CN102965584B - High-nitrogen high-manganese stainless steel and smelting method thereof - Google Patents
High-nitrogen high-manganese stainless steel and smelting method thereof Download PDFInfo
- Publication number
- CN102965584B CN102965584B CN201210550153.4A CN201210550153A CN102965584B CN 102965584 B CN102965584 B CN 102965584B CN 201210550153 A CN201210550153 A CN 201210550153A CN 102965584 B CN102965584 B CN 102965584B
- Authority
- CN
- China
- Prior art keywords
- nitrogen
- manganese
- refining
- steel
- content
- 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.)
- Active
Links
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Abstract
The invention discloses a smelting method of stainless steel. The smelting method comprises the following steps: (1) an electric furnace smelting process: adding chromium-containing waste steel and manganese-containing waste steel into an electric furnace for smelting, and tapping after waste steel is molten completely in the electric furnace, wherein the content of manganese is controlled to be 3-6%, and the content of chromium is controlled to be 24-28%; (2) a nitrogen-oxygen decarbonization refining process: transferring molten steel into a refining station of a nitrogen-oxygen refining furnace for refining under the condition that nitrogen is introduced at the flow rate of 2000-2200Nm<3>/h in the whole refining course, decarbonizing at first, adding metal Mn after decarbonizing is completed, raising the temperature, then, reducing, slagging after reducing, adding manganese alloy after slagging under the condition that the flow rate of nitrogen is 900-1100Nm<3>/h at the moment, stirring, and then tapping molten steel into a die casting ladle; (3) a ladle refining process, wherein nitrogen-manganese alloy is added stepwise in a refining process, and then argon blowing treatment is carried out; and (4) a die casting process. The invention further provides stainless steel obtained by using the smelting method. The smelting method disclosed by the invention has the advantages of shortening smelting time, improving nitrogen adding efficiency, reducing nitrogen adding cost and improving the purity degree of the molten steel.
Description
Technical field
The present invention relates to the stainless smelting process of a kind of high-nitrogen high-manganese, also relate to the high-nitrogen high-manganese stainless steel that the method prepares.
Background technology
In stainless application, the high nitrogen magnetism-free stainless steel of low-carbon high-manganese is mainly used in petroleum industry manufacture and measures the high-strength materials such as the non-magnetic drill collar in oil well orientation, bridge cable, automobile support, high-strength bolt, wear resistance net, resilient material.Various demands constantly increase, and are also more and more higher to the requirement of its smelting process.
The following technique of the general employing of the smelting of the high nitrogen magnetism-free stainless steel of low-carbon high-manganese at present: electric furnace-ladle refining furnace (LF stove)-die casting, (LF the stove)-die casting of intermediate frequency furnace-ladle refining furnace or converter-vacuum-oxygen decarbonizing (VOD)-ladle refining furnace (LF stove)-die casting, and in this production technique, major control difficult point has control, the alloying of manganese and the control of nitrogen of carbon, need to add a large amount of nitrogenized manganeses or chromium nitride.Converter adopts the processing of dephosphorization molten steel decarburization, and VOD carries out dark decarburization, and LF is by adding expensive nitrogenized manganese to carry out the alloying of nitrogen, manganese, LF adds alloy amount large, need the reinforced and feeding temperature-raising continuing, tap to tap time is long, production efficiency is low, and smelting cost is higher.
Summary of the invention
The technical problem that the present invention solves is: overcome that in prior art, to smelt in Tenelon technique tap to tap time long, production efficiency is low, and the defect that smelting cost is higher has been developed a kind of smelting technology of the new violent high nitrogen stainless steel of height.
The present invention is achieved through the following technical solutions:
A kind of stainless smelting process, is characterized in that, the method comprises the steps:
(1) electrosmelting operation: will add electric furnace to smelt containing chromium steel scrap and containing manganese steel scrap, controlling manganese content be 3-6%, and chromium content is 24%-28%, and electric furnace clears out steel;
(2) nitrogen oxygen Decarburising and refining operation: the molten steel of step (1) is transferred to nitrogen oxygen refining furnace refining station and carries out refining, refining process whole process passes into nitrogen, the flow 2000-2200Nm of nitrogen
3/ h, first carries out decarburization, heats up after adding metal M n after decarburization finishes; Reduce afterwards, after reduction, carry out slag making; After slag making, add nitrogen manganese alloy, the flow that now passes into nitrogen is 900-1100Nm
3/ h, stirs, and afterwards molten steel is tapped in die casting bag;
(3) ladle refining operation: the ladle furnace refining station that the die casting ladle of step (2) is transferred to carries out refining, refining process substep adds nitrogen manganese alloy, carries out afterwards Argon processing, and refining treatment is complete; And
(4) die casting operation: the ladle that step (3) is disposed winches to die casting station and carries out cast steel.
Wherein, described step (2) is in smelting process, and oxygen nitrogen volume ratio is adjusted to 1:7 gradually from 7:1, and preferred nitrogen oxygen volume ratio passes through 3:2 successively from 7:1,1:2, and 1:3,1:5 adjusts to 1:7.
Wherein, in described step (1) containing chromium steel scrap be Cr13 steel scrap and/or high carbon ferro-chrome; Be 20Mn23Al steel scrap containing manganese steel scrap.
Wherein, in step (3), adding nitrogen manganese alloy is step by step nitrogenized manganese, and it is below 200kg that preferred every step adds the amount of nitrogenized manganese.
Wherein, in described step (2), the carbon content after decarburization is 0.015%-0.025%; In preferred described step (2), after reduction, C content is at 0.015-0.10%, and Mn content is more than 16.00%, more than N content reaches 4000ppm.
Wherein, add molybdenum-iron and ferrosilicon to be warmed up to 1670 DEG C-1730 DEG C after adding metal M n described in step (2).
Wherein, in step (3), add in the process of nitrogenized manganese, give electricity during lower than 1500 DEG C when temperature and heat up; After increasing the temperature to 1540-1560 DEG C after nitrogenized manganese adds, start Argon processing.
Wherein, in described step (2), while starting to pass into nitrogen, temperature is 1470-1520 DEG C.
Wherein, in step (3), Argon is adjusted to 1492-1498 DEG C of end refining by temperature after processing.
Wherein, step is carried out slag making described in (2), and the slag making materials adding is lime, fluorite, Al powder and/or CaSi powder; In preferred steps (2), molybdenum alloy is molybdenum-iron, and silicon alloy is ferrosilicon, adds ferrosilicon and fluorite when reduction; The nitrogen manganese alloy adding after slag making in preferred steps (2) is nitrogenized manganese; The manganese adding in preferred steps (2) is manganese metal or/or electrolytic manganese.
Wherein the process of the Argon processing of step (3) is: first carry out Argon 10-20 minute with flow 50-300L/min, carry out Argon 10-15 minute afterwards with flow 20-50L/min.
A kind of above-mentioned smelting process is smelted the stainless steel obtaining.
In described stainless steel, manganese content is more than 16%, and chromium content is more than 15%, and nitrogen content is more than 5000ppm.
In described stainless steel, carbon content is less than 0.04%, and phosphorus content is below 0.030%.
The decarbonization method using is in the present invention nitrogen oxygen carbon rejection processes, and therefore expression in this article " AOD(argon oxygen decarbonization) " should be understood to nitrogen oxygen decarbonization method.
Beneficial effect of the present invention is as follows:
1, shorten the heat:
By adopting smelting process of the present invention, make full use of that AOD decarbonization rate is fast, short feature of nitrogen pick-up time, the exclusive oxygen-nitrogen mixture of AOD make a large amount of Cr can be in electric furnace alloying, in AOD, directly add, reduce the reinforced burden of LF, in omnidistance technological process, electric furnace, AOD, LF are respectively 70,120,60 minutes cycle time, adopt traditional technology, and total time in cycle is more than 350 minutes;
2, improve nitrogen pick-up efficiency, reduce nitrogen pick-up cost:
Large flow nitrogen that AOD has, make gas nitrogen pick-up practical, smelting process is by nitrogen flushing nitrogen pick-up, and more than after AOD tapping, nitrogen content has reached 4500ppm, AOD ton steel nitrogen consumption is 120Nm
3/ t, nitrogen market price is 0.5 yuan/Nm
3, steel nitrogen pick-up cost per ton is only 60 yuan/t;
3, reach raw materials cost optimization by reasonable batching
Because AOD has nitrogen pick-up effect, nitrogenized manganese nitrogen pick-up is supplementary means, in steel, join Mn and there is looser condition, the present invention adopts electric furnace high mangaenese steel to join Mn to finish and reduction finishes manganese metal and joins Mn and reach more than 16.5% to 3-6%, AOD oxidation, before tapping, add the nitrogenized manganese of 2t-2.5t to join Mn with LF, what process use was more cheap contains manganese steel raw material, can reduce costs;
4, improve Molten Steel Cleanliness
Fully powerful deoxidation and the sweetening power of AOD, by once reducing and secondary slagging method again, AOD molten steel S content can reach below 0.002%, even lower, and the reinforced burden of LF is lighter, has more times to carry out refining, Argon stirs fully, slag system stability is strong, be conducive to the abundant floating of inclusion and molten steel cost and temperature evenly.
Embodiment
Stainless steel smelting method adopting process route of the present invention is electric furnace-AOD-LF-die casting.This smelting process has many-sided improvement on smelting Tenelon, first by optimizing electric furnace proportioning process, what employing was cheap contains manganese steel scrap Substitute For Partial manganese metal proportioning process, reduces raw materials cost, solves the oxidation affects of high manganese decarburization and manganese simultaneously; Second, by optimizing AOD blowing technology and alloying of manganese technique, adopt the control nitrogen mode of gas nitrogen pick-up and alloy nitrogen pick-up combination, form a set of normal pressure and smelt high manganese and high nitrogen smelting optimization method, solve and adopted the restriction to production efficiency under VOD-LF processing condition, the high nitrogen kind that realizes AOD smelt nitrogen content > 5000ppm under normal pressure.
Smelting process of the present invention is used nitrogen oxygen carbon rejection processes to smelt, and wherein in this stainless steel, manganese content is more than 17%, and chromium content is more than 15%, and nitrogen content is more than 5000ppm.That is to say, smelting process of the present invention is suitable for the stainless smelting of high-nitrogen high-manganese.
Smelting process of the present invention comprises the steps:
(1) electrosmelting operation: will add electric furnace to smelt containing chromium steel scrap and containing manganese steel scrap, controlling manganese content be 3-6%, and chromium content is 20-24.5%, and electric furnace clears out steel;
In this step, adopt the cheap expensive manganese metal of high manganese steel scrap Substitute For Partial, creatively technical solution problem, join by optimizing electric furnace the optimization batching that Mn amount reaches the optimum efficiency of AOD decarburization and prevents manganese oxidation, lower cost, it is 3-6% that the electric furnace of wherein optimizing is joined manganese, and preferably the control of manganese content is 4.5%.
