CN102477474B - Sulfur feeding method for smelting molten steel in vacuum induction furnace - Google Patents
Sulfur feeding method for smelting molten steel in vacuum induction furnace Download PDFInfo
- Publication number
- CN102477474B CN102477474B CN 201010557767 CN201010557767A CN102477474B CN 102477474 B CN102477474 B CN 102477474B CN 201010557767 CN201010557767 CN 201010557767 CN 201010557767 A CN201010557767 A CN 201010557767A CN 102477474 B CN102477474 B CN 102477474B
- Authority
- CN
- China
- Prior art keywords
- steel
- induction furnace
- sulfur
- molten steel
- master alloy
- 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
- Manufacture And Refinement Of Metals (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
The invention relates to a sulfur feeding method for smelting molten steel in a vacuum induction furnace. The method comprises the following steps of: (I) melting pure iron in a medium-frequency induction furnace: feeding pure iron into the medium-frequency induction furnace, melting, tapping, and pouring the molten steel into a FeS-loaded ladle for tapping and casting; (II) processing a steel ingot: cutting an intermediate alloy steel ingot into pieces; (III) feeding the vacuum induction furnace: feeding pure iron and iron alloys into the crucible of the vacuum induction furnace, evacuating, and supplying power to heat the furnace materials; (IV) melting the furnace materials with a melting speed not more than 1/2 the furnace maximum capacity/hour; (V) refining: performing high-vacuum refining when all the materials in the crucible are melted to form molten steel and the pressure is not more than 2.0 Pa; (VI) filling gases: stopping evacuation and introducing argon gas into the furnace; (VII) alloying: adjusting other elements than sulfur element in the shielding atmosphere of argon gas; and (VIII) feeding sulfur-containing intermediate alloy: feeding intermediate alloy to the crucible for melting. The sulfur feeding method for smelting molten steel in the vacuum induction furnace increases the recovery rate of sulfur element.
Description
Technical field
The present invention relates to a kind of vulcanization method of vacuum induction furnace smelting molten steel.
Background technology
For the needs of producing, must add element sulphur in some steel grades, the vapour pressure of sulphur is higher, if add under vacuum state, volatilization in a large number, the element sulphur rate of recovery is lower and unstable.The vulcanization method of existing vacuum induction furnace smelting molten steel is directly FeS powder or small-particle to be added the molten bath before tapping, because FeS density is little, floats on the molten steel face, is difficult to enter molten steel, the rate of recovery＜60%.
Summary of the invention
In order to overcome the above-mentioned deficiency that increases the sulphur method of existing vacuum induction furnace smelting molten steel, what the invention provides the high vacuum induction furnace smelting molten steel of a kind of element sulphur rate of recovery increases the sulphur method.
Technical scheme of the present invention is to smelt the sulfur-bearing master alloy in medium-frequency induction furnace, after the use pure iron as raw material of making steel melts in medium-frequency induction furnace, when medium-frequency induction furnace is tapped, FeS is added in ladle, molten steel pours in ladle FeS is melted, and makes the master alloy of sulfur-bearing 0.3%; During the vacuum induction furnace smelting Sulphur Steel, after refining finishes, be filled with argon gas in stove, according to sulphur content requirement in finished product, the weight of the master alloy that calculating need to add adds in stove by hopper, taps after adding high-power fusing.In steel ingot, element sulphur is evenly distributed, and sulfur recovery rate is stable to be reached more than 95%.
The sulphur method that increases of this vacuum induction furnace smelting molten steel comprises following step successively:
I medium-frequency induction furnace fusing pure iron
To make steel and pack in medium-frequency induction furnace with pure iron as raw material, after fusing, tapping, put into ladle with the FeS powder, and molten steel pours in ladle after the FeS fusing, steel tapping casting.Make the master alloy steel ingot of sulfur-bearing 0.25%-0.35%.
II processes steel ingot
For the ease of fusing, the master alloy steel ingot is cut into the bloom that granularity is not more than 30mm, be generally 30 * 30 * 30mm
3Square.
