Hot continuous rolling wear-resistant high-nickel-chromium working roll and preparation method thereof

Abstract

The invention discloses a hot continuous rolling wear-resistant high-nickel-chromium working roll and a preparation method thereof, and belongs to the field of roll manufacturing, the outer layer molten iron alloy of the working roll comprises the following components in percentage by mass: 2.80-4.00% of C, 0.50-1.50% of Si, 0.30-1.50% of Mn and less than or equal to 0.03% of P; the steel comprises the following components in percentage by weight: less than or equal to 0.03% of S, 1.00-3.00% of Cr, 4.00-6.00% of Ni, 0.20-3.00% of Mo, 0.10-3.00% of V, 0.1-2.0% of Nb, 0.5 < = Cr / C < = 0.7, 2.0 < = Ni / Cr < = 2.5, 1.0% of Mo / V, and the balance of Fe and inevitable impurities. The core molten iron is nodular cast iron. According to the prepared roller, the problem that the service life of the roller is short when high-strength steel is rolled through hot continuous rolling is solved, and high abrasion resistance, accident resistance and good structure uniformity can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of roll manufacturing, in particular to a hot rolling wear-resistant high-nickel-chromium working roll and a preparation method thereof. Background Art

[0002] At present, the working rolls in the latter stage of hot rolling finishing are basically high nickel-chromium working rolls. Because they are used in the finished product rack, they are closely related to the surface quality of the strip, so the surface quality requirements are high. At the same time, because of the poor plate shape during the latter rolling process, tail swinging is more frequent, so the rolls are also required to have higher accident resistance. Therefore, when designing the material, it is necessary to ensure that there is a certain amount of graphite in the matrix structure. However, the increase in graphite content will lead to the deterioration of roll wear resistance. How to increase the wear resistance of the roll while ensuring the accident resistance of the roll has always been the focus of research for roll researchers. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a hot rolling wear-resistant high nickel-chromium working roll and a preparation method thereof, which solves the problem of short roll service when hot rolling high-strength steel, and can achieve relatively high wear resistance, accident resistance and relatively good organizational uniformity.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A hot rolling wear-resistant high-nickel-chromium working roll, the working roll is a centrifugal composite casting roll, comprising an outer layer and a core, the outer layer molten iron alloy composition and mass percentage content are: C: 2.80-4.00%, Si: 0.50-1.50%, Mn: 0.30-1.50%, P≤0.03%; S≤0.03%, Cr: 1.00-3.00%, Ni: 4.00-6.00%, Mo: 0.20-3.00%, V: 0.10-3.00%, Nb: 0.1-2.0%, the rest is Fe and inevitable impurities; the core molten iron is made of ductile iron; the addition amounts of C, Cr, Ni, Mo and V in the outer layer molten iron are limited to meet 0.5≤Cr / C≤0.7, 2.0≤Ni / Cr≤2.5, and Mo / V=1.0.

[0006] A method for preparing a hot rolling wear-resistant high-nickel-chromium working roll comprises the following steps:

[0007] Step 1, placing the selected outer layer raw material and core raw material into an electric furnace for smelting respectively, and adjusting the alloy composition;

[0008] Step 2, after the smelting in step 1 is completed, the molten iron is calmed for a period of time, and the outer molten iron is poured when it reaches the pouring temperature, and a certain amount of inoculant is added for flow inoculation, and the core molten iron is poured after the cavity reaches a certain temperature;

[0009] Step 3, after the pouring in step 2 is completed, heat treatment is performed, and cooling is performed after unpacking;

[0010] Step 4, when the material in step 3 is cooled to a certain temperature, mechanical processing is performed to obtain a structure containing a certain amount of graphite and carbide, and a high nickel-chromium working roll that meets the requirements of hot rolling high-strength steel.

[0011] A further improvement of the technical solution of the present invention is that in step 2, the molten iron calming time is 10 to 15 minutes, and the temperature of the outer layer of molten iron when pouring is 50 to 80° C. above the melting point.

