CN111411188A - Preparation method for controlling large-particle inclusions in non-quenched and tempered steel - Google Patents

Preparation method for controlling large-particle inclusions in non-quenched and tempered steel Download PDF

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CN111411188A
CN111411188A CN202010162001.1A CN202010162001A CN111411188A CN 111411188 A CN111411188 A CN 111411188A CN 202010162001 A CN202010162001 A CN 202010162001A CN 111411188 A CN111411188 A CN 111411188A
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tapping
converter
slag
steel
quenched
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殷天颖
胡志勇
周杨
鲁川
陈鹏涛
刘义
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Nanjing Iron and Steel Co Ltd
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Nanjing Iron and Steel Co Ltd
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    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21CPROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28Manufacture of steel in the converter
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21CPROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/0006Adding metallic additives
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21CPROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/04Removing impurities by adding a treating agent
    • C21C7/06Deoxidising, e.g. killing
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21CPROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/10Handling in a vacuum
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C33/00Making ferrous alloys
    • C22C33/04Making ferrous alloys by melting
    • C22C33/06Making ferrous alloys by melting using master alloys
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/001Ferrous alloys, e.g. steel alloys containing N
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/002Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/02Ferrous alloys, e.g. steel alloys containing silicon
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/04Ferrous alloys, e.g. steel alloys containing manganese
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/06Ferrous alloys, e.g. steel alloys containing aluminium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/12Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/16Ferrous alloys, e.g. steel alloys containing copper
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/20Ferrous alloys, e.g. steel alloys containing chromium with copper
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/24Ferrous alloys, e.g. steel alloys containing chromium with vanadium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/46Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Treatment Of Steel In Its Molten State (AREA)
  • Carbon Steel Or Casting Steel Manufacturing (AREA)

Abstract

The invention discloses a preparation method for controlling large-particle inclusions in non-quenched and tempered steel, which comprises the following steps of: (1) smelting in a converter: in the process of smelting the converter, controlling the mass percentage content of the end point C of the converter to be more than or equal to 0.10 percent or the oxygen site of the tapped TSO to be less than or equal to 300ppm and the tapping temperature to be more than or equal to 1600 ℃; (2) tapping by a converter: before molten steel tapping, the bottom of a converter is opened for stirring, so that the oxidability of the molten steel and the P content of the molten steel are reduced; adding carbon powder for pre-deoxidation at the early stage of tapping, sequentially adding a deoxidizer, an alloy and slag charge for deoxidation alloying, keeping full-process nitrogen blowing in the deoxidation alloying process, tapping at the later stage of tapping in a double-gear mode, and strictly controlling slag tapping. The non-quenched and tempered steel can be stably controlled to be below 15ppm of total oxygen and below 1.5ppm of H, the H and O content in the steel is effectively reduced, the product quality is improved, the produced automobile steel is guaranteed to have low total O, H and higher purity level, and the non-quenched and tempered automobile steel is guaranteed to have excellent fatigue failure resistance.

Description

Preparation method for controlling large-particle inclusions in non-quenched and tempered steel
Technical Field
The invention belongs to the technical field of production of non-quenched and tempered steel, and particularly relates to a preparation method for controlling large-particle inclusions in the non-quenched and tempered steel.
Background
With the progress of automobile manufacturing, the requirements of parts such as automobile crankshafts, connecting rods and the like on non-quenched and tempered steel materials are continuously improved, and the materials are required to have good processing performance, high strength, high toughness and the like. The strength of the non-quenched and tempered steel is controlled in a proper range mainly by adding trace elements such as Nb, Ti, V and the like and combining with a subsequent forging and cooling control process.
The inclusions of the non-quenched and tempered steel are mainly composite inclusions containing Al, Ca, O and S, the external dimension is cluster-shaped inclusions with the width or the diameter of 50-200 um, wherein the large-particle inclusions in the clusters are small in size and are fine inclusions smaller than 19um (equivalent to DS class 0.5). The flaw detection yield of the round steel is less than 70% because a large amount of cluster-shaped inclusions are generated in the steel.
CN201811308589.6, the name of which is that the production mode of reducing large-particle inclusions in steel by converter-L F-RH-continuous casting is mainly introduced, and the method has the defects that the control of gaseous elements and inclusions such as O, H in the steel is difficult, and the stability and the service life of products are influenced.
Disclosure of Invention
The purpose of the invention is as follows: the invention aims to provide a preparation method for controlling large-particle inclusions in non-quenched and tempered steel, and solves the problem that the mechanical properties of the non-quenched and tempered steel are poor due to insufficient control of gaseous elements such as O, H and the inclusions in the conventional non-quenched and tempered steel. The non-quenched and tempered steel prepared by the method has the advantages of less large-particle inclusions, good mechanical property and strong fatigue failure resistance.
The technical scheme is as follows: the invention relates to a preparation method for controlling large-particle inclusions in non-quenched and tempered steel, which comprises the following steps of:
(1) smelting in a converter: in the process of smelting the converter, controlling the mass percentage content of the end point C of the converter to be more than or equal to 0.10 percent or the oxygen site of the tapped TSO to be less than or equal to 300ppm and the tapping temperature to be more than or equal to 1600 ℃;
(2) tapping by a converter: before molten steel tapping, the bottom of a converter is opened for stirring, so that the oxidability of the molten steel and the P content of the molten steel are reduced; adding carbon powder for pre-deoxidation at the early stage of tapping, sequentially adding a deoxidizer, an alloy and slag charge for deoxidation alloying, keeping full-process nitrogen blowing in the deoxidation alloying process, tapping at the later stage of tapping in a double-gear mode, and strictly controlling slag tapping;
(3) l F furnace refining, wherein the refining time is more than or equal to 40min, lime and refining slag are added in the refining, and the percentage content of inclusions in the steel is controlled to be 45-60% of CaO and SiO210 to 20% of Al2O315-25%, controlling the final slag alkalinity at 3.0-4.0, performing composite diffusion deoxidation by using SiC, aluminum wires or calcium carbide in the power supply smelting process, ensuring that the total mass percentage of TFe and MnO is less than or equal to 0.80%, keeping white slag in the process, and ensuring that the oxygen content is less than 5ppm when the slag is out of the station;
(4) RH vacuum: controlling the vacuum degree below 2.5 mbar, keeping the vacuum for more than 15min, adding nitrogen components by using a silicon-nitrogen alloy and a composite vanadium-nitrogen alloy, forbidding calcium treatment, and soft-blowing for more than 20 min;
(5) continuous casting: casting through continuous casting to obtain non-quenched and tempered steel, and controlling the superheat degree of a continuous casting tundish to be 10-35 ℃.
Further, it is characterized in that: in the step (2), the alloy is ferrosilicon and ferromanganese, the deoxidizer is an aluminum block, and the slag is lime.
Further, it is characterized in that: and (3) reducing the P content to below 0.025 percent by bottom stirring of the discharged steel of the converter in the step (2).
Further, it is characterized in that: and (3) in the step (2), the double-gear mode is a mode of adding a slag blocking cone by a sliding plate or adding a slag blocking ball by a sliding plate, so that the slag discharge during the converter tapping is effectively reduced.
Further, it is characterized in that: and (3) adding a slag fishing and raking process after tapping in the step (2) to ensure that the slag amount of the converter is less than or equal to 2 kg/ton of steel.
Further, it is characterized in that: the non-quenched and tempered steel comprises the following chemical components in percentage by weight: c: 0.42 to 0.49%, Si: 0.3-0.6%, Mn: 1.0-1.5%, P: less than or equal to 0.025%, S: 0.035-0.075%, V: 0.06-0.13%, Alt: 0.005-0.025%, Ni is less than or equal to 0.3%, Cu is less than or equal to 0.3%, Cr is less than or equal to 0.3%, and N: not less than 80ppm, and the balance of Fe and inevitable impurities.
The invention has the beneficial effects that: the non-quenched and tempered steel can be stably controlled to be below 15ppm of total oxygen and below 1.5ppm of H, the H and O content in the steel is effectively reduced, the product quality is improved, the produced automobile steel is guaranteed to have low total O, H and higher purity level, and the non-quenched and tempered automobile steel is guaranteed to have excellent fatigue failure resistance.
Detailed Description
The invention is further described below with reference to examples:
the non-quenched and tempered steel prepared by the invention comprises the following chemical components in percentage by weight: c: 0.42 to 0.49%, Si: 0.3-0.6%, Mn: 1.0-1.5%, P: less than or equal to 0.025%, S: 0.035-0.075%, V: 0.06-0.13%, Alt: 0.005-0.025%, Ni is less than or equal to 0.3%, Cu is less than or equal to 0.3%, Cr is less than or equal to 0.3%, and N: not less than 80ppm, and the balance of Fe and inevitable impurities.
The preparation method comprises the following steps:
example 1
The invention relates to a preparation method for controlling large-particle inclusions in non-quenched and tempered steel, which comprises the following steps of:
(1) smelting in a converter: and in the process of smelting the converter, controlling the end point C of the converter: 0.105% (TSO: 281ppm) of tapping, the tapping temperature is 1631 ℃, the oxygen level is strictly controlled, and good conditions are created for the next working procedure;
(2) tapping by a converter: before tapping of molten steel, starting stirring at the bottom of a converter to reduce the oxidability of the molten steel and the P content of the molten steel, and reducing the P content to be below 0.025 percent by stirring at the bottom of the converter after tapping; adding carbon powder of 0.2 kg/ton steel for pre-deoxidation at the early stage of tapping, sequentially adding an aluminum block (0.6-0.7 kg/ton steel), ferrosilicon (4 kg/ton steel), ferromanganese (18 kg/ton steel) and lime (4-5 kg/ton steel) for deoxidation alloying, keeping nitrogen blowing in the whole process in the deoxidation alloying process, tapping in a double-gear mode of a sliding plate and a slag blocking cone (slag blocking ball) at the later stage of tapping, strictly controlling to effectively reduce tapping slag of the converter, adding a slag scooping process after tapping steel, ensuring that the slag amount of the converter is less than or equal to 2 kg/ton steel, reducing oxidizing slag of the converter from entering molten steel, and providing good conditions for slag making in the later process;
(3) l F furnace refining, wherein the refining time is more than or equal to 40min, lime and refining slag are added in the refining, and the percentage content of inclusions in the steel is controlled to be 46.39 percent of CaO and SiO216.7% of Al2O319.57 percent, controlling the alkalinity of final slag at 3.52, carrying out composite diffusion deoxidation by adopting deoxidizers such as SiC, aluminum wires or calcium carbide in the power supply smelting process, ensuring the total mass percentage content of TFe and MnO to be 0.76 percent, keeping white slag in the process, and ensuring that the oxygen content is below 5ppm when the slag is out of the station;
(4) RH vacuum: pumping the vacuum degree to be below 2.5 millibar within 5min, controlling the vacuum degree to be below 2.5 millibar, keeping the high vacuum for 18min, ensuring that the H mass percentage content of the molten steel is 1.5ppm, increasing nitrogen components by using silicon nitrogen alloy and composite vanadium nitrogen alloy, forbidding calcium treatment, and soft blowing for 26 min;
(5) continuous casting: casting through continuous casting to obtain non-quenched and tempered steel, and controlling the superheat degree of a continuous casting tundish to be 31-35 ℃.
Example 2
The invention relates to a preparation method for controlling large-particle inclusions in non-quenched and tempered steel, which comprises the following steps of:
(1) smelting in a converter: and in the process of smelting the converter, controlling the end point C of the converter: 0.137% (TSO of tapping: 256ppm), the tapping temperature is 1642 ℃, and the oxygen level is strictly controlled, thereby creating good conditions for the next working procedure;
(2) tapping by a converter: before tapping of molten steel, starting stirring at the bottom of a converter to reduce the oxidability of the molten steel and the P content of the molten steel, and reducing the P content to be below 0.025 percent by stirring at the bottom of the converter after tapping; adding carbon powder of 0.2 kg/ton steel for pre-deoxidation at the early stage of tapping, sequentially adding an aluminum block (0.6-0.7 kg/ton steel), ferrosilicon (4 kg/ton steel), ferromanganese (18 kg/ton steel) and lime (4-5 kg/ton steel) for deoxidation alloying, keeping nitrogen blowing in the whole process in the deoxidation alloying process, tapping in a double-gear mode of a sliding plate and a slag blocking cone (slag blocking ball) at the later stage of tapping, strictly controlling to effectively reduce tapping slag of the converter, adding a slag scooping process after tapping steel, ensuring that the slag amount of the converter is less than or equal to 2 kg/ton steel, reducing oxidizing slag of the converter from entering molten steel, and providing good conditions for slag making in the later process;
(3) l F furnace refining, wherein the refining time is more than or equal to 40min, lime and refining slag are added in the refining, and the percentage content of inclusions in the steel is controlled to be 59.3 percent of CaO and SiO212.95% of Al2O3The final slag alkalinity is controlled to be 3.94 percent, and the power supply smelting process adopts deoxidizers such as SiC, aluminum wires or calcium carbide and the like to carry out composite diffusion deoxidation, so as to ensure that the total mass percentage content of TFe and MnO is 0.53 percent, maintain the white slag in the process and ensure that the oxygen content is below 5ppm when the slag is out of the station;
(4) RH vacuum: pumping the vacuum degree to be below 2.5 millibar within 5min, controlling the vacuum degree to be below 2.5 millibar, keeping the high vacuum for 23min, ensuring that the mass percentage content of the molten steel is 1.5ppm, increasing nitrogen components by using a silicon nitrogen alloy and a composite vanadium nitrogen alloy, forbidding calcium treatment, and carrying out soft blowing for 31 min;
(5) continuous casting: casting through continuous casting to obtain non-quenched and tempered steel, and controlling the superheat degree of a continuous casting tundish to be 28-33 ℃.
Example 3
The invention relates to a preparation method for controlling large-particle inclusions in non-quenched and tempered steel, which comprises the following steps of:
(1) smelting in a converter: and in the process of smelting the converter, controlling the end point C of the converter: 0.163% (TSO for tapping: 217ppm), the tapping temperature is 1638 ℃, and the oxygen level is strictly controlled, thereby creating good conditions for the next working procedure;
(2) tapping by a converter: before tapping of molten steel, starting stirring at the bottom of a converter to reduce the oxidability of the molten steel and the P content of the molten steel, and reducing the P content to be below 0.025 percent by stirring at the bottom of the converter after tapping; adding carbon powder of 0.2 kg/ton steel for pre-deoxidation at the early stage of tapping, sequentially adding an aluminum block (0.6-0.7 kg/ton steel), ferrosilicon (4 kg/ton steel), ferromanganese (18 kg/ton steel) and lime (4-5 kg/ton steel) for deoxidation alloying, keeping nitrogen blowing in the whole process in the deoxidation alloying process, tapping in a double-gear mode of a sliding plate and a slag blocking cone (slag blocking ball) at the later stage of tapping, strictly controlling to effectively reduce tapping slag of the converter, adding a slag scooping process after tapping steel, ensuring that the slag amount of the converter is less than or equal to 2 kg/ton steel, reducing oxidizing slag of the converter from entering molten steel, and providing good conditions for slag making in the later process;
(3) l F furnace refining, wherein the refining time is more than or equal to 40min, lime and refining slag are added in the refining, and the percentage content of inclusions in the steel is controlled to be 55.62 percent of CaO and SiO218.62% of Al2O321.37 percent, controlling the alkalinity of final slag at 3.76, carrying out composite diffusion deoxidation by adopting deoxidizers such as SiC, aluminum wires or calcium carbide in the power supply smelting process, ensuring the total mass percentage content of TFe and MnO to be 0.64 percent, keeping white slag in the process, and ensuring that the oxygen content is below 5ppm when the slag is out of the station;
(4) RH vacuum: pumping the vacuum degree to be below 2.5 millibar within 5min, controlling the vacuum degree to be below 2.5 millibar, keeping the high vacuum for 21min, ensuring that the mass percentage content of the molten steel is 1.5ppm, increasing nitrogen components by using silicon nitrogen alloy and composite vanadium nitrogen alloy, forbidding calcium treatment, and carrying out soft blowing for 35 min;
(5) continuous casting: casting through continuous casting to obtain non-quenched and tempered steel, and controlling the superheat degree of a continuous casting tundish to be 29-32 ℃.
And (3) performance testing:
the non-quenched and tempered steel of the invention is tested, and the test result is as follows:
1. the total oxygen content of T.O in the steel is stably controlled to be below 15ppm, and the content of H in the steel is stably controlled to be below 1.5 ppm;
2. inclusion level: the non-metallic inclusion is detected according to GB/T10561, the class A and class B inclusion are both less than or equal to 2.5, and the class C and class D inclusion are both less than or equal to 0.5, thus meeting the requirements.

Claims (6)

1. The preparation method for controlling large-particle inclusions in non-quenched and tempered steel is characterized by comprising the following steps of:
(1) smelting in a converter: in the process of smelting the converter, controlling the mass percentage content of the end point C of the converter to be more than or equal to 0.10 percent or the oxygen site of the tapped TSO to be less than or equal to 300ppm and the tapping temperature to be more than or equal to 1600 ℃;
(2) tapping by a converter: before molten steel tapping, the bottom of a converter is opened for stirring, so that the oxidability of the molten steel and the P content of the molten steel are reduced; adding carbon powder for pre-deoxidation at the early stage of tapping, sequentially adding a deoxidizer, an alloy and slag charge for deoxidation alloying, keeping full-process nitrogen blowing in the deoxidation alloying process, tapping at the later stage of tapping in a double-gear mode, and strictly controlling slag tapping;
(3) l F furnace refining, wherein the refining time is more than or equal to 40min, lime and refining slag are added in the refining, and the percentage content of inclusions in the steel is controlled to be 45-60% of CaO and SiO210 to 20% of Al2O315-25%, controlling the final slag alkalinity at 3.0-4.0, performing composite diffusion deoxidation by using SiC, aluminum wires or calcium carbide in the power supply smelting process, ensuring that the total mass percentage of TFe and MnO is less than or equal to 0.80%, keeping white slag in the process, and ensuring that the oxygen content is less than 5ppm when the slag is out of the station;
(4) RH vacuum: controlling the vacuum degree below 2.5 mbar, keeping the vacuum for more than 15min, adding nitrogen components by using a silicon-nitrogen alloy and a composite vanadium-nitrogen alloy, forbidding calcium treatment, and soft-blowing for more than 20 min;
(5) continuous casting: casting through continuous casting to obtain non-quenched and tempered steel, and controlling the superheat degree of a continuous casting tundish to be 10-35 ℃.
2. The method for preparing large-particle inclusions in non-quenched and tempered steel according to claim 1, wherein the method comprises the following steps: in the step (2), the alloy is ferrosilicon and ferromanganese, the deoxidizer is an aluminum block, and the slag is lime.
3. The method for preparing large-particle inclusions in non-quenched and tempered steel according to claim 1, wherein the method comprises the following steps: and (3) reducing the P content to below 0.025 percent by bottom stirring of the discharged steel of the converter in the step (2).
4. The method for preparing large-particle inclusions in non-quenched and tempered steel according to claim 1, wherein the method comprises the following steps: and (3) in the step (2), the double-gear mode is a mode of adding a slag blocking cone by a sliding plate or adding a slag blocking ball by a sliding plate, so that the slag discharge during the converter tapping is effectively reduced.
5. The method for preparing large-particle inclusions in non-quenched and tempered steel according to claim 1, wherein the method comprises the following steps: and (3) adding a slag fishing and raking process after tapping in the step (2) to ensure that the slag amount of the converter is less than or equal to 2 kg/ton of steel.
6. The method for preparing large-particle inclusions in non-quenched and tempered steel according to claim 1, wherein the method comprises the following steps: the non-quenched and tempered steel comprises the following chemical components in percentage by weight: c: 0.42 to 0.49%, Si: 0.3-0.6%, Mn: 1.0-1.5%, P: less than or equal to 0.025%, S: 0.035-0.075%, V: 0.06-0.13%, Alt: 0.005-0.025%, Ni is less than or equal to 0.3%, Cu is less than or equal to 0.3%, Cr is less than or equal to 0.3%, and N: not less than 80ppm, and the balance of Fe and inevitable impurities.
CN202010162001.1A 2020-03-10 2020-03-10 Preparation method for controlling large-particle inclusions in non-quenched and tempered steel Pending CN111411188A (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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CN107287504A (en) * 2017-06-16 2017-10-24 上海大学 The middle carbon easy-cutting non-hardened and tempered steel and its manufacturing technique method of sulfur-bearing, tellurium
CN109402320A (en) * 2018-11-27 2019-03-01 南京钢铁股份有限公司 A kind of preparation method of high cleanliness wind-powered electricity generation fastener
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CN113652512A (en) * 2021-07-29 2021-11-16 南京钢铁股份有限公司 Smelting method for directly turning non-quenched and tempered steel

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Application publication date: 20200714