Production method of hardening and tempering-free wear-resistant rod

Abstract

The invention belongs to the technical field of metallurgy, and relates to a production method of a hardening and tempering-free wear-resisting rod. The key procedures adopt the measures of converter smelting, LF furnace refining, RH vacuum treatment, continuous casting pouring and a deformation heat treatment method, and the material strength is improved through high C and Mn elements. H removal control is enhanced in the smelting process, and the superheat degree, the pulling speed and tail end electromagnetic stirring parameters are reasonably optimized in the continuous casting process to reduce casting blank macroscopic defects. In the rolling process, the structure is homogenized through high-temperature diffusion and high-pressure rolling processes, and the comprehensive performance of the material is greatly improved through a thermomechanical treatment method. The method is suitable for producing an alloy structure wear-resisting rod with the diameter phi of 20-160 mm and has the advantages that the surface hardness is high, the core part toughness is high, the surface hardness reaches 45 HRC or above, the core part U-shaped impact is 45 J or above, and the wear-resisting performance is good.

Description

Technical Field

[0001] The present invention belongs to the technical field of metallurgy and relates to a production method of non-quenched and tempered wear-resistant bars. Background Art

[0002] In the international environment of energy conservation and emission reduction, low-carbon economy is the general trend. Mining machinery is developing towards large-scale and lightweight directions. The domestic iron and steel industry and construction machinery industry are both facing the challenges and opportunities of "adjusting the structure and transforming the mode". Moreover, the contradiction between energy supply and demand and environmental pollution problems are becoming increasingly prominent with the rapid development of economic construction. The development and application of scientific research and technology work for energy conservation, emission reduction and pollution reduction have become very important. According to statistics, the application amount of quenched and tempered structural steel accounts for more than 35% of the total amount of special steel. Quenched and tempered steel usually requires a time-consuming, energy-consuming and environmentally polluting quenching and tempering process to ensure its mechanical properties. While non-quenched and tempered steel can shorten the construction period and reduce energy consumption costs by 25% - 38% due to omitting the quenching and tempering process. Therefore, if this new type of steel is used to replace quenched and tempered structural steel to manufacture mechanical structural parts, it will have significant economic and social benefits.

[0003] The non-quenched and tempered technology innovates the traditional process through "replacing forging with rolling and replacing heat treatment with cold treatment" and has been applied on a large scale in fields such as automobiles and machinery. With the progress of material design and intelligent manufacturing, the proportion of replacing quenched and tempered steel is expected to increase from the current 30% to more than 50%.

[0004] In recent years, the mining vehicle industry has developed rapidly, and the competition in manufacturing costs among enterprises has become increasingly fierce. Currently, traditional quenched and tempered structural parts materials with complex production processes, high energy consumption and serious heat treatment defects are gradually being replaced by non-quenched and tempered steel with simple production processes, low energy consumption and few defects. Traditional quenched and tempered wear-resistant bars consume a large amount of energy during the heat treatment process, and will also bring problems such as oxidation, deformation and even cracking during the heating process of parts. When the wear-resistant bars are quenched during heat treatment, bending and twisting deformation often occur, increasing energy waste and material loss. Non-quenched and tempered steel is attracting wide attention from machinery manufacturers due to its low cost, energy conservation and environmental protection and other advantages. Based on the above requirements, it is imperative to develop non-quenched and tempered wear-resistant bars with high wear resistance. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a high-strength and high-wear-resistant non-quenched and tempered bar and its preparation method. The present invention can avoid problems such as high energy consumption, easy oxidation and cracking during the quenching and tempering process, and also solve the problems of hardenability, strength and surface hardness of non-quenched and tempered steel.

[0006] The technical solution adopted by the present invention is: a production method of a non-quenched wear-resistant rod. The chemical composition of the wear-resistant rod by weight percentage is: C: 0.50% - 0.80%, Si: 0.10% - 0.40%, Mn: 1.0% - 2.0%, Cr ≤ 0.30%, Ni ≤ 0.030%, P ≤ 0.035%, S ≤ 0.035%, Cu ≤ 0.30%, and the rest is Fe and inevitable impurities; the key processes include:

[0007] (1) Smelting: The converter controls the weight of the molten iron and scrap steel entering the furnace, and controls the target composition of the molten steel at the end point: C ≥ 0.15%, P ≤ 0.020%. Leave some molten steel when tapping, and prevent the lower oxidation slag. Add a composite deoxidizer during tapping to make slag for deoxidation;

