CN104726646B - A kind of method of nitrogen content in control high-temperature alloy steel P 91 - Google Patents
A kind of method of nitrogen content in control high-temperature alloy steel P 91 Download PDFInfo
- Publication number
- CN104726646B CN104726646B CN201510159224.1A CN201510159224A CN104726646B CN 104726646 B CN104726646 B CN 104726646B CN 201510159224 A CN201510159224 A CN 201510159224A CN 104726646 B CN104726646 B CN 104726646B
- Authority
- CN
- China
- Prior art keywords
- nitrogen
- steel
- content
- blowing
- refining
- 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
Abstract
Disclose a kind of method for controlling nitrogen content in high-temperature alloy steel P 91 year of the invention, technological process is：Refining → LF stoves refining → VD stove evacuations → cast at the beginning of electric furnace or converter, the equal blowing argon gas during the refining of LF stoves with VD stove evacuations, only after VD stove evacuations terminate, the nitrogen content in steel is increased to nitrogen is blown into steel by ladle bottom air brick, the nitrogen content in steel is reached target content.Replaced by nitrogen blowing plus nitrided ferro-chromium mode nitrogen pick-up, but in ladle refining (LF) and the equal blowing argon gas of VD vacuums, the only nitrogen blowing nitrogen pick-up again after VD vacuumizes end (breaking sky), can not only stability contorting nitrogen in steel content, precise control chromium content, and be prevented from VD vacuums, steel and the serious problem of slag splash, while operation is simple.
Description
Technical field
During the present invention relates to the smelting process of nitrogenous steel, more particularly to a kind of smelting production P91 steel, in control steel
The method of nitrogen content.
Background technology
High-temperature alloy steel P 91 is a kind of steel grade in standard ASTM A335, and the T91 steel with standard ASME SA335 is identical.
Leaded wastewater is required in the chemical composition of P91 steel for 300~700ppm, wherein, ppm is solute concentration unit, represents that part per million is dense
Degree.
The general production procedure of P91 steel is:Refining → LF stoves refining → VD vacuum refinings → cast (continuous casting at the beginning of electric furnace or converter
Or be molded into).
The final control of nitrogen in steel content is completed before cast after vacuum refining, the one of the control nitrogen content of early stage
As technique be:After molten steel is through vacuum refining, to liquid steel sampling, nitrogen in steel content is analyzed, according to existing nitrogen content in steel, pressed
Certain recovery rate is calculated, and is added the nitrided ferro-chromium of respective numbers and is carried out nitrogen pick-up.Problem existing for this technique:1. because of nitrided ferro-chromium
It is higher by about one time than common ferrochrome price, cause smelting cost higher；2. because nitrided ferro-chromium be face after application of vacuum tapping before
Can add in steel, nonmetallic inclusionsin steel and [O], [H] gas content will be increased, so that molten steel is polluted, if taking nitrogen flushing
Gas nitrogen pick-up does not exist this problem then；3. nitrided ferro-chromium not only containing N but also contains Cr, increases N and necessarily increases Cr, it is difficult to while in precise control steel
The content of chromium and nitrogen.
Therefore, some have been proposed in the prior art by being blown into the method that nitrogen increases nitrogen in steel content, but passes through
Present inventor's long-term experiment and analysis, discovery are still present certain problem, for example:Prior art 1 is application number
" CN200610147658.0 ", the patent of invention of title " smelting process of high-temperature alloy steel P 91 ", the process of its control nitrogen in steel
It is:Nitrogen is blown into during ladle refining (i.e. LF), it is desirable to refining terminal nitrogen in steel content is reached 400~500ppm, then
Processed through VD stoves vacuum suction (i.e. VD), nitrogen blowing nitrogen pick-up again after the broken skies of VD.But by present inventor's long-term experiment
And analysis, find that certain problem is still present:1. LF blowing argon gas switch with nitrogen blowing, and troublesome poeration will extend refining time；
2. again through application of vacuum after making nitrogen in steel content reach 400~500ppm through LF refining nitrogen blowing, it is this under the conditions of application of vacuum
During, steel is very violent with slag splash, easily causes potential safety hazard；Although 3. nitrogen content basically reaches target and contains after LF refining
Amount, but after application of vacuum, (general clearance is 20~50%, because receiving vacuum bar for the removal that nitrogen in steel content has by a relatively large margin
Part changes and initial N contents change and fluctuate very greatly), nitrogen content is higher before application of vacuum, and vacuum removal nitrogen content is more, makes
During LF refining nitrogen blowing increase the effect of nitrogen content and have a greatly reduced quality, therefore, LF refining nitrogen flushing increases the effect of nitrogen content
It is relatively low, or even the effect for not reaching nitrogen pick-up.