The charging of III vacuum induction furnace
In the crucible of the dry steel-making of cleaning with pure iron as raw material and iron alloy (according to the steel grades corresponding iron alloy of selection such as ferrochrome, molybdenum-iron, the vanadium iron etc.) vacuum induction furnace of packing into, close bell and vacuumize 12-16 minute, when in stove, pressure is not more than 10Pa, power transmission heating furnace charge.
The IV melting batch
Burn-off rate≤1/2 stove maximum capacity/hour.
The V refining
The raw material in crucible (steel-making with the iron alloys such as pure iron as raw material and ferrochrome, molybdenum-iron, vanadium iron) of packing into all is fused into molten steel, when the pressure in stove is not more than 2.0Pa, change the high vacuum refining over to, refining vacuum tightness 0.4Pa-0.6Pa, be generally 0.5Pa, refining time 18-22 minute, general 20 minutes.
The VI inflation
Refining is closed vacuum pump after finishing, and stops vacuumizing, and be filled with argon gas in stove, and applying argon gas pressure is not less than 5 * 10
4Pa.
The VII alloying
Under the protective atmosphere of argon gas, adjust the composition of element sulphur other element in addition, make them meet the requirement of smelting steel grade.
VIII adds the master alloy of sulfur-bearing
Weight according to the sulphur content in the sulfur-bearing steel grade and molten steel, calculate the weight of the sulphur that sulphur will add, the per-cent of the sulphur contained according to the sulfur-bearing master alloy again, calculate the weight of the master alloy that will add, again according to this weight that calculates, the master alloy that is cut into piece is added fusing smelting in crucible by the material basket, and the weight percent of the composition in molten steel reaches the steel grade requirement.
After melting finishes, adopt the mode of charged cast, molten steel is poured in ingot mould.
The weight percent of the composition of the present invention's sulfur-bearing master alloy used is:
C 0.017％-0.023％；Mn 0.065％-0.075％；S 0.25％-0.35％；P≤0.013％；
All the other are Fe and inevitable impurity.
The sulfur-bearing master alloy is the composition that content has the sulphur of certainweight per-cent, and the content of other element can not work the mischief to the quality of smelting steel grade.
The present invention smelts the sulfur-bearing master alloy by medium-frequency induction furnace, as the sulfur-containing additive due to the vacuum induction furnace smelting Sulphur Steel, after being filled with argon gas latter stage, refining adds in crucible, avoided the volatilization of sulphur, overcome the little shortcoming that is not easy to enter molten steel of iron sulphide density, improved the rate of recovery of element sulphur, and element sulphur is evenly distributed in the finished product steel ingot, in steel, sulphur content is controlled accurately.When in stove, pressure is not more than 10Pa, power transmission heating again, be conducive to fully remove moisture in stove, avoids the element oxidational losses, and can remove the trace harmful elements of a part of gas and high vapour pressure.
Degas and normal fusing for furnace charge is given full play in melting process, splash does not occur, guarantee vacuum tightness in stove, the general control burn-off rate is not more than 1/2nd of stove maximum capacity.The high vacuum refining can be removed a part of gas, reduces oxygen level in steel, improves the element recovery rate.Sneak in beam for fear of temperature decline and oxide film during steel tapping casting, usually adopt charged cast.In order to reduce the moisture in crucible refractory material, the minimum stove of smelting of the crucible of high vacuum induction furnace, the purity of high vacuum induction furnace argon gas used is not less than 99%, and water content is not more than 0.1%.
Method of the present invention is applicable to smelt the steel grade of sulphur content 0.01%-0.05%, and method is simple and reliable.
Embodiment
Describe the specific embodiment of the present invention in detail below in conjunction with embodiment, but the specific embodiment of the present invention is not limited to following embodiment.
Embodiment one
Equipment adopts the 200kg high vacuum induction furnace: final vacuum is 6.67 * 10
-2Pa, power are 250KW, and frequency is 2500HZ, batch 139kg.
Steel grade: OCr17 standard specimen
The present invention smelts a stove OCr17 steel and need to make steel the control target (weight percent) that sees Table 1, OCr17 composition with pure iron as raw material, iron alloy and sulfur-bearing master alloy weight and see Table 2.