[0012] A further improvement of the technical solution of the present invention is that in step 2, the inoculant is Fe-Si particles and ZL80 particles, and the added amount is 5 to 10 kg.

[0013] A further improvement of the technical solution of the present invention is that in step 3, the heat treatment is specifically as follows: three stages of annealing are performed after unpacking, the first stage annealing temperature is 350-420°C, and the annealing time is 20-40h; the second stage annealing temperature is 400-460°C, and the annealing time is 20-40h; the third stage annealing temperature is 440-500°C, and the annealing time is 20-40h.

[0014] A further improvement of the technical solution of the present invention is that in step 4, the steel is taken out of the furnace when cooled to 150° C., and mechanical processing is performed when the steel is cooled to room temperature by cold air.

[0015] The further improvement of the technical solution of the present invention is that the graphite content in the prepared hot rolling wear-resistant high nickel-chromium working roll structure is 1.0-2.0%, the carbide content is 28-34%, and the matrix microhardness is greater than 520HV.

[0016] Due to the adoption of the above technical solution, the technical progress achieved by the present invention is:

[0017] 1. The present invention limits 0.5≤Cr / C≤0.7. By designing a reasonable Cr and C element ratio, it is ensured that the organization contains a high content of carbides. The carbides have a high matrix microhardness, ensuring that the wear-resistant high nickel-chromium working roll has higher wear resistance and indentation resistance than conventional high nickel-chromium.

[0018] 2. The present invention also defines 2.0≤Ni / Cr≤2.5. Ni is an alloy element that promotes graphitization. By setting the content ratio of Ni and Cr elements, it can not only ensure that the wear-resistant high-nickel-chromium working roll has high wear resistance, but also make the structure contain a certain amount of graphite, thereby improving the thermal cracking resistance of the rolling roll. At the same time, it has a matrix strength and toughness higher than that of conventional materials, thereby improving the accident resistance during the rolling process.

[0019] 3. The present invention limits Mo / V to 1.0, and strengthens the matrix by adding relatively high content of strong carbide alloying elements such as V and Mo, while ensuring that there are certain amounts of carbides at different depths, thereby ensuring the wear resistance of the roller throughout its life.

[0020] 4. The present invention limits the above-mentioned components to ensure that the amount of graphite in the structure is 1.0-2.0%, the amount of carbide is 28-34%, and the matrix microhardness is greater than 520HV. At the same time, by adding a certain amount of Nb element and coordinating the heat treatment process, the purpose of grain refinement is achieved, and ultimately the comprehensive performance of the roller can meet the rolling requirements of the special working conditions in the latter stage of hot rolling and finishing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative labor.

[0022] Figure 1 is a graphite photograph of a working roll prepared in an embodiment of the present invention;

[0023] Figure 2 3 is a metallographic structure photograph of the working roll prepared in the embodiment of the present invention. DETAILED DESCRIPTION

[0024] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or apparatus.

[0025] The present invention is further described in detail below with reference to the accompanying drawings and embodiments:

[0026] The present invention discloses a hot rolling wear-resistant high nickel-chromium working roll and a preparation method thereof. The manufacturing method includes the chemical composition range of the working roll, casting and heat treatment parameters, control of the microstructure and performance indexes, and flow inoculation during the molten iron pouring process. Through the study of the material and the preparation process, a hot rolling wear-resistant high nickel-chromium working roll is prepared to ensure that the microstructure and performance indexes meet the set expected goals, effectively solving the problem of insufficient plate shape retention ability when rolling high-strength steel.

[0027] Example 1

[0028] A method for preparing a hot rolling wear-resistant high nickel-chromium work roll comprises the following steps:

[0029] Step 1, putting the selected outer layer raw material and core raw material into an electric furnace for smelting, the outer layer alloy composition and the mass percentage of each alloy component are C: 3.00%, Si: 1.30%, Mn: 0.80%, Cr: 1.80%, Ni: 4.50%, Mo: 0.30%, V: 0.30%, Nb: 0.30%, incidental P≤0.03%; S≤0.03%, the rest is Fe and unavoidable impurities; the core molten iron is made of ductile cast iron.

