JP2023506822A - High-hardness wear-resistant steel with excellent low-temperature impact toughness and method for producing the same - Google Patents

Abstract

The present invention provides a wear-resistant steel that has wear resistance, high impact toughness at low temperatures, and high hardness, and a method for producing the same. [Solution] In weight percent, carbon (C): 0.25 to 0.50%, silicon (Si): 1.0 to 1.6%, manganese (Mn): 0.6 to 1.6%, Phosphorus (P): 0.05% or less (0% excluded), Sulfur (S): 0.02% or less (0% excluded), Aluminum (Al): 0.07% or less (0% excluded) , chromium (Cr): 0.5 to 1.5%, calcium (Ca): 0.0005 to 0.004%, nitrogen (N): 0.006% or less, the balance consisting of Fe and other inevitable impurities, The microstructure is characterized by containing a composite structure of martensite and bainite, and a retained austenite phase with an area fraction of 2.5 to 10%. [Selection diagram] Figure 2

Description

TECHNICAL FIELD The present invention relates to high-hardness wear-resistant steel with excellent low-temperature impact toughness and a method for producing the same. More specifically, the present invention relates to a wear-resistant steel having excellent low-temperature impact toughness and high hardness, which is suitable for construction machinery and the like. and its manufacturing method.

Industrial machinery such as bulldozers and power shovels, mining equipment such as crushers and chutes, and large dump trucks are required to be lighter and have higher performance. .
In particular, in order to extend the service life of such parts, the wear-resistant steel used for these parts tends to be increasingly hardened. are both required.

On the other hand, high-hardness wear-resistant steel with excellent toughness is also widely used as bulletproof steel.
Currently, the following techniques have been proposed for wear-resistant steels used in industrial machinery, construction machinery, and the like.

In Patent Document 1, the steel contains a certain amount of Ti, B, etc. in addition to C, Si, Mn, and the steel plate in which the content of H is limited is set to a cooling end temperature of 300 ° C. or less during reheating and quenching. A method for producing steel having a Brinell hardness of 450 or less with excellent soundness is disclosed.
Patent Document 2 discloses a method of reheating and quenching a steel plate to which Cr, Mo, and B are added in addition to C, Si, and Mn to produce steel having a Brinell hardness of 500 class.

In addition, in Patent Document 3, the content of Cr, Mo, Ti, Nb, B, etc. is limited in steel together with C, Si, Mn, and Cu, Ni, V, Ca, etc. are further included as necessary. It is disclosed that a steel with excellent low-temperature toughness and a Brinell hardness of 500 grade can be manufactured by a step of hot-rolling the steel, cooling it to 100° C. or less, and continuously tempering it.
Furthermore, in Patent Document 4, both impact resistance and wear resistance are improved by tempering steel containing relatively low content of C, high content of Si, and other elements as appropriate. A secured high modulus high strength special purpose steel is disclosed.

However, Patent Document 1 does not satisfy the hardness level required in the actual environment, Patent Document 2 satisfies the hardness level but has the disadvantage of inferior toughness, and Patent Document 3 contains a large amount of expensive elements. , is economically disadvantageous and has limited application. Patent Document 4 has the drawback that it is difficult to ensure low-temperature toughness and the production cost is high.
Therefore, it is desired to develop a wear-resistant steel excellent in low-temperature toughness as well as wear resistance by an economical method without containing a large amount of expensive elements.

Japanese Patent Publication No. 64-010564 Japanese Patent Publication No. 1-021846 JP-A-8-041535 Korean Patent No. 10-0619841

SUMMARY OF THE INVENTION An object of the present invention is to provide a wear-resistant steel having high impact toughness at low temperature and high hardness as well as wear resistance, and a method for producing the same.
A person having ordinary knowledge in the technical field to which the present invention pertains will have no difficulty in understanding the additional problems of the present invention from what has been described throughout the specification of the present invention.

The high-hardness wear-resistant steel excellent in low-temperature impact toughness of the present invention contains, by weight %, carbon (C): 0.25 to 0.50%, silicon (Si): 1.0 to 1.6%, manganese ( Mn): 0.6 to 1.6%, Phosphorus (P): 0.05% or less (excluding 0%), Sulfur (S): 0.02% or less (excluding 0%), Aluminum (Al) : 0.07% or less (excluding 0%), chromium (Cr): 0.5-1.5%, calcium (Ca): 0.0005-0.004%, nitrogen (N): 0.006% Hereinafter, the balance consists of Fe and other unavoidable impurities, and the microstructure is characterized by containing a composite structure of martensite and bainite and a retained austenite phase with an area fraction of 2.5 to 10%.

A method for producing high-hardness wear-resistant steel with excellent low-temperature impact toughness according to the present invention comprises the steps of preparing a steel slab having the above alloy composition, heating the steel slab in a temperature range of 1050 to 1250° C., rough rolling the heated steel slab in a temperature range of 950 to 1150° C.; after the rough rolling, finishing hot rolling in a temperature range of 850 to 950° C. to produce a hot rolled steel sheet; cooling the hot-rolled steel sheet to 200 to 400° C. at a cooling rate of 25° C./s or more, and then air cooling.

According to the present invention, it is possible to provide a wear-resistant steel having high hardness and excellent low-temperature toughness.
In particular, the present invention is economically advantageous because it can provide wear-resistant steel with target levels of physical properties without further heat treatment by optimizing the alloy composition and manufacturing conditions. Characteristic.

1 is a photograph of an optical microscopic observation of a microstructure of an inventive steel according to an example of the present invention; 1 is a photograph of a microstructure of an invention steel according to an example of the present invention, measured by a scanning electron microscope (a) and EBSD (b); 1 is a photograph of a microstructure of a comparative steel according to an example of the present invention observed with an optical microscope; 1 is a photograph of a microstructure of a comparative steel according to an example of the present invention measured by a scanning electron microscope (a) and EBSD (b);

The present inventors provide a steel material that can secure wear resistance, which is a core physical property, and has excellent physical properties such as strength and toughness as a material that can be suitably applied to construction machinery and the like. I have done extensive research for this.
As a result, the inventors have provided the present invention which improves the wear resistance of steel materials by an economically advantageous method.
The present invention will be described in detail below.

The high hardness wear resistant steel according to one aspect of the present invention contains, in weight percent, carbon (C): 0.25-0.50%, silicon (Si): 1.0-1.6%, manganese (Mn): Phosphorus (P): 0.05% or less (excluding 0%), Sulfur (S): 0.02% or less (excluding 0%), Aluminum (Al): 0.6% to 1.6%. 07% or less (excluding 0%), chromium (Cr): 0.5-1.5%, calcium (Ca): 0.0005-0.004%, nitrogen (N): 0.006% or less be able to.

Hereinafter, the reasons for restricting the alloy composition of the wear-resistant steel provided by the present invention as described above will be described in detail.
On the other hand, unless otherwise specified in the present invention, the content of each element is based on the weight, and the ratio of the structure is based on the area.

Carbon (C): 0.25-0.50%
Carbon (C) is an element that effectively improves the strength and hardness of steel having a low-temperature transformation phase such as a martensite or bainite phase, and is effective in improving hardenability. In order to sufficiently obtain the above effects, it is preferable to contain 0.25% or more of C, but if the content exceeds 0.50%, the weldability and toughness of the steel may be impaired.
Therefore, C should preferably be contained in an amount of 0.25 to 0.50%.

Silicon (Si): 1.0-1.6%
Silicon (Si) has a deoxidizing effect and is effective in improving strength through solid-solution strengthening. It suppresses the formation of carbides such as cementite in high-carbon steel containing a certain amount or more of C, and promotes the formation of retained austenite. It is an element that
In particular, homogeneously distributed retained austenite in steel having a low-temperature transformation phase such as martensite and bainite contributes to improving impact toughness without reducing strength. is an advantageous element for
In order to sufficiently obtain the above effects, it is preferable that the Si content is 1.0% or more.
Therefore, the Si content is preferably 1.0 to 1.6%, more preferably 1.2% or more.

Manganese (Mn): 0.6-1.6%
Manganese (Mn) is an element that suppresses the formation of ferrite and lowers the Ar3 temperature, thereby improving the hardenability of the steel and enhancing the strength and toughness.
In order to obtain the target level of hardness in the present invention, it is preferable to contain 0.6% or more of the above Mn, but if the content exceeds 1.6%, the weldability decreases and center segregation occurs There is a possibility that the physical properties of the core of the steel will deteriorate.
Therefore, Mn should preferably be contained in an amount of 0.6 to 1.6%.

Phosphorus (P): 0.05% or less (excluding 0%)
Phosphorus (P) is an element inevitably contained in steel and an element that reduces the toughness of steel. Therefore, it is preferable to reduce the content of P as much as possible.
In the present invention, the content of P is limited to 0.05% or less because the physical properties of the steel are not significantly affected even if the P content is 0.05% at most. More preferably, it should be restricted to 0.03% or less. However, 0% is excluded in consideration of the unavoidable content level.

Sulfur (S): 0.02% or less (excluding 0%)
Sulfur (S) is an element that reduces the toughness of steel by combining with Mn in steel to form MnS inclusions. Therefore, it is preferable to reduce the content of S described above as much as possible.
In the present invention, the S content is limited to 0.02% or less because the physical properties of the steel are not significantly affected even if the S content is 0.02% at most. More preferably, it should be limited to 0.01% or less. However, 0% is excluded in consideration of the unavoidable content level.

Aluminum (Al): 0.07% or less (excluding 0%)
Aluminum (Al) is an effective element for reducing the oxygen content in molten steel as a steel deoxidizing agent. If the content of Al exceeds 0.07%, the steel may lose its cleanliness.
Therefore, the Al content is preferably 0.07% or less. However, if the content of Al is excessively reduced, a load is generated during the steelmaking process, resulting in an increase in production costs.

Chromium (Cr): 0.5-1.5%
Chromium (Cr) is an element that increases the hardenability of steel, improves strength, and ensures hardness of the surface and center of steel. Since such Cr is a relatively inexpensive element, it is preferable to contain 0.5% or more in order to secure high hardness and high toughness of steel by utilizing Cr. However, if the content exceeds 1.5%, the weldability of the steel may deteriorate.
Therefore, the Cr content is preferably 0.5 to 1.5%, more preferably 0.65% or more.

Calcium (Ca): 0.0005-0.004%
Calcium (Ca) has a strong binding force with sulfur (S), so it can suppress the stretching of MnS by forming CaS around MnS, and is an element that improves the toughness in the direction perpendicular to the rolling direction. be. In addition, CaS generated by the addition of Ca also has the effect of improving corrosion resistance in a humid external environment.
In order to sufficiently obtain the above effect, Ca content is preferably 0.0005% or more, but if the Ca content exceeds 0.004%, there is a risk of causing defects such as nozzle clogging during steelmaking operations. be.
Therefore, Ca should preferably be contained in an amount of 0.0005 to 0.004%.

Nitrogen (N): 0.006% or less Nitrogen (N) is an element that forms precipitates in steel and improves the strength of steel. There is a possibility that the toughness of the steel may rather decrease.
In the present invention, it is preferable that the content of N is 0.006% or less because strength can be secured even if the content of N is not included. However, 0% is excluded in consideration of the unavoidable content level.

In addition to the above alloy composition, the wear-resistant steel of the present invention may further contain the following elements for the purpose of advantageously securing the target physical properties.
Specifically, the wear-resistant steel may further include at least one of nickel (Ni), molybdenum (Mo), titanium (Ti), boron (B), and vanadium (V).

Nickel (Ni): 0.01-0.5%
Nickel (Ni) is an element that improves the strength and toughness of steel at the same time. However, since it is an expensive element, when its content exceeds 0.5%, there is a problem that the manufacturing cost rises greatly.
Therefore, when Ni is contained, it is preferable to make it 0.01 to 0.5%.

Molybdenum (Mo): 0.01-0.3%
Molybdenum (Mo) is an element that is advantageous in increasing the hardenability of steel and, in particular, in increasing the hardness of a thick material having a certain thickness or more. In order to sufficiently obtain the above effect, it is preferable to contain 0.01% or more, but if the content exceeds 0.3%, not only the manufacturing cost increases but also the weldability may be deteriorated. .
Therefore, when Mo is contained, it is preferably 0.01 to 0.3%.

Titanium (Ti): 0.005 to 0.025%
Titanium (Ti) is an element advantageous for maximizing the effect of B that improves the hardenability of steel. That is, the above Ti combines with N in the steel to precipitate TiN, thereby reducing the content of dissolved N, thereby suppressing the formation of BN of B and increasing the dissolved B, thereby improving the hardenability. can be maximized.
In order to sufficiently obtain the above effect, it is preferable to contain Ti at 0.005% or more, but if the content exceeds 0.025%, coarse TiN precipitates are formed, and the toughness of the steel is reduced. is likely to decrease.
Therefore, when Ti is contained, it is preferable to make it 0.005 to 0.025%.

Boron (B): 0.0002-0.005%
Boron (B) is an element effective in significantly increasing the hardenability of steel and improving strength even when added in a small amount. In order to sufficiently obtain such effects, it is preferable to contain 0.0002% or more of B. On the other hand, if the content is excessive, the toughness and weldability of the steel may be impaired, so the content is limited to 0.005% or less.
Therefore, when the above B is contained, it should be 0.0002 to 0.005%. Preferably, B is 0.0040% or less, more preferably 0.0035% or less, still more preferably 0.0030% or less.

Vanadium (V): 0.2% or less Vanadium (V) suppresses the growth of austenite grains by forming VC carbides during reheating after hot rolling, thereby improving the hardenability of steel and increasing the strength and It is an element that plays a role in ensuring toughness. Since V is a relatively expensive element, if its content exceeds 0.2%, there is a problem in that the manufacturing cost rises significantly.
Therefore, when V is added, it is preferably 0.2% or less.

The remaining component of the present invention is iron (Fe). However, in normal manufacturing processes, unintended impurities from raw materials or the surrounding environment may inevitably be mixed in, and this cannot be eliminated. These impurities are well known to anyone skilled in the art of normal manufacturing processes, and their contents are not specifically addressed herein.

The wear-resistant steel of the present invention having the above alloy composition preferably has a microstructure composed of a composite structure of martensite and bainite phases.
Specifically, the wear-resistant steel of the present invention preferably contains a composite structure of martensite and bainite phases in an area fraction of 90% or more. It becomes difficult to secure target levels of strength and hardness. Here, the martensite and bainite phases can include tempered martensite and tempered bainite phases, respectively.

In the wear-resistant steel of the present invention, the composite structure preferably has an average lath size of 0.3 μm or less. When the average lath size of the composite structure exceeds 0.3 μm, there is a problem that the toughness of the steel is lowered.
The wear-resistant steel of the present invention can contain a retained austenite phase in addition to the above composite structure, and at this time, it can contain 2.5 to 10% in terms of area fraction. If the fraction of the retained austenite phase is less than 2.5%, the low-temperature impact toughness is lowered, whereas if it exceeds 10%, the hardness may be lowered.
On the other hand, the wear-resistant steel of the present invention has the above structure over the entire thickness.

The wear-resistant steel of the present invention having the proposed microstructure together with the above alloy composition can have a thickness of 5-40 mm, and such wear-resistant steel has a high surface hardness of 460-540 HB, It has an impact absorption energy of 17 J or more at -40°C and is excellent in low temperature toughness.
Here, the surface hardness means a hardness value measured at a point of 2 mm to 5 mm in the thickness direction from the surface of the wear resistant steel.

Hereinafter, a method for producing a high-hardness wear-resistant steel according to another aspect of the present invention will be described.
Briefly, after preparing a steel slab that satisfies the above alloy composition, the steel slab can be manufactured through [heating-rolling-cooling] steps. Below, each process condition is demonstrated in detail.

[Steel slab heating process]
First, a steel slab having the alloy composition proposed in the present invention is prepared and then heated in the temperature range of 1050-1250°C.
If the heating temperature is less than 1050°C, the deformation resistance of the steel is large, and the subsequent rolling process cannot be performed effectively. There is a possibility that crystal grains become coarse and a non-uniform structure is formed.
Therefore, the steel slab is preferably heated in the temperature range of 1050-1250.degree.

[Rolling process]
Roll the steel slab heated as above. At this time, a hot-rolled steel sheet can be manufactured through the processes of rough rolling and finish hot rolling.
First, the heated steel slab is roughly rolled at a temperature range of 950-1150°C to produce a bar, which is then finish hot-rolled at a temperature range of 850-950°C.

If the temperature during rough rolling is less than 950° C., the rolling load increases and the reduction is relatively weak, so deformation is not sufficiently transmitted to the center of the slab in the thickness direction, resulting in , defects such as voids may not be removed. On the other hand, if the temperature exceeds 1150° C., the recrystallized grain size may become excessively coarse, resulting in poor toughness.
If the temperature during finish hot rolling is less than 850° C., two-phase region rolling is performed, and ferrite may be generated in the microstructure. On the other hand, if the temperature exceeds 950° C., the grain size of the final structure may become coarse and the low temperature toughness may be deteriorated.

[Cooling process]
The hot-rolled steel sheet manufactured through the above rolling process is water-cooled to a certain temperature and then air-cooled.
Specifically, in the present invention, when cooling the hot rolled steel sheet, water cooling is performed to a temperature range of 200 to 400 ° C. at an average cooling rate of 25 ° C./s or more, and then air cooling is performed at 150 ° C. or less. Therefore, there is an effect that self-tempering is exhibited during the air cooling. That is, the martensite and bainite phases are tempered during air cooling, and the retained austenite phase is formed in a constant fraction, thereby improving the toughness of the steel.
The air cooling may be performed to room temperature.

Alternatively, the cooling can be initiated above Ar3. Here, Ar3 depends on the alloy composition system, which is well known to any ordinary technician.
If the cooling rate during water cooling is less than 25° C./s, a ferrite phase is formed during cooling, or the average lath size of the hard phase (martensite + bainite) increases, resulting in high hardness. It becomes difficult to ensure Although the upper limit of the cooling rate during water cooling is not particularly limited, the maximum cooling rate can be 100° C./s in consideration of the cooling equipment.

If the cooling end temperature is less than 200° C. when cooling at the above cooling rate, the self-tempering effect is small, making it difficult to ensure the target level of toughness. On the other hand, when the temperature exceeds 400° C., the average lath size of the hard phase (martensite + bainite) becomes large, and the strength or toughness decreases, so that the target level of hardness or toughness cannot be secured. Gone.
The hot-rolled steel sheet obtained through the series of manufacturing processes described above is a steel material having a thickness of 5 to 40 mm, and can have abrasion resistance, high hardness, and high toughness.
In particular, according to the present invention, since self-tempering can be achieved during the cooling process, a subsequent tempering process is not required, thereby producing an economical wear-resistant steel.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples. However, it should be noted that the following examples are only for illustrating and embodying the present invention, and are not intended to limit the scope of the present invention. The scope of rights of the present invention is determined by matters described in the claims and matters reasonably inferred therefrom.

After preparing a steel slab having the alloy composition shown in Table 1 below, it was subjected to [heating-rolling-cooling] under the process conditions shown in Table 2 below to produce each hot-rolled steel sheet. At this time, at the time of cooling, after water cooling was performed to a constant temperature, air cooling was performed at 150° C. or less.
Then, the microstructure and mechanical properties of each hot-rolled steel sheet were measured, and the results are shown in Table 3 below.

The microstructure of each hot-rolled steel sheet was examined by cutting a test piece to an arbitrary size to produce a mirror surface, corroding it with a Nital etchant, and then examining it with an optical microscope and a scanning electron microscope (SEM). A point of 1/2t, which is the central part of the thickness, was observed. At this time, the lath size of the composite structure of martensite and bainite was measured using electron back-scattered diffraction (EBSD) analysis.
The hardness and toughness of each hot-rolled steel sheet were measured using a Brinell hardness tester (load of 3000 kgf, 10 mm tungsten press-fit ball) and a Charpy impact tester. At this time, the average value of the values measured three times after milling the surface of the hot-rolled sheet by 2 mm was used as the surface hardness. In the Charpy impact test, a test piece was sampled from a 1/4t point in the thickness direction, and the average value of the values measured three times at -40°C was used.

（表１中、Ｐ＊、Ｓ＊、Ｃａ＊、Ｂ＊、Ｎ＊は、ｐｐｍで示したものである。）

(In Table 1, P*, S*, Ca*, B*, and N* are indicated in ppm.)

（表２中、発明例の冷却開始温度はＡｒ３以上である。）

(In Table 2, the cooling start temperature of the invention examples is Ar3 or higher.)

（表３中、Ｍはマルテンサイト、Ｂはベイナイト、Ｆはフェライト、ｒ－γは残留オーステナイト相を意味する。）

(In Table 3, M means martensite, B means bainite, F means ferrite, and r-γ means retained austenite phase.)

As shown in Tables 1 to 3 above, invention examples 1 to 10, which satisfy all the alloy compositions and manufacturing conditions proposed in the present invention, have a microstructure containing a fixed fraction of the retained austenite phase together with martensite + bainite. It can be confirmed that there is Moreover, the lath size of the above martensite and bainite was formed to be 0.3 μm or less. Therefore, in Examples 1 to 10, excellent hardness and low-temperature impact toughness could be ensured.
In contrast, in Comparative Examples 1 to 8, which satisfy the alloy composition proposed by the present invention but the manufacturing conditions are different from the present invention, ferrite phases are formed in the microstructures, or laths of martensite and bainite are formed. ) It was difficult to secure both excellent high hardness and low temperature impact toughness because the size was coarse or the fraction of austenite phase was minute.

On the other hand, in Comparative Examples 9 to 11, since the content of C in the steel was insufficient, the hardenability was low, and the proeutectoid ferrite phase was excessively formed, resulting in extremely poor hardness and toughness. In addition, Comparative Examples 12 and 13 were cases in which the C content in the steel was too high, the fraction of the retained austenite phase was very small, and the low temperature impact toughness was remarkably inferior.
In Comparative Example 14, in which the content of Si and Cr in the steel is insufficient, the formation of the retained austenite phase is not sufficient, and the formation of the cementite phase, which is inferior in toughness, is promoted, and although the hardness is high, the toughness is poor. rice field.
In Comparative Example 15, the content of Si and Cr was insufficient, and the retained austenite phase was not sufficiently formed, and the formation of the cementite phase was promoted, resulting in poor toughness and excessive Mo content. , showed significantly inferior toughness compared to the standard due to the increase in hardenability.

1 and 2 show microstructure photographs of Inventive Example 5. FIG.
Among these, FIG. 1 is a photograph observed with an optical microscope, and FIG. 2 is a photograph observed with a scanning electron microscope and EBSD. can be confirmed, and it can be seen that the retained austenite phase is finely distributed at the lath boundary between martensite and bainite.

3 and 4 show microstructure photographs of Comparative Example 6. FIG.
Among these, FIG. 3 is a photograph observed with an optical microscope, and FIG. 4 is a photograph observed with a scanning electron microscope (a) and EBSD (b). However, it can be confirmed that the retained austenite phase is formed very finely.

Claims (10)

% by weight, carbon (C): 0.25-0.50%, silicon (Si): 1.0-1.6%, manganese (Mn): 0.6-1.6%, phosphorus (P) : 0.05% or less (excluding 0%), sulfur (S): 0.02% or less (excluding 0%), aluminum (Al): 0.07% or less (excluding 0%), chromium (Cr ): 0.5 to 1.5%, calcium (Ca): 0.0005 to 0.004%, nitrogen (N): 0.006% or less, the balance consisting of Fe and other inevitable impurities,
A high-hardness wear-resistant steel with excellent low-temperature impact toughness, characterized by containing a composite structure of martensite and bainite as a microstructure and a retained austenite phase with an area fraction of 2.5 to 10%. The wear-resistant steel is, in weight percent, nickel (Ni): 0.01 to 0.5%, molybdenum (Mo): 0.01 to 0.3%, titanium (Ti): 0.005 to 0.025 %, boron (B): 0.0002 to 0.005%, and vanadium (V): 0.2% or less. Excellent high hardness wear resistant steel. 2. The high-hardness wear-resistant steel with excellent low-temperature impact toughness according to claim 1, wherein the composite structure of martensite and bainite has an average lath size of 0.3 [mu]m or less. 2. The high-hardness wear-resistant steel excellent in low-temperature impact toughness according to claim 1, wherein the wear-resistant steel contains the composite structure of martensite and bainite in an area fraction of 90% or more. The high-hardness wear-resistant steel excellent in low-temperature impact toughness according to claim 1, wherein the wear-resistant steel has a surface hardness of 460 to 540 HB and an impact absorption energy of 17 J or more at -40°C. . The high-hardness wear-resistant steel with excellent low-temperature impact toughness according to claim 1, wherein the wear-resistant steel has a thickness of 5 to 40 mm. % by weight, carbon (C): 0.25-0.50%, silicon (Si): 1.0-1.6%, manganese (Mn): 0.6-1.6%, phosphorus (P) : 0.05% or less (excluding 0%), sulfur (S): 0.02% or less (excluding 0%), aluminum (Al): 0.07% or less (excluding 0%), chromium (Cr ): 0.5 to 1.5%, calcium (Ca): 0.0005 to 0.004%, nitrogen (N): 0.006% or less, and the balance being Fe and other inevitable impurities. stages and
heating the steel slab to a temperature range of 1050-1250° C.;
rough rolling the heated steel slab at a temperature range of 950-1150° C.;
After the rough rolling, finish hot rolling is performed in a temperature range of 850 to 950° C. to produce a hot rolled steel sheet;
cooling the hot-rolled steel sheet to 200 to 400° C. at a cooling rate of 25° C./s or more, and then air cooling;
A method for producing high-hardness wear-resistant steel with excellent low-temperature impact toughness, comprising: The steel slab has, in weight percent, nickel (Ni): 0.01 to 0.5%, molybdenum (Mo): 0.01 to 0.3%, titanium (Ti): 0.005 to 0.025% , Boron (B): 0.0002 to 0.005%, and Vanadium (V): 0.2% or less. A method for producing high-hardness wear-resistant steel. 8. The method of claim 7, wherein self-tempering occurs during air cooling. 8. The method for producing high hardness wear resistant steel excellent in low temperature impact toughness according to claim 7, wherein the air cooling is performed at 150[deg.] C. or lower.

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