CN102329920A - Method for smelting high-aluminum low-silicon ultra pure ferritic stainless steel - Google Patents
Method for smelting high-aluminum low-silicon ultra pure ferritic stainless steel Download PDFInfo
- Publication number
- CN102329920A CN102329920A CN201110327941A CN201110327941A CN102329920A CN 102329920 A CN102329920 A CN 102329920A CN 201110327941 A CN201110327941 A CN 201110327941A CN 201110327941 A CN201110327941 A CN 201110327941A CN 102329920 A CN102329920 A CN 102329920A
- Authority
- CN
- China
- Prior art keywords
- stainless steel
- aluminium
- content
- steel
- molten steel
- 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.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/06—Deoxidising, e.g. killing
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/068—Decarburising
- C21C7/0685—Decarburising of stainless steel
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/10—Handling in a vacuum
Abstract
The invention provides a method for smelting high-aluminum low-silicon ultra pure ferritic stainless steel. The method comprises the following steps of: performing vacuum oxygen decarburization and free decarburization treatment on molten ferritic stainless steel in a vacuum oxygen decarburization (VOD) furnace, improving the reduction process of a VOD vacuum treatment process, performing preliminary deoxidation, final deoxidation and vacuum breaking, adding high-density aluminum iron, controlling the alkalinity of slag, performing wire feeding treatment, performing continuous casting by adopting the measures of protective casting and the like, and thus obtaining the high-aluminum low-silicon ultra pure ferritic stainless steel based on VOD to continuous casting treatment. By the method, the acid washing performance of the ultra pure ferritic stainless steel is improved, the purity of the molten steel and the casting performance of the continuous casting process are further improved, formation of magnesia alumina spinel serving as a harmful inclusion is effectively inhibited, Al2O3 inclusion is effectively removed, oxidation of the titanium in the titanium-containing steel is inhibited, and tundish water gap blockage of the continuous casting process is avoided.
Description
Technical field
The present invention relates to the stainless steel smelting field, particularly, relate to a kind of smelting process of ferritic stainless steel, more specifically, relate to the smelting process of the low silicon super-purity ferrite stainless steel of a kind of high alumina.
Background technology
Super-purity ferrite stainless steel is the elaboration of ferritic stainless steel; General requirement carbon nitrogen total content is less than 150ppm; Total oxygen content is lower than 40ppm, and the quantity of inclusion, size and type be effectively controlled, and super-purity ferrite stainless steel can partly substitute austenitic stainless steel; Because it does not require and contains nickel element, has played the effect of practicing thrift nickel resources.
The smelting process of super-purity ferrite stainless steel generally will be passed through vacuum-oxygen decarbonizing stove (being called for short the VOD stove) and carried out the dark decarburization of oxygen blast, denitrogenation processing under the ultravacuum condition, and the routine operation of said VOD stove is following:
One, the molten steel of handling through AOD gets into VOD with the ladle transportation and handles station, measures temperature and composition, and qualified back gets into vacuum processing chamber, stirs with the ugly vacuum and the end earlier; Two, begin oxygen decarburization under the vacuum condition and handle, top blowing oxygen decarburization under the end agitation condition judges whether stop oxygen blast according to composition of fumes, CO+CO in furnace gas
2When content is lower than certain value, stop oxygen blast; Three, free carbonization treatment under the ultravacuum condition adopts greatly and stirs; Four, reduction process adds the Alloying Treatment that ferrosilicon, aluminium, lime and fluorite carry out deoxidation and silicon; Five, vacuum breaker; Six, feed silk and soft stirring under the atmospheric condition, send casting at last.
Yet in the oxygen decarburization treating processes in above-mentioned second step, oxygen blast can not be used for decarburization fully, has quite a few oxygen will get into the molten bath and exists with the form of chromic oxide or dissolved oxygen, so after the 3rd free decarburization, also will carry out deoxidation treatment.
Wherein, silicon, aluminium are the deoxidant elements of using always.Each Iron And Steel Company's original adoption of Europe be the pure silicon deoxy technology, reason is to adopt the aluminium deoxidation can a large amount of Al that form
2O
3Is mingled with, and then most steel grades are produced detrimentally affects, yet the entire oxygen content in the steel content of silicon deoxidation is very high, in the strand total oxygen more than 60ppm, thereby influence the performance of the finished product.
Along with to super-purity ferrite stainless steel require increasingly high; It is extremely low-level to need its total oxygen content also to be in, and people begin to attempt adopting sial complex deoxidization technology, with further reduction oxygen content in steel; For sial complex deoxidization technology, mainly exist following patent to ask down at present:
Day the present invention JP2002030324 (A) has provided the sial complex deoxidization and has smelted the method that prevents strip flaw (also claiming watt rib shape defective) ferritic stainless steel; Deoxidation process adds ferrosilicon earlier; The target silicone content is controlled at 0.20～3.0wt%, basicity of slag (CaO and SiO in the slag
2Mass ratio) be controlled at 1.2～2.4; Use aluminium deoxidation at last; The ratio that requires molten steel Al content and Ti content before casting is between 0.01～0.10, and this method can improve molten steel and (wherein form equiax crystal after being crystalline solidification and account for whole crystalline percentage at the equiaxial crystal ratio of casting process.Like strand center equiaxial crystal ratio is exactly center equiax crystal district diameter and strand diameter per-cent.) reach 60%, and control composition of inclusions well, preventing that the casting cycle middle water containing opening from stopping up, final molten steel total oxygen content also remains on lower level.Yet it is still very high that this patent basicity of slag is controlled at the oxygen activity that means slag between 1.2～2.4, is difficult to the molten steel oxygen level is reduced to extremely low-level.
Chinese patent CN101058837, patent name: in the smelting process of a kind of super-purity ferrite stainless steel decarburization, denitrogenation, provided a kind of smelting process of super-purity ferrite stainless steel; After the molten steel vacuum-treat decarburization, (vacuum tightness≤5mbar), add the ferrosilicon deoxidation earlier under vacuum condition; Add the aluminium deep deoxidation again, deaeration time 5～10 minutes, and then finely tune with alloy; This method of deoxidation treatment time is short, and deoxidation effect is pretty good, is widely used.
Yet JP2002030324 (A) and CN101058837 do not provide the method for concrete interpolation aluminium in the molten steel; Because aluminium block or aluminum shot density are significantly less than molten steel density; Direct adding under the VOD vacuum condition will on float over molten steel top and directly contact with slag and react and a large amount of heat releases; Be difficult to effectively to get into the molten steel molten bath and carry out bulk deoxidation, this just causes directly adding aluminium and is difficult to the aluminium content of control steel after processing finishes, thereby can't guarantee the bulk deoxidation effect.
Simultaneously; The final content of silicon, aluminium element that adopts the sial complex deoxidization to relate to is handled by deoxidation effect, the back operation of steel and the structure property of steel also has certain influence, and mainly show: one) if aluminium content is low in the steel, deoxidation effect is then not obvious; Be that oxygen level is higher in the molten steel; Handle if will feed titanium subsequently, then can form a large amount of titanium oxide and be mingled with, a large amount of titanium oxide is mingled with may stop up middle water containing opening; Two), current research shows that the ferritic stainless steel of high silicon content (it is generally acknowledged that content is higher than 0.3%) is big in back operation pickling difficulty, has influenced the stainless steel product surface smoothness.So, in order further to improve the quality of products and to guarantee to produce smoothly, for a lot of super-purity ferrite stainless steel kinds; The control of deoxidant element content develops towards low silicon, high alumina direction; Be specially the silicone content requirement less than 0.3% or lower, other require to confirm lower limit according to steel grade, and aluminium content is controlled in 0.01～0.1% the scope; Total oxygen content can be reduced effectively, and the oxidation of titanium alloy process titanium subsequently can be prevented.
Smelting for low silicon, high alumina super-purity ferrite stainless steel; The front is also mentioned; Related patent U.S. Patent No. and ordinary method can not improve in the steel aluminium content effectively to the target content scope in the VOD treating processes, simultaneously, if improved aluminium content; In case basicity of slag control is improper, silicone content also is difficult to be controlled in the OK range in the steel.If copy the aluminium deoxidation method of carbon steel smelting process; Promptly improve aluminium content in the steel,, can only could feed aluminium wire at the non-vacuum condition behind vacuum-treat end and the vacuum breaker so because hello silk difficulty is too big under the vacuum condition through hello aluminium wire; This can improve aluminium content in the steel really; Yet, can not stir the Al of generation more greatly to the stainless steel molten steel behind hello the aluminium wire
2O
3Be mingled with and be difficult to grow up rapidly and to get rid of, and non-vacuum condition feeds the risk that aluminium wire can increase absorption of nitrogen by steel down, and prolong the treatment time, so non-vacuum condition hello aluminium wire down is not a scientific approach.If the winding-up aluminium powder can realize improving aluminium content in the steel, but the vacuum blowing device is complicated under vacuum condition, and the control difficulty is very big.
Therefore, prior art and routine operation can not solve conscientiously and under vacuum condition, improve aluminium content and effective technical problem of controlling silicone content in the steel.
Summary of the invention
For solving the problem of above-mentioned existence; The object of the present invention is to provide the smelting process of the low silicon super-purity ferrite stainless steel of a kind of high alumina; Through the reduction process of VOD vacuum-treat process is improved, add highdensity ferro-aluminum, control basicity of slag, feed that silk is handled subsequently and adopt measure such as protection casting at casting process, realization is smelted high alumina from VOD to the continuous casting treating processes and is hanged down the silicon super-purity ferrite stainless steel; Improve the pickling performance of super-purity ferrite stainless steel; And further improve molten steel purity and casting process castability can, effectively suppress the formation of harmful inclusion magnesium-aluminium spinel simultaneously, effectively remove Al
2O
3Inclusion, and in Ti-containing steel, suppressed the oxidation of titanium, avoided the middle water containing opening of casting process to stop up.
