CN102409133A - Method for producing 23MnB steel by vacuum method - Google Patents
Method for producing 23MnB steel by vacuum method Download PDFInfo
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- CN102409133A CN102409133A CN2011103973714A CN201110397371A CN102409133A CN 102409133 A CN102409133 A CN 102409133A CN 2011103973714 A CN2011103973714 A CN 2011103973714A CN 201110397371 A CN201110397371 A CN 201110397371A CN 102409133 A CN102409133 A CN 102409133A
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Abstract
The invention discloses a method for producing 23MnB steel by a vacuum method, belonging to the field of ferrous metallurgy. The invention aims to solve the technical problem of providing a method for producing 23MnB steel by enabling a large-size continuous casting machine to cast smoothly, which comprises the following steps: a. smelting in a converter; b. adding calcium carbide into the molten steel during tapping, and then adding aluminum to ensure that the weight percentage content of acid-soluble aluminum in the molten steel is 0.014-0.019%; c. refining in an LF furnace; d. carrying out vacuum circulation treatment after refining, wherein in the treatment, aluminum is added into molten steel to ensure that the content of acid-soluble aluminum is 0.025-0.055%, titanium is added to ensure that the content of titanium is 0.02-0.06%, and boron is added to ensure that the content of boron is 0.0005-0.003%; e. and continuous casting. The method strictly controls the content of acid-soluble aluminum in each step, has high boron yield and good hardenability of 23MnB steel, and avoids the water gap of a large-size continuous casting machine from becoming small.
Description
Technical field
The invention belongs to the ferrous metallurgy field, be specifically related to the method that a kind of vacuum method is produced the 23MnB steel.
Background technology
Trace B (about 0.001%) can be adsorbed on austenite grain boundary; Reduce the crystal boundary energy; Prevent the formation of ferritic nucleus, improve the hardening capacity of middle low carbon steel exponentially, so the trace B of the normal interpolation 0.0005～0.003% of middle low carbon steel improves the hardening capacity of steel.But boron is one of as lively as a cricket element, can form stable inclusion with residual oxygen and the nitrogen in the steel, and lose beneficial effect, and the boron that only exists with the solid solution form just can play useful effect.
Existing research shows that boron and oxygen and nitrogen all have very strong avidity, and boron is easy to oxidized generation B
6O or B
2O
3, perhaps generating BN with nitrification, these all are the objectionable impuritiess that stop boron performance raising hardening capacity effect in the boron-containing steel.Therefore, improve the effect of hardening capacity, must in the smelting process of steel, at first adopt aluminium to slough the free oxygen of molten steel, and, could guarantee the useful effect of adding boron with the fixing nitrogen in the molten steel of titanium for guaranteeing boron.
The 23MnB steel is a boracic class formation steel; Be usually used in making the grip-pad that pitch is 216 following dozers or excavator, chemical composition is by weight percentage: C:0.20～0.0.27%, Mn:0.80～1.10%, Si:0.15～0.35%, P≤0.030%, S≤0.015%, Cr≤0.30%, Ni≤0.25%, Cu≤0.30%, B:0.0005～0.0035%.Generally, also require to contain the aluminium and the titanium of certain mass for guaranteeing that boron improves the effect of hardening capacity.For example:
The patent CN100519769C that open day is on July 29th, 2009 discloses the method that a kind of converter smelting is produced boron-containing steel; It is characterized in that adopting the explained hereafter boron-containing steel of converter smelting → ladle deoxidation, refining → boron alloyization; Concrete operational provisions is: at first be behind converter tapping, to add aluminium and refining slag carries out deoxidation to molten steel and slag; The acid of control molten steel is dissolved aluminium in 0.02%～0.04% scope, FeO+MnO≤2.0% in LF stove refining controlling slag, and the α of molten steel then
[O]≤10ppm adds after aluminium carries out deep deoxidation to ladle at last once more, adds ferrotianium and ferro-boron and carries out alloying.The yield height that adopts this technology boron is 69.4%～91.8%.This patent improves the effect of hardening capacity in order to guarantee boron; Adding aluminium and refining slag carry out deoxidation to molten steel and slag behind converter tapping; The acid of control molten steel is dissolved aluminium in 0.02%～0.04% scope, in molten steel, adds aluminium again after the refining of LF stove finishes, and guarantees the yield of boron and the hardening capacity of boron-containing steel with this; But this patent is not considered and is added the influence of aluminium to the continuous caster continuous casting.The applicant finds that aluminium can lose a part in the process of producing the 23MnB steel, wayward for the content of aluminium, has part aluminium can be oxidized to Al
2O
3, these Al
2O
3The conticaster crystallizer mouth of a river is diminished, and molten steel flow reduces, thereby influences continuous casting, brings very big difficulty for the control of continuous caster, and security incident is caused at the when serious even obstruction continuous caster mouth of a river.Therefore, be badly in need of a kind of method of production boron-containing steel of strict CONTROL PROCESS, this method can improve the yield of boron, the hardening capacity of assurance boron-containing steel, can avoid the continuous caster mouth of a river to diminish, make continuous casting smooth simultaneously at present.
Summary of the invention
That technical problem to be solved by this invention provides is a kind of when guaranteeing boron-containing steel hardening capacity, avoid the method for the production 23MnB steel that the big specification continuous caster mouth of a river diminishes.
The technical solution adopted for the present invention to solve the technical problems is:
Vacuum method is produced the method for 23MnB steel, comprises the steps:
A, in converter, add molten iron smelting;
B, molten steel are tapped to ladle; In molten steel, add calcium carbide during tapping; It is foundation that the calcium carbide consumption just refines endpoint carbon content according to converter; When converter terminal carbon weight percent drops into by molten steel 3.5～4.5kg per ton when following 0.10%, when converter terminal carbon weight percent drops into by molten steel 2.5～3.5kg per ton greater than 0.10%, less than 0.15% the time, when converter terminal carbon weight percent 0.15% when above by molten steel 1.5～2.5kg input per ton; Add aluminium again, the weight percent content that makes the molten aluminium of acid in the molten steel is 0.014～0.019%;
C, ladle move into the refining of LF stove;
After d, the refining ladle is moved into the RH vacuum treatment installation and carry out the vacuum cycle processing; In molten steel, add aluminium in the processing; Make in the molten steel acid dissolve the aluminium weight percent content 0.025～0.055%; Add titanium again and make in the molten steel titanium weight percent content, add boron and make in the molten steel boron weight percent content 0.0005～0.003% 0.02～0.06%;
E, vacuum cycle are carried out continuous casting after handling.
Wherein, in the aforesaid method steps d, in molten steel, add aluminium, make in the molten steel acid dissolve the aluminium weight percent content 0.035～0.04%.
Wherein, also add steel scrap when in converter, adding molten iron among the aforesaid method step a, the weight of steel scrap can not surpass 15% of weight of molten iron.
Further, be 0.05%～0.15% when molten steel composition just refines by weight percentage C, in the ladle of molten steel being tapped when P≤0.030% and S≤0.015%.
Also add when wherein, adding calcium carbide among the aforesaid method step b ferrosilicon make in the molten steel silicon weight percent content 0.15～0.35%, add ferromanganese make in the molten steel manganese weight percent content 0.80%～1.10%, add carburelant and make the carbon weight percent content 0.20～0.27%.
Said carburelant mainly is meant and contains the pitch glue of fixed carbon more than 98% or contain the hard coal of fixed carbon more than 92%.
Wherein, among the aforesaid method step c, molten steel stops heating when being heated to 1590～1610 ℃, ladle is moved into the RH vacuum treatment installation.
Wherein, pressure≤300Pa when aforesaid method steps d vacuum cycle is handled, 10～15 minutes treatment times.
Wherein, during aforesaid method step e continuous casting in the continuous caster bag temperature be 1535 ± 20 ℃.
Wherein, calcium carbide contains CaC described in the aforesaid method
2More than 70%.
The inventive method specifically can be implemented by following mode: vacuum method is produced the method for 23MnB steel, comprises the steps:
A, in converter, add molten iron and smelting, the weight of steel scrap can not surpass 15% of weight of molten iron, be 0.05%～0.15% when molten steel composition just refines by weight percentage C, P≤0.030% and S≤ladle of molten steel being tapped 0.015% time in;
B, molten steel are tapped to ladle, in molten steel, add during tapping and contain CaC
2Calcium carbide more than 70%; It is foundation that the calcium carbide consumption just refines endpoint carbon content according to converter; When converter terminal carbon weight percent drops into by molten steel 3.5～4.5kg per ton when following 0.10%; When converter terminal carbon weight percent drops into by molten steel 2.5～3.5kg per ton greater than 0.10%, less than 0.15% the time, when converter terminal carbon weight percent 0.15% when above by molten steel 1.5～2.5kg input per ton; Add aluminium again; Make in the molten steel weight percent content that acid dissolves aluminium 0.014～0.019%, also add when adding calcium carbide ferrosilicon make in the molten steel silicon weight percent content 0.15～0.35%, add ferromanganese make in the molten steel manganese weight percent content 0.80%～1.10%, add carburelant and make the carbon weight percent content 0.20～0.27%;
C, ladle move into the refining of LF stove, and molten steel stops heating when being heated to 1590～1610 ℃, ladle is moved into the RH vacuum treatment installation;
After d, the refining ladle is moved into the RH vacuum treatment installation and carry out the vacuum cycle processing; In molten steel, add aluminium in the processing; Make in the molten steel acid dissolve the aluminium weight percent content, add titanium again and make in the molten steel titanium weight percent content, add boron and make in the molten steel boron weight percent content 0.0005～0.003% 0.02～0.06% 0.035～0.04%; Pressure≤300Pa when vacuum cycle is handled, 10～15 minutes treatment times;
E, vacuum cycle are carried out continuous casting after handling, and wrapping temperature in the continuous caster during continuous casting is 1535 ± 20 ℃.