[0008] (2) Refining: The basicity of LF is controlled at 6.0 - 8.0. Feed pure Ca wire before tapping, and then add a covering agent to protect the molten steel. The vacuum extraction target of RH is ≤ 0.5 torr (67 Pa), and the vacuum holding time is ≥ 10 min. Determine the hydrogen content of the molten steel when it leaves the station, and the soft blowing time before tapping is 25 - 35 min;

[0009] (3) Continuous casting: Adopt weak cooling, the specific water volume is 0.14 - 0.18 L / kg, the target value of the superheat of the tundish is 20 - 30 °C, the temperature entering the straightening machine is 1100 - 1150 °C, and the cast billet is stacked and cooled for 24 h;

[0010] (4) Rolling: The heating temperature in the soaking section is 1180 - 1220 °C, and the reduction rate of the first pass and the second pass is greater than 70%; After rolling, use a heat preservation cover for heat preservation to reduce the temperature gradient between the surface and the core, and control the finishing rolling temperature at 900 - 950 °C;

[0011] (5) Post-rolling heat treatment; The temperature after rolling is controlled between 860 - 900 °C. Quenching is carried out before the grains begin to grow, and self-tempering is carried out with the residual heat in the core. Control the water inlet temperature at 850 ± 20 °C, the quenching time is 30 - 500 S, control the surface temperature at 100 - 200 °C within 10 - 30 S after water outlet, and enter the cooling pit for slow cooling for ≥ 24 h.

[0012] Further, in the (1) smelting, the weight of the molten iron entering the furnace is controlled at 120 ± 1 ton, and the weight of the scrap steel is 20 ± 1 ton.

[0013] Further, in the (2) refining, 100 - 200 m of pure Ca wire is fed before tapping.

[0014] Further, in the (2) refining, the hydrogen content of the molten steel when it leaves the station is determined according to the target value [H] ≤ 2.0 ppm.

[0015] Furthermore, the wear-resistant bar is composed of tempered martensite + tempered troostite + bainite, with a tensile strength of over 1200 MPa, a surface hardness of 45 - 60 HRC, and a U-notch impact in the core of over 45 J.

[0016] The beneficial effects of the present invention are as follows:

[0017] 1. The present invention adopts a method combining pressure processing and heat treatment. The steel is heated to a temperature 20 - 60 °C higher than Ac3 to make it austenitized, followed by hot rolling to cause strong deformation of the austenite. Then, it is isothermally treated between 860 - 900 °C to initiate recrystallization of the deformed austenite, and quenching is carried out before the grains start to grow, so that a significant ultra-fine grain effect can be obtained.

[0018] 2. The φ20 - 160 mm alloy structural wear-resistant bar produced by the present invention has the characteristics of high surface hardness and high core toughness, with a surface hardness of 45 - 60 HRC and a U-notch impact in the core of over 45 J.

[0019] 3. The wear-resistant bar produced by the present invention combines high wear resistance, high strength (Rm≥1200 MPa) and excellent low-temperature toughness, and is suitable for manufacturing wear-resistant components such as construction machinery and mining equipment.

[0020] 4. The present invention creates a process without significantly increasing investment and production costs, meets the performance and quality requirements, and can provide experience for the research and development of high-quality steel to special steel products. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 It is the metallographic diagram of the surface B structure of the wear-resistant bar in Embodiment 1 of the present invention: tempered troostite and tempered martensite;

[0023] Figure 2 It is the metallographic diagram of the structure at 1 / 4R of the wear-resistant bar in Embodiment 1 of the present invention: troostite, bainite, and a small amount of ferrite;

[0024] Figure 3 It is the metallographic diagram of the core structure of the wear-resistant bar in Embodiment 1 of the present invention: troostite, bainite, and a very small amount of martensite;

[0025] Figure 4 It is the metallographic diagram of the core structure of the wear-resistant bar in Comparative Example 1 of the present invention;

[0026] Figure 5 It is the metallographic diagram of the core structure of the wear-resistant rod in Comparative Example 2 of the present invention. Specific Embodiments