For achieving the above object, the present invention takes following technical scheme:
The present invention provides the smelting process of the low silicon super-purity ferrite stainless steel of a kind of high alumina, it is characterized in that, comprises the steps:
(1), the ferritic stainless steel molten steel is carried out vacuum-oxygen decarbonizing and free carbonization treatment in the VOD stove; The ferritic stainless steel molten steel staple that obtains after the processing requires: chromium quality percentage composition 10～23%; Carbonaceous amount percentage composition is less than 0.01%, and nitrogen quality percentage composition is less than 0.01%;
(2), preliminary dexidation: in the ferritic stainless steel molten steel that after step (1) is handled, obtains, add ferrosilicon and/or aluminium block and carry out preliminary dexidation and handle, and add lime and fluorite carries out slag making, then under high vacuum strong mixing condition, treatment time 5～10min;
(3), final deoxygenation: in the ferritic stainless steel molten steel that after step (2) is handled, obtains; Add ferro-aluminum and carry out final deoxygenation and handle, the quality percentage composition of aluminium is 20～60% in the said ferro-aluminum, and adds lime and fluorite carries out slag making; Then under vacuum condition; Middle intensity stirs 2～5min, under high vacuum strong mixing condition, handles 12～18min then;
(4), vacuum breaker;
(5), under condition of normal pressure, with the soft stirring 8～10min of said ferritic stainless steel molten steel, then under condition of normal pressure, feed the calcium silk to said ferritic stainless steel molten steel, feed after the calcium silk finishes soft stirring 5～10min;
(6), continue soft stirring 15～30min, afterwards the ferritic stainless steel molten steel is carried out continuous casting in protective atmosphere, finally obtain the low silicon super-purity ferrite stainless steel of high alumina.
Smelting process according to the low silicon super-purity ferrite stainless steel of a kind of high alumina provided by the invention; What adopt is; In the step (2); The total add-on of said ferrosilicon and/or aluminium block is 4～9kg/t, and the quality percentage composition of silicon is 70～80% in the said ferrosilicon, and it is the higher value in following two scopes that said lime adds the quality value: ferrosilicon adds 4～6 times or 2～3 times of aluminium block adding quality of quality; It is 0.05～0.3 times that lime adds quality that said fluorite adds quality, and after step (2) was handled, the mass content of silicon was less than 0.1%, greater than 0 in the said ferritic stainless steel molten steel, and the mass content that requires oxygen is greater than 0.01%.
Smelting process according to the low silicon super-purity ferrite stainless steel of a kind of high alumina provided by the invention; What adopt is that in the step (3), the add-on of fine aluminium is 2～6kg/t in the said ferro-aluminum; The add-on of said lime is 2～3 times of fine aluminium add-on in the ferro-aluminum; The fluorite add-on is 0.05～0.3 times that lime adds quality, and after step (3) was handled, the mass content of silicon was less than 0.3%, greater than 0 in the said ferritic stainless steel molten steel; The mass content of aluminium is 0.01～0.1%, and the mass content of oxygen is less than 0.003%.
Smelting process according to the low silicon super-purity ferrite stainless steel of a kind of high alumina provided by the invention; What adopt is; In step (5), the said calcium silk of feeding is the pure calcium silk of feeding in the ferritic stainless steel molten steel, and said pure calcium silk feed quantity is 0.1～0.3kg/t; After step (5) was handled, the mass content of calcium was 15～30ppm in the said ferritic stainless steel molten steel.
According to the smelting process of the low silicon super-purity ferrite stainless steel of a kind of high alumina provided by the invention, employing be, in step (5), fed the calcium silk also after the soft stirring, in the ferritic stainless steel molten steel, feed the titanium silk, the pure titanium amount in the said titanium silk is 1～3kg/t.
According to the smelting process of the low silicon super-purity ferrite stainless steel of a kind of high alumina provided by the invention, employing be, in the low silicon super-purity ferrite stainless steel of final prepared high alumina, siliceous amount percentage composition is less than 0.3%, aluminium quality percentage composition is 0.01～0.1%.
According to the smelting process of the low silicon super-purity ferrite stainless steel of a kind of high alumina provided by the invention, employing be, in the step (2),
When the higher limit of siliceous amount content in the low silicon super-purity ferrite stainless steel of the high alumina that requires finally to make is 0.3%, all add ferrosilicon;
When the higher limit of siliceous amount content in the low silicon super-purity ferrite stainless steel of the high alumina that requires finally to make is lower than or equals 0.2%, all add aluminium block;
When the higher limit of siliceous amount content in the low silicon super-purity ferrite stainless steel of the high alumina that requires finally to make is between 0.2～0.3%; Add ferrosilicon and aluminium block, the additional proportion of said ferrosilicon and aluminium block=(higher limit-0.2% of siliceous amount content in the low silicon super-purity ferrite stainless steel of the high alumina that finally makes)/(higher limit of siliceous amount content in the low silicon super-purity ferrite stainless steel of the high alumina that 0.3%-finally makes).
According to the smelting process of the low silicon super-purity ferrite stainless steel of a kind of high alumina provided by the invention, employing be, in the step (3), said ferro-aluminum is shaped as block or spherical, density is 4.5～6.5g/cm
3, diameter 3～6cm; After step (3) is handled, CaO and SiO in the slag
2Mass ratio be higher than 2.8, CaO and Al in the slag
2O
3Mass ratio be higher than 1.
According to the smelting process of the low silicon super-purity ferrite stainless steel of a kind of high alumina provided by the invention, employing be,
The condition of said high vacuum strong mixing is: vacuum pressure is controlled at below the 800Pa, and VOD furnace bottom argon blowing rate is controlled between 4～8L/ (mint);
The intensity stirring condition is in said: vacuum pressure is controlled at below the 2000Pa, and VOD furnace bottom argon blowing rate is controlled between 1～4L/ (mint);
Said soft stirring condition is: under condition of normal pressure, between VOD furnace bottom argon blowing rate control 1～5L/ (mint).
The smelting process beneficial effect of the low silicon super-purity ferrite stainless steel of a kind of high alumina provided by the present invention is:
1, can in the VOD smelting process, improve aluminum precipitation deoxidation efficient effectively; Improve aluminium content in the steel effectively; And prevent that element silicon turns back in the molten steel in the slag, and be in lower level with the control silicone content, realized the smelting of high alumina low silicon content super-purity ferrite stainless steel;
2, casting process adopts protection casting measure, can prevent the secondary oxidation of high aluminium content molten steel, handles in conjunction with calcium, can avoid the obstruction of middle water containing opening; Moreover, owing to just realized aluminium deoxidation effect and the target control of aluminium content, the Al of generation in the VOD process
2O
3Being mixed in the big whipping process of VOD can fully grow up, and can effectively float behind the vacuum breaker, and then improve the purity of molten steel;
3, because the aluminium that institute adds the high-density ferro-aluminum can fully get into molten steel, reduced greatly its with slag in the MgO direct reaction generate the probability of magnesium-aluminium spinel, effectively inhibition is harmful to the formation of inclusion magnesium-aluminium spinel, Al
2O
3The formation of effective removal that is mingled with and inhibition magnesium-aluminium spinel can be avoided the obstruction of middle water containing opening equally;
4, because the lifting of aluminium content needs titanium alloyization like steel grade, then in feeding the titanium process, can suppress the oxidation of titanium greatly, can improve the yield of titanium, the present invention has active effect to preventing owing to the nozzle clogging that titanium oxide causes;
5, the method for the present invention's design is safe and reliable, and operating performance is strong, can improve the stability and the quality product of smelting greatly.
Embodiment
Technological principle of the present invention is following:
One, the present invention requires to smelt target silicon, the aluminium content of super-purity ferrite stainless steel and is: siliceous amount percentage composition is less than 0.3%, and the purpose of aluminium quality percentage composition between 0.01～0.1% is:
The silicone content requirement mainly is in order to improve this stainless pickling performance less than 0.3%, if silicone content is higher than 0.3%, then the pickling difficulty of steel becomes big, has influenced the smooth finish of steel, and in addition, the silicon of this content range can be guaranteed the toughness of steel, improves its processing characteristics; The aluminium specification of quality is mainly considered from deoxidation effect between 0.01～0.1%, through calculation of thermodynamics; Under 1550 ℃ of conditions, for the ferrite stainless molten steel of different Cr content, Al content is that 0.01% corresponding dissolved oxygen scope is 0.002～0.0025% (promptly 20～25ppm); Owing to also include inclusion in the total oxygen; So under the condition of total oxygen requirement less than 30ppm in the strand, the aluminium content requirement that this patent relates to is higher than 0.01%; Simultaneously, the aluminium upper content limit is 0.1%, and main consideration is to some Ti-containing steels; Need to guarantee aluminium-titanium content than greater than 0.15, the aluminium upper content limit is 0.1% can guarantee that titanium content can design and be limited to 0.7%, certainly; If aluminium content surpasses 0.1%, it is big that smelting cost becomes, and there is no need.
Two, preliminary dexidation and final deoxygenation:
For the as above smelting of the ferritic stainless steel of sial content range, the present invention adopts and carries out preliminary dexidation with ferrosilicon and aluminium block earlier, adds ferro-aluminum again and carries out final deoxygenation, shown in step (2) and (3).The present invention also requires to adopt the mode that ferrosilicon, aluminium block and ferro-aluminum carry out deoxidation that adds, and reason is, if whole deoxidation process only adds ferro-aluminum, because the ferro-aluminum cost is high than ferrosilicon, then whole smelting cost can promote, and causes carburetting serious easily; If only add ferrosilicon and aluminium block, because aluminium block is light, can not effectively get into molten steel, then can not accomplish the purpose that improves aluminium content in the steel; And if ferrosilicon, aluminium block and ferro-aluminum add the realization final deoxygenation together, because the binding ability of aluminium and oxygen is much larger than the bonding force of silicon and oxygen, Cr in slag
2O
3Under basic reductive situation, aluminium meeting and SiO
2Kickback taking place, cause that silicone content raises fast in the steel, probably can not satisfy the terminal point silicone content less than 0.3% requirement.So; The present invention adopts and to add the mode that ferrosilicon and part aluminium block carry out preliminary dexidation earlier; In the preliminary dexidation process, oxygen content in steel can not drop to very low, according to the thermodynamics formula of silicon, oxygen balance; Preliminary dexidation process element silicon can react with oxygen in large quantities, thereby has guaranteed that silicone content is in than the low value scope in the treating processes steel.After preliminary dexidation is handled, add ferro-aluminum and carry out final deoxygenation, because that the density of ferro-aluminum will be higher than the fine aluminium piece is a lot; Major part can sink in the molten steel after then ferro-aluminum can guarantee to get into the molten steel molten bath, and the aluminium that the fusing back discharges then can be introduced into molten steel, realizes effective bulk deoxidation; And improve aluminium content in the steel effectively; Certainly, also have aluminium behind the partial melting and can directly get in the slag and react, but this does not hinder the fast lifting of aluminium content in the steel.
1), preliminary dexidation
Step of the present invention (2) preliminary dexidation; Adding the silicone content mass percent and be 70～80% ferrosilicon and/or aluminium block carries out preliminary dexidation and handles; The total add-on of ferrosilicon and/or aluminium block is 4～9kg/t, and adds lime and fluorite carries out slag making, and it is that ferrosilicon adds the higher value in 4～6 times of quality with the aluminium block add-on 2～3 times that lime adds quality; It is 0.05～0.3 times that lime adds quality that fluorite adds quality; High vacuum strong mixing 5～10min of following treatment time of condition, processing requires siliceous amount content less than 0.1% after finishing, and the oxygen mass content is greater than 0.01%.
Before this step; Molten steel has just passed through the processing of oxygen decarburization; A large amount of dissolved oxygens and chromic oxide are arranged in the molten bath, and adding the purpose that ferrosilicon and aluminium block carry out preliminary dexidation is to utilize ferrosilicon or aluminium block that the chromium in the chromic oxide is restored, and does not reduce the oxygen level in the steel as far as possible; Aluminium block has very strong reducing power, can be directly and Cr in the slag
2O
3React, the reducing power of silicon mainly is discussed here, the Si reduction reactional equation is following:
1.5[Si]+(Cr
2O
3)＝2[Cr]+1.5(SiO
2)
Through calculation of thermodynamics, suppose oxide compound (Cr
2O
3) and (SiO
2) be that the thermodynamic activity of standard is 1 with the pure substance; Calculate in chromium content is 18% stainless steel; Silicone content need just can impel reaction forward to carry out greater than 0.6%, and this density that just means ferrosilicon can not be too big, guarantee to float on the ferrosilicon molten steel top directly and (the Cr in the slag
2O
3) react, the molten steel local silicon content that guarantees to contact with slag is greater than 0.6%, and thus, this patent is selected ferrosilicon commonly used, and its silicone content is 70～80%, can satisfy the not too high requirement of ferrosilicon density, certainly, and along with the fusing of lime, the middle mutually SiO of slag
2Activity reduces, and has also accelerated silicon and has carried out preliminary dexidation.Why the present invention also selects aluminium to carry out preliminary dexidation, mainly is that Wen Houyou further discusses to some lower steel grades of target silicone content requirement.Since the ferrosilicon that contains 75% silicon with etc. the aluminium block deoxidation amount of weight approach 1, so for ferrosilicon and aluminium block add-on scope, the also low situation of chromium content initial carbon content of low while in steel; It is fewer needing ferrosilicon and aluminium block to add total amount; On the contrary, the high initial carbon content simultaneously of chromium content is also high in the steel, and it is many needing ferrosilicon and aluminium block total amount; Below with two kinds of extreme cases that possibly occur aborning as the example of analyzing, confirm the scope of ferrosilicon and aluminium block adding total amount with this.Through calculating, for the ferrite stainless smelting steel of low chromium content, be 11.6% steel grade like chromium content, molten steel gets into that initial carbon is under 0.3% condition before the VOD, the about 7Nm of ton steel blowing oxygen quantity
3/ t can remove carbon under vacuum condition, according to experience in the past, has 30～40% oxygen to form Cr by chromic oxide approximately
2O
3The pure silicon or the 3.5～4.6kg fine aluminium that then need about 2.6～3.45kg are considered the content of silicon in the ferrosilicon, and the lower value that the present invention sets demand ferrosilicon and aluminium block total amount is 4kg/t; And for the smelting of high chromium steel; Like chromium content is 22.6% steel grade, gets into initial carbon before the VOD and is under 0.6% the situation, the about 13Nm of ton steel blowing oxygen quantity
3/ t can remove carbon under vacuum condition, according to experience in the past, has 35～45% oxygen to form Cr by chromic oxide approximately
2O
3, then need the pure silicon of about 5.6～7.24kg or the fine aluminium of 7.5～9.7kg, consider the content of silicon in the ferrosilicon, the higher limit that the present invention sets demand ferrosilicon and the total add-on of aluminium block is 9kg/t.The add-on of lime is according to the SiO that generates
2Amount come to be confirmed, satisfy the scope that basicity requires, and the present invention confirms that it is that ferrosilicon adds the higher value in 4～6 times of quality with the aluminium block add-on 2～3 times that lime adds quality, can satisfy basicity of slag and be controlled at the scope more than 2.8, CaO and Al in the slag
2O
3Mass ratio be higher than 1.For the adding of fluorite, main purpose is to accelerate the dissolving and the fusing of lime, and its add-on will be confirmed according to the complexity of lime fusing itself, according to knowhow, confirms that it is 0.05～0.3 times that lime adds quality that fluorite adds quality.Because the ferrosilicon and the aluminium block that add in the step (2) do not reduce dissolved oxygen content in the steel significantly, and require oxygen level greater than 0.01%, can guarantee after the reaction that silicone content is less than 0.1% in the steel.Though this step has been stipulated the scope of ferrosilicon and the total add-on of aluminium block; In practical implementation; Also will confirm the oxygen amount that ferrosilicon and aluminium block need be sloughed in the concrete allocation proportion in decarburization, secondary combustion, loss, entering molten bath according to the carbon rejection process institute oxygen blast gas of smelting process, because decarburized amount is known, post-combustion rate can analyze according to composition of fumes; Loss amount also can return out according to historical data; Then the ratio in oxygen entering molten bath can calculate, and can calculate the occurrence of ferrosilicon and the total add-on of aluminium block thus, and this value is in the scope that the present invention confirms.
The present invention is for step (2), also requires to confirm the ferrosilicon that relates to and/or the additional proportion of aluminium block:
If be limited at 0.3% o'clock on the siliceous amount content (being the target silicone content) in the low silicon super-purity ferrite stainless steel of high alumina that a requires finally to make, all add ferrosilicon;
If siliceous amount upper content limit requirement is lower in the low silicon super-purity ferrite stainless steel of high alumina that b requires finally to make, promptly when higher limit was lower than for 0.2% (comprising 0.2%), require all to add aluminium blocks;
C, when siliceous amount upper content limit in the low silicon super-purity ferrite stainless steel of the high alumina that requires finally to make between 0.2～0.3% the time, the additional proportion of ferrosilicon and aluminium block=(higher limit-0.2% of siliceous amount content in the low silicon super-purity ferrite stainless steel of the high alumina that finally makes)/(high alumina that 0.3%-finally makes hangs down the higher limit of siliceous amount content in the silicon super-purity ferrite stainless steel).
Wherein, the higher limit of siliceous amount content is represented the value that silicone content can not surpass in the low silicon super-purity ferrite stainless steel of the said high alumina that finally makes.
Why the present invention also selects aluminium to carry out preliminary dexidation, mainly is to some lower steel grades of target silicone content requirement, when the target silicone content only requires less than 0.3% the time; All add ferrosilicon here and the control of the basicity through thereafter can be realized this goal, yet, if the target silicone content requires less than 0.2%; Consider that the final deoxygenation process also can form certain silicon amount that increases, greatly about about 0.1～0.2%, form and increase silicon and just can not satisfy final silicone content less than 0.2% requirement if then add ferrosilicon here; So; This situation requires all to add aluminium, and between 0.2～0.3%, the present invention designs ferrosilicon and aluminium block is mixed for the siliceous amount upper content limit of target value; Concrete ratio requires to confirm according to target silicone content higher limit, can meet the demands.
2), final deoxygenation
Step of the present invention (3) final deoxygenation process adds ferro-aluminum and carries out the final deoxygenation processing, and ferro-aluminum contains aluminium quality percentage composition 20～60%;, carbonaceous amount content is less than 0.1%, and all the other are iron and some micro impurity elements; Add-on 2～the 6kg/t of fine aluminium in the ferro-aluminum, and add lime and fluorite, lime additional amount are 2～3 times of fine aluminium amount in the ferro-aluminum; It is 0.05～0.3 times that lime adds quality that fluorite adds quality; Material add the back earlier under vacuum condition in intensity stirring 2～5min, handle 12～18min under the high vacuum strong mixing condition then, can guarantee that siliceous amount content is less than 0.3% after the processing end; Aluminium mass content 0.01～0.1%, the oxygen mass content is less than 0.003%.
Selection is discussed as the front with the reductor of the high relatively ferro-aluminum of density as final deoxygenation, after ferro-aluminum adds; Its aluminium that comprises can get into the molten steel molten bath, and do not resemble add the fine aluminium after in large quantities with slag in oxide compound reaction and do not get into the molten steel molten bath basically, this point that production practice are verified; Aluminium quality percentage composition 20～60% is lower than 20% if also considered aluminium content in the selection ferro-aluminum except satisfying the density requirements scope, and then iron content is excessive; Because the present invention has requirement to the add-on of fine aluminium, then can cause the add-on of ferro-aluminum own excessive, not only can cause carbon increasing amount to increase; And can cause the molten bath temperature drop excessive; Participate in energy that reaction discharges and can satisfy about 4kg iron and be heated to current 1700 ℃ of molten steel through calculating 1kg aluminium, thus, confirm that ferro-aluminum aluminium content at end should be higher than 20% from room temperature; Aluminium content is lower than 60% and mainly requires to consider from density control in the ferro-aluminum, and ferro-aluminum requires density to be higher than 4.5g/cm
3, corresponding aluminium content is 60%.Carbon content mainly is to consider from the aspect of control carburetting less than 0.01% in the requirement ferro-aluminum, is ultra low-carbon steel owing to smelt steel grade; Should controlling ferro-aluminum, to add back carburetting more little good more, is 0.1% situation for the ferro-aluminum carbon containing, and a ton steel adds under the situation of ferro-aluminum amount 10kg; The molten steel carbon increasing amount is 10ppm; This still is acceptable basically, so require that carbon content should be less than 0.1% in the ferro-aluminum, this also is that ferro-aluminum is produced attainable carbon content scope.The add-on of ferro-aluminum is by wherein fine aluminium, and the present invention requires the fine aluminium add-on at 2～6kg/t, and aluminium adds not only will slough the dissolved oxygen in the steel, Cr in the slag that the preliminary dexidation process ferrosilicon that also will further reduce fails to remove
2O
3, consume fine aluminium 0.5～2.4kg/t approximately, and might with SiO in the slag
2Further reaction; The silicon amount 0.1%～0.2% of returning that causes consumes fine aluminium 1.4～2.6kg/t approximately, also satisfies the target 0.01～0.1% of final aluminium content in addition; Consume fine aluminium 0.1～1kg/t approximately; To draw the scope 2～6kg/t of fine aluminium add-on like upper lower limit value addition and higher limit addition, the ferro-aluminum add-on is that the fine aluminium add-on is divided by its aluminum content.The purpose of adding lime is to continue to guarantee CaO and Al in the slag
2O
3Mass ratio.The present invention require this step material add the back earlier under vacuum condition in intensity stir 2～5min, its objective is that requirement on the one hand has the stirring of certain intensity to molten steel, impels aluminium entering molten steel; On the other hand; If stirring intensity is excessive, can be sprayed onto ferro-aluminum on the top of the slag, cause aluminium to get into not in the molten steel; So intensity stirs in taking here.This step requires high vacuum strong mixing treatment time 12～18min will guarantee that mainly adequate time lets Al
2O
3Be mingled with and grow up, could the soft whipping process under atmospheric condition thereafter fully floating is able to remove.In addition, it is pointed out that because the aluminium in the ferro-aluminum can fully get into molten steel; When deoxidation is arrived to a certain degree; Avoided aluminium directly to get into the MgO that goes in the slag in the reducing slag, thereby restricted the formation of magnesium-aluminium spinel greatly, for stainless steel; Magnesium-aluminium spinel is very deleterious inclusion, can cause product defects.Just because of adopt ferro-aluminum to realize the control of aluminium and the control of silicon, processing can guarantee siliceous amount content less than 0.3% after finishing, aluminium mass content 0.01～0.1%, and the oxygen mass content is less than 0.003%.
This patent has been done requirement to shape and density that step (3) adds ferro-aluminum, and for the ferro-aluminum that step (3) relates to, it is block or spherical to require it to be shaped as, real density 4.5～6.5g/cm
3, diameter 3～6cm.
Be shaped as and block or spherically make for ease and make things convenient for addings, and if diameter less than 3cm, may cause ferro-aluminum to get into the molten steel molten bath from feed bin after, its impact depth is not enough, and the size need are less than 6cm, considers mainly that size is too big then to be inconvenient to feed in raw material.Require 4.5～6.5g/cm for density range
3, mainly be to want 2/3 part to be immersed in the molten steel after it adds in order to satisfy, molten steel density 6.9～7.2g/cm
3About, so require density to be greater than 4.5g/cm
3, consider that simultaneously aluminium content can not be lower than 20%, then upper density limit is 6.5g/cm
3
This patent is for smelting step (3), require final deoxygenation after, basicity of slag is CaO and SiO in the slag
2Mass ratio control be higher than 2.8, CaO and Al in the slag
2O
3Mass ratio be higher than 1.
Requiring basicity of slag to be higher than 2.8 behind the final deoxygenation mainly is from control SiO
2Consider on the activity, according to CaO-SiO
2-Al
2O
3Ternary activity figure is standard state SiO with the pure substance under this basicity value condition
2Activity quotient be approximately 0.028, through calculation of thermodynamics, be example for the super-purity ferrite stainless steel of smelting 22.6%Cr content, balance SiO in the slag that 0.01% aluminium content and 0.3% silicone content are corresponding in the steel
2Activity is 0.009, and under this basicity condition, further inverse goes out SiO
2X 0.32 in slag, because basicity set and has been higher than 2.8, and SiO then
2Percentage composition inevitable less than 26%, this scope can draw its x basically and generally can be controlled in 0.32, can find out thus, this basicity scope can guarantee that as above Al no longer removes the SiO in the reducing slag under the sial content condition
2For the steel grade of other chromium content, if chromium content less than 22.6%, owing to chromium is to reduce the element that silicon activity improves aluminium activity, according to smelting thermodynamic principles, silicon activity becomes big and aluminium activity reduces in the steel, the Al element further can not remove the SiO in the reducing slag
2Otherwise the Al element agree to remove SiO in the reducing slag
2Consider that it is not a lot of that chromium content is higher than 22.6% steel grade, and can be through regulating SiO in the slag
2The mode of content stops SiO in the further reducing slag of Al
2, and the too high meeting of basicity lower limit set causes the quantity of slag to increase, so the present invention confirms that finally basicity of slag should be higher than 2.8, this also is the minimum requirements to the basicity of slag value.For basicity of slag, there is not upper limit requirement, mainly consider if the aluminium content requirement is higher Al in the slag
2O
3Increase, basicity of slag may raise, even final slag becomes SiO
2The low-down aluminium calcium slag of content, promptly slag is with CaO-Al
2O
3Be the slag of staple, this allows in the present invention.The present invention requires CaO and Al in the slag
2O
3Mass ratio be higher than 1, mainly be to SiO in the slag
2Content is lower, develops into the situation of aluminium calcium slag, CaO and Al in the requirement
2O
3Mass ratio be higher than 1, can guarantee well that slag has and absorb Al well
2O
3Ability, for aluminium calcium slag, CaO and Al
2O
3Mass ratio under the 1.1-1.4 situation, slag has the ability of good absorption inclusion, and has good flowability.The present invention is to CaO and Al
2O
3The also not restriction of the ratio upper limit, mainly also is to the situation of non-aluminium calcium slag series, allow Al
2O
3In the low levels scope.For the control of CaO content in the slag, in the setting of step (2) and (3) lime adding amount, control.
Three, for step (5)
1), soft stirring
Feed soft stirring before the pure calcium silk and let the inclusion Al that under vacuum condition, has grown up
2O
3Inclusion floating gets into the slag phase, feeds soft stirring behind the pure calcium silk and promotes to feed the lower melting point calcium aluminate that generates behind the calcium and be mingled with further come-up and get into the slag phase.
2), feed silk
A), feed calcium silk (being the calcium treatment process)
The calcium treatment process; Promptly under normal pressure, feed pure calcium silk with wire feeder to molten steel, pure calcium feed quantity is 0.1～0.3kg/t, fed the calcium silk after; Under condition of normal pressure; The bottom Argon is carried out soft stirring to molten steel, and soft churning time 5～10min requires after processing finishes that the mass content of calcium is controlled at 15～30ppm in the steel.
Because what the present invention smelted is high aluminum steel, the add-on of deoxidation process aluminium is relatively very big, though through the Al of various measures to generating
2O
3Be mingled with and carried out from molten steel, discharging, and prevent secondary oxidation, yet, in production practice, still there is Al
2O
3Stop up the risk of middle water containing opening, reason is under the high situation of aluminium content, the MgO in the still possible reducing slag of aluminium, and the magnesium-aluminium spinel of formation is mingled with very difficult the eliminating, thereby possibly form the origin of obstruction, adds and does not get rid of clean Al
2O
3Be mingled with, thereby have the risk of nozzle clogging.This case has dropped to this risk through various measures very low, yet, in order to ensure high aluminum steel produce highly stable, the present invention has still adopted the calcium treatment technology, with the risk of avoiding nozzle clogging to form.It mainly is with Al that calcium is handled
2O
3Be mingled with and change into 12CaO7Al
2O
3Lower melting point be mingled with, it is generally acknowledged Al in the steel
2O
3Content is 0.01% to the maximum, with the Al of this amount
2O
3Become 12CaO7Al
2O
3The calcium contents that needs is 67ppm, and the dissolving content general requirement of the back of calcium processing end simultaneously calcium constituent self is 0.09 times to 0.15 times of aluminium content, if aluminium content 0.03%; Then solubilize calcium content requires 30ppm approximately, and the pure calcium amount that needs like this to get into molten steel considers that then for 100ppm is 0.01% the yield for high aluminum steel hello calcium process calcium is higher than 30%; Final definite pure calcium feed quantity is 0.1～0.3kg/t; And finally confirm calcium contents span of control 15～30ppm, and can satisfy the calcium of aluminium content range of the present invention and handle, realize effective sex change of inclusion; If final ca content is higher than 30ppm, the risk that corrodes middle water containing opening is arranged.
B), feed the titanium silk
For requiring to smelt titaniferous steel grade, can in the ferritic stainless steel molten steel, feed the titanium silk again, pure titanium amount is 1～3kg/t in the said titanium silk, realizes titanium alloyization.Wherein, pure titanium amount is that titanium silk feed quantity multiply by titanium content in the titanium silk.
Four, for step (6)
1), soft stirring 15～30min
This soft churning time fully guarantees the further come-up of inclusion, has further improved the purity of molten steel.
2), require molten steel is carried out continuous casting under protective atmosphere
Carry out argon shield and the argon shield of middle water containing opening and the argon shield of tundish top that continuous casting has comprised big water-coating port under the protective atmosphere; Purpose is the secondary oxidation that prevents molten steel; For the high alumina smelting steel; These protections also need, and these are attainable ripe continuous casting technology, exceed description here.
Five, for intensity stirring, high vacuum strong mixing and soft stirring in said
The intensity stirring condition is in said: vacuum pressure is controlled at below the 2000Pa, and VOD furnace bottom argon blowing rate is controlled between 1～4L/ (mint);
The condition of said high vacuum strong mixing is: vacuum pressure is controlled at below the 800Pa, and VOD furnace bottom argon blowing rate is controlled between 4～8L/ (mint);
Said soft stirring condition is: under condition of normal pressure, between VOD furnace bottom argon blowing rate control 1～5L/ (mint).
Wherein, The setting of correlation parameter confirms according to production practice, vacuum condition down in intensity stir and will guarantee that the top of the slag is not fierce and seethe that high vacuum strong mixing condition will guarantee that the molten steel splash does not influence production; And soft stirring will guarantee that the top of the slag is not blown open; Under these conditions, grope, finally confirmed relevant bottom blowing flow range according to production.
Need to prove; Symbol in the unit that the present invention relates to " t " expression ton molten steel, " L " be for rising, " min " expression minute; The kilogram amount that " kg/t " expression adds in molten steel per ton, the argon gas amount that " L/ (mint) " representes in steel per ton, PM is blown into.
Embodiment
Specifying the inventive method in the embodiment of producing low silicon high-aluminum ferritic stainless steel and the effect that obtains below in conjunction with embodiment, is that example is explained with the super-purity ferrite stainless steel of producing 409,443 and 445 these 3 trade mark steel grades respectively.
Embodiment 1
Present embodiment is to the requirement of refining unit VOD stove: equipment can be handled molten steel 120t, and final vacuum is less than 300Pa, and Argon air blowing ability always in bottom is higher than 60Nm
3/ h, ladle lining are magnesia-calcium brick.Steel grade is 409, molten steel amount 116000kg, i.e. and 116t, the initial composition of molten steel was before VOD smelted:
C:0.3%, Si:0.25%, Cr:11.6%, S:0.010%, N:0.025%, Mn:0.56%, P:0.015%, full O:0.02%, Ti:0.01%, Al:0.001%, all the other are Fe and micro impurity element.
1580 ℃ of molten steel initial temperatures.
Present embodiment silicone content target is less than 0.26%, aluminium content about 0.03%, and concrete steps are following:
1) molten steel is after oxygen decarburization and free carbonization treatment, and the oxygen depletion amount is 885Nm
3, free decarburization time 15min, after processing finishes, 1630 ℃ of molten steel temperatures, composition is following:
C:0.003%, Si:0.01%, Cr:11.1%, S:0.008%, N:0.007%, Mn:0.14%, P:0.015%, full O:0.04%, Ti:0.01%, Al:0.001%, all the other are Fe and micro impurity element.
2) preliminary dexidation is 0.27% according to siliceous amount content requirement higher limit in the low silicon super-purity ferrite stainless steel of the high alumina that finally makes, and adding siliceous 77% ferrosilicon 400kg (is 3.45kg/t; Conversion method: 400kg ÷ molten steel amount 116t, in embodiment 1 scope, except that the quality of delime and fluorite; Conversion method down with) add up to 600kg (being 5.16kg/t) to carry out preliminary dexidation with aluminium block 200kg (being 1.71kg/t), and adding lime 1.6t, fluorite 200kg carries out slag making; Material adds the final vacuum pressure-controlling below 800Pa, and argon bottom-blowing stirring intensity 600L/min (be 5.17L/ (mint), conversion method: 600L/min ÷ molten steel amount 116t; In embodiment 1 scope; Conversion method is down together), treatment time 8min guarantees that lime tentatively melts.Processing finishes back silicone content 0.08%, oxygen level 0.015%.
3) final deoxygenation adds the ferro-aluminum 650kg that contains aluminium 40%, ferro-aluminum diameter 5cm, density 5.4g/cm
3, carbon containing 0.008%; Contain fine aluminium 260kg (being 2.24kg/t), and add lime 600kg, fluorite 50kg; Carry out final deoxygenation, material adds back adjustment end stirring argon blowing rate to 150L/min, and middle intensity stirs 3min; Carry out HS subsequently and stir argon bottom-blowing flow 800L/min (being 6.90L/ (mint)), treatment time 15min.After processing finishes, silicone content 0.19%, aluminium content 0.054%, oxygen level 7.8ppm.The slag staple is: CaO 60%, SiO
212%, Al
2O
317%, MgO 3%, satisfies basicity of slag requirement and CaO and Al
2O
3Ratio is greater than 1.Processing finishes 1570 ℃ of back temperature.
4) vacuum breaker.
5) soft stirring 10min, argon bottom-blowing stirring intensity 200L/min (being 1.72L/ (mint)).Calcium is handled, and adds pure calcium silk 20kg (being 0.17kg/t) through wire feeder, feeds silk and finishes the soft stirring 10min in back, argon bottom-blowing stirring intensity 200L/min (being 1.72L/ (mint)).This steel grade need feed the titanium silk and carry out titanium alloyization, and the pure titanium amount in the titanium silk is 150kg (being 1.38kg/t), terminal point titanium 0.1%.
6) continue soft stirring 20min, argon bottom-blowing stirring intensity 180L/min (being 1.55L/ (mint)).Continuous casting in the protective atmosphere, big water-coating port, middle water containing opening all have blowing argon.
The middle water containing opening opening degree is highly stable in the casting cycle, and violent fluctuation does not take place, and total fluctuation range shows that mouth of a river knot does not take place to be filled in, and the mouth of a river does not take place yet corrode in 3%.
Final molten steel is cast into base, and composition is following:
C:0.006%, Si:0.20%, Cr:11.7%, S:0.001%, N:0.008%, Mn:0.23%, P:0.015%, full O:0.0020%, Ti:0.09%, Al:0.044%, all the other are Fe and micro impurity element.
Wherein silicone content slightly rises behind vacuum breaker, possibly be SiO in the slag
2On a small quantity by the result of aluminium reducing; And aluminium content slightly descends, reason is along with the passing of the reduction of temperature and time and possible secondary oxidation, has impelled contacting of aluminium and oxygen, causes its composition to descend slightly; Deoxidation process causes carbon content before the processing to a certain degree rising to be arranged relatively because the ferro-aluminum that adds contains a certain amount of carbon, but still in hyperpure scope.
The relative old process of magnesium-aluminium spinel The amount of inclusions significantly reduces in the strand, and mainly to be size be mingled with and globular plasticity CaO-Al below the 10 μ m at the TiN below the 5 μ m or Ti (CN) inclusion
2O
3-SiO
2Be mingled with (part contain a small amount of MgO), the performance of steel especially surface property is not had harmful effect.
Embodiment 2
Present embodiment is to the requirement of refining unit VOD: equipment can be handled molten steel 120t, and final vacuum is less than 300Pa, and Argon air blowing ability always in bottom is higher than 60Nm
3/ h, ladle lining are magnesia-calcium brick.Steel grade is 443, molten steel amount 108400kg, i.e. and 108.4t, the initial composition of molten steel was before VOD smelted:
C:0.36%, Si:0.018%, Cr:20.8%, S:0.005%, N:0.015%, Mn:0.3%, P:0.010%, full O:0.02%, Ti:0.01%, Al:0.001%, all the other are Fe and micro impurity element.
1600 ℃ of molten steel initial temperatures.
Present embodiment silicone content target is less than 0.2%, aluminium content about 0.02%, and concrete steps are following:
1) molten steel is after oxygen decarburization and free carbonization treatment, and the oxygen depletion amount is 1266Nm
3, free decarburization time 20min, after processing finishes, 1670 ℃ of molten steel temperatures, composition is following:
C:0.005%, Si:0.01%, Cr:19.7%, S:0.004%, N:0.004%, Mn:0.14%, P:0.015%, full O:0.05%, Ti:0.01%, Al:0.001%, all the other are Fe and micro impurity element.
2) preliminary dexidation is 0.2% according to siliceous amount content requirement higher limit in the low silicon super-purity ferrite stainless steel of the high alumina that finally makes, and this requirement condition all adds aluminium block down, and does not add ferrosilicon; Avoid increasing silicon, and adding aluminium block 780kg (be 7.20kg/t, conversion method: 780kg ÷ molten steel amount 108.4t; In embodiment 2 scopes, except that the quality of delime and fluorite, conversion method down with) carry out preliminary dexidation; And add lime 1.6t, and fluorite 100kg carries out slag making, and material adds the final vacuum pressure-controlling below 800Pa; Argon bottom-blowing stirring intensity 700L/min (be 6.46L/ (mint), conversion method: 700L/min ÷ molten steel amount 108.4t, in embodiment 2 scopes; Conversion method is down together), treatment time 6min guarantees that lime tentatively melts.Processing finishes back silicone content 0.04%, oxygen level 0.02%.
3) final deoxygenation adds the ferro-aluminum 500kg (being 4.61kg/t) that contains aluminium 40%, ferro-aluminum diameter 5cm, density 5.4g/cm
3, carbon containing 0.01% contains fine aluminium 200kg (being 1.85kg/t); And adding lime 400kg, fluorite 50kg carries out final deoxygenation; Material adds back adjustment end stirring argon blowing rate to 200L/min (being 1.85L/ (mint)), and middle intensity stirs 4min, carries out HS subsequently and stirs; Argon bottom-blowing flow 800L/min (being 7.38L/ (mint)), treatment time 18min.After processing finishes, silicone content 0.20%, aluminium content 0.018%, oxygen level 10ppm.The slag staple is: CaO55%, SiO
22%, Al
2O
337%, MgO 5%, satisfies basicity of slag requirement and CaO and Al
2O
3Ratio is greater than 1.Processing finishes 1605 ℃ of back temperature.
4) vacuum breaker.
5) soft stirring 9min, argon bottom-blowing stirring intensity 200L/min (being 1.85L/ (mint)).Calcium is handled, and adds pure calcium silk 12.8kg (being 0.12kg/t) through wire feeder, feeds silk and finishes the soft stirring 10min in back, argon bottom-blowing stirring intensity 200L/min (being 1.85L/ (mint)).This steel grade need feed the titanium silk and carry out titanium alloyization, and pure titanium amount is 300kg (being 2.77kg/t) in the said titanium silk, terminal point titanium 0.2%.
6) continue soft stirring 25min, argon bottom-blowing stirring intensity 160L/min (being 1.48L/ (mint)).Continuous casting in the protective atmosphere, big water-coating port, middle water containing opening all have blowing argon.
The middle water containing opening opening degree is highly stable in the casting cycle, and violent fluctuation does not take place, and total fluctuation range shows that mouth of a river knot does not take place to be filled in, and the mouth of a river does not take place yet corrode in 3%.
Final molten steel is cast into base, and composition is following:
C:0.008%, Si:0.20%, Cr:20.8%, S:0.001%, N:0.006%, Mn:0.21%, P:0.015%, full O:0.0018%, Ti:0.15%, Al:0.019%, all the other are Fe and micro impurity element.
Wherein aluminium content slightly rises, and this is owing to feeding the reason that titanium further reduces molten steel oxygen gesture; And silicone content remains unchanged, and reason is SiO in the slag
2Content is extremely low, has avoided silicon deoxidation process in the further reducing slag of aluminium or titanium; Because the ferro-aluminum that adds contains a certain amount of carbon, cause carbon content before the processing to a certain degree rising to be arranged relatively, but still in hyperpure scope.
The relative old process of magnesium-aluminium spinel The amount of inclusions significantly reduces in the strand, and mainly to be size be mingled with and globular plasticity CaO-Al below the 10 μ m at the TiN below the 5 μ m or Ti (CN) inclusion
2O
3-SiO
2Be mingled with (part contain a small amount of MgO), the performance of steel especially surface property is not had harmful effect.
Embodiment 3
Present embodiment is to the requirement of refining unit VOD: equipment can be handled molten steel 120t, and final vacuum is less than 300Pa, and Argon air blowing ability always in bottom is higher than 60Nm3/h, and ladle lining is a magnesia-calcium brick.Steel grade is 444, molten steel amount 110000kg, i.e. and 110t, the initial composition of molten steel was before VOD smelted:
C:0.40%, Si:0.06%, Cr:18.8%, S:0.005%, N:0.012%, Mn:0.3%, P:0.010%, full O:0.02%, Ti:0.01%, Al:0.001%, all the other are Fe and micro impurity element.
1620 ℃ of molten steel initial temperatures.
Present embodiment silicone content target is less than 0.3%, aluminium content about 0.04%, and concrete steps are following:
1) molten steel is after oxygen decarburization and free carbonization treatment, and the oxygen depletion amount is 1440Nm
3, free decarburization time 20min, after processing finishes, 1700 ℃ of molten steel temperatures, composition is following:
C:0.006%, Si:0.20%, Cr:17.4%, S:0.005%, N:0.005%, Mn:0.14%, P:0.015%, full O:0.05%, Ti:0.01%, Al:0.001%, all the other are Fe and micro impurity element.
2) preliminary dexidation is 0.3% according to siliceous amount content requirement higher limit in the low silicon super-purity ferrite stainless steel of the high alumina that finally makes, and this requirement condition is complete down to add ferrosilicon, and does not add aluminium block; Add the ferrosilicon 900kg contain 77% silicon (be 8.12kg/t, conversion method: 900kg ÷ molten steel amount 110t, in embodiment 3 scopes; Except that the quality of delime and fluorite, conversion method is down together), do not add the aluminium block preliminary dexidation; And add lime 3.6t, and fluorite 200kg carries out slag making, and material adds the final vacuum pressure-controlling below 400Pa; Argon bottom-blowing stirring intensity 800L/min (be 7.27L/ (mint), conversion method: 800L/min ÷ molten steel amount 110t, in embodiment 3 scopes; Conversion method is down together), treatment time 10min guarantees that lime tentatively melts.Processing finishes back silicone content 0.1%, oxygen level 0.013%.
3) final deoxygenation adds the ferro-aluminum 750kg (being 6.82kg/t) that contains aluminium 47%, ferro-aluminum diameter 5cm, density 5.1g/cm
3, carbon containing 0.007% contains fine aluminium 350kg (being 3.18kg/t); And adding lime 700kg, fluorite 200kg carries out final deoxygenation; Material adds back adjustment end stirring argon blowing rate to 200L/min (being 1.82L/ (mint)), and middle intensity stirs 5min, carries out HS subsequently and stirs; Argon bottom-blowing flow 750L/min (being 6.82L/ (mint)), treatment time 18min.After processing finishes, silicone content 0.27%, aluminium content 0.035%, oxygen level 10ppm.The slag staple is: CaO65%, SiO
218%, Al
2O
310%, MgO5% satisfies basicity of slag requirement and CaO and Al
2O
3Ratio is greater than 1.Processing finishes 1642 ℃ of back temperature.
4) vacuum breaker.
5) soft stirring 10min, argon bottom-blowing stirring intensity 200L/min (being 1.82L/ (mint)).Calcium is handled, and adds pure calcium silk 25kg (being 0.23kg/t) through wire feeder, feeds silk and finishes the soft stirring 10min in back, argon bottom-blowing stirring intensity 180L/min (being 1.64L/ (mint)).This steel grade need not titanium alloyization, so need not to feed the titanium silk.
6) continue soft stirring 15min, argon bottom-blowing stirring intensity 180L/min (being 1.64L/ (mint)).Continuous casting in the protective atmosphere, big water-coating port, middle water containing opening all have blowing argon.
The middle water containing opening opening degree is highly stable in the casting cycle, and violent fluctuation does not take place, and total fluctuation range shows that mouth of a river knot does not take place to be filled in, and the mouth of a river does not take place yet corrode in 5%.
Final molten steel is cast into base, and composition is following:
C:0.01%, Si:0.29%, Cr:18.6%, S:0.001%, N:0.007%, Mn:0.21%, P:0.015%, full O:0.0017%, Ti:＜0.01%, Al:0.030%, all the other are Fe and micro impurity element.
And aluminium content slightly descends, and silicone content keeps slightly rising, and reason is SiO in the slag
2Content is higher, has caused silicon in the further reducing slag of aluminium, and deoxidation process causes carbon content before the processing to a certain degree rising to be arranged relatively because the ferro-aluminum that adds contains a certain amount of carbon, but still in hyperpure scope.
The relative old process of magnesium-aluminium spinel The amount of inclusions significantly reduces in the strand, and inclusion mainly is the globular plasticity CaO-Al of size below 10 μ m
2O
3-SiO
2Be mingled with (part contain a small amount of MgO), the performance of steel especially surface property is not had harmful effect.
The smelting process of the low silicon super-purity ferrite stainless steel of a kind of high alumina provided by the present invention; Can smelt silicone content less than 0.3%; The ultrapure clean ferritic stainless steel of low silicon high alumina of aluminium content 0.01～0.1%, the steel billet total oxygen content has improved the pickling performance of product less than 30ppm; Present method also can effectively suppress the formation of harmful inclusion magnesium-aluminium spinel, effectively removes Al
2O
3Inclusion, and in Ti-containing steel, suppressed the oxidation of titanium, avoided the middle water containing opening of casting process to stop up.
Claims (9)
1. the smelting process of the low silicon super-purity ferrite stainless steel of high alumina is characterized in that, comprises the steps:
(1), the ferritic stainless steel molten steel is carried out vacuum-oxygen decarbonizing and free carbonization treatment in the VOD stove; The ferritic stainless steel molten steel staple that obtains after the processing requires: chromium quality percentage composition 10～23%; Carbonaceous amount percentage composition is less than 0.01%, and nitrogen quality percentage composition is less than 0.01%;
(2), preliminary dexidation: in the ferritic stainless steel molten steel that after step (1) is handled, obtains, add ferrosilicon and/or aluminium block and carry out preliminary dexidation and handle, and add lime and fluorite carries out slag making, then under high vacuum strong mixing condition, treatment time 5～10min;
(3), final deoxygenation: in the ferritic stainless steel molten steel that after step (2) is handled, obtains; Add ferro-aluminum and carry out final deoxygenation and handle, the quality percentage composition of aluminium is 20～60% in the said ferro-aluminum, and adds lime and fluorite carries out slag making; Then under vacuum condition; Middle intensity stirs 2～5min, under high vacuum strong mixing condition, handles 12～18min then;
(4), vacuum breaker;
(5), under condition of normal pressure, with the soft stirring 8～10min of said ferritic stainless steel molten steel, then under condition of normal pressure, feed the calcium silk to said ferritic stainless steel molten steel, feed after the calcium silk finishes soft stirring 5～10min;
(6), continue soft stirring 15～30min, afterwards the ferritic stainless steel molten steel is carried out continuous casting in protective atmosphere, finally obtain the low silicon super-purity ferrite stainless steel of high alumina.
2. the smelting process of the low silicon super-purity ferrite stainless steel of a kind of high alumina according to claim 1; It is characterized in that; In the step (2); The total add-on of said ferrosilicon and/or aluminium block is 4～9kg/t, and the quality percentage composition of silicon is 70～80% in the said ferrosilicon, and it is the higher value in following two scopes that said lime adds the quality value: ferrosilicon adds 4～6 times or 2～3 times of aluminium block adding quality of quality; It is 0.05～0.3 times that lime adds quality that said fluorite adds quality, and after step (2) was handled, the mass content of silicon was less than 0.1%, greater than 0 in the said ferritic stainless steel molten steel, and the mass content that requires oxygen is greater than 0.01%.
3. the smelting process of the low silicon super-purity ferrite stainless steel of a kind of high alumina according to claim 1; It is characterized in that in the step (3), the add-on of fine aluminium is 2～6kg/t in the said ferro-aluminum; The add-on of said lime is 2～3 times of fine aluminium add-on in the ferro-aluminum; The fluorite add-on is 0.05～0.3 times that lime adds quality, and after step (3) was handled, the mass content of silicon was less than 0.3%, greater than 0 in the said ferritic stainless steel molten steel; The mass content of aluminium is 0.01～0.1%, and the mass content of oxygen is less than 0.003%.
4. the smelting process of the low silicon super-purity ferrite stainless steel of a kind of high alumina according to claim 1; It is characterized in that; In step (5), the said calcium silk of feeding is the pure calcium silk of feeding in the ferritic stainless steel molten steel, and said pure calcium silk feed quantity is 0.1～0.3kg/t; After step (5) was handled, the mass content of calcium was 15～30ppm in the said ferritic stainless steel molten steel.
5. the smelting process of the low silicon super-purity ferrite stainless steel of a kind of high alumina according to claim 1; It is characterized in that, in step (5), fed calcium silk and soft stirring after; Feeding titanium silk in the ferritic stainless steel molten steel, the pure titanium amount in the said titanium silk is 1～3kg/t.
6. the smelting process of the low silicon super-purity ferrite stainless steel of a kind of high alumina according to claim 1; It is characterized in that; In the low silicon super-purity ferrite stainless steel of final prepared high alumina, siliceous amount percentage composition is less than 0.3%, and aluminium quality percentage composition is 0.01～0.1%.
7. the smelting process of the low silicon super-purity ferrite stainless steel of a kind of high alumina according to claim 1 and 2 is characterized in that, in the step (2),
When the higher limit of siliceous amount content in the low silicon super-purity ferrite stainless steel of the high alumina that requires finally to make is 0.3%, all add ferrosilicon;
When the higher limit of siliceous amount content in the low silicon super-purity ferrite stainless steel of the high alumina that requires finally to make is lower than or equals 0.2%, all add aluminium block;
When the higher limit of siliceous amount content in the low silicon super-purity ferrite stainless steel of the high alumina that requires finally to make is between 0.2～0.3%; Add ferrosilicon and aluminium block, the additional proportion of said ferrosilicon and aluminium block=(higher limit-0.2% of siliceous amount content in the low silicon super-purity ferrite stainless steel of the high alumina that finally makes)/(higher limit of siliceous amount content in the low silicon super-purity ferrite stainless steel of the high alumina that 0.3%-finally makes).
8. according to the smelting process of claim 1 or the low silicon super-purity ferrite stainless steel of 3 described a kind of high aluminas, it is characterized in that in the step (3), said ferro-aluminum is shaped as block or spherical, density is 4.5～6.5g/cm
3, diameter 3～6cm; After step (3) is handled, CaO and SiO in the slag
2Mass ratio be higher than 2.8, CaO and Al in the slag
2O
3Mass ratio be higher than 1.
9. the smelting process of the low silicon super-purity ferrite stainless steel of a kind of high alumina according to claim 1 is characterized in that,
The condition of said high vacuum strong mixing is: vacuum pressure is controlled at below the 800Pa, and VOD furnace bottom argon blowing rate is controlled between 4～8L/ (mint);
The intensity stirring condition is in said: vacuum pressure is controlled at below the 2000Pa, and VOD furnace bottom argon blowing rate is controlled between 1～4L/ (mint);
Said soft stirring condition is: under condition of normal pressure, between VOD furnace bottom argon blowing rate control 1～5L/ (mint).
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201110327941 CN102329920B (en) | 2011-10-25 | 2011-10-25 | Method for smelting high-aluminum low-silicon ultra pure ferritic stainless steel |
| EP12843727.4A EP2772554B1 (en) | 2011-10-25 | 2012-01-06 | Method for smelting high-aluminum-low-silicon ultrapure ferritic stainless steel |
| JP2014537454A JP5833767B2 (en) | 2011-10-25 | 2012-01-06 | Smelting method of high aluminum low silicon ultra pure ferritic stainless steel |
| IN1547CHN2014 IN2014CN01547A (en) | 2011-10-25 | 2012-01-06 | |
| KR1020147003789A KR101787179B1 (en) | 2011-10-25 | 2012-01-06 | Method for smelting high-aluminum-low-silicon ultrapure ferritic stainless steel |
| PCT/CN2012/070096 WO2013060101A1 (en) | 2011-10-25 | 2012-01-06 | Method for smelting high-aluminum-low-silicon ultrapure ferritic stainless steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201110327941 CN102329920B (en) | 2011-10-25 | 2011-10-25 | Method for smelting high-aluminum low-silicon ultra pure ferritic stainless steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102329920A true CN102329920A (en) | 2012-01-25 |
| CN102329920B CN102329920B (en) | 2013-04-24 |
Family
ID=45481880
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201110327941 Active CN102329920B (en) | 2011-10-25 | 2011-10-25 | Method for smelting high-aluminum low-silicon ultra pure ferritic stainless steel |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP2772554B1 (en) |
| JP (1) | JP5833767B2 (en) |
| KR (1) | KR101787179B1 (en) |
| CN (1) | CN102329920B (en) |
| IN (1) | IN2014CN01547A (en) |
| WO (1) | WO2013060101A1 (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103225034A (en) * | 2013-04-25 | 2013-07-31 | 山西太钢不锈钢股份有限公司 | Method for improving yielding rate of ultra pure ferrite stainless steel titanium |
| CN103388052A (en) * | 2013-08-08 | 2013-11-13 | 山西太钢不锈钢股份有限公司 | Production method of deoxidizing low-silicon steel by adding silicon-containing alloy |
| CN103397141A (en) * | 2013-07-30 | 2013-11-20 | 山西太钢不锈钢股份有限公司 | Smelting method of high-aluminum stainless steel |
| CN104946855A (en) * | 2015-07-15 | 2015-09-30 | 武汉钢铁(集团)公司 | Vacuum treatment method for high-aluminum ultralow-carbon steel |
| CN105648148A (en) * | 2016-01-06 | 2016-06-08 | 山西太钢不锈钢股份有限公司 | Super-pure ferrite stainless steel deoxidation and inclusion control method |
| WO2019037544A1 (en) * | 2017-08-25 | 2019-02-28 | 宝山钢铁股份有限公司 | Smelting method for ultra-low carbon 13cr stainless steel |
| CN112063801A (en) * | 2020-09-17 | 2020-12-11 | 浦项(张家港)不锈钢股份有限公司 | Stainless steel and preparation method thereof |
| CN112475255A (en) * | 2020-11-18 | 2021-03-12 | 山西太钢不锈钢股份有限公司 | Continuous casting production method of high-aluminum ferrite stainless steel |
| CN113151637A (en) * | 2021-03-31 | 2021-07-23 | 北京科技大学 | Method for controlling pit defect of chromium-containing steel surface polishing inclusion |
| CN113737081A (en) * | 2021-08-31 | 2021-12-03 | 中国科学院上海应用物理研究所 | Stainless steel smelting method, stainless steel modification method and stainless steel |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107876211B (en) * | 2017-11-28 | 2023-08-29 | 嘉峪关天源新材料有限责任公司 | Composite magnetic focusing medium rod with high magnetic field strength and preparation method thereof |
| CN113560509B (en) * | 2021-07-27 | 2023-02-24 | 上海电气上重铸锻有限公司 | Method for manufacturing low-silicon boron-controlled steel large steel ingot |
| CN115287403A (en) * | 2022-08-15 | 2022-11-04 | 广东韶钢松山股份有限公司 | Low-carbon low-silicon cold heading steel deoxidation method |
| CN115369207A (en) * | 2022-09-06 | 2022-11-22 | 重庆钢铁股份有限公司 | Method for controlling nitrogen content of non-vacuum smelting plate blank |
| CN115522124B (en) * | 2022-09-20 | 2023-03-14 | 中天钢铁集团有限公司 | Method for improving continuous casting castability and sulfide form of medium-carbon S-containing Al-containing steel |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101058837A (en) * | 2007-05-30 | 2007-10-24 | 山西太钢不锈钢股份有限公司 | Smelting method for decarburization and denitrogenation of ultra-pure ferrite stainless steel |
| CN101768656A (en) * | 2008-12-31 | 2010-07-07 | 宝山钢铁股份有限公司 | Method for refining ultra-low carbon ferritic stainless steel under vacuum |
| CN102199684A (en) * | 2010-03-25 | 2011-09-28 | 宝山钢铁股份有限公司 | Production method of ultralow-oxygen titanium-containing ferrite stainless steel |
| CN102199688A (en) * | 2010-03-25 | 2011-09-28 | 宝山钢铁股份有限公司 | Method for efficiently refining ultra-pure ferritic stainless steel |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5763620A (en) * | 1980-09-01 | 1982-04-17 | Sumitomo Metal Ind Ltd | Denitriding and refining method for high chromium steel |
| JPH06128620A (en) * | 1992-10-19 | 1994-05-10 | Nippon Steel Corp | Method for adding ca |
| JPH09287016A (en) * | 1996-04-19 | 1997-11-04 | Nippon Steel Corp | Method for melting stainless steel |
| JPH101710A (en) * | 1996-06-13 | 1998-01-06 | Daido Steel Co Ltd | Manufacture of chromium-aluminum-(low n)-silicon steel |
| JPH1180826A (en) * | 1997-09-01 | 1999-03-26 | Nippon Steel Corp | Low silicon steel and production thereof |
| JPH11158537A (en) * | 1997-12-02 | 1999-06-15 | Sumitomo Metal Ind Ltd | Production of extra-low carbon steel excellent in cleanliness |
| JP3855553B2 (en) * | 1999-08-30 | 2006-12-13 | Ｊｆｅスチール株式会社 | Al concentration adjustment method for high Si content molten steel |
| JP3624804B2 (en) | 2000-07-14 | 2005-03-02 | 住友金属工業株式会社 | Method for producing ridging resistant ferritic stainless steel |
| JP2008274329A (en) * | 2007-04-26 | 2008-11-13 | Jfe Steel Kk | Low-carbon ferritic stainless steel with excellent ridging characteristic, and its manufacturing method |
| KR100922061B1 (en) * | 2007-12-12 | 2009-10-16 | 주식회사 포스코 | Method of manufacturing ultra low carbon ferritic stainless steel |
-
2011
- 2011-10-25 CN CN 201110327941 patent/CN102329920B/en active Active
-
2012
- 2012-01-06 EP EP12843727.4A patent/EP2772554B1/en active Active
- 2012-01-06 JP JP2014537454A patent/JP5833767B2/en active Active
- 2012-01-06 IN IN1547CHN2014 patent/IN2014CN01547A/en unknown
- 2012-01-06 KR KR1020147003789A patent/KR101787179B1/en active IP Right Grant
- 2012-01-06 WO PCT/CN2012/070096 patent/WO2013060101A1/en active Application Filing
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101058837A (en) * | 2007-05-30 | 2007-10-24 | 山西太钢不锈钢股份有限公司 | Smelting method for decarburization and denitrogenation of ultra-pure ferrite stainless steel |
| CN101768656A (en) * | 2008-12-31 | 2010-07-07 | 宝山钢铁股份有限公司 | Method for refining ultra-low carbon ferritic stainless steel under vacuum |
| CN102199684A (en) * | 2010-03-25 | 2011-09-28 | 宝山钢铁股份有限公司 | Production method of ultralow-oxygen titanium-containing ferrite stainless steel |
| CN102199688A (en) * | 2010-03-25 | 2011-09-28 | 宝山钢铁股份有限公司 | Method for efficiently refining ultra-pure ferritic stainless steel |
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103225034A (en) * | 2013-04-25 | 2013-07-31 | 山西太钢不锈钢股份有限公司 | Method for improving yielding rate of ultra pure ferrite stainless steel titanium |
| CN103225034B (en) * | 2013-04-25 | 2015-05-06 | 山西太钢不锈钢股份有限公司 | Method for improving yielding rate of ultra pure ferrite stainless steel titanium |
| CN103397141A (en) * | 2013-07-30 | 2013-11-20 | 山西太钢不锈钢股份有限公司 | Smelting method of high-aluminum stainless steel |
| CN103388052A (en) * | 2013-08-08 | 2013-11-13 | 山西太钢不锈钢股份有限公司 | Production method of deoxidizing low-silicon steel by adding silicon-containing alloy |
| CN104946855B (en) * | 2015-07-15 | 2017-03-08 | 武汉钢铁(集团)公司 | A kind of vacuum processing method of high alumina ultra-low-carbon steel |
| CN104946855A (en) * | 2015-07-15 | 2015-09-30 | 武汉钢铁(集团)公司 | Vacuum treatment method for high-aluminum ultralow-carbon steel |
| CN105648148A (en) * | 2016-01-06 | 2016-06-08 | 山西太钢不锈钢股份有限公司 | Super-pure ferrite stainless steel deoxidation and inclusion control method |
| WO2019037544A1 (en) * | 2017-08-25 | 2019-02-28 | 宝山钢铁股份有限公司 | Smelting method for ultra-low carbon 13cr stainless steel |
| CN112063801A (en) * | 2020-09-17 | 2020-12-11 | 浦项(张家港)不锈钢股份有限公司 | Stainless steel and preparation method thereof |
| CN112475255A (en) * | 2020-11-18 | 2021-03-12 | 山西太钢不锈钢股份有限公司 | Continuous casting production method of high-aluminum ferrite stainless steel |
| CN112475255B (en) * | 2020-11-18 | 2022-04-01 | 山西太钢不锈钢股份有限公司 | Continuous casting production method of high-aluminum ferrite stainless steel |
| CN113151637A (en) * | 2021-03-31 | 2021-07-23 | 北京科技大学 | Method for controlling pit defect of chromium-containing steel surface polishing inclusion |
| CN113737081A (en) * | 2021-08-31 | 2021-12-03 | 中国科学院上海应用物理研究所 | Stainless steel smelting method, stainless steel modification method and stainless steel |
Also Published As
| Publication number | Publication date |
|---|---|
| EP2772554B1 (en) | 2017-03-01 |
| EP2772554A4 (en) | 2015-11-11 |
| JP5833767B2 (en) | 2015-12-16 |
| JP2015501382A (en) | 2015-01-15 |
| KR101787179B1 (en) | 2017-11-15 |
| WO2013060101A1 (en) | 2013-05-02 |
| CN102329920B (en) | 2013-04-24 |
| KR20140092800A (en) | 2014-07-24 |
| EP2772554A1 (en) | 2014-09-03 |
| IN2014CN01547A (en) | 2015-05-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102329920B (en) | Method for smelting high-aluminum low-silicon ultra pure ferritic stainless steel | |
| CN101956040B (en) | Producing method of clean steel | |
| CN102199684B (en) | Production method of ultralow-oxygen titanium-containing ferrite stainless steel | |
| CN101457272B (en) | Two-step stainless steel smelting method | |
| CN102134628A (en) | Smelting method of low-carbon aluminium killed steel with low silicon content | |
| CN104212935B (en) | A kind of method with high titanium ferrochrome production high-quality GCr15 bearing steel | |
| CN103924157B (en) | A kind of smelting process of titaniferous ferritic stainless steel | |
| CN101768656B (en) | Method for refining ultra-low carbon ferritic stainless steel under vacuum | |
| CN101660021A (en) | Method for desulfurizing ultra-low carbon pure steel in circulating vacuum degassing method | |
| CN108486313B (en) | A kind of smelting technology promoting heat resisting steel intergranular degree of purity | |
| CN108396097A (en) | A kind of smelting process of low Ca, low Al welding wire steels | |
| CN114807730B (en) | Nickel-free copper-phosphorus weather-resistant steel casting blank | |
| CN110983161B (en) | Smelting method for realizing ultrahigh purity of bearing steel by controlling adding time of low-aluminum low-titanium ferrosilicon and combining with tundish electromagnetic stirring | |
| CN105525055A (en) | Method for controlling splashing in less slag smelting decarbonization period of converter | |
| CN107312906A (en) | A kind of smelting process of inexpensive ultrapure low titanium bearing steel | |
| CN108588541A (en) | A kind of low nitrogen boron-containing steel smelting process improving boron element recovery rate | |
| CN111349758B (en) | Method for improving castability of non-oriented silicon steel molten steel of CSP production line | |
| CN102787206B (en) | Smelting method for controlling nitrogen content in steel ingot of medium carbon chromous mold steel and steel ingot | |
| CN107164605A (en) | A kind of LF refining method of deoxidation for producing low-carbon welding wire steel | |
| CN115044820B (en) | Smelting method of ultralow-carbon ultralow-sulfur pure iron | |
| CN114350879B (en) | Smelting method of low-carbon ultralow-sulfur pure iron | |
| CN102277471B (en) | Manufacturing method of steel | |
| CN108118115B (en) | A kind of method of VD process smelting high carbon chromium bearing steel | |
| CN102234702B (en) | Method for controlling content of oxygen in steel | |
| CN108251598B (en) | Carbon increasing and nitrogen controlling production method of medium-carbon high-alloy 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 |