special thick hot rolling high-alloy hot work mould steel according to claim 4, which is characterized in that institute It states in step (3), the finish-milling is to carry out milling 1-2mm to steel billet welding surface and contact surface.
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CN111876662A (en) * 2020-06-18 2020-11-03 江阴兴澄特种钢铁有限公司 Hot-work die steel plate and manufacturing method thereof
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