CN110846557B - High-carbon chromium grinding ball steel and preparation method thereof - Google Patents

High-carbon chromium grinding ball steel and preparation method thereof Download PDF

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CN110846557B
CN110846557B CN201911233178.XA CN201911233178A CN110846557B CN 110846557 B CN110846557 B CN 110846557B CN 201911233178 A CN201911233178 A CN 201911233178A CN 110846557 B CN110846557 B CN 110846557B
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grinding ball
steel
carbon chromium
equal
chromium grinding
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CN110846557A (en
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冯杰斌
胡昭锋
张正波
叶德新
邓湘斌
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Baowu JFE Special Steel Co Ltd
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Baosteel Special Steel Shaoguan Co Ltd
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/04—Making ferrous alloys by melting
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/10—Supplying or treating molten metal
    • B22D11/11—Treating the molten metal
    • B22D11/114—Treating the molten metal by using agitating or vibrating means
    • B22D11/115—Treating the molten metal by using agitating or vibrating means by using magnetic fields
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/10—Handling in a vacuum
    • 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
    • C21D1/84—Controlled slow cooling
    • 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
    • C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
    • C21D8/065—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires of ferrous alloys
    • 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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/0075—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for rods of limited length
    • 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
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • 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
    • C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium 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
    • C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium

Abstract

The application relates to the field of steel, in particular to high-carbon chromium grinding ball steel and a preparation method thereof. The steel comprises the following components: c: 0.75-0.90%, Si: 0.15 to 0.40%, Mn: 0.95-1.10%, Cr: 1.01-1.10%, Mo: 0.030 to 0.110%, Al: 0.015-0.024%, N: 0.0045-0.0100%, Ti: 0.006-0.025 wt%, P not more than 0.020 wt%, S not more than 0.012 wt%, and Fe for the rest. The DI of the high-carbon chromium grinding ball steel is more than or equal to 5.25. The ratio of the carbon content at the center of the same section to the carbon content at the radius of 80 percent from the center is less than or equal to 1.08. By optimizing the component proportion of the steel and adjusting the process parameters and mutually cooperating, the carbon segregation proportion of the high-carbon chromium grinding ball steel is reduced, and the round steel is less bent and has no fracture.

Description

High-carbon chromium grinding ball steel and preparation method thereof
Technical Field
The application relates to the field of steel, in particular to high-carbon chromium grinding ball steel and a preparation method thereof.
Background
The wear-resistant steel balls are a crushing medium used in ball mills for crushing materials in the mills. High-carbon chromium grinding ball steel is one kind of wear-resistant steel ball.
At present, high-carbon chromium grinding ball steel is made of round steel produced by steel mills by hot rolling. The steel ball has high performance requirement, generally uniform hardness, high core hardness, low breakage rate and large impact value.
In order to obtain such high carbon chromium grinding ball steel with excellent properties, the properties of the round steel need to be strictly controlled. In particular, the degree of segregation, the degree of bending, whether or not to break, and the like.
In the known method, the Cr content is lower, the DI value of the critical dimension of hardenability is lower, the C, Mn content needs to be increased, the DI value is increased, the segregation of the C content is easy to cause, and the uniformity control difficulty of the C content is increased. And the carbon segregation degree of the round steel is not evaluated and controlled in the method. In the method, a slow cooling pit is used for slow cooling, the round steel has large bending degree and needs to be straightened through a straightening process, and the bending degree is reduced. The residual stress of the round steel after straightening is increased, resulting in an increased risk of breakage of the round steel.
Disclosure of Invention
The embodiment of the application aims to provide the high-carbon chromium grinding ball steel and the preparation method thereof, so that the high-carbon chromium grinding ball steel has good structure and performance.
In a first aspect, the present application provides a high carbon chromium grinding ball steel:
the high-carbon chromium grinding ball steel comprises the following components in percentage by weight: c: 0.75-0.90%, Si: 0.15 to 0.40%, Mn: 0.95-1.10%, Cr: 1.01-1.10%, Mo: 0.030 to 0.110%, Al: 0.015-0.024%, N: 0.0045-0.0100%, Ti: 0.006-0.025, P is less than or equal to 0.020%, S is less than or equal to 0.012%, and the balance is Fe;
the DI value of the hardenability critical dimension of the high-carbon chromium grinding ball steel is more than or equal to 5.25; the ratio of the carbon content of the same section center of the round steel to the carbon content of the radius position 80% away from the center is less than or equal to 1.08.