Prior art 2 be application number " CN201010594778.1, title " smelting process of high temperature high voltage resistant steel alloy "
Patent of invention, its control nitrogen in steel content process be:Nitrogen is blown into during ladle refining (i.e. LF), was vacuumized in VD
Also it is blown into nitrogen in journey, nitrogen blowing nitrogen pick-up content again after the broken skies of VD, but by present inventor's long-term experiment and analysis, hair
Certain problem is now still present:1. LF nitrogen flushing gas agitating, because the nitrogen major part being blown into can be dissolved in steel, therefore nitrogen flushing
The mixing power of gas is very weak so that uniform molten steel composition and the time lengthening of temperature, causes refining time very long；2. because through LF refining
Nitrogen in steel content is very high after nitrogen blowing, and in VD vacuums nitrogen blowing (rather than argon gas) so that steel more aggravates with slag splash
It is strong, it is easier to cause potential safety hazard；3. because being that under vacuum, its nitrogen pick-up effect is unsatisfactory, therefore, LF refining is taken out with VD
Vacuum process nitrogen flushing seems and there is no need.
The content of the invention
In order to solve problems of the prior art, the technical problems to be solved by the invention are to provide one kind can not only
Enough precise control nitrogen in steel contents, and potential safety hazard can be reduced, preventing in VD vacuums, steel is serious with slag splash
The method of nitrogen content in control high-temperature alloy steel P 91.
The present invention solves the method for nitrogen content in a kind of control high-temperature alloy steel P 91 that its technical problem is used, technique
Flow is：Refining → LF stoves refining → VD stove evacuations → cast at the beginning of electric furnace or converter, in the refining of LF stoves and VD stove evacuation processes
In equal blowing argon gas, only after VD stove evacuations terminate, in increasing steel to nitrogen is blown into steel by ladle bottom air brick
Nitrogen content, makes the nitrogen content in steel reach target content.
Further, following steps are specifically included：
Refined at the beginning of A, electric furnace or converter；
B, LF stove are refined:Whole Argon gas agitating, adds common ferrochrome by Cr composition adjustments to target content, together
When, other various compositions in steel in addition to N content are adjusted to target content, VD stoves are sent in tapping after temperature meets technological requirement
Vacuumize；
C, VD stove evacuation:In VD vacuums, only Argon gas agitating to reach and keep regulation under the high vacuum of regulation
Time after breaking vacuum；
After D, breaking vacuum, sampling analysis nitrogen in steel content, with will blowing argon gas be changed to nitrogen blowing, flow is controlled 6
~8Nl/min/t steel；When nitrogen in steel content is 50~100ppm, then nitrogen flushing time control is in 20~25min；When nitrogen in steel content
It is 100~150ppm, then nitrogen flushing time control is in 15~20min；
After E, nitrogen blowing terminate, change Argon 2~3min of gas agitating, then sampling analysis nitrogen in steel content, if nitrogen in steel contains
Amount is less than target content, then re-blow nitrogen according to flow 6~8Nl/min/t steel, the nitrogen pick-up speed according to step D, it is determined that needing
Re-blow time of nitrogen, after nitrogen blowing terminates, change Argon 2~3min of gas agitating, then sampling analysis nitrogen in steel content；
F, after nitrogen in steel content reaches target content, change blowing argon gas to adjust liquid steel temperature, when meet regulation molten steel
After temperature requirement, cast is sent in tapping.
The beneficial effects of the invention are as follows:
(1) nitrogen blowing nitrogen pick-up is used, than nitrided ferro-chromium mode nitrogen pick-up is added, is this have the advantage that:
1. the cost of production alloy can be significantly reduced instead of nitrided ferro-chromium using common ferrochrome:Produced with certain steel mill
As a example by high-temperature alloy steel P 91, using adding nitrided ferro-chromium mode to increase N, nitrided ferro-chromium about 7kg/t, nitrided ferro-chromium unit price need to be added
By 23000 yuan/ton of calculating, cost is 23000*7/1000=161 units/t steel；N is increased using nitrogen flushing mode, it is common with about 7kg/t
Ferrochrome can meet the content requirement of corresponding Cr, and common ferrochrome is univalent 12000 yuan/ton, and cost is 12000*7/
1000=84 units/t steel；Therefore, nitrogen pick-up is cost-saved compared to nitrided ferro-chromium mode nitrogen pick-up is added by the way of nitrogen is blown into
161-84=77 units/t steel.
2. due to being the common ferrochrome control chromium content of addition, controlling nitrogen content by nitrogen blowing, the two does not interfere with each other,
Therefore the precise control to chromium, nitrogen in steel can be realized；Take plus nitrided ferro-chromium mode to increase N be to face tapping after the broken skies of VD
Before carry out, nonmetallic inclusionsin steel and [O], [H] gas content will be increased, pollute molten steel, and do not take nitrogen blowing nitrogen pick-up then not
There are problems that this, make steel purer.
(2) compared with contrast patent document " smelting process of CN200610147658.0- high-temperature alloy steel P 91s ", it is not
It is with putting:Require to be blown into nitrogen during ladle refining (i.e. LF) in the document, make refining terminal nitrogen in steel reach 400~
500ppm, and the present invention only blowing argon gas during liquid steel refining, not nitrogen blowing, to refining terminal nitrogen no requirement (NR).The present invention with
The advantage compared be：1. LF refining process nitrogen blowing is omitted, LF operations are greatly simplified, the LF refining time is saved；2. the document
Methods described nitrogen in steel is reached 400~500ppm through LF refining nitrogen blowing after again through application of vacuum, it is this under the conditions of at vacuum
Steel is very violent with slag splash during reason, without nitrogen blowing before easily causing potential safety hazard, and the present invention because vacuumizing, in steel
Nitrogen content is not (general low 180ppm) high, while vacuum Argon gas agitating, it is therefore prevented that steel occurs in vacuum process
With slag vigorous splash.
(3) compared with contrast patent document " smelting process of CN201010594778.1- high temperature high voltage resistant steel alloys ", its
Difference is:Require to be blown into nitrogen during ladle refining (i.e. LF) in the document, while being blown in VD vacuums
Enter nitrogen, and the present invention only blowing argon gas in liquid steel refining process and VD vacuums, not nitrogen blowing.The present invention is by comparison
Advantage be：1. LF refining process and VD vacuum nitrogen blowings are omitted, operation is greatly simplified, the LF refining time is saved, and
Avoid causing the uneven problem of contents temperature because nitrogen blowing mixing power is weak in LF refining process；2. document methods described is blown through LF
Nitrogen in steel content is very high after nitrogen and in VD vacuums nitrogen blowing (rather than argon gas) such that steel more aggravates with slag splash
It is strong, it is easier to not high (generally below without nitrogen blowing, nitrogen in steel content before causing potential safety hazard, and the present invention because vacuumizing
180ppm), while vacuum Argon gas agitating, it is therefore prevented that steel and slag vigorous splash occur in vacuum.
Specific embodiment
With reference to embodiment, the present invention is further described.
A kind of method for controlling nitrogen content in high-temperature alloy steel P 91 of the invention, technological process is：Refined at the beginning of electric furnace or converter
→ LF stoves refining → VD stove evacuations → cast, equal blowing argon gas, only take out in VD stoves during the refining of LF stoves with VD stove evacuations
After vacuum terminates, the nitrogen content in steel is increased to nitrogen is blown into steel by ladle bottom air brick, make the nitrogen content in steel
Reach target content.When smelting P91 steel, each manufacturer has the target content of regulation, the mesh to each composition in steel
Mark content is in the range of standard ASTM A335 regulations.
Difference compared with prior art 1 and prior art 2：Ladle is in the refining of LF stoves and the VD equal Argons of stove evacuation process
Gas, the only just nitrogen blowing nitrogen pick-up after VD stove evacuations terminate (break sky)；Have the advantage that：Can not only stability contorting steel
Middle nitrogen content, precise control chromium content, and be prevented from VD vacuums, steel and the serious problem of slag splash, while
Operation is simple.
Further, as a kind of implementation method, following steps are specifically included：
Refined at the beginning of A, electric furnace or converter；Using the conventional method of prior art；
B, LF stove are refined:Whole Argon gas agitating, adds common ferrochrome by Cr composition adjustments to target content, together
When, other various compositions in steel in addition to N content are adjusted to target content, VD stoves are sent in tapping after temperature meets technological requirement
Vacuumize；, it is necessary to each composition is adjusted into corresponding target content in smelting process；The whole process Argon gas mixing of LF refining process
Mix, rather than nitrogen flushing gas agitating, greatly save the LF refining time；
C, VD stove evacuation:In VD vacuums, only Argon gas agitating to reach and keep regulation under the high vacuum of regulation
Time after breaking vacuum, generally, the breaking vacuum after 12~18 minutes below 67Pa retention times；Due to LF refining
Process and VD stove evacuations process are Argon gas agitatings, and nitrogen in steel content is low, therefore in VD vacuums, is prevented from steel
The problem serious with slag splash, reduces potential safety hazard；
After D, breaking vacuum, sampling analysis nitrogen in steel content, with will blowing argon gas be changed to nitrogen blowing, flow is controlled 6
~8Nl/min/t steel；When nitrogen in steel content is 50~100ppm, then nitrogen flushing time control is in 20~25min；When nitrogen in steel content
It is 100~150ppm, then nitrogen flushing time control is in 15~20min；
After E, nitrogen blowing terminate, change Argon 2~3min of gas agitating, then sampling analysis nitrogen in steel content, under normal circumstances,
Now nitrogen in steel content can reach 350~550ppm, if nitrogen in steel content is less than target content, according to 6~8Nl/ of flow
Min/t steel is re-blow nitrogen, the nitrogen pick-up speed according to step D, it is determined that needs are re-blow
The time of nitrogen, the time of typically re-blowing just can reach target content no more than 5min, after nitrogen blowing terminates, change Argon
2~3min of gas agitating, then sampling analysis nitrogen in steel content；Nitrogen content of the nitrogen pick-up speed of step D in steel after broken sky, blow
The nitrogen content that nitrogen time, nitrogen flushing terminate in rear steel is calculated；
F, after nitrogen in steel content reaches target content, change blowing argon gas to adjust liquid steel temperature, when meet regulation molten steel
After temperature requirement, cast is sent in tapping.Cast can be continuous casting or be molded into that routinely technological requirement is performed.
In the following examples：[N] refers to nitrogen content.
Embodiment 1
Certain company, P91 steel is produced using EAF steelmaking plant, and target nitrogen content is 350~550ppm, and technological process is:70t
Refining → LF stoves refining → VD vacuum refinings at the beginning of electric furnace ultra high electric arc furnace → pour continuous casting.Production process:
Refined at the beginning of electric furnace：Smelted by smelting process requirement dispensing, terminal C is 0.020%, terminal P is 0.002%, whole
1620 DEG C of temperature of point, tapping adds dispensing Al blocks, SiAlBaCa, low-carbon (LC) FeMn, 61.2 tons of tap；
LF refining：Whole blowing argon gas, using low-carbon ferrochromium by Cr composition adjustments in place, while by C, Mo, Nb, Ni, Mn, Si
It is adjusted in place Deng element, the percentage by weight of LF terminal chemical compositions is (%)：C:0.100、Si:0.46、Mn:0.52、P:
0.008、S:0.003、V:0.224、Ni:0.15、Cr:8.64、Mo:0.96、Nb:0.086、Al:0.019th, balance of Fe, LF ends
1697 DEG C of temperature of point, terminal [N] is 110ppm.
VD treatment：Bull ladle enters tank, opens blowing argon gas, and liquid level is in wriggling state, and 1690 DEG C of thermometric closes cover and vacuumizes, reaches
To after 67Pa, Argon throughput is stepped up, sky is broken in retention time 16 minutes under 67Pa；1633 DEG C of thermometric, take composition sample and
Gas sample, the percentage by weight of composition is (%)：C:0.104、Si:0.45、Mn:0.52、P:0.008、S:0.003、V:
0.221、Ni:0.15、Cr:8.66、Mo:0.97、Nb:0.088、Al:0.016th, balance of Fe, now [N] content is in steel
82ppm.Stop blowing argon gas, change nitrogen blowing, flow 490Nl/min (about 6.8Nl/min/t steel), after 21 minutes nitrogen blowing time,
Stop nitrogen flushing, change blowing argon gas 3 minutes, take the analysis of gas sample, [N] reaches 400ppm, meet target call.1595 DEG C of thermometric, adjusts
Whole Argon throughput is quiet to blow, and it is in wriggling state to keep liquid level, and quiet blowing argon gas 16 minutes, 1573 DEG C of thermometric, tapping is hung toward continuous casting.
Embodiment 2
Certain company, P91 steel is produced using EAF steelmaking plant, and target nitrogen content is 350~550ppm, and technological process is:70t
Refining → LF stoves refining → VD vacuum refinings at the beginning of electric furnace ultra high electric arc furnace → pour continuous casting.Production process:
Refined at the beginning of electric furnace：Smelted by smelting process requirement dispensing, terminal C is 0.023%, terminal P is 0.002%, whole
1632 DEG C of temperature of point, tapping adds dispensing Al blocks, SiAlBaCa, low-carbon (LC) FeMn, 61.5 tons of tap；
LF refining：Whole blowing argon gas, using low-carbon ferrochromium by Cr composition adjustments in place, while by C, Mo, Nb, Ni, Mn, Si
Target content is adjusted to Deng element, the percentage by weight of LF terminal chemical compositions is (%)：C:0.097、Si:0.48、Mn:
0.53、P:0.009、S:0.002、V:0.218、Ni:0.14、Cr:8.67、Mo:0.94、Nb:0.087、Al:0.022nd, it is balance of
1700 DEG C of Fe, LF outlet temperature, terminal [N] is 145ppm.
VD treatment：Bull ladle enters tank, opens blowing argon gas, and liquid level is in wriggling state, and 1694 DEG C of thermometric closes cover and vacuumizes, reaches
To after 67Pa, Argon throughput is stepped up, sky is broken in retention time 17 minutes under 67Pa.1638 DEG C of thermometric, takes composition sample point
Analysis, the percentage by weight of composition is (%)：C:0.101、Si:0.46、Mn:0.53、P:0.009、S:0.002、V:0.220、Ni:
0.14、Cr:8.66、Mo:0.96、Nb:0.088、Al:0.018th, balance of Fe, [N] is 110ppm in steel.Stop blowing argon gas, change
Nitrogen blowing, flow 500Nl/min (about 6.9Nl/min/t steel) after 18 minutes nitrogen blowing time, stops nitrogen flushing, changes 3 points of blowing argon gas
Clock, takes the analysis of gas sample, and [N] is 345ppm.1612 DEG C of thermometric, the nitrogen 3 minutes of re-blowing, changes blowing argon gas 2 minutes, then takes gas sample point
Analysis, [N] is 385ppm, meets and requires.1588 DEG C of thermometric, Argon throughput is quiet blows for adjustment, and it is in wriggling state to keep liquid level, quiet to blow
Argon gas 14 minutes, 1569 DEG C of thermometric, tapping is hung toward continuous casting.
Embodiment 3
P91 steel is produced using EAF steelmaking plant, target nitrogen content is 350~550ppm, and technological process is:70t electric furnaces surpass
Refining → LF stoves refining → VD vacuum refinings at the beginning of high power electric arc furnace → pour continuous casting.Production process:
Refined at the beginning of electric furnace：Smelted by smelting process requirement dispensing, terminal C is 0.025%, terminal P is 0.003%, whole
1632 DEG C of temperature of point, tapping adds dispensing Al blocks, SiAlBaCa, low-carbon (LC) FeMn, 60.1 tons of tap；
LF refining：Whole blowing argon gas, using low-carbon ferrochromium by Cr composition adjustments in place, while by C, Mo, Nb, Ni, Mn, Si
Target content is adjusted to Deng element, the percentage by weight of LF terminal chemical compositions is (%)：C:0.098、Si:0.47、Mn:
0.55、P:0.009、S:0.003、V:0.208、Ni:0.14、Cr:8.63、Mo:0.94、Nb:0.089、Al:0.019th, it is balance of
1705 DEG C of Fe, LF outlet temperature, terminal [N] is 77ppm.
VD treatment：Bull ladle enters tank, opens blowing argon gas, and liquid level is in wriggling state, and 1692 DEG C of thermometric closes cover and vacuumizes, reaches
To after 67Pa, Argon throughput is stepped up, sky is broken in retention time 16 minutes under 67Pa.1628 DEG C of thermometric, takes composition sample point
Analysis, the percentage by weight of composition is (%)：C:0.103、Si:0.46、Mn:0.55、P:0.009、S:0.002、V:0.210、Ni:
0.14、Cr:8.64、Mo:0.96、Nb:0.088、Al:0.013rd, balance of Fe, now [N] is 61ppm in steel.Stop Argon
Gas, changes nitrogen blowing, and flow 555Nl/min (about 7.8Nl/min/t steel) after 24 minutes nitrogen blowing time, stops nitrogen flushing, changes Argon
Gas 3 minutes, takes the analysis of gas sample, and [N] reaches 395ppm, meet and require.1590 DEG C of thermometric, Argon throughput is quiet blows for adjustment, protects
Liquid level is held in wriggling state, quiet blowing argon gas 15 minutes, 1572 DEG C of thermometric, tapping is hung toward continuous casting.
Embodiment 4
P91 steel is produced using EAF steelmaking plant, target nitrogen content is 350~550ppm, and technological process is:70t electric furnaces surpass
Refining → LF stoves refining → VD vacuum refinings at the beginning of high power electric arc furnace → pour continuous casting.Production process:
Refined at the beginning of electric furnace：Smelted by smelting process requirement dispensing, terminal C is 0.022%, terminal P is 0.003%, whole
1625 DEG C of temperature of point, tapping adds dispensing Al blocks, SiAlBaCa, low-carbon (LC) FeMn, 60.9 tons of tap；
LF refining：Whole blowing argon gas, using low-carbon ferrochromium by Cr composition adjustments in place, while by C, Mo, Nb, Ni, Mn, Si
It is adjusted in place Deng element, the percentage by weight (%) of LF terminal chemical compositions：C:0.101、Si:0.48、Mn:0.52、P:
0.008、S:0.003、V:0.214、Ni:0.15、Cr:8.65、Mo:0.97、Nb:0.087、Al:0.015th, balance of Fe, LF ends
1695 DEG C of temperature of point, terminal [N] is 175ppm.
VD treatment：Bull ladle enters tank, opens blowing argon gas, and liquid level is in wriggling state, and 1683 DEG C of thermometric closes cover and vacuumizes, reaches
To after 67Pa, Argon throughput is stepped up, sky is broken in retention time 15 minutes under 67Pa；1621 DEG C of thermometric, take composition sample and
Gas sample, the percentage by weight of composition is (%)：C:0.105、Si:0.47、Mn:0.53、P:0.009、S:0.003、V:
0.211、Ni:0.15、Cr:8.66、Mo:0.97、Nb:0.088、Al:0.011st, balance of Fe, [N] is 130ppm in steel.Stop
Blowing argon gas, change nitrogen blowing, and flow 510Nl/min (about 7.3Nl/min/t steel) after 16 minutes nitrogen blowing time, stops nitrogen flushing, changes
Blowing argon gas 3 minutes, take the analysis of gas sample, and [N] reaches 380ppm, meet and require.1592 DEG C of thermometric, adjustment Argon throughput is quiet
Blow, it is in wriggling state to keep liquid level, and quiet blowing argon gas 17 minutes, 1573 DEG C of thermometric, tapping is hung toward continuous casting.
Claims (1)
1. a kind of method for controlling nitrogen content in high-temperature alloy steel P 91, technological process is：Refining → LF stoves refining at the beginning of electric furnace or converter
→ VD stove evacuations → cast, it is characterised in that：Equal blowing argon gas, only take out in VD stoves during the refining of LF stoves with VD stove evacuations
After vacuum terminates, the nitrogen content in steel is increased to nitrogen is blown into steel by ladle bottom air brick, make the nitrogen content in steel
Target content is reached, following steps are specifically included：
Refined at the beginning of A, electric furnace or converter；
B, LF stove are refined:Whole Argon gas agitating, adds common ferrochrome by Cr composition adjustments to target content, meanwhile, will
Other various compositions in steel in addition to N content are adjusted to target content, go out after LF outlet temperatures reach 1695 DEG C~1705 DEG C
Steel send VD stove evacuations；
C, VD stove evacuation:In VD vacuums, only Argon gas agitating, kept under the high vacuum for reaching regulation regulation when
Between after breaking vacuum；
After D, breaking vacuum, sampling analysis nitrogen in steel content, with will blowing argon gas be changed to nitrogen blowing, flow control 6~
8Nl/min/t steel；When nitrogen in steel content is 50~100ppm, then nitrogen flushing time control is in 20~25min；When nitrogen in steel content is
100~150ppm, then nitrogen flushing time control is in 15~20min；
After E, nitrogen blowing terminate, change Argon 2~3min of gas agitating, then sampling analysis nitrogen in steel content, if nitrogen in steel content is low
In target content, then re-blow nitrogen, the nitrogen pick-up speed according to step D, it is determined that needs are re-blow according to flow 6~8Nl/min/t steel
The time of nitrogen, after nitrogen blowing terminates, change Argon 2~3min of gas agitating, then sampling analysis nitrogen in steel content；
F, after nitrogen in steel content reaches target content, change blowing argon gas to adjust liquid steel temperature, when meet regulation liquid steel temperature
It is required that after, cast is sent in tapping.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510159224.1A CN104726646B (en) | 2015-04-03 | 2015-04-03 | A kind of method of nitrogen content in control high-temperature alloy steel P 91 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510159224.1A CN104726646B (en) | 2015-04-03 | 2015-04-03 | A kind of method of nitrogen content in control high-temperature alloy steel P 91 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104726646A CN104726646A (en) | 2015-06-24 |
| CN104726646B true CN104726646B (en) | 2017-06-20 |
Family
ID=53451056
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510159224.1A Active CN104726646B (en) | 2015-04-03 | 2015-04-03 | A kind of method of nitrogen content in control high-temperature alloy steel P 91 |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104726646B (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106048139B (en) * | 2016-07-11 | 2019-10-22 | 宝钢特钢有限公司 | The nitrogen flushing alloyage process of 18CrNiMo7-6 steel |
| CN108998632A (en) * | 2018-09-04 | 2018-12-14 | 本钢板材股份有限公司 | A kind of increasing method for nitrogen of pinion steel 18CrMnBH |
| CN110438291B (en) * | 2019-07-30 | 2021-06-18 | 石家庄钢铁有限责任公司 | Nitrogen control method for carburized gear steel |
| CN111411198A (en) * | 2020-05-20 | 2020-07-14 | 建龙北满特殊钢有限责任公司 | Method for increasing nitrogen of nitrogen-containing steel for wind power flange by utilizing RH vacuum degassing system |
| CN112063912A (en) * | 2020-09-22 | 2020-12-11 | 攀钢集团攀枝花钢铁研究院有限公司 | Nitrogen alloying method of martensitic stainless steel for plastic mould |
| CN114032357A (en) * | 2021-10-19 | 2022-02-11 | 石家庄钢铁有限责任公司 | Smelting method for accurately controlling nitrogen content in steel |
| CN114457278A (en) * | 2022-02-16 | 2022-05-10 | 江苏联峰能源装备有限公司 | Oxygen content control method for continuous casting round billet casting furnace of supercritical steel |
| CN115558839B (en) * | 2022-09-22 | 2023-11-21 | 石钢京诚装备技术有限公司 | Production method of P91 steel ingot |
| CN115505681A (en) * | 2022-10-18 | 2022-12-23 | 山东莱钢永锋钢铁有限公司 | Control prediction method for nitrogen content in molten steel |
| CN115652025B (en) * | 2022-10-28 | 2024-04-16 | 南京钢铁股份有限公司 | Accurate nitrogen increasing method for nitrogen-containing non-quenched and tempered steel |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100535154C (en) * | 2006-12-21 | 2009-09-02 | 宝山钢铁股份有限公司 | Method for smelting high-temperature alloy steel P91 |
| CN102719610A (en) * | 2012-06-26 | 2012-10-10 | 山西太钢不锈钢股份有限公司 | Nitrogen increasing method for stainless steel |
| CN103627841B (en) * | 2013-11-01 | 2015-04-15 | 南京钢铁股份有限公司 | Control method for nitrogen content of molten steel of wear-resistant steel |
-
2015
- 2015-04-03 CN CN201510159224.1A patent/CN104726646B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN104726646A (en) | 2015-06-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104726646B (en) | A kind of method of nitrogen content in control high-temperature alloy steel P 91 | |
| CN106086593B (en) | It is a kind of to prevent the smelting molten steel technique of nozzle clogging in sulfur-bearing Aluminum steel casting process | |
| CN102071287B (en) | Method for melting high-temperature-resistance and high-pressure-resistance alloy steel | |
| CN100535154C (en) | Method for smelting high-temperature alloy steel P91 | |
| CN105463150B (en) | A kind of automobile hub bearing steel smelting technique | |
| CN103627841B (en) | Control method for nitrogen content of molten steel of wear-resistant steel | |
| CN1247799C (en) | Production method for reducing and fining the high-carbon chromium bearing steel D-type impurity | |
| CN111334642B (en) | Smelting and casting method of sulfur-containing and nitrogen-containing molten steel | |
| CN102248142B (en) | Method for producing medium and low carbon aluminum killed steel | |
| CN108330245A (en) | A kind of high-purity smelting process of stainless steel | |
| CN104962800B (en) | Smelting method for stainless steel material | |
| CN103741006B (en) | A kind of preparation method containing the low nitrogen stainless steel of Ti | |
| CN107287502A (en) | A kind of nitrogenous steel smelting process | |
| CN110093553B (en) | Production method for greatly increasing number of continuous casting furnaces of high-carbon chromium bearing steel | |
| CN107338342B (en) | Single-mouth refining furnace smelts high-cleanness art for refining bearing steel | |
| CN104278130A (en) | Process of quickly regulating alkalinity of LF (ladle furnace) slag | |
| CN103498066B (en) | A kind of containing Mg superalloy smelting process | |
| CN103045948B (en) | High-chromium steel and manufacturing method thereof | |
| CN110607413A (en) | Smelting method of low-cost high-nitrogen steel | |
| CN105483501A (en) | Method for smelting phosphorus-containing ultra-low carbon steel | |
| CN111663072B (en) | Anti-nodulation high-sulfur non-quenched and tempered steel smelting process | |
| CN115044820B (en) | Smelting method of ultralow-carbon ultralow-sulfur pure iron | |
| CN106191375A (en) | Seamless steel pipe titanium-containing austenitic stainless steel circular pipe blank continuous casting producing method | |
| CN114350879B (en) | Smelting method of low-carbon ultralow-sulfur pure iron | |
| CN103642967A (en) | Method for producing high-chromium steel by converter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |