CN102248142B - Method for producing medium and low carbon aluminum killed steel - Google Patents
Method for producing medium and low carbon aluminum killed steel Download PDFInfo
- Publication number
- CN102248142B CN102248142B CN 201110181120 CN201110181120A CN102248142B CN 102248142 B CN102248142 B CN 102248142B CN 201110181120 CN201110181120 CN 201110181120 CN 201110181120 A CN201110181120 A CN 201110181120A CN 102248142 B CN102248142 B CN 102248142B
- Authority
- CN
- China
- Prior art keywords
- molten steel
- steel
- aluminium
- refining
- molten
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
Abstract
The invention provides a method for producing medium and low carbon aluminum killed steel, which comprises the following steps of: controlling the content of sulfur in molten iron to be not more than 0.015 percent; primarily smelting the molten iron to form molten steel, and tapping; adding an aluminum deoxidizer into the molten steel when 20 to 30 weight percent of molten steel is tapped; adding 4.0 to 6.0kg of active lime and fluorite in an amount which is 0.2 times that of the active lime into each ton of molten steel when 31 to 50 weight percent of molten steel is tapped; performing argon blowing refining for the first time; adding aluminum in two or three batches and 1.5 to 4kg of refining slag into each ton of steel in a steel ladle, heating, and refining; performing calcium treatment on the molten steel; performing argon blowing refining for the second time; and performing continuous casting. By the method, the castability of the molten steel can be improved, the phenomenon of water nozzle clogging is avoided, and the continuous casting heats of a single tundish in the continuous casting process of the medium and low carbon aluminum killed steel are not less than 8 heats.
Description
Technical field
The present invention relates to Ferrous Metallurgy and continuous casting technology field, more particularly, relate to the method that the stove number waters in the company of carbon aluminium-killed steel in a kind of can the raising.
Background technology
In the prior art, during low-carbon (LC) contains the technical process of aluminum steel (that is, middle carbon aluminium-killed steel) in adopting the continuous casting process cast, due to the dystectic aluminium oxide (Al in molten steel
2O
3) be field trash and calcium silicates (CaSiO
3) etc. field trash easily stick on the crystallizer submersed nozzle inwall, it is stopped up, so cause the company of a tundish list bag to water stove number lower (for example, less than 6 stoves), production cost increases, organization of production is subject to very big impact.And generally, in steel, sour molten aluminium ([Al]) content is higher, and the probability that obstruction occurs is higher, stops up also more serious.In addition, less (for example, section is not more than 40000mm to casting section
2) continuous casting billet the time, because the crystallizer submersed nozzle internal diameter is less, stop up even more serious.In order to overcome the problems referred to above, the modes such as available technology adopting calcium processing are to dystectic Al
2O
3Be that field trash carries out degenerative treatments, make it change the Al of low melting point into
2O
3Be field trash, thereby reach the purpose of improving pourability of molten steel, but the method has increased production cost.
Summary of the invention
The invention provides a kind of production method of middle carbon aluminium-killed steel, described method can be improved the aluminium weight percentage and be not less than 0.01% middle low carbon steel pourability of molten steel.More particularly, described method is particularly suitable for (for example, the strand cross sectional area≤40000mm of light section in employing
2) when the sour molten aluminium percentage composition of billet continuous casting technique casting is not less than 0.01% middle low carbon steel, improve pourability of molten steel.
the invention provides a kind of production method of middle carbon aluminium-killed steel, said method comprising the steps of: the sulfur content in molten iron is controlled to be is not more than 0.015%, molten iron is carried out just refining forming molten steel, molten steel is tapped in ladle, in 20%～30% the process of tapping by weight percentage, add the aluminium deoxidier in molten steel, the addition of aluminium deoxidier is high by 0.02%～0.04% for acid-soluble aluminum content in the molten steel that requires before can making after the completing ar blowing refining for the first time acid-soluble aluminum content in molten steel by weight percentage than continuous casting, in 31%～50% the process of tapping by weight percentage, adding the active lime of 4.0～6.0Kg/ ton steel and addition in the molten steel is 20% fluorite of active lime weight, ar blowing refining for the first time, the place adds aluminium and 1.5～4kg/ ton steel refining slag to the ladle top of the slag, then heating, carry out ladle refining, described aluminium divides 2～3 batches to add, wherein first follows closely after refining slag and adds, and the addition of this first aluminium is 10%～20% of refining slag addition, the expectation recovery rate of the addition sum of all the other batches=(acid-soluble aluminum content in the molten steel after this first aluminium refining of the molten steel acid-soluble aluminum content that requires before continuous casting-add) * molten steel amount/aluminium, wherein, the expectation recovery rate of described all the other batches aluminium is calculated according to 65%～85%, be preferably 75%～80%, Xiang Gangzhong adds calcium containing alloy to carry out the calcium processing to molten steel, the addition of calcium containing alloy=[mass fraction of calcium in (the molten aluminium mass fraction of 0.2～0.4+ molten steel acid * 1000) * 0.29/ calcium containing alloy] kg/ ton molten steel, ar blowing refining for the second time, adopt continuous casting process to cast.
In one embodiment of the invention, the step of described ar blowing refining for the first time also can comprise the appropriate aluminium of feeding in the molten steel, so that in the molten steel that the acid-soluble aluminum content in molten steel requires before by weight percentage than continuous casting after completing ar blowing refining for the first time, acid-soluble aluminum content is high by 0.02%～0.04%.
In one embodiment of the invention, in described ladle refining step, the fluorite that described 1.5～4kg/ ton steel refining slag can be active lime weight 20% with active lime and the weight of 1.5～4kg/ ton steel replaces.
In one embodiment of the invention, described aluminium deoxidier can be one or more in metallic aluminium, alfer, aluminium barium alloy, alusil alloy and alumal.
In one embodiment of the invention, the Argon intensity of the described step of ar blowing refining for the first time can be 0.8～1.5NL/ (ton steel minute), and the argon blowing time of ar blowing refining can be 5～15 minutes for the first time.
In one embodiment of the invention, the Argon intensity of the described step of ar blowing refining for the second time can be 0.8～1.5NL/ (ton steel minute), and the argon blowing time of ar blowing refining can be 5～15 minutes for the second time.
In one embodiment of the invention, described calcium containing alloy can be one or more in calcium-silicon, Ca-Fe alloy.