The invention has the beneficial effects as follows: the contriver finds that continuous caster mold gap in casting cycle diminishes even stops up, owing to aluminium too high levels in the molten steel causes, and therefore must the strict aluminum content of controlling in the molten steel.But, usually effect in order to guarantee that boron improves hardening capacity in the boron-containing steel, boron-containing steel must at first adopt aluminium to slough the free oxygen of molten steel in the smelting process of steel, and with the fixing nitrogen in the molten steel of titanium, could guarantee the useful effect of adding boron.Therefore, those skilled in the art have often ignored the influence of aluminium to the continuous caster continuous casting for the hardening capacity that guarantees boron-containing steel.Analyze boron-containing steel production key point in the prior art; Add aluminium just in order to slough the free oxygen in the molten steel as much as possible; The inventive method adopts calcium carbide to carry out preliminary dexidation earlier at the tapping process of molten steel after just refining finishes, and is generally the relation of a constant again according to carbon in the converter steelmaking process and equilibrium oxygen, and technology of the present invention has been taked according to converter difference end point carbons; The way of the different calcium carbide quantity of corresponding adding is carried out preliminary dexidation; And then adopt the further deoxidation of aluminium, and the weight percent content that makes the molten aluminium of acid in the molten steel is between 0.014～0.019%, and strict control adds the amount of aluminium.After the above-mentioned deoxidation of molten steel process, molten steel oxygen activity α
[O]Can be controlled in below 0.0015%.Ladle moves on to the LF refining furnace molten steel is carried out refining; After the refining ladle is moved into the RH vacuum treatment installation and carry out the vacuum cycle processing; In molten steel, add aluminium, make in the molten steel acid dissolve the aluminium weight percent content 0.025～0.055%, preferred content is 0.035～0.04%.Control acid is here dissolved aluminium (Als) in 0.025～0.055% scope, is to consider that rear portion continuous casting steel machine process has the molten aluminium of part acid and is oxidized to Al
2O
3Phenomenon, learn that through a large amount of practices the continuous casting steel machine process has 0.005%～0.010% acid to dissolve aluminium and is oxidized to Al
2O
3So adding aluminium control acid is dissolved aluminium in 0.025～0.055% scope, the scope that aluminium (Als) is dissolved in acid is controlled in strictness, also has 0.02～0.05% the molten aluminium of acid to guarantee final molten steel of casting, and big specification continuous caster can be cast smoothly.Therefore, the present invention is dissolved aluminium (Als) content from the strict control acid of each step, has guaranteed that the free oxygen of molten steel is removed; The boron yield is high; The 23MnB steel hardenability is good, and don't as for making the aluminium in the molten steel too high, avoids the continuous caster mouth of a river to diminish; Thereby guarantee that big specification continuous caster casts smoothly, the inventive method is specially adapted to the above continuous caster of 200 * 200mm specification.
Embodiment
The specific embodiment of the invention is following:
Vacuum method is produced the method for 23MnB steel, comprises the steps:
A, in converter, add molten iron smelting;
B, molten steel are tapped to ladle; In molten steel, add calcium carbide during tapping; It is foundation that the calcium carbide consumption just refines endpoint carbon content according to converter; When converter terminal carbon weight percent drops into by molten steel 3.5～4.5kg per ton when following 0.10%, when converter terminal carbon weight percent drops into by molten steel 2.5～3.5kg per ton greater than 0.10%, less than 0.15% the time, when converter terminal carbon weight percent 0.15% when above by molten steel 1.5～2.5kg input per ton; Add aluminium again, the weight percent content that makes the molten aluminium of acid in the molten steel is 0.014～0.019%;
C, ladle move into the refining of LF stove;
After d, the refining ladle is moved into the RH vacuum treatment installation and carry out the vacuum cycle processing; In molten steel, add aluminium in the processing; Make in the molten steel acid dissolve the aluminium weight percent content 0.025～0.055%; Add titanium again and make in the molten steel titanium weight percent content, add boron and make in the molten steel boron weight percent content 0.0005～0.003% 0.02～0.06%;
E, vacuum cycle are carried out continuous casting after handling.