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] A production method of a non-normalized wear-resistant rod, the chemical composition of the wear-resistant rod by weight percentage is C: 0.50% - 0.80%, Si: 0.10% - 0.40%, Mn: 1.0% - 2.0%, Cr ≤ 0.30%, Ni ≤ 0.030%, P ≤ 0.035%, S ≤ 0.035%, Cu ≤ 0.30%, and the rest is Fe and inevitable impurities. The key processes include converter smelting, LF furnace refining, RH vacuum treatment, continuous casting, and thermomechanical treatment. By combining pressure processing and heat treatment, the steel is heated to a temperature 20 - 60°C higher than Ac3 to make it austenitized, then hot-rolled to cause strong deformation of the austenite, and then isothermally treated between 860 - 900°C to cause the deformed austenite to undergo initial recrystallization, and quenched before the grains start to grow, so that a significant ultra-fine grain effect can be obtained. It is suitable for producing alloy structural wear-resistant rods with a diameter of φ20 - 160mm, having the characteristics of high surface hardness and high core toughness, the surface hardness reaching 45 - 60HRC, the core U-notch impact being above 45J, and having a combination of high wear resistance, high strength (Rm ≥ 1200MPa) and excellent low-temperature toughness, and is suitable for manufacturing wear-resistant components such as construction machinery and mining equipment.

[0029] The technical solution to solve the above technical problems in this aspect is a manufacturing method of a non-normalized wear-resistant rod, and the process route is smelting - continuous casting - rolling - post-rolling heat treatment - slow cooling - warehousing, which can meet the requirements of users.

[0030] The specific production process and technical parameters are as follows:

[0031] (1) Smelting: The converter controls the weight of the molten iron charged into the furnace to be 120 ± 1 ton, and the weight of the scrap steel to be 20 ± 1 ton; controls the target composition of the molten steel at the end point to be C ≥ 0.15%, P ≤ 0.020%, retains the steel and taps the steel, prohibits the lower oxidation slag, and adds a composite deoxidizer during the tapping process to make slag and deoxidize;

[0032] (2) Refining: The alkalinity of LF is controlled at 6.0 - 8.0. Before tapping, 100 - 200 m of pure Ca wire is fed. Then a covering agent is added to protect the molten steel; when entering RH, the vacuum extraction target is ≤0.5 torr (67 Pa) at 7.3, and the vacuum holding time is ≥10 min; the hydrogen content of the molten steel is determined before tapping, and is controlled according to the target value [H] ≤ 2.0 ppm; the soft blowing time before tapping is 25 - 35 min.

[0033] (3) Continuous casting: Weak cooling is adopted, the specific water volume is 0.14 - 0.18 L / kg, the target value of the superheat in the tundish is 20 - 30 °C, the water distribution in each zone is finely adjusted through the soft reduction process, and the continuous casting segregation is weakened by combining the mold and the final electromagnetic stirring. The temperature of the center point on the inner arc surface of the slab entering the straightening machine is monitored at 1100 - 1150 °C, and the slab is stacked and air-cooled for 24 h after being discharged;

[0034] (4) Rolling: The heating temperature in the soaking section is controlled at 1180 - 1220 °C, and the reduction ratios in the first and second passes are greater than 70%; after rolling, a heat preservation cover is used for heat preservation to reduce the temperature gradient between the surface and the core, and the finishing rolling temperature is controlled at 900 - 950 °C.

[0035] (5) Heat treatment after rolling: The temperature after rolling is controlled between 860 - 900 °C. Quenching is carried out before the grains start to grow, and self-tempering is carried out with the residual heat in the core. The water inlet temperature is controlled at 850 ± 20 °C, the quenching time is 30 - 500 S, the surface temperature is controlled at 100 - 200 °C within 10 - 30 S after discharging water, and slow cooling in a cooling pit is carried out for ≥24 h.

[0036] The following is further described in conjunction with the embodiments. Each embodiment is produced according to the technological processes such as converter - refining - continuous casting - rolling, etc.; the chemical compositions of the steel in each embodiment are shown in Table 1, and the rest are Fe and inevitable impurities; the results of the metallographic structure of the square steel produced in each embodiment are shown in Table 2.

[0037] Example 1:

[0038] The chemical composition by weight percentage is C: 0.68%, Si: 0.24%, Mn: 1.52%, Cr: 0.057%, Ni: 0.0184%, P: 0.022%, S: 0.0044%, Cu: 0.029%, and the rest are Fe and inevitable impurities.

[0039] Key process steps and process parameters:

[0040] (1) Smelting: The weight of the hot metal entering the converter is 120 tons, and the weight of the scrap steel is 20 tons; the C content of the molten steel at the end point is 0.16% and the P content is 0.011%.

[0041] (2) Refining: The final slag alkalinity of the refining slag in the LF furnace is 6.5; soft blowing in RH for 30 min, and the tapping temperature is 1535 °C.

[0042] (3) The specific water consumption for secondary cooling in continuous casting is 0.14 L / kg, the superheat of tundish is 21 °C, monitor the temperature of the center point on the inner arc surface of the casting blank entering the straightening machine at 1110 - 1120 °C, and finely adjust the secondary cooling water distribution.

[0043] (4) Rolling: The heating time of the casting blank is 250 min, the temperature in the high-temperature section is controlled at 1220 °C for 65 min, the surface temperature in medium rolling is 920 °C, the core temperature is 1000 °C, and the finishing rolling temperature is 920 °C;

[0044] (5) Post-rolling quenching and tempering: Utilize the waste heat after rolling for quenching and self-tempering, the inlet water temperature is 865 °C, and the outlet surface temperature is 180 °C.

[0045] Example 2:

[0046] The chemical composition by weight percentage is C: 0.67%, Si: 0.25%, Mn: 1.53%, Cr: 0.057%, Ni: 0.0184%, P: 0.022%, S: 0.0044%, Cu: 0.029%, and the rest is Fe and inevitable impurities.

[0047] (1) Smelting: The weight of hot metal charged into the converter is 120 tons, and the weight of scrap steel is 21 tons; the C content of the molten steel at the end point is 0.17% and the P content is 0.012%;

[0048] (2) Refining: The final slag basicity of the refining slag in the LF furnace is 7.0; RH soft blowing is carried out for 35 min, and the tapping temperature is 1545 °C.

[0049] (3) The specific water consumption for secondary cooling in continuous casting is 0.14 L / kg, the superheat of tundish is 23 °C, monitor the temperature of the center point on the inner arc surface of the casting blank entering the straightening machine at 1111 - 1125 °C, and finely adjust the secondary cooling water distribution.

[0050] (4) Rolling: The heating time of the casting blank is 255 min, the temperature in the high-temperature section is controlled at 1219 °C for 70 min, the surface temperature in medium rolling is 930 °C, the core temperature is 1020 °C, and the finishing rolling temperature is 930 °C;

[0051] (5) Post-rolling quenching and tempering: Utilize the waste heat after rolling for quenching and self-tempering, the inlet water temperature is 860 °C, and the outlet surface temperature is 185 °C.

[0052] Example 3:

[0053] The chemical composition by weight percentage is C: 0.69%, Si: 0.23%, Mn: 1.51%, Cr: 0.054%, Ni: 0.0179%, P: 0.021%, S: 0.0043%, Cu: 0.028%, and the rest is Fe and inevitable impurities.

[0054] (1) Smelting: The weight of hot metal charged into the converter is 120 tons, and the weight of scrap is 20 tons; the C content of the molten steel at the end point is 0.18%, and the P content is 0.011%.

[0055] (2) Refining: The final slag basicity of the refining slag in the LF furnace is 7.5; the RH soft blowing time is 31 min, and the tapping temperature is 1542 °C.

[0056] (3) Continuous casting: The secondary cooling water ratio is 0.14 L / kg, the superheat of the tundish is 25 °C, monitor the temperature of the center point of the inner arc surface of the continuous casting billet entering the straightening machine at 1113 - 1128 °C, and finely adjust the secondary cooling water distribution.

[0057] (4) Rolling: The heating time of the continuous casting billet is 249 min, the temperature in the high-temperature section is controlled at 1215 °C for 75 min, the surface temperature in the medium rolling is 915 °C, the core temperature is 985 °C, and the finish rolling temperature is 915 °C;

[0058] (5) Post-rolling quenching and self-tempering: Quenching and self-tempering are carried out using the waste heat after rolling, the inlet water temperature is 855 °C, and the outlet surface temperature is 175 °C.

[0059] Example 4:

[0060] The chemical composition by weight percentage is C: 0.68%, Si: 0.25%, Mn: 1.52%, Cr: 0.055%, Ni: 0.0183%, P: 0.022%, S: 0.0042%, Cu: 0.029%, and the rest are Fe and unavoidable impurities.

[0061] (1) Smelting: The weight of hot metal charged into the converter is 120 tons, and the weight of scrap is 21 tons; the C content of the molten steel at the end point is 0.19%, and the P content is 0.015%.

[0062] (2) Refining: The final slag basicity of the refining slag in the LF furnace is 7.0; the RH soft blowing time is 32 min, and the tapping temperature is 1548 °C.

[0063] (3) Continuous casting: The secondary cooling water ratio is 0.14 L / kg, the superheat of the tundish is 26 °C, monitor the temperature of the center point of the inner arc surface of the continuous casting billet entering the straightening machine at 1118 - 1138 °C, and finely adjust the secondary cooling water distribution.

[0064] (4) Rolling: The heating time of the continuous casting billet is 239 min, the temperature in the high-temperature section is controlled at 1215 °C for 75 min, the surface temperature in the medium rolling is 918 °C, the core temperature is 990 °C, and the finish rolling temperature is 918 °C;

[0065] (5) Post-rolling quenching and self-tempering: Quenching and self-tempering are carried out using the waste heat after rolling, the inlet water temperature is 851 °C, and the outlet surface temperature is 178 °C.

[0066] Table 1: Chemical compositions of the steel in each example (%)

[0067] Embodiment C Si Mn P S Cr Cu Ni 1 0.68 0.24 1.52 0.022 0.0044 0.057 0.029 0.0184 2 0.67 0.25 1.53 0.023 0.0045 0.056 0.030 0.0163 3 0.69 0.23 1.51 0.021 0.0043 0.054 0.028 0.0179 4 0.68 0.25 1.52 0.022 0.0042 0.055 0.029 0.0183

[0068] Table 2: Metallographic structure and strength results of square steel samples in each example

[0069]

[0070] Comparative example 1:

[0071] The difference from Example 1 is that (5) post-rolling quenching and tempering: Using the waste heat after rolling for quenching and self-tempering, the inlet water temperature is 720 - 730 °C, the outlet surface temperature is 550 - 580 °C, and the red return temperature is 400 °C.

[0072] The test results are shown in Table 3, and the metallographic structure is as Figure 4 shown.

[0073] Table 3: Metallographic structure and strength results of square steel samples in Comparative example 1

[0074]

[0075]

[0076] The cross-sectional hardness of this experiment was 19.9 - 37.0 HRC, which did not reach the expected target (>45 HRC). The quenching and cooling effect was not good (insufficient cooling time and cooling intensity), resulting in a high-temperature tempered structure. Subsequently, the rolling speed was reduced or the cooling capacity of the water tank was increased to ensure the cooling effect.

[0077] Comparative example 2:

[0078] The difference from Example 2 is that (5) post-rolling quenching and tempering: Using the waste heat after rolling for quenching and self-tempering, the inlet water temperature is 730 - 740 °C, the outlet surface temperature is 500 - 550 °C, and the red return temperature is 223 - 229 °C.

[0079] The cross-sectional hardness of this experiment was 32.2 - 34.2 HRC, which did not reach the expected target (>45 HRC). The quenching and cooling effect was not good (insufficient cooling time and cooling intensity), and the metallographic structure was as Figure 5 shown, resulting in a high-temperature tempered structure. Subsequently, the rolling speed was reduced or the cooling capacity of the water tank was increased to ensure the cooling effect.

[0080] Comparative example 3:

[0081] The difference from Example 3 is that (5) post-rolling quenching and tempering: Using the waste heat after rolling for quenching and self-tempering, the inlet water temperature is 852 °C, the outlet surface temperature is 500 - 550 °C, and the red return temperature is 337 °C.

[0082] The cross-sectional hardness of this experiment was 28.4-39.4HRC, which did not reach the expected target (>45HRC). The quenching cooling effect was not good (insufficient cooling time and cooling intensity), resulting in high-temperature tempered structure. Subsequent measures were taken to reduce the rolling speed or increase the cooling capacity of the water tank to ensure the cooling effect.

[0083] Comparative Example 4:

[0084] The difference from Example 4 is that (5) post-rolling tempering: quenching and self-tempering are performed using the residual heat after rolling, the water inlet temperature is 891°C, the water outlet surface temperature is 556°C, and the red-return temperature is 171°C.