(2) nitrogen oxygen refining furnace refining procedure: the molten steel of step (1) is transferred to nitrogen oxygen refining furnace refining station and smelts, omnidistance nitrogen flushing, the flow of nitrogen is 1800-2300Nm
3/ h decarburization, the carbon content after decarburization is 0.015%-0.025%; After finishing, decarburization adds metal M n, molybdenum-iron and ferrosilicon; Add afterwards ferrosilicon and fluorite once to reduce, once after reduction, carry out slag making; After slag making, add nitrogenized manganese, stir, pass into nitrogen, afterwards molten steel is tapped in die casting bag; Preferably, pass into nitrogen, nitrogen flow 900-1100Nm
3/ h; More preferably, in smelting process, adjust oxygen nitrogen ratio according to C content and temperature, oxygen nitrogen ratio is adjusted to 1:7 from 7:1; The slag making materials adding is lime, fluorite, Al powder and/or CaSi powder.
In this step, adjust oxygen nitrogen ratio according to C content and temperature, oxygen nitrogen ratio is adjusted to 1:7 from 7:1, specifically sees the following form 1, at least through following several ratios change finally reach carbon content is dropped to minimum.
The rule that table 1 is adjusted nitrogen oxygen ratio according to carbon content and temperature
Remarks: * carbon content refers to the content range of carbon while finishing this stage.
The mode of adjusting nitrogen oxygen ratio in upper table is specific as follows: under initial carbon content, in temperature is the scope of 1680-1720 DEG C, keeping nitrogen oxygen ratio is 7/1, in the time that carbon content reaches 1.0%-0.8% scope, if now temperature is measured to temperature within the scope of 1690-1740 DEG C, continuing to keep nitrogen oxygen ratio is 7/1 to carry out nitrogen flushing oxygen, until carbon content is while reaching 0.5%-0.6% scope, temperature is within the scope of 1700 DEG C-1730 DEG C time, nitrogen oxygen ratio is adjusted into 3/2 and carries out nitrogen flushing oxygen, until carbon content is while reaching 0.3%-0.35%, when temperature is 1700-1740 DEG C of scope, nitrogen oxygen ratio is adjusted into 1/2 and carries out nitrogen flushing oxygen, until carbon content is while reaching 0.12%-0.16%, when temperature is 1690-1730 DEG C of scope, nitrogen oxygen ratio is adjusted into 1/3 and carries out nitrogen flushing oxygen, until carbon content is while reaching 0.05%-0.08% scope, when temperature is 1700-1720 DEG C of scope, nitrogen oxygen ratio is adjusted into 1/5 and carries out nitrogen flushing oxygen, until carbon content is while reaching 0.03%-0.04% scope, when temperature is 1720-1740 DEG C of scope, nitrogen oxygen ratio is adjusted into 1/7 and carries out nitrogen flushing oxygen, until carbon content stops nitrogen flushing oxygen while reaching 0.011%-0.015% scope.
The omnidistance nitrogen blowing of AOD carbon rejection process, carbon rejection process does not add manganese alloy, is oxidized latter stage, adds electrolytic manganese or manganese metal to carry out Mn alloying; By adding ferrosilicon heating by O2 blowing, solve the oxidation of temperature-rise period manganese, reach reduction and require temperature to reduce; Reduction adopts lime, fluorite to make new slag after skimming, and uses aluminium powder residue adjustment, and product S≤0.003% is guaranteed in strengthening deoxidation; According to adjusting nitrogenized manganese and control nitrogen flushing stirring intensity and churning time before the tapping of reduction composition, the problem of solution is the recovery rate of nitrogen, and because nitrogenized manganese nitrogen content reaches 8.0%, excessively strong stirring will cause a large amount of nitrogen to overflow, and directly affects the recovery rate of nitrogen.Preferably adjust nitrogenized manganese add-on 1000kg left and right, nitrogen flushing churning time 1 minute, flow 900-1100Nm
3/ h.Above-mentioned once reduction and the secondary slagging method again of passing through, realizes S content≤0.002%, improves Molten Steel Cleanliness.
(3) ladle refining operation: the ladle furnace refining station that the die casting ladle of step (2) is transferred to carries out refining, refining process substep adds nitrogen manganese alloy, carries out afterwards Argon processing, afterwards temperature is adjusted to 1492-1498 DEG C, and refining treatment is complete; And
In this step, LF stove, according to molten steel composition, adds nitrogenized manganese to carry out the adjustment of manganese and nitrogen in batches, and the add-on control≤200kg of every batch of manganese prevents from once adding in a large number nitrogenized manganese melting process nitrogen to discharge and causes the excessive slag of ladle boiling.Nitrogenized manganese adjustment amount 1200-1500kg; After LF stove adjustment nitrogenized manganese, firmly blow (flow: 50-300L/min) >=10 points; Soft blow afterwards (flow 20-100L/min) >=10 points, soft blow is carried out die casting after handling well.
(4) die casting operation: the ladle that step (3) is disposed winches to die casting station and carries out cast steel.
It is a lot of as TSMF 166(TWZ-2 that smelting process of the present invention can be smelted steel grade), TQS-1,10Cr21Mn16NiN, is particularly applicable to the smelting of the stainless steel product of high manganese and high nitrogen.
One specifically preferred embodiment in, smelting process of the present invention is as follows:
Smelt steel grade: TSMF 166(TWZ-2), the feature of steel grade and purposes: TSMF 166 belongs to high strength austenitic nonmagnetic steel, is mainly used in petroleum industry manufacture and measures the parts such as non-magnetic drill collar in oil well orientation.
Composition will be asked for an interview to table 2:
Each constituent content of table 2TSMF166 steel grade
1, batching and electrosmelting
Carrying out in the smelting process of steel of the present invention, a kind of preferred embodiment in the food ingredient target of electric furnace be C 2.00%, Cr 21%, Mn 4.5%, adopt the material such as 20Mn23Al steel scrap, Cr13, high Cr, 90t electric furnace the first tank material dress Cr13 steel scrap 13.2t, 20Mn23Al steel scrap 29.85t, high carbon ferro-chrome 13.8t; The second tank high carbon ferro-chrome 9.35t, Cr13 steel scrap 12.2t, electric furnace clears out steel;
2, AOD smelts
2.1 point of two bag is blended in 45tAOD, the omnidistance nitrogen flushing of AOD;
2.2AOD opens blowing temp 1500, and smelting process does not stop to change oxygen nitrogen ratio according to C content and temperature, and omnidistance oxygen nitrogen changes to 1:7 than by 7:1 ladder, and terminal C content reaches 0.015%-0.025%, 1700 DEG C of temperature;
2.3 carbon rejection processs add lime, high carbon ferro-chrome etc., and lime overall control is in 5.5t, and carbon rejection process does not add manganese alloy;
2.4 decarburizations finish to add 6.5t metal M n and 400kg molybdenum-iron, and nitrogen gas stirring adds ferrosilicon heating by O2 blowing after 3 minutes, 1700 DEG C of intensification targets;
2.5 add ferrosilicon 2t, fluorite 700kg once reduces, reduction process nitrogen blowing 12 minutes;
2.6 once reduction finish blow off climb stove, sampling analysis composition: C0.015%, Si0.35%, Mn16.01%, Cr18.2%, S0.005%, N 4000ppm;
2.7 1 times reducing slag removes more than 90%, rejoins lime, fluorite, Al powder, CaSi powder and makes new slag, reaches the object of deep deoxidation and desulfurization;
2.8 add 1t nitrogenized manganese, stir flow 1000Nm 1 minute
3/ h;
2.9 tap to the large bag of die casting;
Sampling in bag after 2.10 tappings, composition (%) is in table 3.
Sampling analysis result in bag after table 3 tapping
| C(%) | Si(%) | Mn(%) | P(%) | S(%) | Cr(%) | Mo(%) | N(%) |
| 0.02 | 0.31 | 17.5 | 0.025 | 0.001 | 17.5 | 0.63 | 0.500 |
2.11 enter LF station, and starting temperature is that 1560, LF divides 5 batches to add nitrogenized manganese 1.0t, and every batch of add-on is 200kg, and reinforced process temperature heated up to electricity lower than 1500 o'clock;
After 2.12 nitrogenized manganeses add, temperature starts Argon processing in the time of 1540-1560 DEG C, 10 points of flow 300L/Min Argons, and 15 points of flow 50L/min Argons, temperature is adjusted to 1492-1498 DEG C and is disposed, and winches to die casting station cast steel.
2.13 product composition control results (%) are in table 4
Table 4 die casting product composition control result
Embodiment
Below the various alloys and the relative unit that in following embodiment, use are described:
20Mn23Al steel scrap: Mn:22%, Si:0.5%, C:0.2%, P:0.02%, surplus are iron and inevitable impurity;
Cr13 steel scrap: Cr12%Mn:0.5%C:0.1%Si:0.5%, P:0.02%, surplus is iron and inevitable impurity;
High carbon ferro-chrome: Cr 67%C 6.7%Si1.5%P 0.02%S 0.026%, surplus is iron and inevitable impurity;
Lime: CaO 90%SiO
22.1%P 0.012% S0.085% MgO 3.5%, surplus is inevitable impurity;
Manganese metal: C 0.01%Si 0.002%P 0.005%S 0.03%Mn 99.8% surplus is inevitable impurity;
Molybdenum-iron: Mo:60%, all the other are iron and inevitable impurity.
Ferrosilicon: Si:75.2%, all the other are iron and inevitable impurity.
Fluorite: CaF
285%SiO
212%P 0.032%S 0.12%, surplus is inevitable impurity;
Aluminium powder: Al:99.6%, all the other are iron and inevitable impurity.
Nitrogenized manganese: Mn:88.9%, N7.8%, all the other are iron and inevitable impurity.
Silicon calcium powder: Ca:28%, Si 55-60%, all the other are iron and inevitable impurity.
Embodiment 1
1. batching and electrosmelting
The Cr13 steel scrap of the 20Mn23Al steel scrap of 16t, 40t and the high carbon ferro-chrome of 20t are mixed, join in the electric furnace of 90t after mixing, electric furnace clears out steel; Measuring the now composition of steel is: C 1.86%, Si 0.76%, Cr 23.95%, Mn 4.89%, P 0.02%.Above-mentioned molten steel is poured in the AOD ladle of two 45t, prepared to carry out AOD smelting;
2, AOD smelts
(1) carbon rejection process: above-mentioned two ladles that molten steel is housed are all transferred to AOD station and smelt, omnidistance nitrogen flushing in AOD smelting process, nitrogen flow is 2100Nm
3/ h, the temperature that AOD starts nitrogen flushing is 1500 DEG C, carries out carbon rejection process, in carbon rejection process, in each ladle, constantly adds lime, high carbon ferro-chrome, and adding the total amount of lime is 5.5t, and the total amount that adds high carbon ferro-chrome is 1t; In smelting process, according to C content and temperature, according to adjust oxygen nitrogen ratio as the corresponded manner of following table 5, omnidistance oxygen nitrogen ratio is finally adjusted to 1:7 by 7:1.
In table 5 embodiment 1, carry out the adjustment process of nitrogen oxygen ratio according to amount and temperature
(2) alloying: add 7.9t metal M n and 400kg molybdenum-iron after decarburization finishes, stir 3-4 minute under nitrogen blowing condition, add afterwards the ferrosilicon heating by O2 blowing of 400kg, be warming up to 1700 DEG C;
(3) once reduction: add ferrosilicon 2t and fluorite 700kg once to reduce under the condition of nitrogen blowing, reduction process nitrogen blowing 12 minutes; Once reduction finishes rear blow off nitrogen and climbs stove, and sampling analysis composition result is: C 0.015%, Si 0.35%, Mn 16.01%, Cr 18.2%, S 0.005% and N 4000ppm;
(4) slag making again a: reducing slag is removed more than 90%, rejoin lime 500kg, fluorite 200kg, Al powder 20kg, CaSi powder 20kg make new slag, thereby reach the object of deep deoxidation and desulfurization;
(5) fine setting composition: add 1t nitrogenized manganese, stir nitrogen flow 900Nm 1 minute
3/ h; This molten steel is tapped in the large bag of die casting, carry out afterwards sampling analysis, result is as follows: C0.02%, Si0.31%, Mn17.00%, P 0.025%, S0.001%, Cr18.10%, Mo 0.63% and N 4600ppm;
3. ladle refining operation:
Large die casting bag transfer is entered to ladle furnace refining (LF) station and carry out refining, the beginning temperature of refining is 1560 DEG C, in LF process, divide and add nitrogenized manganese 1.2t 6 times, every batch of add-on is 200kg, adds in the process of nitrogenized manganese, gives electricity during lower than 1500 DEG C heat up when temperature; After nitrogenized manganese adds, increase the temperature to 1540 DEG C, now start Argon processing, first carry out Argon 20 minutes with flow 50L/min, carry out Argon 10 minutes with flow 20L/min afterwards, afterwards temperature is adjusted to 1492-1498 DEG C, be disposed;
4. die casting operation: ladle is winched to die casting station and carry out cast steel, adopt argon for protecting pouring, 1572 DEG C of teeming temperatures;
8.4t ingot shape, be the duration of pouring: the first dish: ingot body 14 minutes 30 seconds, cap mouth 8 minutes.
The second dish: ingot body 12 minutes, cap mouth 6 minutes.
Pouring the first dish gets melting chemical composition and is analyzed as follows.
Steel ingot is red to be sent, and is rolled into 250 × 250(mm) square billet.
The smelting component analytical results of the steel ingot that table 6 embodiment 1 smelts
Embodiment 2
1, batching and electrosmelting
The Cr13 steel scrap of the 20Mn23Al steel scrap of 16t, 28t and the high carbon ferro-chrome of 32t are mixed, join in the electric furnace of 90t after mixing, electric furnace clears out steel; Measuring the now composition of steel is: C 2.56%, Si 0.86%, Cr 25.95%, Mn 4.6%, P 0.02%.Above-mentioned molten steel is poured in the AOD ladle of two 45t, prepared to carry out AOD smelting.
2, AOD smelts
(1) carbon rejection process: above-mentioned two ladles that molten steel is housed are all transferred to AOD station and smelt, omnidistance nitrogen flushing in AOD smelting process, nitrogen flow is 2200Nm
3/ h, the temperature that AOD starts nitrogen flushing is 1470 DEG C, carries out carbon rejection process, in carbon rejection process, in each ladle, constantly adds lime, high carbon ferro-chrome, and adding the total amount of lime is 6.0t, and the total amount that adds high carbon ferro-chrome is 2t; In smelting process, enter to adjust oxygen nitrogen ratio according to C content and temperature according to the corresponded manner in following form, omnidistance oxygen nitrogen ratio is finally adjusted to 1:7 by 7:1.
In table 7 embodiment 2, carry out the adjustment process of nitrogen oxygen ratio according to amount and temperature
(2) alloying: add 6.8t metal M n after decarburization finishes, stir 3-4 minute under nitrogen blowing condition, add afterwards 300 ferrosilicon heating by O2 blowing, be warming up to 1670 DEG C;
(3) once reduction: add ferrosilicon 2.5t and fluorite 800kg once to reduce under the condition of nitrogen blowing, reduction process nitrogen blowing 13 minutes; Once reduction finishes rear blow off nitrogen and climbs stove, and sampling analysis composition result is: C0.085%, Si0.35%, Mn14.01%, Cr18.2%, S0.005% and N4200ppm;
(4) slag making again a: reducing slag is removed more than 90%, rejoin lime 500kg, fluorite 300kg, Al powder 25kg, CaSi powder 25kg make new slag, thereby reach the object of deep deoxidation and desulfurization;
(5) fine setting composition: add 1.4t nitrogenized manganese, stir nitrogen flow 1100Nm 1 minute
3/ h; This molten steel is tapped in the large bag of die casting, carry out afterwards sampling analysis, result is as follows: C0.088%, Si0.31%, Mn 15.5%, P 0.025%, S0.001%, Cr21.3%, Mo 0.63% and N 4600ppm;
3. ladle refining operation:
Large die casting bag transfer is entered to ladle furnace refining (LF) station and carry out refining, the beginning temperature of refining is 1560 DEG C, in LF process, divide and add nitrogenized manganese 900kg 6 times, every batch of add-on is 150kg, adds in the process of nitrogenized manganese, gives electricity during lower than 1500 DEG C heat up when temperature; After nitrogenized manganese adds, increase the temperature to 1560 DEG C, now start Argon processing, first carry out Argon 15 minutes with flow 200L/min, carry out Argon 13 minutes with flow 30L/min afterwards, afterwards temperature is adjusted within the scope of 1492-1498 DEG C, be disposed;
4. die casting operation (please supplement or confirm the step and method of die casting engineering): ladle is winched to die casting station and carry out cast steel, adopt argon for protecting pouring, 1572 DEG C of teeming temperatures;
8.4t ingot shape, be the duration of pouring: the first dish: ingot body 14 minutes 30 seconds, cap mouth 8 minutes.