The inventive method does not adopt aluminium to carry out preliminary dexidation at the tapping process that molten steel just refines after finishing; And the employing calcium carbide is generally the relation of a constant again according to carbon in the converter steelmaking process and equilibrium oxygen, and technology of the present invention has been taked according to the different end point carbons of converter; The way of the different calcium carbide quantity of corresponding adding is carried out preliminary dexidation; Can play the effect of deoxidation, can avoid carbon to exceed standard again, carbon is controlled in the suitable scope.The present invention has guaranteed that from the strict control of each step acid-soluble aluminum content the free oxygen of molten steel is removed, and the boron yield is high, and the 23MnB steel hardenability is good, and don't as for making the aluminium in the molten steel too high, thereby guarantees that big specification continuous caster casts smoothly.
Preferably, in the aforesaid method steps d, in molten steel, add aluminium, make in the molten steel acid dissolve the aluminium weight percent content 0.035～0.04%.Control acid is here dissolved aluminium (Als) in 0.035～0.04% scope, is to consider that rear portion continuous casting steel machine process has the molten aluminium of part acid and is oxidized to Al
2O
3Phenomenon, learn that through a large amount of practices the continuous casting steel machine process has 0.005%～0.010% acid to dissolve aluminium and is oxidized to Al
2O
3So the LF stove must add aluminium control acid and dissolve aluminium in 0.035～0.04% scope, the scope that aluminium is dissolved in acid is controlled in strictness, also has 0.025～0.035% the molten aluminium of acid to guarantee final molten steel of casting, and big specification continuous caster can be cast smoothly.
Preferably, also add steel scrap when in converter, adding molten iron among the aforesaid method step a, the weight of steel scrap can not surpass 15% of weight of molten iron.Steel scrap can derive from salvage station, also can derive from steel mill inside.Converter steelmaking does not have the external heat source; All rely on carbon in the oxidation molten iron, and a spot of silicon and manganese emit heat, thereby make molten steel obtain heating, with respect to molten iron; The steel scrap carbon content is generally very low, and the steel scrap that adds in the converter smelting can play the reduction action of temperature.Simultaneously in order to economize on resources; And produce qualified Finished Steel; Because remaining Cr, Ni and Cu in the steel scrap are uncontrollable; Can cause Cr＞0.30%, Ni＞0.25% in the molten steel, the phenomenon of Cu＞0.30% to occur for fear of excessive adding steel scrap, the weight of steel scrap can not surpass 15% of weight of molten iron.
Further, be 0.05%～0.15% when molten steel composition just refines by weight percentage C, in the ladle of molten steel being tapped when P≤0.030% and S≤0.015%.In fact steelmaking process is exactly initial oxidation, and then the reductive process during converter steelmaking, is only carried out oxidizing reaction in converter, and reduction reaction is carried out in ladle.C is 0.05%～0.15% o'clock, explains that oxidizing reaction is through with, and should tap and carry out reduction reaction.
In order to produce qualified 23MnB steel, also add when adding calcium carbide among the aforesaid method step b ferrosilicon make in the molten steel silicon weight percent content 0.15～0.35%, add ferromanganese make in the molten steel manganese weight percent content 0.80%～1.10%, add carburelant and make the carbon weight percent content 0.20～0.27%.
Preferably, in order to guarantee that the bag temperature is 1535 ± 20 ℃ in the continuous caster, among the aforesaid method step c, molten steel stops heating when being heated to 1590～1610 ℃, ladle is moved into the RH vacuum treatment installation.
Preferably, pressure≤300Pa when aforesaid method steps d vacuum cycle is handled, 10～15 minutes treatment times.To guarantee hydrogen richness≤0.0002%, avoid steel billet cooling back " white point " defective to occur, " white point " is hydrogen pattern during macroscopic examination after the strand enrichment, if any the strand of " white point " defective, can form shank shape crackle through after rolling, causes strand to be scrapped.
Wherein, during aforesaid method step e continuous casting in the continuous caster bag temperature be 1535 ± 20 ℃.23MnB molten steel phase line temperature is 1505 ℃, and the superheating temperature of wrapping in the control continuous caster is 30 ± 20 ℃, and therefore, the bag temperature is 1535 ± 20 ℃ in the control continuous caster.This temperature is that the electrically heated through front LF stove realizes.
Preferably, calcium carbide contains CaC described in the aforesaid method
2More than 70%.With handled easily with avoid adding too much impurity.
Through embodiment the present invention is described further below, but does not therefore limit the present invention among the scope of description of embodiment.
Embodiment one
On 120 tons of nominal capacities, the bof process of actual tap in 120～140 tons of scopes, adopt the present invention's technology to produce the 23MnB steel, production technique is that 120 tons of converters are just made steel water → 120 ton LF stove heating refined molten steel → 120 a ton RH vacuum cycle and handled molten steel → 6 machines, 6 stream billet casters and be cast into 280mm * 380mm strand.
At first in converter, add 130 tons of molten iron and 10 tons of steel scraps; Utilize Converter Oxigen Blowing to take off the function of C; Molten iron and steel scrap just are smelt molten steel; Tap when molten steel composition just refines the Mn of 0.05% C, 0.020% P, 0.015% S, 0.01% Si and 0.05% in the ladle, this moment, actual tap was 133 tons, and about 5% raw material is by scaling loss in the converter steelmaking process.In molten steel, add calcium carbide 530kg in the tapping process; Calcium carbide contains CaC275%; And adding FeSi, FeMn alloy and hard coal simultaneously, to carry out Si, Mn and C element alloyed, and Si content is 74% in the FeSi alloy that wherein adds, and Mn content is 82% in the FeMn alloy; Fixation of C is 92% in the hard coal, and Si content is 0.16% in the control molten steel, Mn content is 1.10%, C content is 0.20%.Gone out behind the steel feeding Al line in the molten steel in ladle, control Als is 0.015%, and having fed behind the Al line with apparatus for determination of oxygen mensuration molten steel oxygen activity α [O] is 0.0015%.
Molten steel begins electrically heated after arriving the LF stove, when liquid steel temperature is heated to 1590 ℃, stops heating, then ladle is moved on to the RH vacuum treatment installation and carries out vacuum-treat.
Molten steel begins to carry out vacuum-treat after arriving the RH vacuum treatment installation, and pressure in vacuum tank reaches 300Pa and after 5 minutes, adds the 17kg aluminum shot, adds that the yield of aluminium is about 80% behind the aluminum shot this moment; Add aluminum shot after 2 minutes; Add 90kg FeTi40 ferrotianium (promptly contain Ti be 40% iron alloy) and 10kgFeB23 ferro-boron (promptly contain B be 23% iron alloy), added behind ferrotianium and the ferro-boron under the ultimate pressure condition recycling processing 3 minutes, the Als of sampling and measuring molten steel is 0.025%; Ti is 0.02%; B is 0.0014%, and the yield of B is 80%, send molten steel to cast to continuous caster then.
Cast 280mm * 380mm strand at 6 machines, 6 stream billet caster top-pours; Tundish temperature is 1520 ℃ during continuous casting; Bag sampling analysis molten steel chemical composition is 0.20% C, 0.15% Si, 1.10% Mn, 0.020% P, 0.014% S, 0.12% Cr, 0.06% Ni, 0.10% Cu, 0.0012% B in continuous caster; And the Als of 0.02% Ti and 0.020% (Als scaling loss 0.005% in the casting cycle), all the other are Fe and inevitable other impurity.
Embodiment two
On 120 tons of nominal capacities, the bof process of actual tap in 120～140 tons of scopes, adopt the present invention's technology to produce the 23MnB steel, production technique is that 120 tons of converters are just made steel water → 120 ton LF stove refined molten steel → 120 tons of RH vacuum cycle and handled molten steel → 6 machines, 6 stream billet casters and be cast into 360mm * 450mm strand.
At first in converter, add 120 tons of molten iron and 20 tons of steel scraps; Utilize Converter Oxigen Blowing to take off the function of C; Molten iron and steel scrap just are smelt molten steel; Tap when molten steel composition just refines the Mn of 0.15% C, 0.015% P, 0.010% S, 0.01% Si and 0.05% in the ladle, this moment, actual tap was 133 tons, and about 5% raw material is by scaling loss in the converter steelmaking process.In molten steel, add calcium carbide 400kg in the tapping process; Calcium carbide contains CaC275%; And adding FeSi, FeMn alloy and hard coal simultaneously, to carry out Si, Mn and C element alloyed, and Si content is 74% in the FeSi alloy that wherein adds, and Mn content is 82% in the FeMn alloy; Fixation of C is 92% in the hard coal, and Si content is 0.35% in the control molten steel, Mn content is 0.80%, C content is 0.27%.Gone out behind the steel feeding Al line in the molten steel in ladle, control Als is 0.025%, and having fed behind the Al line with apparatus for determination of oxygen mensuration molten steel oxygen activity α [O] is 0.0012%.
Molten steel begins electrically heated after arriving the LF stove, when liquid steel temperature is heated to 1610 ℃, stops heating, then ladle is moved on to the RH vacuum treatment installation and carries out vacuum-treat.
Molten steel begins to carry out vacuum-treat after arriving the RH vacuum treatment installation, and pressure in vacuum tank reaches 300Pa and after 5 minutes, adds the 17kg aluminum shot, adds that the yield of aluminium is about 80% behind the aluminum shot this moment; Add aluminum shot after 2 minutes; Add 130kg FeTi40 ferrotianium (promptly contain Ti be 40% iron alloy) and 15kgFeB23 ferro-boron (promptly contain B be 23% iron alloy), added behind ferrotianium and the ferro-boron under the ultimate pressure condition recycling processing 5 minutes, the Als of sampling and measuring molten steel is 0.035%; Ti is 0.031%; B is 0.0021%, and the yield of B is 75%, send molten steel to cast to continuous caster then.
Cast 360mm * 450mm strand at 6 machines, 6 stream billet caster top-pours at last; Tundish temperature is 1555 ℃ during continuous casting; Bag sampling analysis molten steel chemical composition is 0.27% C, 0.35% Si, 0.81% Mn, 0.015% P, 0.009% S, 0.12% Cr, 0.06% Ni, 0.16% Cu, 0.0021% B in continuous caster; And the Als of 0.031% Ti and 0.027% (Als scaling loss 0.008% in the casting cycle), all the other are Fe and inevitable other impurity.
Embodiment three
On 120 tons of nominal capacities, the bof process of actual tap in 120～140 tons of scopes, adopt the present invention's technology to produce the 23MnB steel, production technique is that 120 tons of converters are just made steel water → 120 ton LF stove refined molten steel → 120 tons of RH vacuum cycle and handled molten steel → 6 machines, 6 stream billet casters and be cast into 280mm * 380mm strand.
At first in converter, add 140 tons of molten iron; Utilize Converter Oxigen Blowing to take off the function of C; Molten iron just is smelt molten steel; Tap when molten steel composition just refines the Mn of 0.10% C, 0.025% P, 0.009% S, 0.01% Si and 0.05% in the ladle, this moment, actual tap was 133 tons, and about 5% raw material is by scaling loss in the converter steelmaking process.In molten steel, add calcium carbide 530kg in the tapping process; Calcium carbide contains CaC275%, and add FeSi simultaneously, that FeMn alloy and hard coal carry out Si, Mn and C is element alloyed, wherein Si content is 74% in the FeSi alloy; Mn content is 82% in the FeMn alloy; Fixation of C is 92% in the hard coal, and Si content is 0.25% in the control molten steel, Mn content is 1.01%, C content is 0.23%, has gone out behind the steel to feed the Al line in the molten steel in ladle; Control Als is 0.020%, and having fed behind the Al line with apparatus for determination of oxygen mensuration molten steel oxygen activity α [O] is 0.0013%.
Molten steel begins electrically heated after arriving the LF stove, when liquid steel temperature is heated to 1600 ℃, stops heating, then ladle is moved on to the RH vacuum treatment installation and carries out vacuum-treat.
Molten steel begins to carry out vacuum-treat after arriving the RH vacuum treatment installation; Pressure in vacuum tank reaches 300Pa and through adding 33kg aluminum shot (add this moment the yield of aluminium is about 80% behind the aluminum shot) after 5 minutes, adds aluminum shot after 2 minutes, adds 250kg FeTi40 ferrotianium (promptly contain Ti be 40% iron alloy) and 20kgFeB23 ferro-boron (promptly contain B be 23% iron alloy); Added behind ferrotianium and the ferro-boron under the ultimate pressure condition recycling processing 8 minutes; The Als of sampling and measuring molten steel is 0.04%, and Ti is 0.06%, and B is 0.0024%; The yield of B is 70%, send molten steel to cast to continuous caster then.
Cast 280mm * 380mm strand at 6 machines, 6 stream billet caster top-pours at last; Tundish temperature is 1530 ℃ during continuous casting; Bag sampling analysis molten steel chemical composition is 0.23% C, 0.25% Si, 1.09% Mn, 0.025% P, 0.009% S, 0.06% Cr, 0.06% Ni, 0.05% Cu, 0.0022% B in continuous caster; And the Als of 0.06% Ti and 0.033% (Als scaling loss 0.007% in the casting cycle), all the other are Fe and inevitable other impurity.
Embodiment four
On 120 tons of nominal capacities, the bof process of actual tap in 120～140 tons of scopes, adopt the present invention's technology to produce the 23MnB steel, production technique is that 120 tons of converters are just made steel water → 120 ton LF stove refined molten steel → 120 tons of RH vacuum cycle and handled molten steel → 6 machines, 6 stream billet casters and be cast into 360mm * 450mm strand.
At first in converter, add 120 tons of molten iron and 20 tons of steel scraps; Utilize Converter Oxigen Blowing to take off the function of C; Molten iron and steel scrap just are smelt molten steel; Tap when molten steel composition just refines the Mn of 0.15% C, 0.015% P, 0.010% S, 0.01% Si and 0.05% in the ladle, this moment, actual tap was 133 tons, and about 5% raw material is by scaling loss in the converter steelmaking process.In molten steel, add calcium carbide 400kg in the tapping process; Calcium carbide contains CaC275%; And adding FeSi, FeMn alloy and hard coal simultaneously, to carry out Si, Mn and C element alloyed, and Si content is 74% in the FeSi alloy that wherein adds, and Mn content is 82% in the FeMn alloy; Fixation of C is 92% in the hard coal, and Si content is 0.35% in the control molten steel, Mn content is 0.80%, C content is 0.27%.Gone out behind the steel feeding Al line in the molten steel in ladle, control Als is 0.025%, and having fed behind the Al line with apparatus for determination of oxygen mensuration molten steel oxygen activity α [O] is 0.0012%.
Molten steel begins electrically heated after arriving the LF stove, when liquid steel temperature is heated to 1610 ℃, stops heating, then ladle is moved on to the RH vacuum treatment installation and carries out vacuum-treat.
Molten steel begins to carry out vacuum-treat after arriving the RH vacuum treatment installation; Pressure in vacuum tank reaches 300Pa and through adding 50kg aluminum shot (add this moment the yield of aluminium is about 80% behind the aluminum shot) after 5 minutes, adds aluminum shot after 2 minutes, adds 130kg FeTi40 ferrotianium (promptly contain Ti be 40% iron alloy) and 15kgFeB23 ferro-boron (promptly contain B be 23% iron alloy); Added behind ferrotianium and the ferro-boron under the ultimate pressure condition recycling processing 5 minutes; The Als of sampling and measuring molten steel is 0.055%, and Ti is 0.031%, and B is 0.0021%; The yield of B is 75%, send molten steel to cast to continuous caster then.
Cast 360mm * 450mm strand at 6 machines, 6 stream billet caster top-pours at last; Tundish temperature is 1555 ℃ during continuous casting; Bag sampling analysis molten steel chemical composition is 0.27% C, 0.35% Si, 0.81% Mn, 0.015% P, 0.009% S, 0.12% Cr, 0.06% Ni, 0.16% Cu, 0.0021% B in continuous caster; And the Als of 0.031% Ti and 0.05% (Als scaling loss 0.005% in the casting cycle), all the other are Fe and inevitable other impurity.
The comparative example
On 120 tons of nominal capacities, the bof process of actual tap in 120～140 tons of scopes, adopt the present invention's technology to produce the 23MnB steel, production technique is that 120 tons of converters are just made steel water → 120 ton LF stove refined molten steel → 120 tons of RH vacuum cycle and handled molten steel → 6 machines, 6 stream billet casters and be cast into 280mm * 380mm strand.
At first in converter, add 140 tons of molten iron; Utilize Converter Oxigen Blowing to take off the function of C; Molten iron just is smelt molten steel; Tap when molten steel composition just refines the Mn of 0.10% C, 0.025% P, 0.009% S, 0.01% Si and 0.05% in the ladle, this moment actual tap be in 133 tons, converter steelmaking process about 5% raw material by scaling loss.In molten steel, add calcium carbide 530kg calcium carbide in the tapping process and contain CaC
275%, and adding FeSi, FeMn alloy and hard coal simultaneously, to carry out Si, Mn and C element alloyed, wherein Si content is 74% in the FeSi alloy; Mn content is 82% in the FeMn alloy; Fixation of C is 92% in the hard coal, and Si content is 0.25% in the control molten steel, Mn content is 1.01%, C content is 0.23%, has gone out behind the steel to feed the Al line in the molten steel in ladle; Control Als is 0.025%, has fed behind the Al line with apparatus for determination of oxygen mensuration molten steel oxygen activity α
[O]Be 0.0012%.
Molten steel begins electrically heated after arriving the LF stove, when liquid steel temperature is heated to 1600 ℃, stops heating, then ladle is moved on to the RH vacuum treatment installation and carries out vacuum-treat.
Molten steel begins to carry out vacuum-treat after arriving the RH vacuum treatment installation; Pressure in vacuum tank reaches 300Pa and through adding 67kg aluminum shot (add this moment the yield of aluminium is about 80% behind the aluminum shot) after 5 minutes, adds aluminum shot after 2 minutes, adds 250kg FeTi40 ferrotianium (promptly contain Ti be 40% iron alloy) and 20kgFeB23 ferro-boron (promptly contain B be 23% iron alloy); Added behind ferrotianium and the ferro-boron under the ultimate pressure condition recycling processing 8 minutes; The Als of sampling and measuring molten steel is 0.065%, and Ti is 0.06%, and B is 0.0024%; The yield of B is 70%, send molten steel to cast to continuous caster then.
Cast 280mm * 380mm strand at 6 machines, 6 stream billet caster top-pours at last; Tundish temperature is 1530 ℃ during continuous casting; Bag sampling analysis molten steel chemical composition is 0.23% C, 0.25% Si, 1.09% Mn, 0.025% P, 0.009% S, 0.06% Cr, 0.06% Ni, 0.05% Cu, 0.0022% B in continuous caster; And the Als of 0.06% Ti and 0.055% (Als scaling loss 0.01% in the casting cycle), all the other are Fe and inevitable other impurity.Continuous caster is found the aluminium secondary oxidation is arranged and the continuous caster mouth of a river that the causes phenomenon that diminishes in casting cycle; Continuous caster the 3rd and the 5th stream casting speed can not meet the requirements of 7.0m/min; Can only cast with the casting speed of 4.5～5.0m/min (continuous caster the 3rd and the 5th stream casting speed can only carry out the influence casting to set 70% of casting speed).
The foregoing description explanation adopts the present invention's technology to produce the 23MnB steel, and whole process control effectively to molten steel oxygen activity and acid-soluble aluminum content, and tapping process does not adopt aluminium to carry out preliminary dexidation; And the employing calcium carbide, final Als is controlled in 0.02～0.05% scope, more preferably is controlled in 0.025～0.035% scope; The yield of boron is more than 70% behind the adding ferro-boron; Be in than higher level, both guaranteed the effect that boron improves hardening capacity, again in casting bloom process; The phenomenon of having avoided the continuous caster mouth of a river to diminish, casting are smoothly.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103305655A (en) * | 2012-03-08 | 2013-09-18 | 杰富意钢铁株式会社 | Method for manufacturing ultra low carbon steel by melting techniques using vacuum-degassing system |
| CN105274281A (en) * | 2014-06-23 | 2016-01-27 | 鞍钢股份有限公司 | Method for accurately controlling boron content in steel |
| CN107012287A (en) * | 2017-04-18 | 2017-08-04 | 攀钢集团攀枝花钢铁研究院有限公司 | Smelting process for heat stamping and shaping steel |
| CN108588541A (en) * | 2018-03-09 | 2018-09-28 | 江苏省沙钢钢铁研究院有限公司 | Low-nitrogen boron-containing steel smelting method for improving boron element yield |
| CN111118387A (en) * | 2019-12-13 | 2020-05-08 | 河钢乐亭钢铁有限公司 | Method for improving surface quality of boron-containing steel continuous casting slab |
| CN113490755A (en) * | 2019-03-13 | 2021-10-08 | 杰富意钢铁株式会社 | Method for producing ultra-low carbon steel containing Ti |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63295479A (en) * | 1987-05-27 | 1988-12-01 | Hitachi Ltd | Sintered aluminum nitride body and its production |
| CN101045948A (en) * | 2007-04-29 | 2007-10-03 | 攀钢集团攀枝花钢铁研究院 | Method for producing boron steel by smelting in converter |
| CN101503746A (en) * | 2009-03-19 | 2009-08-12 | 新余钢铁股份有限公司 | Method for producing boron steel by converter |
| CN101660101A (en) * | 2009-09-28 | 2010-03-03 | 莱芜钢铁股份有限公司 | Steel for low-carbon wear-resistant engineering machinery creeper tread and manufacturing method thereof |
-
2011
- 2011-12-05 CN CN 201110397371 patent/CN102409133B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63295479A (en) * | 1987-05-27 | 1988-12-01 | Hitachi Ltd | Sintered aluminum nitride body and its production |
| CN101045948A (en) * | 2007-04-29 | 2007-10-03 | 攀钢集团攀枝花钢铁研究院 | Method for producing boron steel by smelting in converter |
| CN101503746A (en) * | 2009-03-19 | 2009-08-12 | 新余钢铁股份有限公司 | Method for producing boron steel by converter |
| CN101660101A (en) * | 2009-09-28 | 2010-03-03 | 莱芜钢铁股份有限公司 | Steel for low-carbon wear-resistant engineering machinery creeper tread and manufacturing method thereof |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103305655A (en) * | 2012-03-08 | 2013-09-18 | 杰富意钢铁株式会社 | Method for manufacturing ultra low carbon steel by melting techniques using vacuum-degassing system |
| CN105274281A (en) * | 2014-06-23 | 2016-01-27 | 鞍钢股份有限公司 | Method for accurately controlling boron content in steel |
| CN107012287A (en) * | 2017-04-18 | 2017-08-04 | 攀钢集团攀枝花钢铁研究院有限公司 | Smelting process for heat stamping and shaping steel |
| CN108588541A (en) * | 2018-03-09 | 2018-09-28 | 江苏省沙钢钢铁研究院有限公司 | Low-nitrogen boron-containing steel smelting method for improving boron element yield |
| CN108588541B (en) * | 2018-03-09 | 2020-05-26 | 江苏省沙钢钢铁研究院有限公司 | Low-nitrogen boron-containing steel smelting method for improving boron element yield |
| CN113490755A (en) * | 2019-03-13 | 2021-10-08 | 杰富意钢铁株式会社 | Method for producing ultra-low carbon steel containing Ti |
| CN111118387A (en) * | 2019-12-13 | 2020-05-08 | 河钢乐亭钢铁有限公司 | Method for improving surface quality of boron-containing steel continuous casting slab |
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