[0085] The hardness of the round steel in this test was improved compared with the previous two times. The surface hardness of the second round was 41.4-45.4HRC, reaching the target requirement (≥45HRC). Subsequently, the cooling capacity was improved and the rolling speed was increased to achieve uniform performance of the round steel.

[0086] Comparative Example 5: The difference from Example 4 is that (5) post-rolling tempering: quenching and self-tempering are carried out using the residual heat after rolling, the water inlet temperature is 835°C, the water outlet surface temperature is 470-561°C, and the red-return temperature is 271°C.

[0087] In this experiment, the cross-section hardness was 36.6-43.6HRC, and the surface hardness test was 35.2-45.2HRC, which did not fully reach the expected target (>45HRC). The quenching cooling effect was not good (insufficient cooling time and cooling intensity), and the outlet water temperature was 470-561℃, which was too high, resulting in high-temperature tempered structure.

[0088] In summary, the technical solution of the present invention adopts a method combining pressure processing and heat treatment to heat the steel to a temperature higher than Ac3 by 20-60℃ to austenitize it, and then hot-roll it to make the austenite undergo strong deformation, and then isothermally heat it at 860-900℃ to make the deformed austenite undergo initial recrystallization, and quench it before the grains begin to grow, so that a significant ultra-fine effect can be obtained. It is suitable for the production of alloy structural wear-resistant rods with a diameter of φ20-160mm, with the characteristics of high surface hardness and high toughness in the core.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A method for producing a wear-resistant rod without quenching and tempering, characterized in that: The chemical composition of the wear-resistant rod is C: 0.50% to 0.80%, Si: 0.10% to 0.40%, Mn: 1.0% to 2.0%, Cr≤0.30%, Ni≤0.030%, P≤0.035%, S≤0.035%, Cu≤0.30%, and the rest is Fe and unavoidable impurities; The key process steps include: (1) Smelting: The converter controls the weight of molten iron and scrap steel entering the furnace, controls the target composition of the final molten steel to be C ≥ 0.15% and P ≤ 0.020%, retains steel for tapping, prohibits the addition of oxidized slag, and adds a composite deoxidizer for slag formation and deoxidation during the tapping process; (2) Refining: LF basicity is controlled at 6.0-8.0, pure Ca line is fed before leaving the station, and then covering agent is added to protect the molten steel. The vacuum target is ≤0.5torr when entering RH 7.3, and the vacuum maintenance time is ≥10min. Hydrogen is determined before the molten steel leaves the station, and the soft blowing time before leaving the station is 25-35min; (3) Continuous casting: weak cooling is adopted, the specific water content is 0.14-0.18L / kg, the target value of the superheat of the tundish is 20-30℃, the temperature entering the straightening machine is 1100-1150℃, and the billet is piled and cooled for 24h; (4) Rolling: The heating temperature of the soaking section is 1180-1220°C, and the reduction ratio of the first and second passes is greater than 70%. After rolling, a heat preservation cover is used to reduce the temperature gradient between the surface and the core, and the final rolling temperature is controlled at 900-950°C. (5) Heat treatment after rolling: the temperature after rolling is controlled between 860-900℃, quenching is carried out before the grains begin to grow, the residual heat in the core is used for self-tempering, the water inlet temperature is controlled at 850±20℃, the quenching time is 30-500S, the surface temperature is controlled at 100-200℃ 10-30S after exiting the water, and slow cooling is carried out in the cold pit for ≥24h.

2. The method for producing a wear-resistant rod without quenching and tempering as claimed in claim 1, characterized in that: In the smelting process (1), the weight of the molten iron entering the furnace is controlled to be 120±1 tons, and the weight of the scrap steel is controlled to be 20±1 tons.

3. The method for producing a wear-resistant rod without quenching and tempering as claimed in claim 1, characterized in that: The (2) refining process feeds 100-200m of pure Ca line before leaving the station.

4. The method for producing a wear-resistant rod without quenching and tempering as claimed in claim 1, characterized in that: (2) The target value [H] of the hydrogen content of the refined molten steel out of the station is ≤2.0ppm.

5. The method for producing a wear-resistant rod without quenching and tempering according to any one of claims 1 to 4, characterized in that: The wear-resistant rod weave is tempered martensite + tempered troostite + bainite, the tensile strength reaches more than 1200MPa, the surface hardness reaches 45-60HRC, and the core U-shaped impact is more than 45J.

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