Table 1
| Raw material type | Pure iron as raw material | Electrolytic manganese | Chromium metal | The nickel beans | Master alloy | Special silicon |
| Add-on (kg) | 100 | 0.40 | 20.5 | 0.25 | 17.5 | 0.30 |
Table 2
| C％ | Si％ | Mn％ | Cr％ | Ni | P | S | |
| Control target | 0.020 | 0.25 | 0.36 | 16.8 | 0.20 | 0.01 | 0.040 |
The step of the present embodiment is as follows:
I medium-frequency induction furnace fusing pure iron
To make steel and pack in medium-frequency induction furnace with pure iron as raw material, after fusing, tapping, put into ladle with the FeS powder, and molten steel pours in ladle after the FeS fusing, steel tapping casting.Make the master alloy steel ingot of sulfur-bearing 0.3%.
II processes steel ingot
The master alloy steel ingot is cut into 30 * 30 * 30mm
3Square.
The charging of III vacuum induction furnace
The dry steel-making of cleaning is packed in the crucible of vacuum induction furnace with pure iron as raw material and chromium metal and nickel beans, close bell and vacuumize 13 minutes, when in stove during the little 6Pa of pressure, power transmission heats furnace charge.
The IV melting batch
Burn-off rate≤1/2 stove maximum capacity/hour.
The V refining
The interior steel-making of crucible of packing into all is fused into molten steel with pure iron as raw material and chromium metal, nickel beans, when the pressure in stove is not more than 2.0Pa, changes the high vacuum refining over to, refining vacuum tightness 0.4Pa, refining time 20 minutes.
The VI inflation
Refining is closed vacuum pump after finishing, and stops vacuumizing, and be filled with argon gas in stove, applying argon gas pressure 6 * 10
4Pa.
The VII alloying
Under the protective atmosphere of argon gas, add electrolytic manganese 0.4kg, special silicon 0.3kg makes them meet the requirement of smelting steel grade.
VIII adds the master alloy of sulfur-bearing
The master alloy that 17.5kg is cut into piece adds fusing smelting in crucible by the material basket, adds high-power melting 12 minutes, and the weight percent of the composition in molten steel reaches the requirement of table 3 and can tap.
After melting finishes, adopt the mode of charged cast, molten steel is poured in ingot mould, the composition of steel ingot (weight percent) sees Table 3.
Table 3
| C％ | Si％ | Mn％ | Cr％ | Ni％ | P％ | S％ |
| 0.02 | 0.24 | 0.35 | 16.8 | 0.22 | 0.010 | 0.039 |
The rate of recovery of the present embodiment sulphur is 97.5%.
The weight percent of the composition of the master alloy of the present embodiment is:
C 0.02％；Mn 0.070％；S 0.30％；P 0.010％；Fe 99.6％。
Embodiment two
Equipment adopts the 200kg high vacuum induction furnace: final vacuum is 6.67 * 10
-2Pa, power are 250KW, and frequency is 2500HZ, batch 101kg.
Steel grade: oriented silicon steel AMl
The present invention smelts a stove AMl steel and need to make steel the control target (weight percent) that sees Table 4, AMl composition with pure iron as raw material, iron alloy and sulfur-bearing master alloy weight and see Table 5.
Table 4
| Raw material type | Pure iron | Electrolytic manganese | Master alloy | Special silicon |
| Add-on (kg) | 90 | 0.02 | 7.0 | 3.94 |
Table 5
| C％ | Si％ | Mn％ | P％ | S％ | |
| Span of control | 0.03/0.08 | 3.0/3.2 | 0.04/0.09 | ≤0.010 | 0.022/0.028 |
| Control target | 0.05 | 3.1 | 0.06 | ≤0.010 | 0.026 |
The step of the present embodiment is as follows:
I medium-frequency induction furnace fusing pure iron
To make steel and pack in medium-frequency induction furnace with pure iron as raw material, after fusing, tapping, put into ladle with the FeS powder, and molten steel pours in ladle after the FeS fusing, steel tapping casting.Make the master alloy steel ingot of sulfur-bearing 0.35%.
II processes steel ingot
The master alloy steel ingot is cut into 30 * 30 * 30mm
3Square.
The charging of III vacuum induction furnace
The dry steel-making of cleaning is packed in the crucible of vacuum induction furnace with pure iron as raw material, close bell and vacuumize 15 minutes, when in stove during the little 6Pa of pressure, power transmission heating furnace charge.
The IV melting batch
Burn-off rate≤1/2 stove maximum capacity/hour.
The V refining
The interior pure iron as raw material of crucible of packing into all is fused into molten steel, when the pressure in stove is not more than 2.0Pa, changes the high vacuum refining over to, refining vacuum tightness 0.5Pa, refining time 20 minutes.
The VI inflation
Refining is closed vacuum pump after finishing, and stops vacuumizing, and be filled with argon gas in stove, applying argon gas pressure 5 * 10
4Pa.
The VII alloying
Under the protective atmosphere of argon gas, add electrolytic manganese 0.02kg, special silicon 3.94kg makes them meet the requirement of smelting steel grade.
VIII adds the master alloy of sulfur-bearing
The master alloy that 7.0kg is cut into piece adds fusing smelting in crucible by the material basket, adds high-power melting 12 minutes, and the weight percent of the composition in molten steel reaches the requirement of table 6 and can tap.
After melting finishes, adopt the directly mode of cast, molten steel is poured in ingot mould, the composition of steel ingot sees Table 6.
Table 6
| C％ | Si％ | Mn％ | P％ | S％ |
| 0.05 | 3.12 | 0.06 | 0.010 | 0.025 |
The rate of recovery of the present embodiment sulphur is 96.1%.
The weight percent of the composition of the master alloy of the present embodiment is:
C 0.02％；Mn 0.070％；S 0.35％；P 0.010％；
All the other these Fe and inevitable impurity.
Embodiment three
Equipment adopts the 200kg high vacuum induction furnace: final vacuum is 6.67 * 10
-2Pa, power are 250KW, and frequency is 2500HZ, batch 100.7kg.
Steel grade: Sulfur Bearing Steel 1E1813
The control target (weight percent) that the present invention smelts a stove Sulfur Bearing Steel 1E1813 needs pure iron as raw material, conversion pig, iron alloy and master alloy weight to see Table 7,1E1813 composition sees Table 8.
Table 7
| Raw material type | Pure iron | Electrolytic manganese | The pig iron | Master alloy | Special silicon |
| Add-on (kg) | 100 | 1.15 | 6.0 | 5.3 | 0.25 |
Table 8
| C％ | Si％ | Mn％ | P | S | |
| Ingredient standard | 0.23/0.28 | 0.15/0.35 | 1.0/1.3 | ≤0.03 | 0.015/0.030 |
| Control target | 0.025 | 0.25 | 1.20 | ≤0.02 | 0.023 |
The step of the present embodiment is as follows:
I medium-frequency induction furnace fusing pure iron
To make steel and pack in medium-frequency induction furnace with pure iron as raw material, after fusing, tapping, put into ladle with the FeS powder, and molten steel pours in ladle after the FeS fusing, steel tapping casting.Make the master alloy steel ingot of sulfur-bearing 0.25%.
II processes steel ingot
The master alloy steel ingot is cut into 30 * 30 * 30mm
3Square.
The charging of III vacuum induction furnace
The dry steel-making of cleaning is packed in the crucible of vacuum induction furnace with pure iron as raw material, close bell and vacuumize 13 minutes, when in stove during the little 6Pa of pressure, power transmission heating furnace charge.
The IV melting batch
Burn-off rate≤1/2 stove maximum capacity/hour.
The V refining
The interior pure iron as raw material of crucible of packing into all is fused into molten steel, when the pressure in stove is not more than 2.0Pa, changes the high vacuum refining over to, refining vacuum tightness 0.3Pa, refining time 20 minutes.
The VI inflation
Refining is closed vacuum pump after finishing, and stops vacuumizing, and be filled with argon gas in stove, applying argon gas pressure 6 * 10
4Pa.
The VII alloying
Under the protective atmosphere of argon gas, add pig iron 6.0kg, electrolytic manganese 1.15kg, special silicon 0.25kg makes them meet the requirement of smelting steel grade.
VIII adds the master alloy of sulfur-bearing
The master alloy that 5.3kg is cut into piece adds fusing smelting in crucible by the material basket, adds high-power melting 12 minutes, and the weight percent of the composition in molten steel reaches the requirement of table 9 and can tap.
After melting finishes, adopt the mode of charged cast, molten steel is poured in ingot mould, the composition of steel ingot sees Table 9.
Table 9
| C％ | Si％ | Mn％ | P％ | S％ |
| 0.024 | 0.26 | 1.18 | 0.016 | 0.022 |
The rate of recovery of the present embodiment sulphur is 95.7%.
The weight percent of the composition of the master alloy of the present embodiment is:
C 0.02％；Mn 0.070％；S 0.25％；P 0.010％；
All the other these Fe and inevitable impurity.
Outside element in above-mentioned table 2, table 3, table 5, table 6, table 8 and table 9, all the other are Fe and inevitable impurity.
Claims (1)
1. the vulcanization method of a vacuum induction furnace smelting molten steel, it is applicable to smelt the steel grade of sulphur content 0.01%-0.05%, comprises following step successively:
IMedium-frequency induction furnace fusing pure iron
To make steel and pack in medium-frequency induction furnace with pure iron as raw material, after fusing, tapping, put into ladle with the FeS powder, and molten steel pours in ladle after the FeS fusing, steel tapping casting; Make the master alloy steel ingot of sulfur-bearing 0.25%-0.35%; The weight percent of the composition of sulfur-bearing master alloy is:
C 0.017%—0.023% ；Mn 0.065%—0.075% ； S 0.25%—0.35%；
P≤0.013%; All the other are Fe and inevitable impurity;
IIThe processing steel ingot
The master alloy steel ingot is cut into the bloom that granularity is not more than 30mm;
IIIThe vacuum induction furnace charging
The dry steel-making of cleaning is packed in the crucible of vacuum induction furnace with pure iron as raw material and iron alloy, close bell and vacuumize 12-16 minutes, when in stove, pressure was not more than 10Pa, power transmission heated furnace charge;
IVMelting batch
Burn-off rate≤1/2 stove maximum capacity/hour;
VRefining
The interior raw material of crucible of packing into all is fused into molten steel, when the pressure in stove is not more than 2.0Pa, changes the high vacuum refining over to, refining vacuum tightness 0.4Pa-0.6Pa, refining time 18-22 minutes;
VIInflation
Refining is closed vacuum pump after finishing, and stops vacuumizing, and be filled with argon gas in stove, and applying argon gas pressure is not less than 5 * 10
4Pa;
VIIAlloying
Under the protective atmosphere of argon gas, adjust the composition of element sulphur other element in addition, make them meet the requirement of smelting steel grade;
VIIIThe master alloy that adds sulfur-bearing
Weight according to the sulphur content in the sulfur-bearing steel grade and molten steel, calculate the weight of smelting the sulphur that steel grade will add, the per-cent of the sulphur contained according to the sulfur-bearing master alloy again, calculate the weight of the master alloy that will add, again according to this weight that calculates, add the master alloy that is cut into piece in crucible fusing to smelt by the material basket, when the weight percent of the composition in molten steel reaches steel grade and requires, molten steel is poured in ingot mould.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010557767 CN102477474B (en) | 2010-11-20 | 2010-11-20 | Sulfur feeding method for smelting molten steel in vacuum induction furnace |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010557767 CN102477474B (en) | 2010-11-20 | 2010-11-20 | Sulfur feeding method for smelting molten steel in vacuum induction furnace |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102477474A CN102477474A (en) | 2012-05-30 |
| CN102477474B true CN102477474B (en) | 2013-05-22 |
Family
ID=46090258
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201010557767 Active CN102477474B (en) | 2010-11-20 | 2010-11-20 | Sulfur feeding method for smelting molten steel in vacuum induction furnace |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102477474B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103114172A (en) * | 2013-03-04 | 2013-05-22 | 内蒙古包钢钢联股份有限公司 | Calcium treatment method of vacuum induction furnace in smelting experimental steel |