In one embodiment of the invention, the cross sectional area of the strand of described method casting formation can be not more than 40000mm
2
Compared with prior art, the present invention is by adopting suitable deoxidization technique and crossing the methods such as program control aluminum dipping form formula, refining slag making, removal of inclusions, molten steel diffusive deoxidation, deformation processing of inclusion, make that pourability of molten steel is effectively improved, the nozzle blocking phenomenon is alleviated, and make the tundish list continuous cast crystallizer number in middle carbon aluminium-killed steel casting process be not less than 8 stoves, reached the purpose of economical production.In addition, method of the present invention is particularly suitable for solving the strand cross sectional area and is not more than 40000mm
2The continuous casting process process in the nozzle blocking problem.
The specific embodiment
Analyze by reason and blocking mechanism to nozzle blocking, can draw the main cause that causes nozzle blocking and comprise all many-sides such as steel quality, liquid steel temperature, mouth of a river material and structure, mouth of a river heat transfer and secondary oxidation.Experiment show aluminum oxide on the wall of the mouth of a river to adhere to the chemical reaction that occurs between sintering and molten steel and mouth of a river refractory material be the major reason that causes nozzle blocking.
According to experiment and analysis, can learn in steel there be the main source of aluminum oxide:
(1) field trash that suspends in molten steel (for example, is mainly deoxidation products α-Al
2O
3Particle) effect by interfacial tension sticks on the wall of the mouth of a river;
(2) 3SiO occurs in nozzle material and molten steel
2(S)+3C (S)+4Al=2Al
2O
3(S) Al that+3Si+3C (L) reaction generates
2O
3
(3) O that adsorbs in mouth of a river refractory material space
2React with the Al in molten steel the Al that generates
2O
3
(4) airborne O
2React with the Al in molten steel the Al that generates
2O
3(that is, the Al that formed by secondary oxidation of the aluminium in molten steel
2O
3);
(5) Al that descends and separate out with mouth of a river inwall liquid steel temperature
2O
3
According to the sample that gathers in the process for making process is researched and analysed, can draw, along with the increase of CaO content in field trash, Al
2O
3The order that transformation occurs field trash is as follows:
Al
2O
3→CaO·6Al
2O
3→CaO·2Al
2O
3→CaO·Al
2O
3→12CaO·7Al
2O
3→3CaO·Al
2O
3→CaO。
Table 1 shows the physical characteristic of various non-metallic inclusions.Al
2O
3The density and the fusion temperature that are field trash see Table 1.As can be seen from Table 1,12CaO7Al
2O
3Fusion temperature be 1455 ℃, so it is liquid in the pouring molten steel process, 3CaOAl
2O
3Also operative liquid can appear, and Al
2O
3, CaO6Al
2O
3, CaO2Al
2O
3, CaOAl
2O
3Fusing point all higher, can first separate out in the continuous casting steel casting cycle, and adhere to inwall and the end opening end face of stopper and submersed nozzle upper gap and submersed nozzle, thereby cause mouth of a river unsteady flow to stop up.
The various non-metallic inclusion physical characteristics of table 1
Therefore, water the stove number in order to improve the pourability of molten steel that contains aluminum steel to improve to connect, need to control Al in molten steel
2O
3It is the value volume and range of product of high-melting-point field trash.
In addition, except dystectic Al
2O
3Be that field trash can cause outside the mold gap obstruction, the field trashes such as calcium silicates also can cause mold gap to block.
The present invention is based on continuous cast mold nozzle blocking reason and mechanism is carried out drawing on the basis of above-mentioned analysis.In this application, in case of no particular description, percentage all is weight percentage.
can comprise the following steps according to the production method of middle carbon aluminium-killed steel of the present invention: the sulfur content in molten iron is controlled to be is not more than 0.015%, molten iron is carried out just refining forming molten steel, molten steel is tapped in ladle, in 20%～30% the process of tapping by weight percentage, add the aluminium deoxidier in molten steel, the addition of aluminium deoxidier is high by 0.02%～0.04% for the acid-soluble aluminum content in the molten steel that requires before can making after the completing ar blowing refining for the first time acid-soluble aluminum content in molten steel by weight percentage than continuous casting, in 31%～50% the process of tapping by weight percentage, adding the active lime of 4.0～6.0Kg/ ton steel and addition in the molten steel is 20% fluorite of active lime, ar blowing refining for the first time, the place adds 1.5～4kg/ ton steel refining slag and aluminium to the ladle top of the slag, then heating, carry out ladle refining, here, described aluminium divides 2～3 batches to add, wherein first follows closely after refining slag and adds, and first addition is 10%～20% of refining slag addition, the expectation recovery rate of the addition sum of all the other batches=(acid-soluble aluminum content in the molten steel after this first aluminium refining of the molten steel acid-soluble aluminum content that requires before continuous casting-add) * molten steel amount/aluminium, wherein, the expectation recovery rate of described all the other batches aluminium is calculated according to 65%～85%, be preferably 75%～80%, Xiang Gangzhong adds calcium containing alloy to carry out the calcium processing to molten steel, the addition of calcium containing alloy=[mass fraction of calcium in (the molten aluminium mass fraction of 0.2～0.4+ molten steel acid * 1000) * 0.29/ calcium containing alloy] kg/ ton molten steel, ar blowing refining for the second time, adopt continuous casting process to cast.In the present invention, described middle carbon aluminium-killed steel contains and is not less than by weight percentage 0.01% aluminium.In the present invention, if calcium alloy adds too much, easily produce high-melting-point CaS in molten steel, stop up the mouth of a river, even when the calcium alloy addition is too many, the flush water lip reflex can occur, thereby cause the mouth of a river easily bore a hole and increased production cost; If calcium alloy adds very few, can not reach the effect of inclusion conditioning.
In one embodiment of the invention, the step of described ar blowing refining for the first time also can comprise the appropriate aluminum steel of feeding in the molten steel, with by adding appropriate aluminum steel in steel after adding aluminum series alloy and tapping to complete in the steel in the step of ar blowing refining for the first time in tapping 20%～30% process, thereby in the molten steel that requires before making after the completing ar blowing refining for the first time acid-soluble aluminum content in molten steel by weight percentage than continuous casting, acid-soluble aluminum content is high by 0.02%～0.04%.Prescribe a time limit lower than the lower of above-mentioned requirements when the addition of aluminium, molten steel can not reach predetermined deoxidation requirement, affects the degree of purity of molten steel; When the addition of aluminium higher than above-mentioned requirements upper in limited time, thereby the aluminium too high levels in molten steel can cause pourability of molten steel deteriorated.In the present invention, described aluminum steel can be the aluminium solid wire of 0.2～0.25kg/m.
In one embodiment of the invention, can be ladle furnace refining (that is, LF refining) or vacuum circulation degassing refining (RH refining) in ar blowing refining and the refining between ar blowing refining for the second time for the first time.In an embodiment of the present invention, described refining slag can be various types of refining slags, and for example, refining slag can be by CaO, the Al of 2～8 parts of 70～80 parts by weight
2O
3, MgO, the SiO of 0～3 part of 0～5 part
2, the Na of 0～5 part
2CO
3, the CaF of 8～14 parts
2Form.When the addition of refining slag during less than 1.5kg/ ton steel, can not reach the effect of adsorbing preferably steel inclusion and desulfurization, its addition can cause occurring in molten steel the point-like inclusion of CaO particle during greater than 4kg/ ton steel, and this type impurity is not easy to remove from steel.In described refinement step, described 1.5～4kg/ ton steel refining slag can replace with the active lime of 1.5～4kg/ ton steel and for the fluorite of active lime weight 20%.The addition of active lime is during less than 1.5kg/ ton steel, can not reach the effect of adsorbing preferably steel inclusion and desulfurization, the addition of active lime can cause occurring in molten steel the point-like inclusion of CaO particle during greater than 4.0kg/ ton steel, and this type impurity is not easy to remove from steel.Fluorite adds few, and the poor fluidity of ladle slag is unfavorable for the refining slag, has added refractory brick in ladle is corroded seriously.
In the present invention, described active lime can contain 85.0≤CaO≤95.0%, 5% 〉=MgO＞0,2.5% 〉=SiO by mass percentage
2＞0, all the other are the trace impurities such as P, S.The composition of described fluorite can contain CaF by mass percentage
2: 80～90%, SiO
2: 0～15%, surplus is impurity.
In one embodiment of the invention, described aluminium deoxidier can or be usually used in other aluminium-containing alloy of deoxidation for aluminium, alfer, aluminium barium alloy, alusil alloy, alumal.Those skilled in the art can select appropriate aluminium deoxidier to the requirement of deoxidation according to molten steel.For example, the aluminium deoxidier can be alfer, and described alfer is comprised of the Al of 38～46 parts and the Fe of 54～62 parts by weight.
In one embodiment of the invention, the Argon intensity of the described step of ar blowing refining for the first time can be 0.8～1.5NL/ (ton steel minute), and the argon blowing time of ar blowing refining can be 5～15 minutes for the first time.In one embodiment of the invention, the Argon intensity of the described step of ar blowing refining for the second time can be 0.8～1.5NL/ (ton steel minute), and the argon blowing time of ar blowing refining can be 5～15 minutes for the second time.Here, the Argon amount is too little, and is unfavorable to inclusion floating in molten steel, and the Argon amount is excessive, easily causes molten steel oxidized.Argon blowing time is inadequate, and in molten steel, the clearance of deoxidation products is less, and argon blowing time is oversize, easily causes the liquid steel temperature loss serious.
The method according to this invention is carried out calcium to molten steel and is processed dystectic Al that can make in molten steel
2O
3Be that inclusion modification is the Al of low melting point
2O
3Be field trash, and can make sulfide that sex change also occurs.In one embodiment of the invention, described calcium containing alloy can or be usually used in other calcium containing alloy that calcium is processed for calcium-silicon, Ca-Fe alloy.Those skilled in the art can select according to the requirement that molten steel is processed calcium the kind of calcium containing alloy, be preferably silicon-calcium wire, described silicon-calcium wire contains the Si of 55～75 parts and the Ca of 25～45 parts by weight, its diameter is 10～13mm, and the addition of described silicon-calcium wire=[mass fraction of calcium in (the molten aluminium mass fraction of 0.2～0.4+ molten steel acid * 1000) * 0.29/ silicon-calcium wire] Kg/ ton molten steel.For example, the silicon-calcium wire that uses in embodiments of the invention 1 to 4 can contain 27%～30% Ca, 57%～60% Si and the steel shell of surplus by weight percentage.
In one embodiment of the invention, the cross sectional area of the strand of method casting formation of the present invention is not more than 40000mm
2The cross sectional area of the strand that forms when casting is not more than 40000mm
2The time, method of the present invention can be increased to middle continuous cast crystallizer number and be not less than 8 stoves.
Specifically, method of the present invention can adopt following processing step to implement:
(1) molten iron pretreatment
By the modes such as molten iron pretreatment the sulfur content in molten iron is controlled at≤0.015%.
(2) converter is just refined
In converter, molten iron is carried out just refining, the molten steel after then just refining is tapped in ladle.Just the mass percent of the composition of steel-making water may be controlled to: C:0.05～0.08%, and Mn:0.03～0.04%, Cr:0.030～0.04%, P:0.004～0.010%, S:0.08～0.015%, surplus is the inevitable impurity of iron and trace.Yet, the invention is not restricted to this, that is, just the molten steel composition of refining also can form for other.Add the aluminium deoxidier in tapping in molten steel to 20～30% processes.Here, except only adding deoxidier, can also add simultaneously according to steel grade deoxidier, alloy and carburant to the requirement of molten steel component and/or for Optimizing Technical in steel.Here, add carburant can regulate to a certain extent the carbon content in molten steel and optimize to a certain extent the subsequent technique process.Here, adding the purpose of alloy is for molten steel component being adjusted to the scope that steel grade requires.For a person skilled in the art, for different steel grades, add the amount of alloy and the kind can be different.In addition, also can add the needed alloy of steel grades to regulate alloying component in molten steel in ladle refining process.After adding deoxidier and alloy, add the active lime of 4.0～6.0Kg/ ton steel in tapping in ladle to 31～50% processes, and add fluorite, and fluorite addition=described active lime weight * 20%.
(3) Argon after the tapping
Gone out after steel at the Argon station and carried out ar blowing refining.Also can when ar blowing refining, feed aluminum steel in molten steel.The addition of described aluminium is interpreted as the acid-soluble aluminum content in molten steel is controlled to be molten steel acid-soluble aluminum content+(0.02%～0.04%, be preferably 0.03%) that requires before continuous casting.
(4) LF stove ladle refining
The place adds 1.5～4kg/ ton steel refining slag and aluminium at the LF stove ladle refining heating beginning forward direction ladle top of the slag, also can adopt equivalent amount of active lime, and Fluorspar Additives, fluorite addition=described active lime weight * 20%.Described aluminium divides 2～3 batches to add, wherein first follows closely after refining slag and adds, and addition is 10%～20% of refining slag addition, the expectation recovery rate of the addition sum of all the other batches=(acid-soluble aluminum content in the molten steel after this first aluminium refining of the molten steel acid-soluble aluminum content that requires before continuous casting-add) * molten steel amount/aluminium.Specifically, if divide 2 batches to add in aluminium, the addition of second batch equals the difference of the acid-soluble aluminum content in the molten steel acid-soluble aluminum content that requires before continuous casting and current molten steel (that is, adding first aluminium refining molten steel afterwards) * molten steel amount/expectation recovery rate; If divide 3 batches to add in aluminium, the addition sum of second batch and the 3rd batch equals the molten steel acid-soluble aluminum content that requires before continuous casting and current molten steel (namely, add the molten steel after first aluminium refining) in the difference * molten steel amount/expectation recovery rate of acid-soluble aluminum content, add ladle to carry out refining to molten steel in aluminium in batches, can greatly reduce the oxidation of aluminium, thereby improved the utilization rate of aluminium, and improved desulfurization, deoxidation effect.Wherein, the expectation recovery rate of described all the other batches aluminium is calculated according to 65%～85%, is preferably 75%～80%.Here, by to the estimation of the expectation recovery rate of aluminium and will be worth in the calculating of introducing the aluminium addition, make method of the present invention can control more accurately the content of aluminium in molten steel.
(5) calcium is processed
Xiang Gangzhong adds calcium containing alloy to carry out the calcium processing to molten steel, so that the dystectic Al in molten steel
2O
3Be that inclusion modification is the Al of low melting point
2O
3Be field trash, and make sulfide that sex change also occur.
(6) Argon before the casting
Molten steel being sent to before continuous casting working procedure pours into a mould, in order to accelerate inclusion floating to liquid steel level, molten steel to be carried out Argon process, Argon intensity is 0.8～1.5NL/ (ton steel minute), argon blowing time is 5～15 minutes.
(7) continuous casting
Adopt well-known protective casting mode that molten steel is protected during continuous casting, comprise collector nozzle of ladle cover protection tube, Argon between collector nozzle of ladle and protection tube, in tundish, molten steel well covers, and adopts crystallizer submersed nozzle, uses crystallizer protecting residue.Preferably, also use the seal washer sealing between collector nozzle of ladle and protection tube.
Due to above-mentioned method of refining of the present invention controlled that the meeting in the molten steel causes that mold gap stops up such as Al
2O
3Be the value volume and range of product of the field trashes such as high-melting-point field trash and calcium silicates, and can make Al
2O
3Be the Al that the high-melting-point field trash changes low melting point into
2O
3Be field trash, thereby reach the purpose of improving pourability of molten steel, make its crystallizer submersed nozzle inwall be difficult for stopping up, the stove number waters in the company of having improved tundish list bag, greatly reduces production cost.Realize of the present invention a kind of process route although described here, the invention is not restricted to this.For example, the technological process that it should be appreciated by those skilled in the art that the technological process that also can adopt the first refining of electric furnace, Argon, LF stove ladle refining, RH vacuum refining or the first refining of converter, Argon, RH vacuum refining realizes method of the present invention.And, those skilled in the art should understand that, according to different production models, can carry out appropriate design to the various process routes of realizing the inventive method, thereby realize easily linking between each step by controlling parameter in each step, and can be connected with follow-up for example continuous casting working procedure.For example, can make the state of molten steel after the state of first steel-making water and LF stove ladle refining be suitable for the processing of next step.By implementing method of the present invention, pourability of molten steel be improved significantly, middle continuous cast crystallizer number is brought up to 〉=8 stoves, has significantly reduced production cost.
Hereinafter, describe the present invention in detail in connection with exemplary embodiment.
Embodiment 1
Adopt the technological process of 120t converter, the rear Argon of tapping, LF stove ladle refining, 200mm * 200mm billet continuous casting to smelt the 20CrMnTi pinion steel, it is 0.01%～0.04% that this steel grade finished product requires [Al], finished product [C] content 0.17%～0.23% adopts aluminium as deoxidier, molten steel to be carried out deoxidation.
The molten steel sulfur content that is blended into converter is 0.015%, and converter smelting endpoint [C] content is 0.08%., add the aluminium of 3.5kg/ ton molten steel to carry out deoxidation to molten steel, and add the ferrosilicon of 2.0kg/ ton molten steel, the ferromanganese of 16.5kg/ ton molten steel and the low-carbon ferrochromium of 14kg/t steel to carry out the molten steel alloying to molten steel to approximately 30% the time in tapping.Approximately 50% the time, add the active lime of 4kg/ ton molten steel, the fluorite of 0.8kg/ ton molten steel in tapping in ladle.After having tapped, molten steel in ladle is carried out low discharge Argon 10min, deoxidation products is fully floated, improve Molten Steel Cleanliness.Thereby obtain the molten steel of component controlling, the gained molten steel composition is by mass percentage: C:0.13%, Mn:0.86%, P:0.008%, S:0.012%, Si:0.12%, Cr:1.11%, Ti:0.001%, [Al]: 0.065%, Fe:97.45%, surplus is impurity.Described ferrosilicon composition is by mass percentage: Si:74.5%, and Al:18%, Ca:0.5%, Mn:0.3%, Cr:0.2%, P:0.01%, S:0.01%, C:0.08%, surplus is Fe; Described ferromanganese composition is by mass percentage: Mn:74.5%, and C:1.5%, Si:1.5%, P:0.01%, S:0.01%, surplus is Fe; Described low-carbon ferrochromium alloy composition is: Si:3%, and C:0.3%, Cr:59.5%, Fe:18%, surplus is impurity.
LF further controls ladle slag and forms, and improves the ability of its dross inclusion adsorption.When standing, LF adds the active lime of 1.5kg/ ton molten steel and the fluorite of 0.3kg/ ton molten steel by entering at molten steel in ladle, simultaneously aluminium is added ladle in two batches, the addition of first aluminium be 0.36kg/ ton molten steel (namely, the addition sum of active lime and fluorite 20%), due to diffusive deoxidation, in molten steel, sour molten aluminium scaling loss is more, and after first sour molten aluminium added, the acid-soluble aluminum content of molten steel was 0.02%.Heat and added second batch aluminium in 10 minutes afterwards, the addition of second batch aluminium is molten steel acid-soluble aluminum content that continuous casting process the requires difference that deducts the acid-soluble aluminum content in current molten steel and obtain * molten steel amount, it is 0.03%～0.05% that this steel continuous casting requires acid-soluble aluminum content, by middle limit value, i.e. (0.04%-0.02%) * 130000=26kg, and the recovery rate of aluminium is calculated by 80%, and namely adding aluminium in this molten steel is 32.5kg.By adding aluminium and as active lime and the fluorite of refining slag, controlling ladle slag and form and reduce its oxidisability, the reproducibility refining slag of generation contacts with molten steel, and the diffusion rate of dissolved oxygen in molten steel is entered in slag, reaches the purpose of diffusive deoxidation.After the deoxidation of LF enhanced dispersion, the acid-soluble aluminum content in molten steel is that 0.045%, S content is 0.007%.
Carry out calcium after LF handles and process, the silicon-calcium wire of molten steel feeding 0.7kg/ ton molten steel in the ladle, calcium are handled and rear molten steel in ladle are carried out low discharge blowing argon gas 15min, and wherein Argon intensity is 0.8NL/ (ton molten steel minute).The silicon-calcium wire that uses in the present embodiment contains 27% Ca, 60% Si and the steel shell of surplus by weight percentage.
Molten steel is sent to continuous casting waters steel, continuous casting adopts the protection cast, and this pourability of molten steel is good, and middle continuous cast crystallizer number is 9 stoves.
Embodiment 2
The present embodiment is substantially the same manner as Example 1, and difference is, the steel of the present embodiment also carries out vacuum circulation degassing refining treatment (that is, the RH application of vacuum) to molten steel after ar blowing refining for the second time, specific as follows:
Molten steel is carried out the RH application of vacuum, and processing procedure lift gas flow is 1400NL/ minute, and vacuum is 12 minutes less than the processing time of 3mbar; Process after 12 minutes, keep vacuum, add alloy and carburant to carry out alloying and carburetting.Wherein: carburant 0.5kg/ ton molten steel, ferrotianium 1.6kg/ ton molten steel, ferrosilicon 1.3kg/ ton molten steel, ferromanganese 1.2kg/ ton molten steel, low-carbon ferrochromium 0.6kg/ ton molten steel.After alloying, circular treatment 5 minutes makes homogeneous chemical composition.Vacuum breaker, then Argon set off after 8 minutes, and wherein Argon intensity is 1.0NL/ (ton steel minute), 1585 ℃ of out-station temperatures.The mass percent of the composition of final molten steel is: C:0.20%, and Mn:0.95%, P:0.010%, S:0.006%, Si:0.27%, Cr:1.15%, Ti:0.06%, [Al]: 0.035%, Fe:97.12%, surplus is impurity.Described low-carbon ferrochromium alloy composition is: Si:3%, and C:0.3%, Cr:59.5%, Fe:18%, surplus is impurity.Described carburant composition is by mass percentage: CaO:0.2%, SiO
2: 3.19%, MgO:0.2%, Fe
2O
3: 0.676%, FeO:0.901%, C:86.02%, S:0.21%, P:0.09%, surplus is impurity.Molten steel is sent to continuous casting and waters steel, and continuous casting adopts the protection cast, and this pourability of molten steel is good, and middle continuous cast crystallizer number is 10 stoves.
Embodiment 3
Adopt the technological process of 120t converter, the rear Argon of tapping, LF ladle furnace refining, 200mm * 200mm billet continuous casting to smelt the 20CrMnTi pinion steel, it is 0.01%～0.04% that this steel grade finished product requires [Al], finished product [C] content 0.17%～0.23% adopts the ferro-aluminum deoxidation.
the molten steel sulfur content that is blended into converter is 0.012%, converter smelting endpoint [C] content is 0.05%, in tapping to approximately adding the ferro-aluminum of 3.5kg/ ton molten steel to carry out deoxidation to molten steel 20% the time, and add the ferrosilicon of 2.0kg/ ton molten steel, 16.5kg/ the ferromanganese of ton molten steel, the carburant of the low-carbon ferrochromium of 14kg/t steel and 0.85kg/ ton molten steel carries out molten steel alloying and carburetting, approximately add the active lime of 6kg/ ton molten steel 31% the time in the ladle in tapping, 1.2kg/ the fluorite of ton molten steel, the interior feeding of backward ladle aluminum steel 200m has tapped, argon gas with 0.8NL/ (ton steel minute) flow carries out Argon 10min to molten steel in ladle again, deoxidation products is fully floated, improve Molten Steel Cleanliness.Thereby obtain the molten steel of deoxidation alloying, its composition quality percentage is: C:0.14%, and Mn:0.85%, P:0.009%, S:0.011%, Si:0.13%, Cr:1.12%, Ti:0.001%, [Al]: 0.060%, surplus is Fe and impurity.The mass percent of described ferrosilicon composition is: Si:74.5%, and Al:18%, Ca:0.5%, Mn:0.3%, Cr:0.2%, P:0.01%, S:0.01%, C:0.08%, surplus is Fe; The mass percent of described ferromanganese composition is: Mn:74.5%, and C:1.5%, Si:1.5%, P:0.01%, S:0.01%, surplus is Fe; The mass percent of described carburant composition is: CaO:0.2%, SiO
2: 3.19%, MgO:0.2%, Fe
2O
3: 0.676%, FeO:0.901%, C:86.02%, S:0.21%, P:0.09%, surplus is impurity.Described low-carbon ferrochromium alloy composition is: Si:3%, and C:0.3%, Cr:59.5%, Fe:18%, surplus is impurity.Described aluminum steel is the solid aluminum steel of 0.25kg/m.
LF further controls ladle slag and forms, and improves the ability of its dross inclusion adsorption.When standing, LF adds the active lime of 4kg/ ton molten steel, the fluorite of 0.8kg/ ton molten steel by entering at molten steel in ladle, simultaneously aluminium is added ladle in three batches, the addition 0.48kg/ ton molten steel of first aluminium (namely, the addition sum of active lime and fluorite 10%), add second batch aluminium after 8 minutes, the addition of second batch aluminium is 0.10kg/ ton molten steel, due to diffusive deoxidation, in molten steel, sour molten aluminium scaling loss is more, after the molten aluminium of second batch acid added, the acid-soluble aluminum content of molten steel was 0.03%.Add the 3rd batch of aluminium after 5 minutes, the addition of the 3rd batch of aluminium is the expectation recovery rate of molten steel acid-soluble aluminum content that continuous casting process the requires difference that deducts the acid-soluble aluminum content in current molten steel and obtain * molten steel amount/aluminium, it is 0.03%～0.05% that this steel continuous casting requires acid-soluble aluminum content, by middle limit value, i.e. (0.04%-0.03%) * 130000=13kg, and the expectation recovery rate of aluminium is calculated by 70%, and namely adding aluminium in this molten steel is 18.6kg.By adding aluminium and as active lime and the fluorite of refining slag, controlling ladle slag and form and reduce its oxidisability, the reproducibility refining slag of generation contacts with molten steel, and the diffusion rate of dissolved oxygen in molten steel is entered in slag, reaches the purpose of diffusive deoxidation.After the deoxidation of LF enhanced dispersion, the acid-soluble aluminum content in molten steel is that 0.035%, S content is 0.008%.
Carry out calcium after LF handles and process, the silicon-calcium wire of molten steel feeding 0.65kg/ ton molten steel in the ladle, the argon gas with 1.5NL/ (ton steel minute) flow after calcium is handled carries out Argon 5min to molten steel in ladle.The silicon-calcium wire that uses in the present embodiment contains 30% Ca, 57% Si and the steel shell of surplus by weight percentage.The mass percent of the composition of final molten steel is: C:0.19%, Mn:0.98%, P:0.009%, S:0.007%, Si:0.26%, Cr:1.18%, Ti:0.05%, the impurity of [Al]: 0.025%, Fe:97.12% and surplus.Described low-carbon ferrochromium alloy composition is: Si:3%, and C:0.3%, Cr:59.5%, Fe:18%, surplus is impurity.
Molten steel is sent to continuous casting and waters steel, and continuous casting adopts the protection cast, and this pourability of molten steel is good, and middle continuous cast crystallizer number is 10 stoves.
Embodiment 4
Adopt the technological process of 120t electric furnace, the rear Argon of tapping, LF ladle furnace refining, Φ 200mm billet continuous casting to smelt the X52 pipe line steel, it is 0.01%～0.05% that this steel grade finished product requires [Al], and finished product [C] content 0.14%～0.18% adopts the ferro-aluminum deoxidation.
The molten steel sulfur content that is blended into converter is 0.010%, and converter smelting endpoint [C] content is 0.06%., add the ferro-aluminum of 3.5kg/ ton molten steel to carry out deoxidation to molten steel, and add the ferrosilicon of 2.0kg/ ton molten steel, the ferromanganese of 19kg/ ton molten steel and the carburant of 0.6kg/ ton molten steel to carry out molten steel alloying and carburetting to approximately 25% the time in tapping.In tapping approximately 45% the time, add the active lime of 4.5kg/ ton molten steel, the fluorite of 0.9kg/ ton molten steel in ladle, feeding aluminum steel 300m in the backward ladle of having tapped, then molten steel in ladle is carried out low discharge Argon 10min, deoxidation products is fully floated, improve Molten Steel Cleanliness.Thereby obtain the molten steel of deoxidation alloying, its composition quality percentage is: C:0.11%, Mn:1.30%, P:0.009%, S:0.009%, Si:0.13%, the impurity of [Al]: 0.075%, Fe:98% and surplus.The mass percent of described ferrosilicon composition is: Si:74.5%, and Al:18%, Ca:0.5%, Mn:0.3%, Cr:0.2%, P:0.01%, S:0.01%, C:0.08%, surplus is Fe; The mass percent of described ferromanganese composition is: Mn:74.5%, and C:1.5%, Si:1.5%, P:0.01%, S:0.01%, surplus is Fe; The mass percent of described carburant composition is: CaO:0.2%, SiO
2: 3.19%, MgO:0.2%, Fe
2O
3: 0.676%, FeO:0.901%, C:86.02%, S:0.21%, P:0.09%, surplus is impurity.
LF further controls ladle slag and forms, and improves the ability of its dross inclusion adsorption.When standing, LF adds the active lime of 3kg/ ton molten steel, the fluorite of 0.6kg/ ton molten steel by entering at molten steel in ladle, aluminium is divided two batches simultaneously and add ladle, the addition 0.54kg/ ton molten steel of first aluminium (namely, the addition sum of active lime and fluorite 15%), due to diffusive deoxidation, in molten steel, sour molten aluminium scaling loss is more, and after first sour molten aluminium added, the acid-soluble aluminum content of molten steel was 0.03%.Add second batch aluminium after 10 minutes, the addition of second batch aluminium is the expectation recovery rate of molten steel acid-soluble aluminum content that continuous casting process the requires difference that deducts the acid-soluble aluminum content in current molten steel and obtain * molten steel amount/aluminium, it is 0.03%～0.05% that this steel continuous casting requires acid-soluble aluminum content, by upper limit value, i.e. (0.04%-0.03%) * 130000=13kg, and the expectation recovery rate of aluminium is calculated by 75%, and namely adding aluminium in this molten steel is 17.3kg.By adding aluminium and as active lime and the fluorite of refining slag, controlling ladle slag and form and reduce its oxidisability, the reproducibility refining slag of generation contacts with molten steel, and the diffusion rate of dissolved oxygen in molten steel is entered in slag, reaches the purpose of diffusive deoxidation.After the deoxidation of LF enhanced dispersion, add alloy to carry out alloying, carburant 0.5kg/ ton molten steel, ferrosilicon 1.3kg/ ton molten steel, ferromanganese 0.5kg/ ton molten steel.The mass percent of the composition of final molten steel is: C:0.16%, and Mn:1.35%, P:0.010%, S:0.007%, Si:0.27%, [Al]: 0.040%, surplus is Fe and impurity.
Carry out calcium after LF handles and process, the silicon-calcium wire of molten steel feeding 0.75kg/ ton molten steel in the ladle, calcium are handled and rear molten steel in ladle are carried out low discharge blowing argon gas 8min, and wherein Argon intensity is 0.95NL/ ton molten steel minute.After Argon, liquid steel temperature is 1575 ℃.The silicon-calcium wire that uses in the present embodiment contains 29% Ca, 59% Si and the steel shell of surplus by weight percentage.
LF departures molten steel is sent to continuous casting and waters steel, and continuous casting adopts the protection cast, and this pourability of molten steel is good, and middle continuous cast crystallizer number is 8 stoves.
In sum, method of the present invention can be by adopting suitable deoxidization technique and crossing the methods realizations such as program control aluminum dipping form formula, refining slag making, removal of inclusions, molten steel diffusive deoxidation, deformation processing of inclusion to the control of the value volume and range of product of high-melting-point field trash in steel, thereby improved molten steel castability, alleviated the nozzle blocking phenomenon, make tundish list continuous cast crystallizer number in the carbon aluminium-killed steel casting process reach and be not less than 8 stoves, reached the purpose of economical production.
Do not break away from although the above by having described the present invention in conjunction with exemplary embodiment, it will be apparent to those skilled in the art that the spirit and scope that claim limits, can carry out various modifications and change to exemplary embodiment of the present invention.
Claims (9)
1. the production method of carbon aluminium-killed steel in a kind, is characterized in that, said method comprising the steps of:
Sulfur content in molten iron is controlled to be is not more than 0.015%;
Molten iron is carried out just refining forming molten steel, molten steel is tapped in ladle;
In 20%～30% the process of tapping by weight percentage, add the aluminium deoxidier in molten steel, the addition of aluminium deoxidier is high by 0.02%～0.04% for acid-soluble aluminum content in the molten steel that requires before can making after the completing ar blowing refining for the first time acid-soluble aluminum content in molten steel by weight percentage than continuous casting;
In 31%～50% the process of tapping by weight percentage, adding the active lime of 4.0～6.0Kg/ ton steel and addition in the molten steel is 20% fluorite of active lime weight;
Ar blowing refining for the first time;
ladle refining, in described ladle refining step, the place adds aluminium and 1.5～4kg/ ton steel refining slag to the ladle top of the slag, then heating, carry out refining, described aluminium divides 2～3 batches to add, wherein first follows closely after refining slag and adds, and the addition of this first aluminium is 10%～20% of refining slag addition, the expectation recovery rate of the addition sum of all the other batches=(acid-soluble aluminum content in the molten steel after this first aluminium refining of the molten steel acid-soluble aluminum content that requires before continuous casting-add) * molten steel amount/aluminium, wherein, the expectation recovery rate of described aluminium is calculated according to 65%～85%,
Xiang Gangzhong adds calcium containing alloy to carry out the calcium processing to molten steel, the addition of calcium containing alloy=[mass fraction of calcium in (the molten aluminium mass fraction of 0.2～0.4+ molten steel acid * 1000) * 0.29/ calcium containing alloy] kg/ ton molten steel;
Ar blowing refining for the second time;
Adopt continuous casting process to cast, during continuous casting, the molten aluminium of molten steel acid is not less than 0.01%.
2. the method for claim 1, it is characterized in that, the step of described ar blowing refining for the first time also comprises the appropriate aluminium of feeding in the molten steel, so that in the molten steel that the acid-soluble aluminum content in molten steel requires before by weight percentage than continuous casting after completing ar blowing refining for the first time, acid-soluble aluminum content is high by 0.02%～0.04%.
3. the method for claim 1, is characterized in that, in described ladle refining step, described 1.5～4kg/ ton steel refining slag replaces with the fluorite that active lime and the weight of 1.5～4kg/ ton steel is active lime weight 20%.
4. the method for claim 1, is characterized in that, described aluminium deoxidier is one or more in metallic aluminium, alfer, aluminium barium alloy, alusil alloy and alumal.
5. the method for claim 1, is characterized in that, the Argon intensity of the described step of ar blowing refining for the first time is 0.8～1.5NL/ (ton steel minute), and the argon blowing time of ar blowing refining is 5～15 minutes for the first time.
6. the method for claim 1, is characterized in that, the Argon intensity of the described step of ar blowing refining for the second time is 0.8～1.5NL/ (ton steel minute), and the argon blowing time of ar blowing refining is 5～15 minutes for the second time.
7. the method for claim 1, is characterized in that, described calcium containing alloy is one or more in calcium-silicon and Ca-Fe alloy.
8. the method for claim 1, is characterized in that, in the step of described ladle refining, the expectation recovery rate of described aluminium is calculated according to 75%～80%.
9. method as described in any one in claim 1 to 8, is characterized in that, the cross sectional area of the strand that described method casting forms is not more than 40000mm
2
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201110181120 CN102248142B (en) | 2011-06-30 | 2011-06-30 | Method for producing medium and low carbon aluminum killed steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201110181120 CN102248142B (en) | 2011-06-30 | 2011-06-30 | Method for producing medium and low carbon aluminum killed steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102248142A CN102248142A (en) | 2011-11-23 |
| CN102248142B true CN102248142B (en) | 2013-05-08 |
Family
ID=44975917
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201110181120 Expired - Fee Related CN102248142B (en) | 2011-06-30 | 2011-06-30 | Method for producing medium and low carbon aluminum killed steel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102248142B (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102443680A (en) * | 2011-12-07 | 2012-05-09 | 鞍钢股份有限公司 | Method for preventing flocculation flow of first tank of aluminum killed steel produced by medium-thin slab continuous casting machine |
| CN102925626B (en) * | 2012-11-02 | 2014-01-15 | 武汉钢铁(集团)公司 | Method for improving aluminum-containing killed steel casting performance of Ti system |
| CN102962411B (en) * | 2012-11-20 | 2014-12-03 | 攀钢集团攀枝花钢钒有限公司 | Production method of low-carbon and medium-carbon steel |
| CN102943150B (en) * | 2012-11-26 | 2015-03-04 | 湖南华菱湘潭钢铁有限公司 | Refined slag control method |
| CN103469050B (en) * | 2013-09-22 | 2015-02-18 | 中天钢铁集团有限公司 | Aluminum-containing cold forging steel smelting process |
| CN103866088B (en) * | 2014-03-24 | 2015-04-08 | 莱芜钢铁集团有限公司 | Method for determining amount of slagging material and deoxidized alloy added into LF (Low-Frequency) refining furnace by use of reference heat method |
| CN106011379B (en) * | 2016-08-02 | 2019-02-12 | 芜湖新兴铸管有限责任公司 | The method of deoxidation of cold-forging steel |
| CN107236894B (en) * | 2017-06-16 | 2019-03-15 | 马鞍山钢铁股份有限公司 | A kind of method for making steel of low-sulfur, low titanium Aluminum steel |
| CN107999718B (en) * | 2017-12-07 | 2019-05-31 | 安徽工业大学 | A method of improving micro-alloyed steel continuous casting process castability |
| CN108950137B (en) * | 2018-08-07 | 2020-06-09 | 马鞍山钢铁股份有限公司 | Method for rapidly forming slag in high-quality steel tapping process |
| CN111220614B (en) * | 2018-11-27 | 2023-05-09 | 宝山钢铁股份有限公司 | Method for rapidly evaluating quality of molten steel |
| CN109576441B (en) * | 2018-12-21 | 2020-12-15 | 首钢京唐钢铁联合有限责任公司 | RH refining method for controlling wettability of inclusions in low-carbon aluminum killed steel |
| CN115368152B (en) * | 2022-09-26 | 2023-04-28 | 张家港市恒乐阳方高温材料有限公司 | Unshaped refractory material and application thereof |
| CN115537501A (en) * | 2022-11-03 | 2022-12-30 | 石横特钢集团有限公司 | Slagging method for adding fluorite and refining pellets in LF (ladle furnace) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1597998A (en) * | 2003-09-17 | 2005-03-23 | 首钢总公司 | Process for producing steel containing alumium low carbon low ilicon by small square blank continuous caster |
| CN101462155A (en) * | 2007-12-21 | 2009-06-24 | 首钢总公司 | Method for producing ultra-low carbon wire by small square billet continuous casting |
| JP4318119B2 (en) * | 2004-06-18 | 2009-08-19 | 国立大学法人京都大学 | Acoustic signal processing method, acoustic signal processing apparatus, acoustic signal processing system, and computer program |
| CN101597666A (en) * | 2009-07-03 | 2009-12-09 | 首钢总公司 | A kind of method that is used to improve plate of moderate thickness carbon aluminium-killed steel molten steel cleanness |
| CN102051435A (en) * | 2009-11-10 | 2011-05-11 | 攀钢集团钢铁钒钛股份有限公司 | Method for smelting low-carbon aluminium-killed steel and method for continuously casting low-carbon aluminium-killed steel |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04318119A (en) * | 1991-04-16 | 1992-11-09 | Kawasaki Steel Corp | Production of high clean steel |
-
2011
- 2011-06-30 CN CN 201110181120 patent/CN102248142B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1597998A (en) * | 2003-09-17 | 2005-03-23 | 首钢总公司 | Process for producing steel containing alumium low carbon low ilicon by small square blank continuous caster |
| JP4318119B2 (en) * | 2004-06-18 | 2009-08-19 | 国立大学法人京都大学 | Acoustic signal processing method, acoustic signal processing apparatus, acoustic signal processing system, and computer program |
| CN101462155A (en) * | 2007-12-21 | 2009-06-24 | 首钢总公司 | Method for producing ultra-low carbon wire by small square billet continuous casting |
| CN101597666A (en) * | 2009-07-03 | 2009-12-09 | 首钢总公司 | A kind of method that is used to improve plate of moderate thickness carbon aluminium-killed steel molten steel cleanness |
| CN102051435A (en) * | 2009-11-10 | 2011-05-11 | 攀钢集团钢铁钒钛股份有限公司 | Method for smelting low-carbon aluminium-killed steel and method for continuously casting low-carbon aluminium-killed steel |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102248142A (en) | 2011-11-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102248142B (en) | Method for producing medium and low carbon aluminum killed steel | |
| CN103469050B (en) | Aluminum-containing cold forging steel smelting process | |
| CN106086593B (en) | Molten steel smelting process for preventing nozzle nodulation in pouring process of sulfur-containing and aluminum-containing steel | |
| CN104862443B (en) | A kind of smelting process of low carbon low silicon welding wire steel | |
| CN111172353A (en) | Method for controlling cleanliness of molten steel and smelting control method for preventing nozzle nodulation in pouring process of sulfur-containing aluminum-containing steel | |
| CN102268513B (en) | Method for improving castability of molten steel of medium and low carbon steel | |
| CN102296157B (en) | Very low Ti control method of ultralow-carbon aluminum-silicon killed steel | |
| CN109252008A (en) | A kind of production method of low carbon, low nitrogen ultralow-sulfur steel | |
| CN103014221B (en) | Method for producing high-aluminum steel plate blanks | |
| CN102586685B (en) | Smelting process of steel for high-titanium alloy welding wire | |
| CN104278197B (en) | Smelting method of steel for low-silicon high-titanium welding wire | |
| CN101768656B (en) | Method for refining ultra-low carbon ferritic stainless steel under vacuum | |
| CN104212935B (en) | A kind of method with high titanium ferrochrome production high-quality GCr15 bearing steel | |
| CN104694819A (en) | Production method for low-carbon low-silicon steel | |
| CN102071287A (en) | Method for melting high-temperature-resistance and high-pressure-resistance alloy steel | |
| CN103436657A (en) | Welding wire steel smelting process capable of preventing welding spatter | |
| CN104004881A (en) | Method for controlling nitrogen content in process of producing aluminium deoxidation high-carbon steel | |
| CN104278130A (en) | Process of quickly regulating alkalinity of LF (ladle furnace) slag | |
| CN107354269A (en) | The method that RH complex deoxidizations produce ultra-low-carbon steel | |
| CN103741006A (en) | Preparation method of Ti-containing low-nitrogen stainless steel | |
| CN108531807A (en) | A kind of heavy wall heavy caliber X80M pipelines clean steel and smelting process | |
| CN108893682B (en) | Die steel billet and preparation method thereof | |
| CN103045948A (en) | High-chromium steel and manufacturing method thereof | |
| CN103555886A (en) | Method for smelting ultralow-sulfur steel by using vanadium-containing molten iron | |
| CN103484599B (en) | Smelting method of high-manganese wear-resistant steel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130508 Termination date: 20170630 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |