Wear-resistant steel and smelting method thereof

Abstract

The smelting method comprises the following steps that S1, semisteel is discharged from a titanium slag electric furnace, specifically, the semisteel of the titanium slag electric furnace is conveyed to an EAF primary smelting station, oxygen blowing decarburization is conducted, foaming slag is made for rapid dephosphorization, and pre-deoxidation treatment is conducted during EAF tapping; s2, molten steel obtained after EAF primary smelting is conveyed to an LF station, FeAl is added, a deoxidation material is added for composite diffusion deoxidation, and white slag is made; s3, in the earlier stage of LF refining, Ni, Mn and Mo are added for primary alloying, and in the middle and later stages of LF refining, Cr, Mn, Si, Nb and V are added for secondary alloying; s4, at the last stage of LF refining, CaSi wires are fed; and after the CaSi wire is fed and soft argon blowing is carried out, RE wires are fed. The purpose of stably producing qualified steel for the wear-resistant lining plate is achieved through EAF oxygen blowing decarburization, foaming slag rapid dephosphorization, LF deoxidation, desulfurization, alloying and temperature adjustment, and CaSi wires and RE wires are fed into molten steel in the final stage of refining for purification and modification treatment.

Description

Technical Field

[0001] The invention relates to the technical field of high-value utilization of semi-steel, a by-product of titanium slag smelting, and in particular to wear-resistant steel and a smelting method thereof. Background Art

[0002] The main method for producing titanium slag is electric furnace smelting. This method is to mix titanium concentrate with solid reducing agent and add it to the electric furnace for reduction smelting. The iron oxide in the titanium concentrate is selectively reduced to metallic iron, and the titanium oxide is enriched in the slag. Titanium slag and by-product metallic iron are obtained by slag iron separation. The carbon content of metallic iron, a by-product of smelting titanium slag, is between that of steel and pig iron, and is also called semi-steel. The effective use of semi-steel has an important impact on improving the overall economic efficiency of titanium slag production.

[0003] Semi-steel can be developed and processed into steel for wear-resistant lining of crusher. Wear-resistant lining of crusher requires good mechanical properties such as impact toughness and wear resistance, and is cast. The quality of steel castings depends to a large extent on the metallurgical quality of steel. Its mechanical properties are determined by the chemical composition and metallurgical quality of steel, especially plasticity and toughness. Under the same chemical composition conditions, metallurgical quality has a great influence, and various casting defects, such as pores, slag inclusions, slag holes, thermal cracks, etc., are closely related to metallurgical quality.

[0004] In view of this, the existing technology should be improved. Summary of the invention

[0005] The main purpose of the present invention is to provide a wear-resistant steel and a smelting method thereof, which adopts the EAF-LF-WF process flow, wherein EAF is used for oxygen blowing decarburization, foamed slag is used for rapid dephosphorization, LF is used for deoxidation, desulfurization, alloying and temperature adjustment, etc., and CaSi wire and RE wire are fed into the molten steel at the end of refining for purification and modification, so as to achieve the purpose of stably producing qualified wear-resistant liner steel.

[0006] According to one aspect of the present invention, a smelting method for wear-resistant steel is provided, which comprises the following steps: S1, semi-steel is produced from a titanium slag electric furnace, the semi-steel from the titanium slag electric furnace is transported to an EAF primary smelting station, oxygen is blown for decarburization, foamed slag is made for rapid dephosphorization, and pre-deoxidation treatment is performed when the EAF is produced; S2. Send the molten steel after EAF primary refining to the LF station, add FeAl, and add deoxidizing materials in the order of C powder → C powder + FeSi powder → C powder + Al particles to perform composite diffusion deoxidation, quickly produce white slag, and the white slag retention time is ≥30min; S3. In the early stage of LF refining, Ni, Mn and Mo are added for primary alloying; in the middle and late stages of LF refining, Cr, Mn, Si, Nb and V are added for secondary alloying; S4. At the end of LF refining, when the molten steel temperature is ≥1620℃, the mass percentage of S is ≤0.003%, and the mass percentage of Als is ≥0.01%, feed Φ12~14mm CaSi wire; after the CaSi wire is fed and softly blown with argon for ≥3min, feed Φ2~3mmRE wire.

[0007] According to one embodiment of the present invention, in step S1, the conditions for producing semi-steel are: the temperature of molten steel is ≥1480°C, the mass percentage of C is in the range of 1.6-2.0%, the mass percentage of P is ≤0.03%, the mass percentage of S is ≤0.35%, and the oxygen supply during oxygen blowing decarburization is 700-900m 3 / h.

[0008] According to one embodiment of the present invention, before taking out the steel sample, the bottom blowing argon intensity is increased, the strong stirring time is ≥5min, and soft argon blowing is used to purify the molten steel in the later stage of refining to maintain the atmosphere in the furnace at 10-50Pa.

[0009] According to one embodiment of the present invention, in step S1, the mass percentage of C in the molten steel at the end point of EAF smelting is in the range of ≥0.20%, the mass percentage of P is in the range of ≤0.012%; and the temperature of the molten steel is in the range of ≥1600°C.

[0010] According to one embodiment of the present invention, in step S2, 2.0-2.5 kg / t of FeAl is added, and the mass percentage of Al in FeAl is in the range of 40-45%.

[0011] According to one embodiment of the present invention, in step S3, during the initial alloying, the amount of FeMn is determined according to [%Mn] / [%Si]≥2.5 and is added under white slag; the FeMo addition temperature is ≥1600°C; during the secondary alloying, it is added in the order of FeCr→FeMn→FeSi→FeNb→FeV.

[0012] According to one embodiment of the present invention, the amount of refined slag is controlled to be ≥3%, and the mass percentage of the final slag composition is CaO 50-60%, SiO2≤15%, Al2O315-30%, MgO 4-10%, and FeO+MnO≤1.5%.

[0013] According to one embodiment of the present invention, in step S4, the amount of CaSi wire is ≥0.8kg / t, the wire feeding speed is ≥1.9m / s, the mass percentage of Ca in the CaSi wire is 58-65%, and the feeding position is located at 1 / 2R from the ladle wall at the bottom argon blowing and the opposite side of the ladle center; the amount of RE wire is ≥0.2kg / t, the wire feeding speed is ≥2.1m / s, the mass percentage of RE in the RE wire is ≥99%, and after feeding, the RE wire continues to be soft-blown with argon for ≥10min, and the feeding position is located at 1 / 2R from the ladle wall at the bottom argon blowing and the opposite side of the ladle center.

[0014] According to one embodiment of the present invention, the temperature of the molten steel out of the furnace is ≥1590°C; when hanging the ladle, 2-3kg / t of ladle covering agent is evenly added to the slag surface in the ladle.

[0015] According to another aspect of the present invention, a wear-resistant steel is provided, which is prepared by the method mentioned in any one of the above technical solutions.

[0016] In a wear-resistant steel and a smelting method thereof according to an embodiment of the present invention, the method adopts the EAF-LF-WF process flow, EAF is used for oxygen blowing decarburization, foamed slag is used for rapid dephosphorization, LF is used for deoxidation, desulfurization, alloying and temperature adjustment, etc., and CaSi wire and RE wire are fed into the molten steel at the end of refining for purification and modification treatment, so as to achieve the purpose of stably producing qualified wear-resistant liner steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the drawings required for use in the embodiment will be briefly introduced below. Obviously, the drawings described below are only some implementation cases of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A process flow chart of a method for smelting wear-resistant steel according to an exemplary embodiment of the present invention is shown.

[0019] Figure 2 A schematic diagram of a ladle feeding line process arrangement according to an exemplary embodiment of the present invention is shown.

[0020] Description of reference numerals: 1. Ladle; 2. Air brick; 3. RE wire; 4. Conduit; 5. Wire feeding machine; 6. Wire winding machine. DETAILED DESCRIPTION

[0021] The detailed description of the following embodiments is used to exemplify the principles of the present invention, but cannot be used to limit the scope of the present invention. The present invention can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0022] The present invention provides these embodiments to make this disclosure thorough and complete, and fully express the scope of the present invention to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the parts and steps, the composition of materials, numerical expressions and numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary, rather than as limiting.

[0023] It should be noted that, in the description of the present invention, unless otherwise specified, the meaning of "multiple" is greater than or equal to two; the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0024] It should also be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. When a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device.

[0025] All terms used in the present invention have the same meanings as those understood by those of ordinary skill in the art to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, for example, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined herein.

[0026] Technologies, methods, and apparatus known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, these technologies, methods, and apparatus should be considered part of the specification.

[0027] like Figure 1 As shown, the present invention provides a method for smelting wear-resistant steel, which comprises the following steps: S1. Titanium slag electric furnace discharges semi-steel, samples are taken in the iron flow trough to analyze the element contents of C, P, and S, and the semi-steel from the titanium slag electric furnace is transported to the EAF primary smelting station for oxygen decarburization, foam slag is made for rapid dephosphorization, and pre-deoxidation treatment is performed when EAF discharges steel; S2. Send the molten steel after EAF primary refining to the LF station, add FeAl, and add deoxidizing materials in the order of C powder → C powder + FeSi powder → C powder + Al particles to perform composite diffusion deoxidation, quickly produce white slag, and the white slag retention time is ≥30min; S3. In the early stage of LF refining, Ni, Mn and Mo are added for primary alloying; in the middle and late stages of LF refining, Cr, Mn, Si, Nb and V are added for secondary alloying; S4. At the end of LF refining, when the molten steel temperature is ≥1620℃, the mass percentage of S is ≤0.003%, and the mass percentage of Als is ≥0.01%, feed Φ12~14mm CaSi wire; after the CaSi wire is fed and softly blown with argon for ≥3min, feed Φ2~3mmRE wire.

[0028] Among them, rapid white slag production includes rapid production of high-alkalinity and good fluidity white slag, and high alkalinity means that R [R = w (CaO) / w (SiO2)] is controlled at 5 to 6; Before taking out the steel sample, the temperature should be ≥1580℃, and the bottom argon blowing intensity should be appropriately increased to refer to the naked eye diameter of the molten steel to be 200-250mm. In the later stage of refining, soft argon blowing should be used as much as possible to purify the molten steel, based on the creeping of the steel slag without exposing the molten steel.

[0029] In the smelting method of wear-resistant steel according to an embodiment of the present invention, an EAF (electric arc furnace) - LF (refining furnace) - WF (wire feeding) process flow is adopted, EAF is used for oxygen blowing decarburization, foamed slag is used for rapid dephosphorization, LF is used for deoxidation, desulfurization, alloying and temperature adjustment, etc., and CaSi wire and RE wire are fed into the molten steel at the end of refining for purification and modification treatment, so as to achieve the purpose of stably producing qualified wear-resistant liner steel.

[0030] In some specific embodiments, semi-steel is developed and processed into a steel for wear-resistant lining of crusher through the process of electric arc furnace (EAF)-ladle refining furnace (LF)-wire feeding (WF). The semi-steel water produced by the hot-charged titanium slag electric furnace of EAF is decarburized by oxygen blowing, and the foamed slag is rapidly dephosphorized; the LF is deoxidized, desulfurized, alloyed and temperature adjusted; at the end of refining, CaSi wire and RE wire are fed into the molten steel through the wire feeding machine WF.

[0031] In some specific embodiments, in step S1, the conditions for producing semi-steel are: the molten steel temperature is ≥1480°C, the mass percentage of C is in the range of 1.6-2.0%, the mass percentage of P is ≤0.03%, and the mass percentage of S is ≤0.35%.

[0032] Based on the above embodiment, in step S1, the oxygen supply during oxygen decarburization is 700-900m 3 / h.

[0033] In some specific embodiments, before taking out the steel sample, the bottom blowing argon intensity is increased, the strong stirring time is ≥5min, and soft argon blowing is used to purify the molten steel in the later stage of refining to maintain the atmosphere in the furnace at 10-50Pa.

[0034] In some specific embodiments, in step S1, the mass percentage of C in the molten steel at the end of EAF smelting is in the range of ≥0.20%, and the mass percentage of P is in the range of ≤0.012%; the temperature of the molten steel is in the range of ≥1600° C. Preferably, the mass percentage of C in the molten steel is in the range of 0.20-0.25%, and the mass percentage of P is in the range of ≤0.007%.

[0035] On the basis of the above embodiment, in step S2, 2.0-2.5 kg / t of FeAl is added, and the mass percentage of Al in FeAl is in the range of 40-45%.

[0036] In step S2, preferably, when the total amount of steel is between 1 / 4 and 3 / 4, deoxidizer is added to the ladle in the order of FeBaAlSi→FeAl, and the amounts thereof are 2.0-2.5 kg / t and 3.5-4.0 kg / t, respectively, and then 1.0-1.5 kg / t of bauxite and 9-11 kg / t of lime are added.

[0037] In step S2, preferably, the dosage of diffusion deoxidizer C powder, FeSi powder and Al particles is 1.0-1.5 kg / t, 0.5-1.0 kg / t and 1.0-2.0 kg / t respectively.

[0038] In step S3, preferably, the bottom blowing argon intensity during strong stirring is 450-500 L / min, the bottom blowing argon intensity during soft blowing is 50-100 L / min, and the soft blowing time is ≥30 min.

[0039] In some specific embodiments, in step S3, during the primary alloying, the amount of FeMn is determined according to [%Mn] / [%Si]≥2.5 and is added under white slag; the FeMo addition temperature is ≥1600°C; during the secondary alloying, it is added in the order of FeCr→FeMn→FeSi→FeNb→FeV.

[0040] Preferably, [%Mn] / [%Si]=3.8-4.3.

[0041] On the basis of the above embodiment, the amount of refined slag is controlled to be ≥3%, and the mass percentage of the final slag composition is CaO 50-60%, SiO2≤15%, Al2O315-30%, MgO 4-10%, and FeO+MnO≤1.5%.

[0042] Preferably, the amount of refined slag is controlled to be 3-5%.

[0043] Preferably, the mass percentage of the final slag composition is controlled to be CaO 53-59%, SiO2 8-12%, Al2O3 18-25%, MgO 5-8%, and FeO+MnO≤1%.

[0044] In step S4, preferably, Als in the molten steel is controlled to be 0.012-0.025%.

[0045] In step S4, preferably, the amount of Φ13 mm CaSi wire fed is 0.8-1.0 kg / t, and the wire feeding speed is 2.0-2.2 m / s.

[0046] In step S4, preferably, after the CaSi wire is fed, argon is soft-blown for 3 to 5 minutes.

[0047] In step S4, preferably, the amount of Φ2.5 mm RE wire fed is 0.2-0.4 kg / t, the wire feeding speed is 2.2-2.4 m / s, and after the RE wire is fed, argon is continuously soft-blown for 12-15 minutes.

[0048] In step S4, preferably, the temperature of the molten steel out of the furnace is 1590-1610°C.

[0049] In some specific embodiments, in step S4, the amount of CaSi wire is ≥0.8kg / t, the wire feeding speed is ≥1.9m / s, the mass percentage of Ca in the CaSi wire is 58-65%, and the feeding position is located at 1 / 2R from the ladle wall on the opposite side of the bottom argon blowing and the center of the ladle; the amount of RE wire is ≥0.2kg / t, the wire feeding speed is ≥2.1m / s, the mass percentage of RE in the RE wire is ≥99%, and after feeding, the RE wire continues to be soft-blown with argon for ≥10min, and the feeding position is located at 1 / 2R from the ladle wall on the opposite side of the bottom argon blowing and the center of the ladle.

[0050] The feeding position is located at the bottom argon blowing point and 1 / 2R from the ladle wall on the opposite side of the ladle center. Figure 2 shown.

[0051] The bottom of the ladle 1 includes air-permeable bricks 2 , and a wire feeder 5 connected to a wire coiler 6 feeds the RE wire 3 through a conduit 4 .

[0052] In some embodiments, the feeding position of the CaSi wire is the same as that of the RE wire 3 .

[0053] On the basis of the above embodiments, the temperature of the molten steel out of the furnace is ≥1590°C; when hanging the ladle, 2-3kg / t of ladle covering agent is evenly added to the slag surface in the ladle.

[0054] The present invention also provides a wear-resistant steel, which is prepared by the method mentioned in any one of the above technical solutions.

[0055] The components of the wear-resistant steel are in percentage by mass: C 0.38-0.41%, Si 0.92-1.00%, Mn 0.95-1.05%, P≤0.015%, S≤0.003%, Cr 1.65-1.75%, Mo 0.36-0.40%, Ni 0.31-0.35%, V 0.06-0.08%, Nb 0.03-0.04%, RE 0.010-0.025%, Als 0.012-0.025%, and TO≤0.0020%.

[0056] The present application is described below with reference to specific embodiments.

[0057] Example 1 (1) Semi-steel produced from titanium slag electric furnace has a temperature of 1485℃ and the mass percentages of C, P and S are 1.80%, 0.028% and 0.318% respectively.

[0058] (2) The semi-steel is transported to the EAF primary smelting station for oxygen decarburization. The oxygen supply is 812m 3 / h, to make foam slag for rapid dephosphorization.

[0059] (3) The mass percentages of C and P in the molten steel at the end of EAF smelting were 0.22% and 0.005% respectively, and the temperature was 1610℃. When the total amount of steel was between 1 / 4 and 3 / 4, deoxidizers were added into the ladle in the order of FeAlBaSi(FeAl15Ba12Si30)→FeAl(FeAl40), with the dosages of 2.1kg / t and 3.7kg / t respectively. Then, bauxite 1.2kg / t and lime 10.2kg / t were added.

[0060] (4) After entering the LF station, add 2.3 kg / t of FeAl (FeAl40); add deoxidizing materials in the order of C powder → C powder + FeSi powder → C powder + Al particles for composite diffusion deoxidation. The dosage of diffusion deoxidizer C powder, FeSi powder, and Al particles are 1.4 kg / t, 0.6 kg / t, and 1.6 kg / t, respectively. White slag with high alkalinity and good fluidity is quickly produced. The white slag retention time is 55 min.

[0061] (5) Before taking out the steel sample, the temperature was 1590℃, the bottom blowing argon intensity was 467 L / min, and the strong stirring time was 6 min; in the later stage of refining, the bottom blowing argon intensity was 58 L / min, and the soft blowing time was 39 min; the atmosphere in the furnace was maintained at a slightly positive pressure of 38 Pa.

[0062] (6) Alloying In the early stage of refining, the amount of Ni plate (Ni9920) added is 3.3kg / t, the mass percentage of Si in the molten steel is 0.15%, and the primary alloying FeMn (FeMn78C2.0) 7.4kg / t is added under white slag; the temperature is 1610℃ when FeMo (FeMo55-A) 6.7kg / t is added; in the middle and late stages of refining, under white slag, FeCr (FeCr55C2.0) 19.7kg / t, (FeCr55C6.0) 12.0kg / t → FeMn (FeMn78C2.0) 5.9kg / t → FeSi (FeSi75Al2.0) 10.9kg / t → FeNb (FeNb60-A) 0.57kg / t → FeV (FeV50-A) 1.32kg / t were added sequentially.

[0063] (7) The amount of refined slag is controlled at 4.5%; the mass percentage of the final slag composition is controlled at CaO 58.2%, SiO2 10.1%, Al2O3 22.1%, MgO 7.5%, FeO+MnO=0.86%, and R=5.76.

[0064] (8) Calcium treatment When the molten steel temperature is 1628℃, S is 0.0025%, and Als is 0.023%, Φ13mm CaSi (Ca28Si60) wire is fed in at a dosage of 0.9kg / t, a feeding speed of 2.08m / s, and the feeding position is located at 1 / 2R from the ladle wall on the opposite side of the ladle center at the bottom argon blowing.

[0065] (9) Rare earth processing After feeding the CaSi wire and soft blowing argon for 4 minutes, feed Φ2.5mm RE wire at the bottom argon blowing position 1 / 2R away from the ladle wall on the opposite side of the ladle center, with a dosage of 0.3kg / t and a wire feeding speed of 2.32m / s. The mass percentage of RE in the RE wire is ≥99%. After feeding the RE wire, continue to soft blow argon for 13 minutes.

[0066] (10) The temperature of molten steel out of the furnace is 1603℃. When hanging the ladle, 2.5kg / t of ladle covering agent is evenly added to the slag surface in the ladle.

[0067] The mass percentages of the components of the prepared wear-resistant steel are: C 0.39%, Si 0.95%, Mn 1.01%, P 0.008%, S 0.002%, Cr 1.69%, Mo 0.37%, Ni 0.33%, V 0.069%, Nb 0.036%, RE 0.017%, Als 0.021%, TO≤0.0016%, and the balance is Fe and unavoidable impurities.

[0068] Example 2 (1) Semi-steel produced from titanium slag electric furnace has a temperature of 1496℃ and the mass percentages of C, P and S are 1.92%, 0.024% and 0.301% respectively.

[0069] (2) The semi-steel is transported to the EAF primary smelting station for oxygen decarburization. The oxygen supply is 887m 3 / h, to make foam slag for rapid dephosphorization.

[0070] (3) The mass percentages of C and P in the molten steel at the end of EAF smelting were 0.24% and 0.004% respectively, and the temperature was 1605℃. When the total amount of steel was between 1 / 4 and 3 / 4, deoxidizers were added into the ladle in the order of FeAlBaSi(FeAl15Ba12Si30)→FeAl(FeAl40), with the dosages of 2.2kg / t and 3.6kg / t respectively. Then, bauxite 1.3kg / t and lime 9.9kg / t were added.

[0071] (4) After entering the LF station, add 2.1 kg / t of FeAl (FeAl40); add deoxidizing materials in the order of C powder → C powder + FeSi powder → C powder + Al particles for composite diffusion deoxidation. The dosage of diffusion deoxidizer C powder, FeSi powder, and Al particles are 1.2 kg / t, 0.8 kg / t, and 1.5 kg / t, respectively. White slag with high basicity and good fluidity is quickly produced. The white slag retention time is 58 minutes.

[0072] (5) Before taking out the steel sample, the temperature was 1595℃, the bottom blowing argon intensity was 473 L / min, and the strong stirring time was 7 min; in the later stage of refining, the bottom blowing argon intensity was 69 L / min, and the soft blowing time was 42 min; the atmosphere in the furnace was maintained at a slightly positive pressure of 44 Pa.

[0073] (6) Alloying In the early stage of refining, the amount of Ni plate (Ni9920) added is 3.2kg / t, the mass percentage of Si in the molten steel is 0.18%, and the primary alloying FeMn (FeMn78C2.0) 8.9kg / t is added under white slag; the temperature is 1615℃ when FeMo (FeMo55-A) 6.9kg / t is added; in the middle and late stages of refining, under white slag, FeCr (FeCr55C2.0) 7.9kg / t, (FeCr55C6.0) 24.4kg / t → FeMn (FeMn78C2.0) 4.1kg / t→FeSi (FeSi75Al2.0) 10.6kg / t→FeNb (FeNb60-A) 0.57kg / t→FeV (FeV50-A) 1.44kg / t were added sequentially.

[0074] (7) The amount of refined slag is controlled at 4.1%; the mass percentage of the final slag composition is controlled at CaO 57.8%, SiO2 11.1%, Al2O3 23.1%, MgO 6.5%, FeO+MnO=0.76%, and R=5.21.

[0075] (8) Calcium treatment When the molten steel temperature is 1632℃, S is 0.0021%, and Als is 0.019%, Φ13mm CaSi (Ca28Si60) wire is fed in at a dosage of 0.93kg / t, a feeding speed of 2.12m / s, and the feeding position is located at 1 / 2R from the ladle wall on the opposite side of the ladle center at the bottom argon blowing.

[0076] (9) Rare earth processing After the CaSi wire is fed and softly blown with argon for 4.5 minutes, a Φ2.5mm RE wire is fed at the bottom argon blowing position at a position 1 / 2R away from the ladle wall on the opposite side of the ladle center. The amount is 0.28kg / t, the wire feeding speed is 2.28m / s, the mass percentage of RE in the RE wire is ≥99%, and the RE wire is softly blown with argon for 14 minutes after feeding.

[0077] (10) The temperature of molten steel out of the furnace is 1608℃. When hanging the ladle, 2.3kg / t of ladle covering agent is evenly added to the slag surface in the ladle.

[0078] The mass percentages of the components of the prepared wear-resistant steel are: C 0.40%, Si 0.96%, Mn 0.98%, P 0.006%, S 0.0015%, Cr 1.72%, Mo 0.38%, Ni 0.32%, V 0.075%, Nb 0.033%, RE 0.016%, Als 0.017%, TO≤0.0013%, and the balance is Fe and unavoidable impurities.

[0079] Example 3 (1) Semi-steel produced from titanium slag electric furnace has a temperature of 1491°C and the mass percentages of C, P, and S are 1.68%, 0.018%, and 0.263%, respectively.

[0080] (2) The semi-steel is transported to the EAF primary smelting station for oxygen decarburization with an oxygen supply of 850m 3 / h, to make foam slag for rapid dephosphorization.

[0081] (3) The mass percentages of C and P in the molten steel at the end of EAF smelting were 0.23% and 0.003% respectively, and the temperature was 1615℃. When the total amount of steel was between 1 / 4 and 3 / 4, deoxidizers were added into the ladle in the order of FeAlBaSi(FeAl15Ba12Si30)→FeAl(FeAl40), with the dosages of 2.4kg / t and 3.9kg / t respectively. Then, bauxite 1.4kg / t and lime 10.5kg / t were added.

[0082] (4) After entering the LF station, add 2.2 kg / t of FeAl (FeAl40); add deoxidizing materials in the order of C powder → C powder + FeSi powder → C powder + Al particles for composite diffusion deoxidation. The dosage of diffusion deoxidizer C powder, FeSi powder, and Al particles are 1.3 kg / t, 0.7 kg / t, and 1.4 kg / t, respectively. White slag with high alkalinity and good fluidity is quickly produced. The white slag retention time is 53 minutes.

[0083] (5) Before taking out the steel sample, the temperature was 1598℃, the bottom blowing argon intensity was 491 L / min, and the strong stirring time was 8 min; in the later stage of refining, the bottom blowing argon intensity was 87 L / min, and the soft blowing time was 38 min; the atmosphere in the furnace was maintained at a slightly positive pressure of 41 Pa.

[0084] (6) Alloying In the early stage of refining, the amount of Ni plate (Ni9920) added is 3.4kg / t, the mass percentage of Si in the molten steel is 0.12%, and the primary alloying FeMn (FeMn78C2.0) 5.9kg / t is added under white slag; the temperature is 1613℃ when FeMo (FeMo55-A) 7.1kg / t is added; in the middle and late stages of refining, under white slag, FeCr (FeCr55C2.0) 20.6kg / t, (FeCr55C6.0) 10.7kg / t → FeMn (FeMn78C2.0) 6.9kg / t → FeSi (FeSi75Al2.0) 11.7kg / t → FeNb (FeNb60-A) 0.60kg / t → FeV (FeV50-A) 1.22kg / t were added sequentially.

[0085] (7) The amount of refined slag is controlled at 3.8%; the mass percentage of the final slag composition is controlled at CaO 56.8%, SiO2 10.4%, Al2O3 23.5%, MgO 7.2%, FeO+MnO=0.81%, and R=5.46.

[0086] (8) Calcium treatment When the steel liquid temperature is 1625℃, S is 0.0015%, and Als is 0.021%, Φ13mm CaSi (Ca28Si60) wire is fed in at a dosage of 0.85kg / t, a wire feeding speed of 2.16m / s, and the feeding position is located at 1 / 2R from the ladle wall on the opposite side of the ladle center at the bottom argon blowing.

[0087] (9) Rare earth processing After the CaSi wire was fed and soft argon was blown for 3.6 minutes, a Φ2.5mm RE wire was fed at the bottom argon blowing position at 1 / 2R away from the ladle wall on the opposite side of the ladle center. The amount was 0.32kg / t, the wire feeding speed was 2.38m / s, the mass percentage of RE in the RE wire was ≥99%, and the RE wire was soft blown with argon for 13.5 minutes after feeding.

[0088] (10) The temperature of molten steel out of the furnace is 1601℃. When hanging the ladle, 2.8kg / t of ladle covering agent is evenly added to the slag surface in the ladle.

[0089] The mass percentages of the components of the prepared wear-resistant steel are: C 0.39%, Si 0.98%, Mn 0.97%, P 0.005%, S 0.001%, Cr 1.67%, Mo 0.39%, Ni 0.34%, V 0.064%, Nb 0.038%, RE 0.018%, Als 0.018%, TO≤0.0011%, and the balance is Fe and unavoidable impurities.

[0090] The present invention adopts the EAF-LF-WF process flow, wherein EAF is used for oxygen blowing decarburization, foamed slag is used for rapid dephosphorization, LF is used for deoxidation, desulfurization, alloying and temperature adjustment, and CaSi wire and RE wire are fed into the molten steel at the end of refining for purification and modification, so as to achieve the purpose of stably producing qualified wear-resistant liner steel. After the implementation of the present invention, at least the following beneficial effects are achieved: (1) In the EAF stage, oxygen blowing technology can be used to quickly reduce the carbon content in molten steel. At the same time, the foaming slag technology is used to effectively remove phosphorus, which lays a good foundation for the subsequent refining process and significantly improves the purity of the molten steel.

[0091] (2) The introduction of the LF refining furnace achieves deep deoxidation and desulfurization of molten steel, ensuring the stability of steel quality. Precise control of alloying adjusts the composition of steel according to product requirements, improving the mechanical properties and wear resistance of steel. Temperature adjustment ensures the stability of subsequent processes.

[0092] (3) At the end of refining, CaSi wire and RE wire are fed into the molten steel. These additives not only further purify the molten steel and remove harmful impurities, but also improve the organizational structure of the steel through chemical modification, enhance the corrosion resistance, wear resistance and processing performance of the steel, and make the final product more in line with the high standard requirements of wear-resistant linings.

[0093] (4) The entire process is reasonably designed, and each link is closely connected, which can stably produce qualified quality wear-resistant lining steel, meeting the high requirements of industrial production for steel quality consistency and stability.

[0094] (5) By optimizing the process parameters and operating methods at each stage, the process can also reduce energy consumption and emissions to a certain extent, which is in line with the concept of green development of the modern steel industry.

[0095] The above are exemplary embodiments disclosed in the present invention. The order disclosed in the above embodiments of the present invention is for description only and does not represent the advantages and disadvantages of the embodiments. However, it should be noted that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope disclosed in the embodiments of the present invention (including the claims) is limited to these examples. Various changes and modifications may be made without departing from the scope defined in the claims. The functions, steps and / or actions of the method claims according to the disclosed embodiments described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless explicitly limited to the singular.

[0096] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the embodiments of the present invention as described above, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.

Claims

1. A method for smelting wear-resistant steel, comprising adopting an EAF-LF-WF process, characterized in that: S1, titanium slag electric furnace discharges semi-steel, and the semi-steel of titanium slag electric furnace is transported to EAF primary refining station, oxygen is blown for decarburization, foam slag is made for rapid dephosphorization, and pre-deoxidation treatment is performed when EAF discharges steel; S2. Send the molten steel after EAF primary refining to the LF station, add FeAl, and add deoxidizing materials in the order of C powder → C powder + FeSi powder → C powder + Al particles to perform composite diffusion deoxidation, quickly produce white slag, and the white slag retention time is ≥30min; S3. In the early stage of LF refining, Ni, Mn and Mo are added for primary alloying; in the middle and late stages of LF refining, Cr, Mn, Si, Nb and V are added for secondary alloying; S4. At the end of LF refining, when the molten steel temperature is ≥1620℃, the mass percentage of S is ≤0.003%, and the mass percentage of Als is ≥0.01%, feed Φ12~14mm CaSi wire; after the CaSi wire is fed and softly blown with argon for ≥3min, feed Φ2~3mmRE wire.

2. The method for smelting wear-resistant steel according to claim 1, characterized in that: In step S1, the conditions for producing semi-steel are: the temperature of molten steel is ≥1480°C, the mass percentage of C is in the range of 1.6-2.0%, the mass percentage of P is ≤0.03%, the mass percentage of S is ≤0.35%, and the oxygen supply during oxygen blowing decarburization is 700-900m 3 / h.

3. The method for smelting wear-resistant steel according to claim 1, characterized in that: Before taking out the steel sample, increase the bottom argon blowing intensity and ensure that the strong stirring time is ≥5min. In the later stage of refining, use soft argon blowing to purify the molten steel and maintain the atmosphere in the furnace at 10-50Pa.

4. The method for smelting wear-resistant steel according to claim 1, characterized in that: In step S1, the mass percentage of C in the molten steel at the end point of EAF smelting is in the range of ≥0.20%, and the mass percentage of P is in the range of ≤0.012%; and the temperature of the molten steel is in the range of ≥1600°C.

5. The method for smelting wear-resistant steel according to claim 1, characterized in that: In step S2, 2.0-2.5 kg / t of FeAl is added, and the mass percentage of Al in FeAl is in the range of 40-45%.

6. The method for smelting wear-resistant steel according to claim 1, characterized in that: In step S3, during the primary alloying, the amount of FeMn is determined according to [%Mn] / [%Si]≥2.5 and is added under white slag; the FeMo addition temperature is ≥1600°C; during the secondary alloying, it is added in the order of FeCr→FeMn→FeSi→FeNb→FeV.

7. The method for smelting wear-resistant steel according to claim 5, characterized in that: The amount of refined slag is controlled to be ≥3%, and the mass percentage of the final slag composition is CaO 50-60%, SiO2≤15%, Al2O3 15-30%, MgO 4-10%, and FeO+MnO≤1.5%.

8. The method for smelting wear-resistant steel according to claim 1, characterized in that: In step S4, the amount of CaSi wire is ≥0.8kg / t, the wire feeding speed is ≥1.9m / s, the mass percentage of Ca in the CaSi wire is 58-65%, and the feeding position is located at 1 / 2R from the ladle wall on the opposite side of the bottom argon blowing and the center of the ladle; the amount of RE wire is ≥0.2kg / t, the wire feeding speed is ≥2.1m / s, the mass percentage of RE in the RE wire is ≥99%, and after feeding, the RE wire continues to be soft-blown with argon for ≥10min, and the feeding position is located at 1 / 2R from the ladle wall on the opposite side of the bottom argon blowing and the center of the ladle.

9. The method for smelting wear-resistant steel according to claim 1, characterized in that: The temperature of molten steel out of the furnace is ≥1590℃; when hanging the ladle, 2-3kg / t of ladle covering agent is evenly added to the slag surface in the ladle.

10. A wear-resistant steel, characterized in that: The method is prepared by any one of claims 1 to 9.

Images