In a second aspect, the present application provides a method for preparing the high-carbon chromium grinding ball steel, including:
the first step is as follows: smelting in a converter;
the second step is that: refining in an LF ladle furnace;
the third step: RH vacuum degassing;
the fourth step: continuous casting;
the fifth step: slowly cooling the casting blank or conveying the casting blank in red;
and a sixth step: heating and rolling; and
the seventh step: high-temperature heap cooling;
wherein, in the third step, nitrogen circulation is used in the whole process; in the fourth step, the electromagnetic stirring parameter of the crystallizer is 710A +/-10A/2.5 Hz, and the electromagnetic stirring parameter of the tail end is 600A +/-10A/5 Hz; in the seventh step, the heap cooling temperature is more than or equal to 250 ℃, and the heap cooling time is more than or equal to 48 hours.
The high-carbon chromium grinding ball steel and the preparation method thereof provided by the embodiment of the application have the beneficial effects that:
the carbon segregation proportion of the high-carbon chromium grinding ball steel is reduced by optimizing the component proportion of the steel and adjusting the technological parameters in a mutually cooperative manner, the round steel is small in appearance bending and free of fracture.
The component proportion of the steel is mainly optimized in terms of Cr, N, Al and Ti content, so that solid solution strengthening and actual precipitation strengthening are formed in the steel, the strength and hardness of the steel are improved, and good structure performance is guaranteed. As for the process parameters, in the RH vacuum degassing process stage, nitrogen circulation is used in the whole process, so that the steel has a good tissue structure; in the continuous casting stage, the crystallizer and the tail end stirring parameters are optimized, so that the composition segregation is reduced, and the influence on the hardness uniformity of the subsequent steel balls is reduced; by limiting the technological parameters in the high-temperature heap cooling stage, the bending and residual thermal stress of the round steel are reduced, the bending degree of the round steel is reduced, the breakage is avoided, and the good comprehensive performance of the subsequent steel ball is ensured.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.
Fig. 1 is a macroscopic picture (gray scale processed) of a round steel cross-section structure of the high-carbon chromium grinding ball steel provided in example 1 of the present application;
fig. 2 is a picture of the surface characteristics of round steel of the high-carbon chromium grinding ball steel provided in embodiment 1 of the present application (the picture is subjected to gray processing);
FIG. 3 is a macroscopic picture (gray scale processed) of the cross-sectional structure of round steel of the high-carbon chromium grinding ball steel provided by comparative example 4 of the present application;
fig. 4 is a round steel surface characteristic picture (a picture is subjected to gray processing) of the high-carbon chromium grinding ball steel provided by the application and comparative example 4.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.
The embodiment provides high-carbon chromium grinding ball steel, which comprises the following components in percentage by weight: c: 0.75-0.90%, Si: 0.15 to 0.40%, Mn: 0.95-1.10%, Cr: 1.01-1.10%, Mo: 0.030 to 0.110%, Al: 0.015-0.024%, N: 0.0045-0.0100%, Ti: 0.006-0.025 wt%, P not more than 0.020 wt%, S not more than 0.012 wt%, and Fe for the rest.
Further, the critical dimension value DI of hardenability of high-carbon chromium grinding ball steel is [0.062+ 0.409C-0.13%5*C2][1+3.333*Mn][1+0.7*Si][1+2.16*Cr][1+3*Mo][1+0.363*Ni][1+0.365*Cu]Not less than 5.25. The ratio of the carbon content of the round steel of the high-carbon chromium grinding ball steel at the center of the same section to the carbon content of the round steel at the radius of 80 percent away from the center is less than or equal to 1.08.
The high-carbon chromium grinding ball steel optimizes the component proportion of the steel in order to ensure that the high-carbon chromium grinding ball steel has good structure and performance. The contents of Cr, N, Al and Ti are optimized, so that solid solution strengthening and actual precipitation strengthening are formed in the round steel, the strength and hardness of the steel are improved, and good structure performance is ensured.
Specifically, Cr can increase hardenability in steel, and at the same time, form chromium carbides, improving wear resistance of ball steel. However, Cr is too high, and tends to increase the temper brittleness of the steel. In general, the embodiment of the present application determines the content of Cr to be 0.95 to 1.10%.