[0030] In this embodiment: Cr / C=0.6, Ni / Cr=2.5, Mo / V=1.0.

[0031] Step 2, after the smelting in step 1 is completed, the molten iron is calmed for 10 minutes, and pouring begins when the melting point of the molten iron is reached + 60°C. The outer layer of molten iron is poured on a centrifuge using a centrifugal composite pouring method, and 6 kg of Fe-Si particles and ZL80 particles (1:1) are added, and incubated as the pouring proceeds.

[0032] Step 3, after the pouring in step 2 is completed, perform insulation treatment: when the temperature of the outer wall of the cold mold drops to 100°C, open the box, perform heat treatment, and perform three-stage annealing. The first stage annealing temperature is 370°C and the annealing time is 30h; the second stage annealing temperature is 420°C and the annealing time is 21h; the third stage annealing temperature is 450°C and the annealing time is 20h, and then cool.

[0033] Step 4: When the product of step 3 is cooled to 150°C, the product is taken out of the furnace and mechanically processed when it is cooled to room temperature by cold air.

[0034] After testing, the working layer of the working roller prepared in this embodiment has a graphite content of 1.0-2.0%, a carbide content of 28-34%, and a matrix microhardness of 525HV. The graphite photo of the working layer of the working roller prepared is shown in FIG. Figure 1 As shown, the metallographic structure photos are as follows Figure 2 shown.

[0035] Example 2

[0036] A method for preparing a hot rolling wear-resistant high nickel-chromium work roll comprises the following steps:

[0037] Step 1, putting the selected outer layer raw material and core raw material into an electric furnace for smelting, the outer layer alloy composition and the mass percentage of each alloy component are C: 2.90%, Si: 1.20%, Mn: 0.80%, Cr: 2.00%, Ni: 4.10%, Mo: 0.20%, V: 0.20%, Nb: 0.20%, incidental P≤0.03%; S≤0.03%, the rest is Fe and unavoidable impurities; the core molten iron is made of ductile cast iron.

[0038] In this embodiment: Cr / C=0.6897, Ni / Cr=2.05, Mo / V=1.0.

[0039] Step 2, after the smelting in step 1 is completed, the molten iron is calmed for 10 minutes, and pouring begins when the melting point of the molten iron is reached +70°C. The outer layer of molten iron is poured on a centrifuge using a centrifugal composite pouring method, and 5kg of Fe-Si particles and ZL80 particles (1:1) are added, and incubated as the pouring proceeds.

[0040] Step 3, after the pouring in step 2 is completed, perform insulation treatment: when the temperature of the outer wall of the cold mold drops to 100°C, open the box, perform heat treatment, and perform three-stage annealing. The first stage annealing temperature is 370°C and the annealing time is 30h; the second stage annealing temperature is 430°C and the annealing time is 21h; the third stage annealing temperature is 450°C and the annealing time is 20h, and then cool.

[0041] Step 4: Take out of the furnace when the product in step 3 is cooled to 150°C, and perform mechanical processing when the product is cooled to room temperature by cold air.

[0042] According to tests, the working layer of the working roller prepared in this embodiment has a graphite content of 1.0-2.0%, a carbide content of 28-34%, and a matrix microhardness of 527 HV.

[0043] Example 3

[0044] A method for preparing a hot rolling wear-resistant high nickel-chromium work roll comprises the following steps:

[0045] Step 1, putting the selected outer layer raw material and core raw material into an electric furnace for smelting, the outer layer alloy composition and the mass percentage of each alloy component are C: 2.90%, Si: 1.10%, Mn: 0.85%, Cr: 1.70%, Ni: 4.20%, Mo: 0.25%, V: 0.25%, Nb: 0.20%, incidental P≤0.03%; S≤0.03%, the rest is Fe and unavoidable impurities; the core molten iron is made of ductile cast iron.

[0046] In this embodiment: Cr / C=0.5862, Ni / Cr=2.4706, Mo / V=1.0.