| CN103614512A (en) * | 2013-11-30 | 2014-03-05 | 河北钢铁股份有限公司 | Method for smelting sulfur-containing steel in vacuum induction furnace for sulfur alloying |
| CN106319132B (en) * | 2015-06-26 | 2018-02-27 | 鞍钢股份有限公司 | Method for controlling sulfur content in steel |
| CN111411288B (en) * | 2020-03-19 | 2021-08-20 | 靖江新舟合金材料有限公司 | High-temperature alloy smelting method |
| CN114107592B (en) * | 2021-11-03 | 2022-12-16 | 钢铁研究总院 | System and method for preparing high-purity molten iron through electro-hydrogen metallurgy extremely-short process |
| CN117512425B (en) * | 2023-10-31 | 2024-09-27 | 西安钢研功能材料股份有限公司 | Preparation method of ultra-pure high-strength low-segregation stainless steel |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101372721A (en) * | 2008-09-19 | 2009-02-25 | 山西太钢不锈钢股份有限公司 | High vacuum induction furnace nitrogen-containing steel smelting nitrogen pickup method |
| CN101643815A (en) * | 2008-08-09 | 2010-02-10 | 湖北新冶钢有限公司 | Vulcanization method for smelting high-sulfur stainless steel |
-
2010
- 2010-11-20 CN CN 201010557767 patent/CN102477474B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101643815A (en) * | 2008-08-09 | 2010-02-10 | 湖北新冶钢有限公司 | Vulcanization method for smelting high-sulfur stainless steel |
| CN101372721A (en) * | 2008-09-19 | 2009-02-25 | 山西太钢不锈钢股份有限公司 | High vacuum induction furnace nitrogen-containing steel smelting nitrogen pickup method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102477474A (en) | 2012-05-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102400030B (en) | Method for adding nitrogen element into smelting molten steel of vacuum induction furnace | |
| CN105463150B (en) | A kind of automobile hub bearing steel smelting technique | |
| CN102477474B (en) | Sulfur feeding method for smelting molten steel in vacuum induction furnace | |
| CN101372721A (en) | High vacuum induction furnace nitrogen-containing steel smelting nitrogen pickup method | |
| CN104451385B (en) | A kind of low-carbon (LC), low nitrogen, hyperoxia ingot iron and its production method | |
| CN102477473B (en) | Method for controlling boron content of boron-containing steel smelted by vacuum induction furnace | |
| CN102787206B (en) | Smelting method for controlling nitrogen content in steel ingot of medium carbon chromous mold steel and steel ingot | |
| CN101649410B (en) | Method for smelting molten steel and adding rear earth by vacuum induction furnace | |
| CN104313494B (en) | The smelting process of steel SA-335P92 for a kind of super critical boiler | |
| CN103966385A (en) | Process for smelting MC5 roller by using return scraps | |
| CN102409133B (en) | Method for producing 23MnB steel by adopting vacuum process | |
| CN106381441B (en) | A kind of 10Cr11Co3W3NiMoVNbNB low carbon low silicons low-aluminium high boron steel smelting process | |
| CN101372720B (en) | High vacuum induction furnace steel-smelting carburetion method | |
| CN105344949B (en) | A kind of manufacture of iron and steel by melting molds new technology | |
| CN101948979B (en) | Method for producing industrial pure iron | |
| CN102477475A (en) | Method for controlling manganese content during manganese-containing steel smelting in vacuum induction furnace | |
| CN106048134B (en) | A kind of intermediate experiment method of smelting silicon steel | |
| CN101671762A (en) | Production method for medium and low alloy special steel | |
| CN109972062B (en) | High-purity large electroslag ingot and production method thereof | |
| CN112708725A (en) | Method for smelting high manganese steel by vacuum induction furnace | |
| CN102051434B (en) | Method for smelting silicon steel | |
| CN113430449A (en) | Smelting and continuous casting production process of sulfur-containing free-cutting steel ASTM1141 | |
| CN101948980B (en) | Method for producing industrial pure iron | |
| CN105441784A (en) | Ultrahigh chromium alloy wear-resisting cast iron guide plate material and preparation method thereof | |
| CN102424883B (en) | Vacuum method for producing 25CrMnB 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 |