N can form interstitial solid solution nitrides with alloys such as Al and Ti in steel, form solid solution strengthening and effective precipitation strengthening, and improve the strength of the steel, but N is too high, so that bubbles and looseness are easily formed in the steel, and excessive nitride inclusions are easily formed. In comprehensive consideration, the content of N is determined to be 0.0045-0.0100% by the embodiment of the application.
C is an essential component for ensuring the service hardness of the high-carbon chromium grinding ball steel. High, uniform hardness is required for the grinding ball steel. Meanwhile, C is one of the most important elements affecting hardenability of steel. The grinding ball steel with too low C content has insufficient hardness and can not ensure good hardenability; the carbon segregation ratio is affected too high, so that the central carbon content of the grinding ball steel is high, and the hardness is uneven. Accordingly, the embodiment of the present application determines the C content to be 0.75 to 0.90%.
Si is soluble in ferrite and austenite to increase the hardness, strength and hardenability of the steel. In general, the embodiment of the present application determines that Si is controlled to be 0.15-0.40%.
Mn can be dissolved in ferrite to play a role in solid solution strengthening, is an essential component for ensuring the use hardness of the grinding ball steel, is one of elements influencing the hardenability of the steel, and can cause the DI value of the critical dimension of the hardenability to be lower due to too low, so that the hardness of the steel balls prepared subsequently is not uniform. In general, the embodiments of the present application determine the Mn content to be 0.95 to 1.10%.
Mo has similar properties in steel to Cr, and can increase hardenability, improve wear resistance of steel, and improve temper brittleness, but Mo is too high, and increases cost. In general, the content of Mo in the embodiment of the present application is determined to be 0.030 to 0.110%.
Further, the high-carbon chromium grinding ball steel comprises the following components in percentage by weight:
c: 0.79 to 0.88%, Si: 0.20 to 0.35%, Mn: 0.97-1.08%, Cr: 0.97 to 1.08%, Mo: 0.030-0.090%, Al: 0.022-0.024%, N: 0.0060-0.0085%, Ti: 0.006-0.025 wt%, P not more than 0.020 wt%, S not more than 0.012 wt%, and Fe for the rest.
Further, the high-carbon chromium grinding ball steel comprises the following components in percentage by weight: c: 0.80-0.86%, Si: 0.32 to 0.34%, Mn: 1.00-1.08%, Cr: 1.02-1.10%, Mo: 0.049-0.083%, Al: 0.022-0.024%, N: 0.0045-0.0100%, Ti: 0.006-0.025 wt%, P not more than 0.020 wt%, S not more than 0.012 wt%, and Fe for the rest.
Further, the critical dimension of hardenability DI value ═ 0.062+ 0.409C-0.135C2][1+3.333*Mn][1+0.7*Si][1+2.16*Cr][1+3*Mo][1+0.363*Ni][1+0.365*Cu]。
Furthermore, the DI value of the critical dimension of hardenability of the high-carbon chromium grinding ball steel with the component proportion is controlled to be more than or equal to 5.25.
By controlling the DI value of the critical dimension of hardenability to be more than or equal to 5.25, the hardness uniformity of the steel balls prepared subsequently can be ensured.
Further optionally, DI: 5.26 to 7.50.
Further optionally, DI: 5.97 to 7.28.
Illustratively, the high carbon chromium grinding ball steel described above: the high-carbon chromium grinding ball steel comprises the following components in percentage by weight:
c: 0.83%, Si: 0.34%, Mn: 1.01%, Cr: 1.01%, Mo: 0.049%, Al: 0.024%, N: 72ppm, Ti: 0.007, P:0.013, S: 0.001 and the balance Fe.
Then:
DI＝[0.062+0.409*0.83％-0.135*0.832][1+3.333*1.01][1+0.7*0.34][
1+2.16*1.01][1+3*0.049][1+0.363*0][1+0.365*0]＝6.22
furthermore, the ratio of the carbon content of the round steel of the high-carbon chromium grinding ball steel at the same section center to the carbon content of the round steel at the radius position 80% away from the center is less than or equal to 1.08.
Further optionally, the ratio of the carbon content of the round steel of the high-carbon chromium grinding ball steel at the same section center to the carbon content of the round steel at the radius position 80% away from the center is 0.98-1.06.
For example, the ratio of the carbon content at the center of the same cross section of the round steel of the high-carbon chromium grinding ball steel to the carbon content at the radius of 80% from the center is as follows: 1.02.
furthermore, the hardness of the high-carbon chromium grinding ball steel is 310-380 HBW.
Illustratively, the hardness of the high carbon chromium grinding ball steel is 348 HBW.
Furthermore, the austenite grain size of the high-carbon chromium grinding ball steel is 7.5-8.0 grade.
Further, the structure of the high carbon chromium grinding ball steel includes pearlite and reticulated cementite.
Some embodiments of the present application also provide a method of preparing the above high carbon chromium grinding ball steel. The method comprises the following steps:
the first step is as follows: smelting in a converter;
the second step is that: and (5) refining in an LF ladle furnace.
The above two steps can be carried out by adopting the conventional operation flow in the field.
The third step: RH vacuum degassing.
In this step, a nitrogen circulation was used throughout the RH vacuum degassing.
By using nitrogen circulation in the whole RH vacuum degassing process, the N content in the prepared high-carbon chromium grinding ball steel can be ensured to be 0.0045-0.0100% (by weight percent), so that the structure performance of the high-carbon chromium grinding ball steel is ensured.
The fourth step: and (4) continuous casting.
Furthermore, in the fourth step, the electromagnetic stirring parameter of the crystallizer is controlled to be 710A +/-10A/2.5 Hz, and the electromagnetic stirring parameter of the tail end is controlled to be 600A +/-10A/5 Hz.
In the continuous casting process, the component segregation can be effectively reduced by controlling the electromagnetic stirring parameters of the crystallizer and the electromagnetic tail end stirring parameters.
Further, the superheat degree of molten steel is controlled at 15-30 ℃ in the continuous casting process, and the composition uniformity of the casting blank from the surface to the inside is controlled by adopting the electromagnetic stirring of a crystallizer, the electromagnetic stirring of the tail end and the continuous casting static soft reduction technology.
Further optionally, according to the characteristics of the high-carbon chromium grinding ball steel, the solidification tail end is slightly pressed by 14-16 mm.
Within the above range, the component segregation can be effectively reduced. If the rolling reduction is too low, the segregation-improving effect is not good; too large reduction results in reduction cracks in the core of the cast blank and reduced quality of the cast blank.
Illustratively, in the fourth step of continuous casting process, the superheat degree of the molten steel is controlled at 20 ℃, the electromagnetic stirring parameter of the crystallizer is controlled at 715A/2.5Hz, and the electromagnetic stirring parameter of the tail end is controlled at 605A/5 Hz. The solidification end is lightly pressed for 15 mm.
The fifth step: and slowly cooling the casting blank or conveying the casting blank in red.
Further, when the casting blank is slowly cooled, the pit entry temperature of the casting blank entering a slow cooling pit for cooling is more than or equal to 600 ℃, the slow cooling time is more than or equal to 48 hours, and the pit exit temperature is less than or equal to 200 ℃.
The pit entering temperature, the pit slowing time and the pit leaving temperature during the casting blank slow cooling are set in the ranges, so that the thermal stress generated by casting blank cooling can be effectively reduced, and the cracking of the casting blank in the heating and rolling processes is avoided.
Further optionally, the pit entry temperature for cooling the casting blank in the slow cooling pit is 600-750 ℃, the slow cooling time is 50-65 hours, and the pit exit temperature is 175-190 ℃.
Illustratively, the entry temperature of the cast slab into the buffer cooling pit is 687 ℃, the buffer cooling time is 60 hours, and the exit temperature is 179 ℃. Or the pit entry temperature of the casting blank entering the slow cooling pit for cooling is 723 ℃, the slow cooling time is 62 hours, and the pit exit temperature is 185 ℃.
In some embodiments, a casting blank red feeding mode can be adopted in the step. Further, when the casting blank is sent into the heating furnace, the temperature of the casting blank is more than or equal to 350 ℃.
The casting blank temperature during the red delivery of the casting blank is selected within the range, so that the thermal stress generated by the cooling of the casting blank can be effectively reduced, and the breakage of the casting blank in the heating and rolling processes is avoided.
Further optionally, the temperature of the cast slab is 350-490 ℃ when the cast slab is sent into the heating furnace.
Illustratively, the slab temperature is 432 ℃ when the slab is fed into the furnace. Alternatively, the slab temperature is 482 ℃ when the slab is fed into the heating furnace.
And a sixth step: and (4) heating and rolling.