[0047] Step 2, after the smelting in step 1 is completed, the molten iron is calmed for 12 minutes, and pouring begins when the melting point of the molten iron is reached +70°C. The outer layer of molten iron is poured on a centrifuge using a centrifugal composite pouring method, and 5kg of Fe-Si particles and ZL80 particles (1:1) are added, and incubated as the pouring proceeds.

[0048] Step 3, after the pouring in step 2 is completed, perform insulation treatment: when the temperature of the outer wall of the cold mold drops to 100°C, open the box, perform heat treatment, and perform three-stage annealing. The first stage annealing temperature is 380°C and the annealing time is 30h; the second stage annealing temperature is 420°C and the annealing time is 21h; the third stage annealing temperature is 450°C and the annealing time is 24h, and then cool.

[0049] Step 4: When the product of step 3 is cooled to 150°C, the product is taken out of the furnace and mechanically processed when it is cooled to room temperature by cold air.

[0050] According to tests, the working layer of the working roller prepared in this embodiment has a graphite content of 1.0-2.0%, a carbide content of 28-34%, and a matrix microhardness of 526 HV.

[0051] Example 4

[0052] A method for preparing a hot rolling wear-resistant high nickel-chromium work roll comprises the following steps:

[0053] Step 1, putting the selected outer layer raw material and core raw material into an electric furnace for smelting, the outer layer alloy composition and the mass percentage of each alloy component are C: 3.30%, Si: 0.75%, Mn: 0.70%, Cr: 1.90%, Ni: 4.30%, Mo: 0.30%, V: 0.30%, Nb: 0.20%, incidental P≤0.03%; S≤0.03%, the rest is Fe and unavoidable impurities; the core molten iron is made of ductile cast iron.

[0054] In this embodiment: Cr / C=0.5758, Ni / Cr=2.2632, Mo / V=1.0.

[0055] Step 2, after the smelting in step 1 is completed, the molten iron is calmed for 11 minutes, and pouring begins when the melting point of the molten iron is reached +70°C. The outer layer of molten iron is poured on a centrifuge using a centrifugal composite pouring method, and 5 kg of Fe-Si particles and ZL80 particles (1:1) are added, and incubated as the pouring proceeds.

[0056] Step 3, after the pouring in step 2 is completed, perform insulation treatment: when the temperature of the outer wall of the cold mold drops to 100°C, open the box, perform heat treatment, and perform three-stage annealing. The first stage annealing temperature is 400°C and the annealing time is 25h; the second stage annealing temperature is 430°C and the annealing time is 25h; the third stage annealing temperature is 460°C and the annealing time is 26h, and then cool.

[0057] Step 4: Take out of the furnace when the product in step 3 is cooled to 150°C, and perform mechanical processing when the product is cooled to room temperature by cold air.

[0058] According to tests, the working layer of the working roller prepared in this embodiment has a graphite content of 1.0-2.0%, a carbide content of 28-34%, and a matrix microhardness of 522 HV.

[0059] Example 5

[0060] A method for preparing a hot rolling wear-resistant high nickel-chromium work roll comprises the following steps:

[0061] Step 1, putting the selected outer layer raw material and core raw material into an electric furnace for smelting, the outer layer alloy composition and the mass percentage of each alloy component are C: 3.40%, Si: 0.70%, Mn: 0.70%, Cr: 2.00%, Ni: 4.50%, Mo: 0.50%, V: 0.50%, Nb: 0.30%, incidental P≤0.03%; S≤0.03%, the rest is Fe and unavoidable impurities; the core molten iron is made of ductile cast iron.

[0062] In this embodiment: Cr / C=0.5882, Ni / Cr=2.25, Mo / V=1.0.

[0063] Step 2, after the smelting in step 1 is completed, the molten iron is calmed for 13 minutes, and pouring begins when the melting point of the molten iron is reached +80°C. The outer layer of molten iron is poured on a centrifuge using a centrifugal composite pouring method, and 7kg of Fe-Si particles and ZL80 particles (1:1) are added, and incubated as the pouring proceeds.

[0064] Step 3, after the pouring in step 2 is completed, perform insulation treatment: when the temperature of the outer wall of the cold mold drops to 100°C, open the box, perform heat treatment, and perform three-stage annealing. The first stage annealing temperature is 400°C and the annealing time is 31h; the second stage annealing temperature is 430°C and the annealing time is 25h; the third stage annealing temperature is 450°C and the annealing time is 28h, and then cool.

[0065] Step 4: Take out of the furnace when the product in step 3 is cooled to 150°C, and perform mechanical processing when the product is cooled to room temperature by cold air.

[0066] According to tests, the working layer of the working roller prepared in this embodiment has a graphite content of 1.0-2.0%, a carbide content of 28-34%, and a matrix microhardness of 522 HV.

[0067] Example 6

[0068] A method for preparing a hot rolling wear-resistant high nickel-chromium work roll comprises the following steps:

[0069] Step 1, putting the selected outer layer raw material and core raw material into an electric furnace for smelting, the outer layer alloy composition and the mass percentage of each alloy component are C: 3.50%, Si: 0.70%, Mn: 0.70%, Cr: 2.20%, Ni: 4.80%, Mo: 0.30%, V: 0.30%, Nb: 0.30%, incidental P≤0.03%; S≤0.03%, the rest is Fe and unavoidable impurities; the core molten iron is made of ductile cast iron.

[0070] In this embodiment: Cr / C=0.6286, Ni / Cr=2.1818, Mo / V=1.0.

[0071] Step 2, after the smelting in step 1 is completed, the molten iron is calmed for 14 minutes, and pouring begins when the melting point of the molten iron is reached + 90°C. The outer layer of molten iron is poured on a centrifuge using a centrifugal composite pouring method, and 7kg of Fe-Si particles and ZL80 particles (1:1) are added, and incubated as the pouring proceeds.

[0072] Step 3, after the pouring in step 2 is completed, perform insulation treatment: when the temperature of the outer wall of the cold mold drops to 100°C, open the box, perform heat treatment, and perform three-stage annealing. The first stage annealing temperature is 420°C and the annealing time is 30h; the second stage annealing temperature is 450°C and the annealing time is 27h; the third stage annealing temperature is 470°C and the annealing time is 30h, and then cool.

[0073] Step 4: When the product of step 3 is cooled to 150°C, the product is taken out of the furnace and mechanically processed when it is cooled to room temperature by cold air.

[0074] According to tests, the working layer of the working roller prepared in this embodiment has a graphite content of 1.0-2.0%, a carbide content of 28-34%, and a matrix microhardness of 534 HV.

[0075] Comparative Example 1

[0076] A method for preparing a hot rolling wear-resistant high nickel-chromium work roll comprises the following steps:

[0077] a. Put the selected outer layer raw materials and core raw materials into an electric furnace for smelting. The outer layer alloy composition and the mass percentage of each alloy component are C: 3.00%, Si: 0.70%, Mn: 0.70%, Cr: 1.2%, Ni: 4.00%, Mo: 0.50%, V: 0.50%, Nb: 1.00, with incidental P≤0.03%; S≤0.03%, and the rest are Fe and unavoidable impurities; the core molten iron is made of ductile cast iron.

[0078] In this comparative example: Cr / C=0.40, Ni / Cr=3.3333, Mo / V=1.0.

[0079] b. After the smelting in step a is completed, the molten iron is calmed for 14 minutes. When it reaches the melting point of molten iron + 90°C, pouring begins. The outer layer of molten iron is poured on a centrifuge by a centrifugal composite pouring method. 7kg of Fe-Si particles and ZL80 particles (1:1) are added and inoculated as the pouring proceeds.

[0080] c. After pouring in step b, perform insulation treatment: when the outer wall temperature of the cold mold drops to 100°C, open the box and perform heat treatment. Perform three-stage annealing. The first stage annealing temperature is 420°C and the annealing time is 32h; the second stage annealing temperature is 450°C and the annealing time is 28h; the third stage annealing temperature is 480°C and the annealing time is 30h, and then cool.