The second dish: ingot body 12 minutes, cap mouth 6 minutes.
Pouring the first dish gets melting chemical composition and is analyzed as follows.
Steel ingot is red to be sent, and is rolled into 250 × 250(mm) square billet.
The smelting component analytical results of the steel ingot that table 8 embodiment 1 smelts
Embodiment 3
1. batching and electrosmelting
The Cr13 steel scrap of the 20Mn23Al steel scrap of 10t, 24t and the high carbon ferro-chrome of 42t are mixed, join in the electric furnace of 90t after mixing, electric furnace clears out steel; Measuring the now composition of steel is: C 2.20%, Si 0.82%, Cr 27.80%, Mn 3.17%, P 0.02%.Above-mentioned molten steel is poured in the AOD ladle of two 45t, prepared to carry out AOD smelting;
2, AOD smelts
(1) carbon rejection process: above-mentioned two ladles that molten steel is housed are all transferred to AOD station and smelt, omnidistance nitrogen flushing in AOD smelting process, nitrogen flow is 2000Nm
3/ h, the temperature that AOD starts nitrogen flushing is 1520 DEG C, carries out carbon rejection process, in carbon rejection process, in each ladle, constantly adds lime, high carbon ferro-chrome, and adding the total amount of lime is 5.5t, and the total amount that adds high carbon ferro-chrome is 1t; In smelting process, adjust oxygen nitrogen ratio according to C content and temperature according to the corresponded manner in following form, omnidistance oxygen nitrogen ratio is finally adjusted to 1:7 by 7:1.
In table 9 embodiment 3, carry out the adjustment process of nitrogen oxygen ratio according to amount and temperature
(2) alloying: add 8.9t metal M n and 500kg molybdenum-iron after decarburization finishes, stir 3-4 minute under nitrogen blowing condition, add afterwards the ferrosilicon heating by O2 blowing of 200-400kg, be warming up to 1730 DEG C;
(3) once reduction: add ferrosilicon 2t and fluorite 700kg once to reduce under the condition of nitrogen blowing, reduction process nitrogen blowing 12 minutes; Once reduction finishes rear blow off nitrogen and climbs stove, and sampling analysis composition result is: C 0.015%, Si 0.35%, Mn 16.4%, Cr18.2%, S 0.005% and N3640ppm;
(4) slag making again a: reducing slag is removed more than 90%, rejoin lime 600kg, fluorite 400kg, Al powder 30kg, CaSi powder 30kg make new slag, thereby reach the object of deep deoxidation and desulfurization;
(5) fine setting composition: add 1.2t nitrogenized manganese, stir nitrogen flow 1000Nm 1.5 minutes
3/ h; This molten steel is tapped in the large bag of die casting, carry out afterwards sampling analysis, result is as follows: C0.02%, Si0.31%, Mn17.00%, P 0.025%, S0.001%, Cr18.10%, Mo 0.63% and N4600ppm;
3. ladle refining operation:
Large die casting bag transfer is entered to ladle furnace refining (LF) station and carry out refining, the beginning temperature of refining is 1560 DEG C, in LF process, divide and add nitrogenized manganese 1080kg 6 times, every batch of add-on is 180kg, adds in the process of nitrogenized manganese, gives electricity during lower than 1500 DEG C heat up when temperature; After nitrogenized manganese adds, increase the temperature to 1550 DEG C, now start Argon processing, first carry out Argon 10 minutes with flow 300L/min, carry out Argon 15 minutes with flow 50L/min afterwards, afterwards temperature is adjusted within the scope of 1492-1498 DEG C, be disposed;
4. die casting operation: ladle is winched to die casting station and carry out cast steel, adopt argon for protecting pouring, 1572 DEG C of teeming temperatures;
8.4t ingot shape, be the duration of pouring: the first dish: ingot body 14 minutes 30 seconds, cap mouth 8 minutes.
The second dish: ingot body 12 minutes, cap mouth 6 minutes.
Pouring the first dish gets melting chemical composition and is analyzed as follows.
Steel ingot is red to be sent, and is rolled into 250 × 250(mm) square billet.
The smelting component analytical results of the steel ingot that table 10 embodiment 3 smelts
Data by above-described embodiment 1-3 can be found out, in stainless steel product prepared by embodiment 1-3, manganese content is all more than 16%, chromium content is more than 15%, nitrogen content is more than 5000ppm, particularly in embodiment 1 and 3, manganese content only reaches more than 18%, chromium content is more than 17%, and nitrogen content is more than 5400ppm, and particularly in embodiment, nitrogen content has reached 6400ppm.This shows, stainless steel product prepared by embodiment 1-3 meets the requirement of high nitrogen Gao Meng.
Claims (16)
1. a stainless smelting process, is characterized in that, the method comprises the steps:
(1) electrosmelting operation: will add electric furnace to smelt containing chromium steel scrap and containing manganese steel scrap, controlling manganese content be 3-6%, and chromium content is 24%-28%, and electric furnace clears out steel;
(2) nitrogen oxygen Decarburising and refining operation: the molten steel of step (1) is transferred to nitrogen oxygen refining furnace refining station and carries out refining, refining process whole process passes into nitrogen, the flow 2000-2200Nm of nitrogen
3/ h, first carries out decarburization, heats up after adding metal M n after decarburization finishes; Reduce afterwards, after reduction, carry out slag making; After slag making, add nitrogen manganese alloy, the flow that now passes into nitrogen is 900-1100Nm
3/ h, stirs, and afterwards molten steel is tapped in die casting bag;
(3) ladle refining operation: the die casting ladle of step (2) is transferred to ladle furnace refining station and carry out refining, refining process substep adds nitrogen manganese alloy, carries out afterwards Argon processing, and refining treatment is complete; And
(4) die casting operation: the ladle that step (3) is disposed winches to die casting station and carries out cast steel.
2. stainless smelting process as claimed in claim 1, wherein said step (2) is in smelting process, and oxygen nitrogen volume ratio is adjusted to 1:7 gradually from 7:1.
3. stainless smelting process as claimed in claim 2, wherein said step (2) is in smelting process, and nitrogen oxygen volume ratio passes through 3:2 successively from 7:1,1:2,1:3,1:5 adjusts to 1:7.
4. the stainless smelting process as described in claim 1-3 any one, in wherein said step (1) is Cr13 steel scrap and/or high carbon ferro-chrome containing chromium steel scrap; Be 20Mn23Al steel scrap containing manganese steel scrap.
5. the stainless smelting process as described in claim 1-4 any one, wherein in step (3), adding nitrogen manganese alloy is step by step nitrogenized manganese.
6. stainless smelting process as claimed in claim 5, wherein in step (3) every step to add the amount of nitrogenized manganese be below 200kg.
7. the stainless smelting process as described in claim 1-6 any one, the carbon content in wherein said step (2) after decarburization is 0.015%-0.025%.
8. stainless smelting process as claimed in claim 7, in wherein said step (2), after reduction, C content is at 0.015-0.10%, and Mn content is more than 16.00%, more than N content reaches 4000ppm.
9. the stainless smelting process as described in claim 1-8 any one, adds molybdenum-iron and ferrosilicon to be warmed up to 1670 DEG C-1730 DEG C after wherein adding metal M n described in step (2).
10. the stainless smelting process as described in claim 1-9 any one, wherein adds in the process of nitrogenized manganese in step (3), gives electricity during lower than 1500 DEG C heat up when temperature; After increasing the temperature to 1540-1560 DEG C after nitrogenized manganese adds, start Argon processing.
11. stainless smelting processes as described in claim 1-10 any one, in wherein said step (2), while starting to pass into nitrogen, temperature is 1470-1520 DEG C.
12. stainless smelting processes as described in claim 1-11 any one, wherein in step (3), Argon is adjusted to 1492-1498 DEG C by temperature after processing and finishes refining.
13. stainless smelting processes as described in claim 1-12 any one, wherein carry out slag making described in step (2), and the slag making materials adding is lime, fluorite, Al powder and/or CaSi powder.
14. stainless smelting processes as claimed in claim 13, in step (2), molybdenum alloy is molybdenum-iron, silicon alloy is ferrosilicon, adds ferrosilicon and fluorite when reduction.
15. stainless smelting processes as claimed in claim 14, the nitrogen manganese alloy adding after slag making in step (2) is nitrogenized manganese.
16. stainless smelting processes as described in claim 1-15 any one, wherein the process of the Argon processing of step (3) is: first carry out Argon 10-20 minute with flow 50-300L/min, carry out Argon 10-15 minute afterwards with flow 20-50L/min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210550153.4A CN102965584B (en) | 2012-12-17 | 2012-12-17 | High-nitrogen high-manganese stainless steel and smelting method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210550153.4A CN102965584B (en) | 2012-12-17 | 2012-12-17 | High-nitrogen high-manganese stainless steel and smelting method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102965584A CN102965584A (en) | 2013-03-13 |
| CN102965584B true CN102965584B (en) | 2014-11-05 |
Family
ID=47796018
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210550153.4A Active CN102965584B (en) | 2012-12-17 | 2012-12-17 | High-nitrogen high-manganese stainless steel and smelting method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102965584B (en) |
Families Citing this family (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103667594A (en) * | 2013-12-04 | 2014-03-26 | 蚌埠华泰特种钢有限公司 | Two-step stainless steel desulfurization method |
| CN105087865B (en) * | 2015-08-12 | 2017-03-22 | 上海应用技术学院 | Method for smelting high-manganese TWIP steel by adopting argon-oxygen decarburization furnace |
| CN106119460A (en) * | 2016-07-21 | 2016-11-16 | 柳州名品科技有限公司 | A kind of preparation method of foodstuff drying device feeding cylinder |
| WO2018107314A1 (en) * | 2016-12-12 | 2018-06-21 | 机械科学研究总院青岛分院有限公司 | Process for centrifugally casting high-nitrogen austenitic stainless steel pipe at normal pressure |
| JP6551626B2 (en) * | 2017-05-25 | 2019-07-31 | Ｊｆｅスチール株式会社 | Method of melting high manganese steel |
| CN107245637B (en) * | 2017-06-26 | 2019-04-12 | 永兴特种不锈钢股份有限公司 | A kind of AOD smelts the method and a kind of AOD furnace of high manganese stainless steel |
| CN107541585A (en) * | 2017-07-24 | 2018-01-05 | 山西太钢不锈钢股份有限公司 | The method of refining of stainless steel |
| CN109554515B (en) * | 2017-09-27 | 2020-09-01 | 鞍钢股份有限公司 | Method for smelting stainless steel by top-blown converter |
| CN107829010A (en) * | 2017-11-24 | 2018-03-23 | 苏州双金实业有限公司 | A kind of wear-resisting stainless steel of high manganese |
| CN110295329A (en) * | 2018-03-21 | 2019-10-01 | 吉林常春高氮合金研发中心有限公司 | The method of One-step production high-nitrogen austenitic stainless steel |
| CN109055667A (en) * | 2018-09-10 | 2018-12-21 | 河南鑫金汇不锈钢产业有限公司 | A kind of decarburization smelting process of high manganese stainless steel |
| CN109680124A (en) * | 2019-01-21 | 2019-04-26 | 浙江英洛华装备制造有限公司 | A method of improving engineering machinery wear resistance castings performance |
| CN109897938B (en) * | 2019-04-03 | 2020-11-17 | 西宁特殊钢股份有限公司 | Production of Cr13Electric furnace for series stainless steel and refining furnace smelting control method |
| EP3739076A1 (en) * | 2019-05-16 | 2020-11-18 | The Swatch Group Research and Development Ltd | Austenitic stainless steel nickel-free powder composition and part manufactured by sintering by means of said powder |
| CN110724792B (en) * | 2019-09-30 | 2021-08-24 | 河钢股份有限公司 | Smelting method for producing high manganese steel for low-temperature environment by using LF refining furnace |
| CN111763802B (en) * | 2020-07-06 | 2021-09-24 | 甘肃酒钢集团宏兴钢铁股份有限公司 | Method for smelting 20Mn23AlV non-magnetic steel by AOD converter |
| CN113293252A (en) * | 2021-04-29 | 2021-08-24 | 新余华峰特钢有限公司 | Novel method for smelting special steel by converter |
| CN113699428B (en) * | 2021-07-19 | 2022-07-01 | 北京科技大学 | Ti alloying process for reducing TP321 stainless steel seamless tube layering defect |
| CN115478222B (en) * | 2022-09-26 | 2023-08-18 | 河南中原特钢装备制造有限公司 | Nonmagnetic stainless steel with high purity and corrosion resistance and smelting method thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4090869A (en) * | 1976-04-07 | 1978-05-23 | Lucien Antoine | Process of manufacturing alloy steels in a continuously charged arc furnace |
| CN101235461A (en) * | 2007-09-03 | 2008-08-06 | 北京科技大学 | Method for smelting high-nitrogen steel under normal pressure |
| CN101671763A (en) * | 2009-10-13 | 2010-03-17 | 山西太钢不锈钢股份有限公司 | Method for increasing nitrogen for smelting high nitrogen stainless steel in argon oxygen decarburizing furnace |
-
2012
- 2012-12-17 CN CN201210550153.4A patent/CN102965584B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4090869A (en) * | 1976-04-07 | 1978-05-23 | Lucien Antoine | Process of manufacturing alloy steels in a continuously charged arc furnace |
| CN101235461A (en) * | 2007-09-03 | 2008-08-06 | 北京科技大学 | Method for smelting high-nitrogen steel under normal pressure |
| CN101671763A (en) * | 2009-10-13 | 2010-03-17 | 山西太钢不锈钢股份有限公司 | Method for increasing nitrogen for smelting high nitrogen stainless steel in argon oxygen decarburizing furnace |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102965584A (en) | 2013-03-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102965584B (en) | High-nitrogen high-manganese stainless steel and smelting method thereof | |
| CN108330245B (en) | High-purity smelting method for stainless steel | |
| CN102758144B (en) | Production method for steel ingot of large-sized high-nitrogen retaining ring steel | |
| CN102978505B (en) | Smelting method of high-strength IF steel | |
| CN105039648B (en) | Method for smelting low-carbon and high-manganese-content molten steel through argon oxygen decarburizing furnace | |
| CN102787196B (en) | Method for smelting stainless steel by direct reduced iron | |
| CN105018669B (en) | A kind of production method of nuclear power ingot iron | |
| CN105063474B (en) | Electric furnace smelting method of steel for welding wire | |
| CN113774277B (en) | Ultra-low carbon and ultra-low manganese industrial pure iron and preparation method thereof | |
| CN103146875B (en) | Method for smelting high nitrogen steel under ordinary pressure | |
| CN107904510A (en) | Comprehensive high performance hot die steel of one kind and preparation method thereof | |
| CN104060045B (en) | A kind of vanadium-titanium-iron-water smelts the method for the low carbon IF steel of hypoxia | |
| CN104043797B (en) | The continuous cast method of a kind of super-low sulfur high chrome and the bloom of preparation thereof | |
| CN101381787B (en) | Smelting method of high-alloy steel | |
| CN110343949A (en) | HRB400E high-strength anti-seismic steel bar production method and steel containing niobium vanadium | |
| CN110628985A (en) | Method for smelting special steel by bottom-blowing electric arc furnace returning oxygen blowing method | |
| CN102108468A (en) | Steel for railway locomotive axles and manufacturing method thereof | |
| CN106521329A (en) | Production method for non-quenched and tempered free-cutting steel | |
| CN108330240A (en) | Method of the aluminium without calcification processing drops in continuous casting Q235 steel grades | |
| CN103667587B (en) | The smelting process of austenite steel for engine air valve | |
| CN102277532A (en) | Cold working mold steel Cr8 and production method thereof | |
| CN112877587A (en) | Method for smelting high-manganese TWIP steel by adopting electric arc furnace and ladle refining furnace | |
| CN109136467A (en) | Silicon killed steel makes the control method of boron content in acid slag refining process | |
| CN104946845A (en) | Method for producing high-carbon-chrome bearing steel from vanadium-titanium-containing molten iron | |
| CN104946844A (en) | Rail steel refining method |
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 | ||
| CP02 | Change in the address of a patent holder |
Address after: 030003, Shanxi, Taiyuan, pointed lawn area, lawn street, No. 2 Patentee after: Shanxi Taigang Stainless Steel Co.,Ltd. Address before: 030003 No. 2, sharp lawn, Taiyuan City, Shanxi Province Patentee before: Shanxi Taigang Stainless Steel Co.,Ltd. |
|
| CP02 | Change in the address of a patent holder |