CN106521120B - A kind of bearing steel heats Decarburization Control method - Google Patents

A kind of bearing steel heats Decarburization Control method Download PDF

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Publication number
CN106521120B
CN106521120B CN201610944313.1A CN201610944313A CN106521120B CN 106521120 B CN106521120 B CN 106521120B CN 201610944313 A CN201610944313 A CN 201610944313A CN 106521120 B CN106521120 B CN 106521120B
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heating
temperature
air
fuel ratio
furnace
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CN201610944313.1A
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Chinese (zh)
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CN106521120A (en
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席波
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南京钢铁股份有限公司
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    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D3/00Diffusion processes for extraction of non-metals; Furnaces therefor
    • C21D3/02Extraction of non-metals
    • C21D3/04Decarburising
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/74Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D11/00Process control or regulation for heat treatments
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D3/00Diffusion processes for extraction of non-metals; Furnaces therefor
    • C21D3/10Furnaces therefor

Abstract

The invention discloses a kind of bearing steel to heat Decarburization Control method, the walking beam heating furnace gone out using side into side;Fuel is high coke mixed gas;Using reducing atmosphere computer heating control decarburized layer deepness, using a fiery production technology, raw material is GCr15 continuous casting billets, if billet-charging, steel billet enter preheating section, whether setting preheating section, bringing-up section and soaking zone air-fuel ratio, observation heating-up temperature, actual mixing ratio and residual oxygen show value meet the requirements, observe heat exchanger before temperature whether overtemperature, there is exception manual intervention.One fiery bearing steel of present invention solution needs high temperature diffusion heating for a long time, and is difficult to control the contradiction of decarburized layer deepness;Cancel peeling operation, meet that decarburized layer is no more than 0.5%D high request indexs at low cost.

Description

A kind of bearing steel heats Decarburization Control method
Technical field
The invention belongs to special steel heating process field, is related to a kind of using reducing atmosphere progress computer heating control decarburized layer The technology of depth, specifically a kind of bearing steel heating Decarburization Control method.
Background technology
The decarburized layer of bearing steel steel is an important technical indicator, and decarburized layer deepness directly influences the wear-resisting of bearing Performance and used life.The decarburized layer of steel depends primarily upon the control of heating steel billet technique, can also use special coating Guard technology(Need to increase more cost).It is distinctly claimed in standard GB/T/T18254, decarburization layer depth different according to specification Degree requires difference, and generally in the range of 1.2%D ~ 2.0%D, which is easier to reach using common heating technique.But due to fierceness Market competition, present user require it is higher and higher, as long as there is the Production of bearing user of certain market brand influence, all will Total decarburized layer depth is asked to reach 0.8%D ~ 1.0%D, some even requires to be no more than 0.5%D.
The technique of general control decarburized layer deepness is:Low temperature quick heating means are used during heating, if running into the non-meter of milling train Parking is drawn, steel billet should drag for shove charge production again after stove not in being stopped in stove, if detection decarburized layer cannot meet that technology will Ask, then, could qualified storage after carrying out peeling processing to steel.The shortcoming of the technique:
(1) a fiery bearing steel is needed to heat in furnace high-temperature and spread for a long time, the defects of to eliminate carbide liquid-extraction, just Be not suitable for quickly heating using low temperature and prevent decarbonization process;
(2) due to being influenced be subject to rolling line failure rate, quickly heating tapping, steel billet is occasionally wanted to and but can't get out;
(3) if rolling line stops, steel billet is needed to drag for stove, the process operability is not strong, and not only labor intensity is big, and serious shadow Ring production efficiency;
(4) steel of the technique productions, two fiery bearing steels are used(Low temperature rapid heating process can be used)Decarburization layer depth Degree generally can only achieve 1.0%D or so, the order to requirements at the higher level, it is necessary to peeling handle, in this way, ton steel cost increase by 96 yuan with On.
The content of the invention
The object of the present invention is to provide a kind of bearing steel to heat Decarburization Control method, is taken off using reducing atmosphere computer heating control Carbon-coating depth, it is possible to achieve following two purposes, first, solving a fiery bearing steel needs high temperature diffusion heating for a long time, and are difficult to Control the contradiction of decarburized layer deepness;Second, cancelling peeling operation, meet that decarburized layer refers to no more than 0.5%D high requests at low cost Mark.
The purpose of the present invention is achieved through the following technical solutions:
A kind of bearing steel heats Decarburization Control method, it is characterised in that this method requires as follows:
1)The walking beam heating furnace gone out using side into side;Fuel is high coke mixed gas;Heating furnace burner hearth, which is divided into, not to be supplied Hot arc and for hot arc, is divided into preheating section, heating one or two sections and one or two sections of soaking for hot arc along furnace superintendent direction;The parameter bag of heating furnace Include:Temperature before each section of heating-up temperature, heating time, each section of air-fuel ratio, furnace pressure, gas flow, residual oxygen value, heat exchanger, mix Air-cooler throttle opening;
2)Bearing steel is using a fiery production technology, and raw material is GCr15 continuous casting billets, using weak oxide even reducing atmosphere Decarburization, implementation steps are as follows:
(1)GCr15 continuous casting billet shove charges, do not supply hot arc:600~950 DEG C, preheating section:850~1050 DEG C, one section of heating: 1160~1210 DEG C, two sections of heating:1220 ± 20 DEG C, one section of soaking:1220 ± 20 DEG C, two sections of soaking:1200±20℃;Air-fuel Than by 2.4 ~ 2.6 settings;
(2)When GCr15 blanks never step to preheating section for hot arc, preheating section air-fuel ratio heats one by 2.2 settings Section is also set for two sections to soaking by 2.2;
(3)When GCr15 blanks enter each section by certain heating time, each section according to target temperature is set respectively, So that automatic combustion controls;Average stepping rhythm about 130 seconds;
(4)Furnace pressure is observed, is controlled between+15Pa ~+30Pa, prevents suction cold wind;
(5)Observe each section of temperature, gas flow, residual oxygen value situation of change;After air-fuel ratio reduces, heating has certain difficulty Degree is, it is necessary to heighten gas flow, active heat supply;Residual oxygen value can be reduced constantly, until 0.01%;
(6)Whether observation burner hearth afterbody has temperature before phenomenon of burning with anger, and heat exchanger, and highest is no more than 650 DEG C, if constantly Rise and close to 620 DEG C, should just open and mix air-cooler, to ensure heat exchanger safe operation;Because after air-fuel ratio reduces, in burner hearth There is imperfect combustion coal gas to be flowed to flue gas in burner hearth afterbody and flue, it is cold with the suction of shove charge side in stove tail and flue Wind burns, so that heat exchanging device pipe group causes to damage, reduces its service life;
(7)When GCr15 blanks step to stokehold, the air-fuel ratio of back section can Renew theory burning normal value.
Step(3)In, each section of target temperature is 880 DEG C of preheating section, one section 1180 DEG C of heating, heating two sections and soaking one Section 1215 DEG C, 1195 DEG C of soaking two section.It is full open hearth roof construction for hot arc furnace roof in walking beam heating furnace, heat-recovery section stove Push up as screw-down structure, it is each for hot arc between set furnace roof partition wall;Each section has air-fuel ratio setting value and actual value to show, theoretical Air-fuel ratio is about 2.5, and residual oxygen sample point is located at before heat exchanger in main chimney flue, and tubular metal heat exchanger is set in flue.
The walking beam heating furnace that the present invention is gone out using side into side, fuel is high coke mixed gas.Heating furnace overall length 42960mm, effective width 13100mm in stove, heating furnace burner hearth, which is divided into, does not supply hot arc(That is heat-recovery section)With for hot arc, for hot arc It is divided into preheating section, heating one or two sections and one or two sections of soaking again along furnace superintendent direction.It is full open hearth roof construction for hot arc furnace roof, recuperation of heat Section furnace roof is screw-down structure, supplies between hot arc to set furnace roof partition wall each.Each section has air-fuel ratio(That is air and gas flow Ratio)Setting value and actual value show that chemically correct fuel is about 2.5(Daily can be according to the narrow fluctuation of mixed gas calorific value), it is residual Oxygen sample point is located at before heat exchanger in main chimney flue, and 3 group of 2 stroke tubular metal heat exchanger is set in flue(Tube Sheet of Heat Exchanger group 1/4 high temperature side of material is 0Cr18SiAl, and 3/4 high temperature side is 0Cr17, and low temperature side is 20g aluminium impregnation of steel tube, and plug-in unit is 1Cr13.), it is allowed to temperature≤650 DEG C before into heat exchanger, for warm-up combustion-supporting air, recycle waste gas residual heat.To prevent high temperature The damage of side pipe group, when hot blast temperature overtemperature, will alarm and automatically opens up hot wind diffusion valve, in addition, before air heat exchanger Flue be equipped with diluent air system, can mix cold wind from trend flue when flue gas overtemperature to reduce flue-gas temperature, it is right Heat exchanger is protected.These hardware facilities are to perform weak oxide even reducing atmosphere computer heating control decarburized layer deepness technology Basic condition.
The present invention uses reducing atmosphere computer heating control decarburized layer deepness, and solving a fiery bearing steel needs high temperature to expand for a long time Heating is dissipated, and is difficult to control the contradiction of decarburized layer deepness;Cancel peeling operation at the same time, meet that decarburized layer is no more than at low cost 0.5%D high request indexs.
The present invention requires decarburization suitable for special steel manufacturing enterprise high kind, such as bearing steel, spring steel and other vapour Automobile-used steel, application prospect are very wide.After the invention, bearing steel steel decarburization index can be made to reach 0.5%D(D is round steel Diameter, similarly hereinafter)Hereinafter, so as to avoid peeling treatment process, drop this benefit and reach more than 96 yuan/t steel.
Embodiment
A kind of bearing steel heats Decarburization Control method, using reducing atmosphere control technique, is carried out by following technological process: --- steel billet enters preheating section --- setting preheating section, bringing-up section and soaking zone air-fuel ratio --- observation heating temperature to billet-charging If whether degree, actual mixing ratio and residual oxygen show value, which meet the requirements, --- before observation heat exchanger temperature overtemperature --- occurs different Normal manual intervention.
The equipment that Decarburization Control technique uses:Side inlet side outlet walking beam type heating furnace.Need the parameter bag of adjustment heating furnace Include:Temperature before each section of heating-up temperature, heating time, each section of air-fuel ratio, furnace pressure, gas flow, residual oxygen value, heat exchanger, mix Air-cooler throttle opening.
Bearing steel can use a fire or two fiery production technologies, and a fiery bearing steel (GCr15) must use high temperature for a long time Heating process is spread, to the control technology difficulty higher of decarburization.And two fiery bearing steels(Bloom)Can quickly it be added using low temperature Thermal process is smaller to present invention process operation difficulty.Therefore, lower mask body introduces a fiery bearing steel(GCr15 continuous casting billets)It is weak Oxidisability even reducing atmosphere decarbonization process implementation steps:
GCr15 continuous casting billet shove charges, each zone temperatures are still performed by corresponding steel grade heating process in heating-furnace at this time, but mistake Cross section(Refer to the confession hot arc of immediately bearing steel steel billet, such as preheating section)Heating-up temperature starts temperature raising, is created for bearing steel high temperature heating Condition, air-fuel ratio is by 2.4 ~ 2.6 settings.Such as, if 45 steel, preheating section improve 50 ~ 60 DEG C, reach 860~900 DEG C in stove;Add One section of heat improves 90 ~ 120 DEG C, reaches 1120~1160 DEG C, prepares to drop air-fuel ratio for the GCr15 temperature raisings of follow-up shove charge; (Note:45 steel and GCr15 heating-up temperatures of technical papers requirement see the table below 1)
1 unit of table:℃
When GCr15 blanks never step to preheating section for hot arc, preheating section air-fuel ratio heats one section by 2.2 settings Also set to soaking by 2.2 for two sections;
When GCr15 blanks enter each section by certain heating time, each section according to target temperature is set respectively(Preheating 880 DEG C of section, one section 1180 DEG C of heating, heating two sections and 1215 DEG C of soaking one section, 1195 DEG C of soaking two section), so as to automatic combustion Control;Average stepping rhythm about 130 seconds;
Pay attention to observing furnace pressure, control between+15Pa ~+30Pa, prevent suction cold wind;
Pay attention to observing each section of temperature, gas flow, residual oxygen value situation of change.After air-fuel ratio reduces, heating has certain difficulty Degree, it is necessary to heighten gas flow, active heat supply;Residual oxygen value can be reduced constantly, until 0.01%(The minimum value that can be detected.When During insulation, gas flow can be less than 6000Nm3/h, and residual oxygen value can go up not down to 6 ~ 9% at this time);
Pay attention to observing whether burner hearth afterbody has temperature before phenomenon of burning with anger, and heat exchanger, highest is no more than 650 DEG C, if not It is disconnected to rise and close to 620 DEG C, just open and mix air-cooler, to ensure heat exchanger safe operation;Since after air-fuel ratio reduces, burner hearth Inside there is imperfect combustion coal gas to be flowed to flue gas in burner hearth afterbody and flue, sucked in stove tail and flue with shove charge side Cold wind burns, so that heat exchanging device pipe group causes to damage, reduces its service life;
When GCr15 blanks step to stokehold, the air-fuel ratio of back section can Renew theory burning normal value(It is 2.5 left It is right).
Implement the invention about over 5 months, produce about 1100 tons of the qualified bearing steel of decarburization requirement≤0.5%D, ton steel Reduce about 96 yuan of peeling cost.Also, reduce the production process of peeling and secondary check, shorten the delivery date about 15 of steel My god.

Claims (2)

1. a kind of bearing steel heats Decarburization Control method, it is characterised in that this method requires as follows:
1) walking beam heating furnace gone out using side into side;Fuel is high coke mixed gas;Heating furnace burner hearth, which is divided into, does not supply hot arc With for hot arc, it is divided into preheating section, heating one or two sections and one or two sections of soaking along furnace superintendent direction for hot arc;The parameter of heating furnace includes: Temperature before each section of heating-up temperature, heating time, each section of air-fuel ratio, furnace pressure, gas flow, residual oxygen value, heat exchanger, mix cold wind Machine throttle opening;
2) for bearing steel using a fiery production technology, raw material is GCr15 continuous casting billets, is taken off using weak oxide even reducing atmosphere Carbon, implementation steps are as follows:
(1) GCr15 continuous casting billets shove charge, does not supply hot arc:600~950 DEG C, preheating section:850~1050 DEG C, one section of heating:1160~ 1210 DEG C, two sections of heating:1220 ± 20 DEG C, one section of soaking:1220 ± 20 DEG C, two sections of soaking:1200±20℃;Air-fuel ratio is pressed 2.4~2.6 settings;
(2) when GCr15 blanks never step to preheating section for hot arc, preheating section air-fuel ratio heats one section extremely by 2.2 settings Two sections of soaking is also by 2.2 settings;
(3) when GCr15 blanks enter each section by certain heating time, each section according to target temperature is set respectively, so as to Automatic combustion controls;Average stepping rhythm about 130 seconds;Each section of target temperature is that 880 DEG C of preheating section, one section 1180 DEG C of heating, add Two sections of heat and 1215 DEG C of soaking one section, 1195 DEG C of soaking two section;
(4) furnace pressure is observed, is controlled between+15Pa~+30Pa, prevents suction cold wind;
(5) each section of temperature, gas flow, residual oxygen value situation of change are observed;After air-fuel ratio reduces, heating can acquire a certain degree of difficulty, and need Heighten gas flow, active heat supply;Residual oxygen value can be reduced constantly, until 0.01%;
(6) whether observation burner hearth afterbody has temperature before phenomenon of burning with anger, and heat exchanger, and highest is no more than 650 DEG C, if constantly rising And close to 620 DEG C, it should just open and mix air-cooler, to ensure heat exchanger safe operation;Because after air-fuel ratio reduces, have not in burner hearth The coal gas of completely burned will flow in burner hearth afterbody and flue with flue gas, and the cold wind with the suction of shove charge side in stove tail and flue is sent out Raw burning, so that heat exchanging device pipe group causes to damage, reduces its service life;
(7) when GCr15 blanks step to stokehold, the air-fuel ratio of back section can Renew theory burning normal value.
2. bearing steel according to claim 1 heats Decarburization Control method, it is characterised in that:In step 1), stepping beam type It is full open hearth roof construction for hot arc furnace roof in heating furnace, heat-recovery section furnace roof is screw-down structure, supplies between hot arc to set furnace roof each Partition wall;Each section has air-fuel ratio setting value and actual value to show, chemically correct fuel is about 2.5, and residual oxygen sample point is positioned at heat exchange Before device in main chimney flue, tubular metal heat exchanger is set in flue.
CN201610944313.1A 2016-10-26 2016-10-26 A kind of bearing steel heats Decarburization Control method CN106521120B (en)

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CN107385177B (en) * 2017-06-06 2018-12-21 无锡兴澄特种材料有限公司 Medium carbon steel skin decarburization controls hot rolling wire production technology
CN107460301A (en) * 2017-06-29 2017-12-12 南京钢铁股份有限公司 A kind of heating means of mitigation GCr15 bearing steel decarburized layer deepness
CN108611572A (en) * 2018-05-11 2018-10-02 鞍钢股份有限公司 A kind of high-ductility hypereutectoid steel spring plate and its production method
CN109112280B (en) * 2018-08-07 2020-07-14 南京钢铁股份有限公司 Method for controlling decarburization depth of bearing steel wire
CN109385516A (en) * 2018-10-26 2019-02-26 福建三钢闽光股份有限公司 A kind of method of determining heater for rolling steel decarbonization process parameter
CN109943774A (en) * 2019-02-27 2019-06-28 南京钢铁股份有限公司 A kind of Low Alloy Steel for Automobile and its heating Decarburization Control technique
CN110157872B (en) * 2019-04-19 2021-02-26 首钢京唐钢铁联合有限责任公司 Heating method for reducing burning loss rate of plate blank of heat accumulating type heating furnace

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101195853A (en) * 2007-12-19 2008-06-11 莱芜钢铁集团有限公司 Heating method for preventing high carbon belt steel bloom decarburization
CN202660889U (en) * 2012-05-04 2013-01-09 北京首钢国际工程技术有限公司 Liquid deslagging high-temperature oriented silicon steel walking beam type slab heating furnace
CN104190705A (en) * 2014-08-04 2014-12-10 南京钢铁股份有限公司 Production technology for bearing steel wire rod
CN104419818A (en) * 2013-08-22 2015-03-18 南京钢铁股份有限公司 Heating method for cold-heading steel wire
CN105132657A (en) * 2015-09-29 2015-12-09 邢台钢铁有限责任公司 Method for decreasing decarburized layers on surfaces of high-carbon-chromium bearing steel wires

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101195853A (en) * 2007-12-19 2008-06-11 莱芜钢铁集团有限公司 Heating method for preventing high carbon belt steel bloom decarburization
CN202660889U (en) * 2012-05-04 2013-01-09 北京首钢国际工程技术有限公司 Liquid deslagging high-temperature oriented silicon steel walking beam type slab heating furnace
CN104419818A (en) * 2013-08-22 2015-03-18 南京钢铁股份有限公司 Heating method for cold-heading steel wire
CN104190705A (en) * 2014-08-04 2014-12-10 南京钢铁股份有限公司 Production technology for bearing steel wire rod
CN105132657A (en) * 2015-09-29 2015-12-09 邢台钢铁有限责任公司 Method for decreasing decarburized layers on surfaces of high-carbon-chromium bearing steel wires

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