[0081] d. When the product in step c is cooled to 150° C., it is taken out of the furnace and mechanically processed when it is cooled to room temperature by cold air.

[0082] After testing, the matrix microhardness of the working layer of the working roller prepared in this comparative example is 475HV.

[0083] Comparative Example 2

[0084] A method for preparing a hot rolling wear-resistant high nickel-chromium work roll comprises the following steps:

[0085] a. Put the selected outer layer raw materials and core raw materials into an electric furnace for smelting. The outer layer alloy composition and the mass percentage of each alloy component are C: 3.20%, Si: 1.30%, Mn: 0.80%, Cr: 3.30%, Ni: 5.00%, Mo: 0.50%, V: 0.80%, Nb: 0.30, with incidental P≤0.03%; S≤0.03%, and the rest are Fe and unavoidable impurities; the core molten iron is made of ductile cast iron.

[0086] In this comparative example: Cr / C = 1.0313, Ni / Cr = 1.5152, Mo / V = 0.625

[0087] b. After the smelting in step a is completed, the molten iron is calmed for 10 minutes. When it reaches the melting point of molten iron + 60°C, pouring begins. The outer layer of molten iron is poured on a centrifuge by a centrifugal composite pouring method. 6 kg of Fe-Si particles and ZL80 particles (1:1) are added and inoculated as the pouring proceeds.

[0088] c. After pouring in step b, perform insulation treatment: when the outer wall temperature of the cold mold drops to 100°C, open the box and perform heat treatment. Perform three-stage annealing. The first stage annealing temperature is 360°C and the annealing time is 30h; the second stage annealing temperature is 410°C and the annealing time is 20h; the third stage annealing temperature is 450°C and the annealing time is 22h, and then cool.

[0089] d. When the product in step c is cooled to 150° C., it is taken out of the furnace and mechanically processed when it is cooled to room temperature by cold air.

[0090] After testing, the matrix microhardness of the working layer of the working roller prepared in this control example is 482HV.

[0091] The components in Examples 1-6 and Comparative Examples 1-2 are defined as shown in Table 1:

[0092] Table 1 Detailed list of the components in Examples 1-6 and Comparative Examples 1-2

[0093]

[0094]

[0095] The working rolls prepared in Examples 1-6 and Comparative Examples 1-2 were subjected to an indentation resistance and wear resistance test. The test results are shown in Table 2:

[0096] Table 2 Experimental results

[0097]

[0098] As shown in Tables 1 and 2, the addition amounts of C, Cr, Ni, Mo, and V in the outer molten iron of the working roller in Examples 1-6 can satisfy 0.5≤Cr / C≤0.7, 2.0≤Ni / Cr≤2.5, and Mo / V=1.0; without considering the adjustment of the parameters of the preparation method, the matrix microhardness of the working layer of the prepared working roller is greater than 520HV, and the wear resistance is greater than 4.55. In the control examples 1-2, the addition amounts of C, Cr, Ni, Mo, and V in the outer molten iron of the working roller are less than 0.5 or greater than 0.7, and Ni / Cr is less than 2.0 or greater than 2.5. Even when Mo / V=1.0, the matrix microhardness of the working layer of the prepared working roller is much less than 520HV, and the wear resistance is much less than 4.55.

[0099] In summary, the present invention ensures that the structure contains a higher content of carbides by limiting 0.5≤Cr / C≤0.7. The carbides have a high matrix microhardness, which ensures that the wear-resistant high-nickel-chromium working roll has higher wear resistance and indentation resistance than conventional high-nickel-chromium. The Ni element is a graphitization-promoting alloy element. By limiting 2.0≤Ni / Cr≤2.5, it can not only ensure that the wear-resistant high-nickel-chromium working roll has high wear resistance, but also make the structure contain a certain amount of graphite, thereby improving the thermal cracking resistance of the rolling mill, and at the same time, it has a matrix toughness higher than that of conventional materials, thereby improving the accident resistance during the rolling process. By limiting Mo / V=1.0, a higher content of strong carbide alloy elements is added to strengthen the matrix, while ensuring that there are a certain number of carbides at different depths, thereby ensuring the wear resistance of the rolling mill throughout its life. By limiting the above-mentioned components, it is ensured that the graphite content in the working layer structure of the prepared working roll is 1.0-2.0%, the carbide content is 28-34%, and the matrix microhardness is greater than 520HV. At the same time, by adding a certain content of Nb element and coordinating the heat treatment process, the purpose of grain refinement is achieved, and finally the comprehensive performance of the rolling roll can meet the rolling requirements of the special working conditions in the latter stage of hot rolling finishing.

[0100] In addition, the upper and lower limits and interval values ​​of the process parameters (such as mass percentage, temperature, time, ratio, etc.) of the present invention can all realize the present invention, and the embodiments are not listed one by one here.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hot rolling wear-resistant high nickel-chromium working roll, the working roll is a centrifugal composite casting roll, including an outer layer and a core, characterized in that: The alloy composition and mass percentage of the outer layer molten iron are: C: 2.80-4.00%, Si: 0.50-1.50%, Mn: 0.30-1.50%, P≤0.03%; S≤0.03%, Cr: 1.00-3.00%, Ni: 4.00-6.00%, Mo: 0.20-3.00%, V: 0.10-3.00%, Nb: 0.1-2.0%, and the rest are Fe and inevitable impurities; the core molten iron is made of ductile iron; the addition amounts of C, Cr, Ni, Mo and V in the outer layer molten iron are limited to satisfy 0.5≤Cr / C≤0.7, 2.0≤Ni / Cr≤2.5, and Mo / V=1.

0.

2. The method for preparing a hot rolling wear-resistant high nickel-chromium work roll according to claim 1, characterized in that: The steps include: Step 1, placing the selected outer layer raw material and core raw material into an electric furnace for smelting respectively, and adjusting the alloy composition; Step 2, after the smelting in step 1 is completed, the molten iron is calmed for a period of time, and the outer molten iron is poured when it reaches the pouring temperature, and a certain amount of inoculant is added for flow inoculation, and the core molten iron is poured after the cavity reaches a certain temperature; Step 3, after the pouring in step 2 is completed, heat treatment is performed, and cooling is performed after unpacking; Step 4, when the material in step 3 is cooled to a certain temperature, mechanical processing is performed to obtain a structure containing a certain amount of graphite and carbide, and a high nickel-chromium working roll that meets the requirements of hot rolling high-strength steel.

3. The method for preparing a hot rolling wear-resistant high nickel-chromium work roll according to claim 2, characterized in that: In step 2, the cooling time of the molten iron is 10 to 15 minutes, and the temperature of the outer layer of molten iron when pouring is 50 to 80° C. above the melting point.

4. The method for preparing a hot rolling wear-resistant high nickel-chromium work roll according to claim 2, characterized in that: In step 2, the inoculant is Fe-Si particles and ZL80 particles, and the added amount is 5 to 10 kg.

5. The method for preparing a hot rolling wear-resistant high nickel-chromium work roll according to claim 2, characterized in that: In step 3, the heat treatment is specifically as follows: three stages of annealing are performed after unpacking, the first stage annealing temperature is 350-420°C, and the annealing time is 20-40h; the second stage annealing temperature is 400-460°C, and the annealing time is 20-40h; the third stage annealing temperature is 440-500°C, and the annealing time is 20-40h.

6. The method for preparing a hot rolling wear-resistant high nickel-chromium work roll according to claim 2, characterized in that: In step 4, the product is taken out of the furnace when cooled to 150°C, and mechanical processing is performed when the product is cooled to room temperature by cold air.

7. The method for preparing a hot rolling wear-resistant high nickel-chromium work roll according to claim 2, characterized in that: The prepared hot rolling wear-resistant high nickel-chromium work roll has a graphite content of 1.0-2.0%, a carbide content of 28-34%, and a matrix microhardness of >520HV.

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