CN109943685A - A kind of external refining production method of hypoxemia low titanium high-carbon-chromium bearing steel - Google Patents

A kind of external refining production method of hypoxemia low titanium high-carbon-chromium bearing steel Download PDF

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CN109943685A
CN109943685A CN201910127805.5A CN201910127805A CN109943685A CN 109943685 A CN109943685 A CN 109943685A CN 201910127805 A CN201910127805 A CN 201910127805A CN 109943685 A CN109943685 A CN 109943685A
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steel
carbon
refining
production
content
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耿克
许晓红
黄镇
李锋
陈德
尹青
白云
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Jiangyin Xingcheng Special Steel Works Co Ltd
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Jiangyin Xingcheng Special Steel Works Co Ltd
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Abstract

The present invention relates to a kind of external refining production method of hypoxemia low titanium high-carbon-chromium bearing steel, the process used further controls pretreated terminal molten steel sulfur content≤0.005% of (1) KR molten iron for KR → BOF → LF → RH → CC → rolling;(2) BOF oxygen decarburization, for endpoint carbon content 0.15%~0.80%, the aluminum amount that 0.5kg/t or more is added when tapping by alumina balance chart into molten steel makes oxygen content in steel after tapping be down to 30ppm hereinafter, tapping temperature is controlled at 1600 DEG C~1700 DEG C;(3) add refining slag in LF refining, controlling free CaO molar fraction in refining slag is 40%~60%, in control steel aluminium content at 0.03%~0.07%, tapping Control for Oxygen Content in 10ppm hereinafter, 1550 DEG C~1610 DEG C of tapping temperature;(4) RH vacuum outgas whole process argon gas stirs, 100Pa or less vacuum 10min or more of lower retention time.The steady production for realizing hypoxemia low titanium high-carbon-chromium bearing steel continuous casting billet has the characteristics that high efficiency, low cost, energy conservation, total oxygen content T.O≤5ppm, Ti≤10ppm in product.

Description

A kind of external refining production method of hypoxemia low titanium high-carbon-chromium bearing steel
Technical field
The invention belongs to the production technical field of superior quality bearing steel, in particular to outside a kind of furnace of high-carbon-chromium bearing steel Refining production method.
Background technique
With the rapid development of the national economy, the continuous expansion of China's bearing application, the key such as existing automobile, railway The generally raising that bearing requires life and reliability, as automobile bearing life requirements guarantees 250,000 kilometers of traveling or more, high speed EMU bearing life requires traveling to reach 2,400,000 kilometers or more.In this regard, to the research of steel product quality and bearing life relationship Significant achievement is achieved, wherein the degree of purity of steel is the primary factor for influencing fatigue life of bearing.
China is using secondary refining method production existing more than 40 years history of high-carbon-chromium bearing steel, with equipment and technique Horizontal raising, the degree of purity of steel there has been great progress, show total oxygen content T.O be remarkably decreased and large inclusions Substantially reduce.Although existing high-carbon-chromium bearing steel standard GB/T/T18254-2016 to non-metallic inclusion and oxygen content There is specific regulation, it, can not even if being the superfine steel of the highest level such as total oxygen content T.O≤6ppm of the requirement to degree of purity Meet crucial bearing top load, the requirement of long-life and high reliability.And Japanese adret special steel reports its SNRP external refining High cleanliness bearing steel T.O≤5ppm of technique production.
A kind of external refining production method of high-purity high-carbon high-chromium bearing steel of existing patent ZL 01132236.5, patent ZL 200410025102.5 a kind of external refining production method of high cleaning high-carbon-chromium bearing steel, patent ZL 200410089358.2 Reduce and refine external refining production method, 200710048395.2 converter of patent ZL of the D type impurity of high-carbon-chromium bearing steel The method and a kind of high-carbon-chromium bearing steel of patent ZL 201010179893.2 of continuous casting process production low oxygen content high-carbon-chromium bearing steel External refining production method, be all made of secondary refining method production high-carbon-chromium bearing steel, but its steel degree of purity produced Horizontal not high, if total oxygen content T.O is only 7ppm~15ppm, production procedure is not perfect, such as true without molten iron pretreatment, RH The critical equipment that sky degassing etc. is affected to quality;Technology controlling and process is also not perfect, feed sulphur content, converter before such as entering converter Endpoint carbon content etc. is not directed to the key parameter that quality is affected or controlled level is not high.
A kind of smelting production method of extra pure high carbon chromium bearing steel of existing patent ZL 200510027394.0 uses true Empty induction furnace and the production of consumable electrode vacuum furnace duplex technique, the technique and external refining production method are entirely different, and production efficiency Low and high production cost, energy consumption is high, is not suitable for producing in enormous quantities.
The application develops a kind of external refining production method of high-carbon-chromium bearing steel, using converter, vacuum outgas, continuous casting High efficiency, low cost, the production of energy-efficient process route, by improving production procedure and optimizing research and control to critical process System, target is total oxygen content T.O≤5ppm, the Ti≤10ppm for making steel.
Summary of the invention
The object of the present invention is to provide a kind of external refining production methods of hypoxemia low titanium high-carbon-chromium bearing steel, using converter BOF, vacuum outgas (LF+RH), the high efficiency of continuous casting (CC), low cost, the production of energy-efficient process route, by improving production stream Journey simultaneously optimizes research and control to critical process, the oxygen and Ti content of produced steel is reduced, according to the application producer Product total oxygen content T.O≤5ppm, the Ti≤10ppm of method production.
The concrete scheme of the application is a kind of external refining production method of hypoxemia low titanium high-carbon-chromium bearing steel, use Process is KR molten iron pretreatment → BOF → LF → RH → CC → rolling, and is further controlled
(1) material controls: ladle, continuous casting production and steel contacts position utilize more than the high fire resisting of 90%MgO content Spend material;
(2) pretreated terminal molten steel sulfur content≤0.005% of KR molten iron;
(3) BOF oxygen decarburization, endpoint carbon content is 0.15%~0.80%, when tapping by alumina balance chart into molten steel Be added 0.5kg/t or more aluminum amount make tapping after oxygen content in steel be down to 30ppm hereinafter, tapping temperature control 1600 DEG C~ 1700℃;
(4) refining slag is added in LF refining, controlling free CaO molar fraction in refining slag is 40%~60%, electrode Heating, alloying, control steel in aluminium content at 0.03%~0.07%, tapping Control for Oxygen Content in 10ppm hereinafter, tapping temperature 1550 DEG C~1610 DEG C of degree;
(5) RH vacuum outgas whole process argon gas stirs, 100Pa or less vacuum 10min or more of lower retention time;
(6) in CC continuous casting process, ladle to tundish, tundish itself and tundish are whole vacuum to crystallizer or fill Argon.
The KR molten iron pretreatment of step (1) uses mechanical agitation type, and ladle first takes surface off after in place before pretreatment Molten iron slag, add desulfurizing agent and be stirred, finally take the slag of generation off, should the purpose of " one, which stirs two, takes off " technique be to fill Give desulfurizing iron.
For steady production, final sulfur content is controlled, the pretreatment of KR molten iron uses terminal sulphur Forecast Mode: according to original sulphur The combination setting of content, temperature, desulfurization dosage, mixing time these types parameter, makes to reach the terminal molten steel sulfur content.
Preferably, blowing argon gas is continued using packet bottom during step (4) LF refining, removal of inclusions removes while preventing steel Water reoxidizes.
Preferably, step (4) LF refining uses refining slag for prepare in advance containing 40~60%CaO, 3~10%MgO, 3~10%SiO2, 20~40%Al2O3Dedicated refining slag, be directly added at one time in steel, additive amount 800kg~2000kg/ 100t molten steel makes clinker keep stronger deoxidizing capacity.
Preferably, step (6) CC continuous casting is poured using low overheat, low pulling rate, the degree of superheat: 0~25 DEG C, pulling rate 0.40m/ Min~0.60m/min.
Compared with prior art, the application has the characteristics that:
(1) the pretreated final sulfur content control of KR molten iron is had at trace (≤0.005%) in the deoxidation of postorder refining Benefit can reduce the additive amount of postorder deoxidier, be beneficial to control the content of field trash in lower level;
(2) the terminal C content of BOF is controlled, indirectly the Control for Oxygen Content in molten steel in low-level, because of converter Endpoint carbon content and oxygen content in steel have a corresponding relationship, i.e. carbon content height corresponds to that oxygen content is low, and then postorder can lack low oxygen content Killing generates field trash less, highly beneficial to degree of purity.
(3) the tapping temperature range for controlling BOF, makes the requirement for meeting alloying, slugging amount.
(4) to meet the requirement such as alloying, slugging amount, setting BOF tapping temperature is 1600 DEG C~1700 DEG C.
(5) it controls in RH process that the retention time is greater than 10 minutes at high vacuum 100Pa, makes H content in steel extremely 1.5ppm following.
(6) continuous casting process can prevent molten steel oxidation using whole argon filling or vacuum protection.
The application is combined using converter, vacuum outgas, the high efficiency of continuous casting, low cost, the production of energy-efficient process route The above design, improves production procedure and optimizes research and control to critical process, be finally obtained hypoxemia low titanium high carbon chromium The steady production of Continuous Casting Bloom of Bearing Steel obtains the more superior high-carbon-chromium bearing steel of performance, and total oxygen content T.O in product≤ 5ppm、Ti≤10ppm。
With traditional electric furnace and electroslag remelting duplex, the poor efficiency of vaccum sensitive stove and consumable electrode vacuum furnace duplex technique, Gao Cheng Originally, the close super clean high-carbon-chromium bearing steel ratio of the production method production of high energy consumption, the furnace outer refining process that steel of the present invention uses It is suitable for mass production for high efficiency, low cost, energy-efficient production method, facilitate the international competitiveness for promoting high-end bearing steel, It is creative.
Specific embodiment
Present invention is further described in detail with reference to embodiments.
The chemical composition ranges according to designed by high-carbon-chromium bearing steel, referring to table 1, by 100 tons of molten iron pretreatment KR → 100 tons of converter BOF → 100 ton refining furnace LF → 100 ton vacuum degassing furnace RH → big cross section conticaster CC → Rolling Production 10 The steel of the present invention of furnace, 8 specifications.
(1) the high refractoriness material of ladle, continuous casting production and steel contacts part using magnesia content (>=90%), aluminium Alloy as deoxidier, using dedicated slag charge: contain 40~60%CaO, 3~10%MgO, 3~10%SiO2, 20~40%Al2O3 Dedicated refining slag, and controlling in refining slag free CaO molar fraction is 40%~60%;
(2) molten iron pretreatment uses mechanical agitation type, using " one, which stirs two, takes off " technique, i.e., ladle in place after before treatment The molten iron slag for first taking surface off, adds desulfurizing agent and is stirred, and finally takes the slag of generation off.Using terminal sulphur forecasting model: Final sulfur content is set as trace (≤0.005%) according to original sulfur content, temperature, desulfurization dosage, mixing time combination, with And the control of titanium, arsenic, lead, tin, antimony content, it is trace content;
(3) converter BOF oxygen decarburization controls endpoint carbon content 0.15%~0.80%, to reduce postorder deoxidier Additive amount reduces the generation of field trash.To meet the requirement such as alloying, slugging amount, 1600 DEG C~1700 DEG C of tapping temperature are controlled. The aluminum amount greater than 0.5kg/t is added when tapping by alumina balance chart makes oxygen content in steel after tapping be down to 30ppm or so.
(4) LF refining furnace refining is then carried out, pre-configured refining slag is added at one time, adds slag total amount 1600kg, Heated by electrodes, alloying, aluminium content control wraps bottom and continues blowing argon gas promotion inclusion floating in 0.05%-0.07% in steel processed Removal, Control for Oxygen Content is in 10ppm hereinafter, 1550 DEG C~1610 DEG C of tapping temperature when tapping.
(6) vacuum degassing furnace whole process argon gas stirs, and controls the 100Pa vacuum condition lower retention time greater than 10 minutes.
(7) when continuous casting ladle to tundish, tundish itself and tundish to crystallizer whole process argon filling gas shielded, tundish 0 DEG C~25 DEG C of steel molten steel overheat, 0.40 m/min~0.60 m/min of pulling rate.
(8) 1200 DEG C~1240 DEG C of continuous blank heating temperature, the oxidation on continuous casting billet surface is removed before open rolling with high pressure water Skin, start rolling temperature be 1130 DEG C~1200 DEG C, 920 DEG C~970 DEG C of finishing temperature, cogging at 200mm × 200mm and 300mm × The intermediate base of 300mm specification;
(9) intermediate 1100 DEG C~1200 DEG C of heating temperature of base, start rolling temperature are 1050 DEG C~1150 DEG C, finishing temperature 850 DEG C~900 DEG C, mill product specification is Φ 20mm~Φ 140mm;
Finished steel meets the requirement that individual defect is no more than φ 1.2mm flat-bottom hole by ultrasonic examination non-destructive testing.
It samples and examines by high-carbon-chromium bearing steel national standard GB/T18524-2016, the chemical component (heat analysis) of invention steel And total oxygen content T.O (steel analysis) is shown in Table 1.With compared steel GB/T18254-2016 high-carbon-chromium bearing steel superfine steel total oxygen T.O Content 6ppm, Ti content 15ppm are compared, and invention steel total oxygen T.O content 3.5ppm~4.8ppm, Ti content 5ppm~10ppm are more It is low, better than the requirement of national standard GB/T18254-2016 high-carbon-chromium bearing steel superfine steel.
The chemical component heat analysis wt% of 1 invention steel of table
* sampling analysis on finished steel.
The microcosmic field trash testing result of invention steel finished steel is shown in Table 2.With compared steel GB/T18254-2016 high carbon chromium 1.0 grades of bearing steel superfine steel DS rank (19 μm~26 μm of particle size) is compared, and the microcosmic field trash DS class rank of invention steel is 0 grade (4 μm~8 μm of particle size, more tiny), better quality.
The microcosmic field trash of 2 invention steel of table

Claims (7)

1. a kind of external refining production method of hypoxemia low titanium high-carbon-chromium bearing steel, it is characterised in that: the process used is KR iron Water pretreatment → BOF → LF → RH → CC → rolling, and further control
(1) material controls: ladle, continuous casting production and steel contacts position utilize more than the high refractoriness material of 90%MgO content Material;
(2) pretreated terminal molten steel sulfur content≤0.005% of KR molten iron;
(3) BOF oxygen decarburization, endpoint carbon content are added when tapping by alumina balance chart into molten steel 0.15%~0.80% The aluminum amount of 0.5kg/t or more makes oxygen content in steel after tapping be down to 30ppm hereinafter, tapping temperature control is 1600 DEG C~1700 ℃;
(4) refining slag is added in LF refining, controlling free CaO molar fraction in refining slag is 40%~60%, heated by electrodes, Alloying, control steel in aluminium content at 0.03%~0.07%, tapping Control for Oxygen Content in 10ppm hereinafter, tapping temperature 1550 DEG C~1610 DEG C;
(5) RH vacuum outgas whole process argon gas stirs, 100Pa or less vacuum 10min or more of lower retention time;
(6) in CC continuous casting process, ladle to tundish, tundish itself and tundish to crystallizer are whole vacuum or argon filling.
2. the external refining production method of hypoxemia low titanium high-carbon-chromium bearing steel according to claim 1, it is characterised in that: step Suddenly the KR molten iron pretreatment of (1) uses mechanical agitation type, and ladle first takes the molten iron slag on surface off before pretreatment after in place, then Desulfurizing agent is added to be stirred, finally takes the slag of generation off.
3. the external refining production method of hypoxemia low titanium high-carbon-chromium bearing steel according to claim 1, it is characterised in that: step Suddenly (1) KR molten iron pretreatment use terminal sulphur Forecast Mode: according to original sulfur content, temperature, desulfurization dosage, mixing time this The combination of several parameters is set, and makes to reach the terminal molten steel sulfur content.
4. the external refining production method of hypoxemia low titanium high-carbon-chromium bearing steel according to claim 1, it is characterised in that: step Suddenly blowing argon gas is continued using packet bottom during (4) LF refining.
5. the external refining production method of hypoxemia low titanium high-carbon-chromium bearing steel according to claim 1, it is characterised in that: step Suddenly the refining slag that (4) LF refining uses contains 40~60%CaO, 3~10%MgO, 3~10%SiO for what is prepared in advance2, 20~ 40%Al2O3Dedicated refining slag, be directly added at one time in steel, additive amount be 800kg~2000kg/100t molten steel.
6. the external refining production method of hypoxemia low titanium high-carbon-chromium bearing steel according to claim 1, it is characterised in that: step Suddenly (6) CC continuous casting is poured using low overheat, low pulling rate, the degree of superheat: 0~25 DEG C, pulling rate 0.40m/min~0.60m/min.
7. a kind of preparation method of hypoxemia low titanium high-carbon-chromium bearing steel, it is characterised in that: -6 external refining according to claim 1 Production method produces hypoxemia low titanium high carbon chromium continuous casting billet and uses high pressure before open rolling for 1200 DEG C~1240 DEG C of continuous blank heating temperature Water removes the oxide skin on continuous casting billet surface, is arranged 1130 DEG C~1200 DEG C of start rolling temperature, 920 DEG C~970 DEG C of finishing temperature, will even Slab cogging is at the intermediate base of 200mm × 200mm~300mm × 300mm specification;Intermediate 1100 DEG C of the base heating temperature of setting~ 1200 DEG C, 1050 DEG C~1150 DEG C of start rolling temperature, 850 DEG C~900 DEG C of finishing temperature, intermediate base is rolled as Φ 20mm~Φ The trimmed size of 140mm;Finished steel meets individual defect no more than φ 1.2mm flat-bottom hole by ultrasonic examination non-destructive testing Requirement.
CN201910127805.5A 2019-02-20 2019-02-20 A kind of external refining production method of hypoxemia low titanium high-carbon-chromium bearing steel Pending CN109943685A (en)

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CN110527909A (en) * 2019-09-11 2019-12-03 本钢板材股份有限公司 A kind of preparation method of the beating steel GCr15 of ultralow titanium containing Cu-J
CN112410650A (en) * 2020-10-30 2021-02-26 建龙北满特殊钢有限责任公司 Control method for improving low-power quality and segregation index of high-carbon chromium bearing steel

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CN107904498A (en) * 2017-10-20 2018-04-13 江阴兴澄特种钢铁有限公司 A kind of railway freight-car carburizing bearing steel and preparation method thereof
CN108676952A (en) * 2018-03-26 2018-10-19 敬业钢铁有限公司 A kind of preparation method of converter process production bearing steel

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JPS6250403A (en) * 1985-08-29 1987-03-05 Kobe Steel Ltd Production of high-carbon chromium bearing steel
CN102352466A (en) * 2011-11-02 2012-02-15 承德建龙特殊钢有限公司 High-carbon chromium bearing steel GCr15 and production method thereof
CN104178698A (en) * 2014-09-01 2014-12-03 山东钢铁股份有限公司 Method for preparing bearing steel
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110527909A (en) * 2019-09-11 2019-12-03 本钢板材股份有限公司 A kind of preparation method of the beating steel GCr15 of ultralow titanium containing Cu-J
CN112410650A (en) * 2020-10-30 2021-02-26 建龙北满特殊钢有限责任公司 Control method for improving low-power quality and segregation index of high-carbon chromium bearing steel

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Application publication date: 20190628