Furthermore, during heating and rolling, the temperature of the casting blank in the preheating section of the heating furnace is less than or equal to 950 ℃, and the heating time of the preheating section is more than or equal to 55 minutes.
When the heating and rolling are carried out, the temperature of the casting blank in the preheating section of the heating furnace and the preheating time are controlled within the range, so that the thermal stress generated by the casting blank being heated too fast can be further reduced, and the breakage of the casting blank in the heating and rolling processes is avoided.
Further optionally, during heating and rolling, the temperature of the casting blank in the preheating section of the heating furnace is 780-900 ℃, and the heating time of the preheating section is 55-80 minutes.
In the process of heating and rolling, the temperature of a casting blank in a preheating section of a heating furnace is 890 ℃, and the heating time of the preheating section is 66 minutes; or when heating and rolling are carried out, the temperature of the casting blank in a preheating section of a heating furnace is 886 ℃, and the heating time of the preheating section is 62 minutes; or when heating and rolling are carried out, the temperature of the casting blank in a preheating section of a heating furnace is 798 ℃, and the heating time of the preheating section is 75 minutes; or when the casting blank is heated and rolled, the temperature of the casting blank in a preheating section of a heating furnace is 788 ℃, and the heating time of the preheating section is 70 minutes.
The seventh step: and (5) performing high-temperature heap cooling.
Furthermore, the heap cooling temperature is more than or equal to 250 ℃, and the heap cooling time is more than or equal to 48 hours.
At present, slow cooling is generally adopted in conventional operation, and when the slow cooling needs to be carried out at high temperature (more than or equal to 600 ℃), round steel is lifted and stacked into a slow cooling pit to be slowly cooled. But in the high-temperature hoisting and stacking process, the round steel is easy to bend under the action of the self weight of the round steel, so that the residual stress is large, and the subsequent straightening and cracking are caused. In the embodiment, the heap cooling temperature is more than or equal to 250 ℃, compared with the conventional operation, the temperature is greatly reduced, and the round steel is not easy to bend; and heap cold need not hoist round steel to slow cooling hole, further reduced the risk that causes the round steel crooked to greatly reduced the residual thermal stress of round steel.
In some specific embodiments of the present application, the specific operations are: the round steel is quickly collected after being rolled, then is intensively stacked according to a straight line shape, and is slowly cooled.
Further optionally, the heap cooling temperature is controlled to be 280-405 ℃, and the heap cooling time is controlled to be 60-75 hours.
Illustratively, the round steel is quickly collected after being rolled, then is intensively stacked according to a straight line shape, is slowly cooled, and is controlled to have the stack cooling temperature of 403 ℃ and the stack cooling time of 72 hours; or controlling the heap cooling temperature to 389 ℃ and the heap cooling time to 70 hours; or controlling the stack cooling temperature to be 289 ℃ and the stack cooling time to be 65 hours; alternatively, the heap cooling temperature is controlled to be 368 ℃, and the heap cooling time is controlled to be 70 hours.
The bending degree of the round steel obtained after high-temperature heap cooling is 2.5 mm/m-3 mm/m, and the round steel is not broken.
Further optionally, the bending degree of the round steel is 2.6 mm/m-2.9 mm/m.
Illustratively, the bending of the round bar is 2.5mm/m, 2.6mm/m, 2.7mm/m, 2.8mm/m or 2.9 mm/m.
In some specific embodiments, the present invention provides a high-carbon chromium grinding ball steel, which comprises the following components by weight percent:
c: 0.80-0.86%, Si: 0.32 to 0.34%, Mn: 1.00-1.08%, Cr: 1.02-1.10%, Mo: 0.049-0.083%, Al: 0.022-0.024%, N: 0.0045-0.0100%, Ti: 0.006-0.025, P is less than or equal to 0.020%, S is less than or equal to 0.012%, and the balance is Fe; critical dimension of hardenability DI value: 5.97 to 7.28.
When the high-carbon chromium grinding ball steel is prepared, the preparation is carried out according to the first step to the seventh step, wherein in the fourth step, the superheat degree of molten steel is controlled to be 25-30 ℃; the electromagnetic stirring parameter of the crystallizer is 710A +/-10A/2.5 Hz, and the electromagnetic stirring parameter of the tail end is 600A +/-10A/5 Hz; slightly pressing the solidification tail end for 14-16 mm; in the fifth step: when casting blanks are slowly cooled, the temperature of the casting blanks entering a slow cooling pit for cooling is 600-750 ℃, the slow cooling time is 50-65 hours, and the temperature of the casting blanks leaving the pit is 175-190 ℃; or when the casting blank is conveyed into the heating furnace in a red conveying mode, the casting blank temperature is 350-490 ℃. In the sixth step: when heating and rolling are carried out, the temperature of the casting blank in a preheating section of a heating furnace is 780-900 ℃, and the heating time of the preheating section is 55-80 minutes. In the seventh step, the heap cooling temperature is 280-405 ℃, and the heap cooling time is 60-75 hours.
In the range of the component proportion, the high-carbon chromium grinding ball steel prepared under the preparation process conditions has good structure and performance. Macrostructure of round steel: generally, the porosity is 0.5 grade, the central porosity is 1.0 grade to 1.5 grade, the ingot type segregation is 0 grade, and no crack exists. Hardness is 368-387 HBW, and austenite grain size is 7.5-8.0 grade. The structure of the round steel is pearlite and reticular cementite. The shape bending degree of the round steel is 2.5 mm/m-3 mm/m, and the round steel is not broken.
The features and properties of the present application are described in further detail below in conjunction with examples 1-4 and comparative examples 1-3:
examples 1 to 4 and comparative examples 1 to 3 each provide a high carbon chromium grinding ball steel, and the manufacturing method is the same, and the high carbon chromium grinding ball steel is manufactured according to the first to seventh steps in the foregoing embodiment. The difference lies in that the chemical compositions of the steels of different examples and comparative examples and the parameters of the production process are different, and the specific difference is shown in tables 1 to 2:
TABLE 1 chemical composition of grinding ball steel (wt%)
Figure BDA0002303835140000101
Figure BDA0002303835140000111
TABLE 2 main production process parameters of grinding ball steel
Figure BDA0002303835140000112
The properties of the high-carbon chromium grinding ball steels provided in examples 1 to 4 and comparative examples 1 to 3 were examined.
Examples 1 to 4 and comparative examples 1 to 3 used round steel samples of the same diameter. Detecting the macrostructure of the round steel according to GB/T1979; the hardness of the round steel (the hardness at the cross section 1/4) is detected according to GB/T231.1; the austenite grain size of the round steel is detected according to ASTM E112; detecting the microstructure of the round steel according to GB/T13298; the carbon segregation ratio of the round steel is detected according to GB/T20123, and the detection results are summarized in Table 3.
TABLE 3 round steel structure, Performance conditions
Figure BDA0002303835140000121
Figure BDA0002303835140000131
By the content of above-mentioned table 3 combine attached figure 1 ~ attached figure 4, can see that the segregation of the high carbon chromium ball-milling steel round steel that this application embodiment 1 ~ 4 provided is 0 level, and crackle-free, the round steel performance is good, and the crookedness is between 2.5 ~ 3mm/m, all does not have the fracture, satisfies the requirement of high carbon chromium ball-milling steel. In contrast, in comparative example 2 and comparative example 3, the rolling reduction under static soft reduction is 12mm, the soft reduction setting is not reasonable, and cracks appear at the position 1/3D lower than the round steel. Comparative example 1 because the casting blank was not sent into the furnace using a buffer cooling pit for slow cooling or red cooling, excessive stress was generated during the cooling of the casting blank, and round steel breakage occurred during the rolling. Comparative example 2 the round steel adopts a slow cooling pit for slow cooling, the bending degree is overlarge, the metallographic structure of the round steel is a reticular cementite and pearlite structure with poor plasticity, and the round steel is easy to crack under the action of a straightening force, so that the round steel is broken.
The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims (10)

1. The high-carbon chromium grinding ball steel is characterized by comprising the following components in percentage by weight: c: 0.75 to 0.88%, Si: 0.15 to 0.40%, Mn: 0.97-1.10%, Cr: 1.01-1.10%, Mo: 0.030 to 0.110%, Al: 0.015-0.024%, N: 0.0045-0.0100%, Ti: 0.006-0.025, P is less than or equal to 0.020%, S is less than or equal to 0.012%, and the balance is Fe;
the high-carbon chromium grinding ball steel has a critical dimension DI value of [0.062+ 0.409C-0.135C ]2][1+3.333*Mn][1+0.7*Si][1+2.16*Cr][1+3*Mo][1+0.363*Ni][1+0.365*Cu]Not less than 5.25; the ratio of the carbon content of the same section center of the round steel to the carbon content of the radius position 80% away from the center is less than or equal to 1.08.
2. The high carbon chromium grinding ball steel according to claim 1,
the austenite grain size of the high-carbon chromium grinding ball steel is 7.5-8.0 grade; the structure of the high-carbon chromium grinding ball steel comprises pearlite and netlike cementite.
3. The high carbon chromium grinding ball steel according to claim 1,
the hardness of the high-carbon chromium grinding ball steel is 310-380 HBW.
4. The high carbon chromium grinding ball steel according to any one of claims 1 to 3, wherein the component content of the high carbon chromium grinding ball steel comprises, in weight percent:
c: 0.79 to 0.88%, and Si: 0.20 to 0.35%, and Mn: 0.97-1.08%, and Cr: 0.97 to 1.08%, wherein Mo: 0.030 to 0.090%, wherein Al: 0.022-0.024%, wherein N: 0.0060-0.0085%, and the weight ratio of Ti: 0.006-0.025, wherein P is less than or equal to 0.020%, S is less than or equal to 0.012%, and the balance is Fe; critical dimension DI value of hardenability: 5.26 to 7.50.
5. The high carbon chromium grinding steel ball as claimed in any one of claims 1 to 3,
the high-carbon chromium grinding ball steel comprises the following components in percentage by weight: c: 0.80-0.86%, and Si: 0.32 to 0.34%, and Mn: 1.00-1.08%, and the Cr: 1.02 to 1.10%, wherein Mo: 0.049-0.083%, and the weight ratio of Al: 0.022-0.024%, wherein N: 0.0045 to 0.0100%, and the molar ratio of Ti: 0.006-0.025, wherein P is less than or equal to 0.020%, S is less than or equal to 0.012%, and the balance is Fe; critical dimension DI value of hardenability: 5.97 to 7.28.
6. A method for preparing high-carbon chromium grinding ball steel according to any one of claims 1 to 5, which comprises the following steps:
the first step is as follows: smelting in a converter;
the second step is that: refining in an LF ladle furnace;
the third step: RH vacuum degassing;
the fourth step: continuous casting;
the fifth step: slowly cooling the casting blank or conveying the casting blank in red;
and a sixth step: heating and rolling; and
the seventh step: high-temperature heap cooling;
wherein, in the third step, nitrogen circulation is used in the whole process; in the fourth step, the electromagnetic stirring parameter of the crystallizer is 710A +/-10A/2.5 Hz, and the electromagnetic stirring parameter of the tail end is 600A +/-10A/5 Hz; in the seventh step, the heap cooling temperature is more than or equal to 250 ℃, and the heap cooling time is more than or equal to 48 hours.
7. The method for preparing high carbon chromium grinding ball steel according to claim 6,
in the fifth step:
when casting blanks are slowly cooled, the pit entry temperature of the casting blanks entering a slow cooling pit for cooling is more than or equal to 600 ℃, the slow cooling time is more than or equal to 48 hours, and the pit exit temperature is less than or equal to 200 ℃; or
When the casting blank is conveyed in red and the casting blank is conveyed into a heating furnace, the temperature of the casting blank is more than or equal to 350 ℃.
8. The method for preparing high carbon chromium grinding ball steel according to claim 6,
in the sixth step:
when heating and rolling are carried out, the temperature of the casting blank in the preheating section of the heating furnace is less than or equal to 950 ℃, and the heating time of the preheating section is more than or equal to 55 minutes.
9. The method for preparing high carbon chromium grinding ball steel according to claim 6,
in the fourth step, the solidification tail end is slightly pressed for 14-16 mm;
optionally, in the fourth step, the superheat degree of the molten steel is controlled to be 15-30 ℃.
10. The method for preparing high carbon chromium grinding ball steel according to claim 6,
the bending degree of the round steel obtained after the high-temperature heap cooling is 2.5 mm/m-3 mm/m; the round steel has no fracture.
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CN104762562A (en) * 2015-04-23 2015-07-08 山东钢铁股份有限公司 Steel for large-diameter grinding balls and preparation method of steel
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ES2691992T3 (en) * 2015-11-09 2018-11-29 Crs Holdings, Inc. Steel articles of powder metallurgy of free machining and method of preparation of the same

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104762562A (en) * 2015-04-23 2015-07-08 山东钢铁股份有限公司 Steel for large-diameter grinding balls and preparation method of steel
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