CN112063799A - Steelmaking deoxidizer, preparation method, application and use method thereof - Google Patents
Steelmaking deoxidizer, preparation method, application and use method thereof Download PDFInfo
- Publication number
- CN112063799A CN112063799A CN202010954297.0A CN202010954297A CN112063799A CN 112063799 A CN112063799 A CN 112063799A CN 202010954297 A CN202010954297 A CN 202010954297A CN 112063799 A CN112063799 A CN 112063799A
- Authority
- CN
- China
- Prior art keywords
- deoxidizer
- steel
- molten steel
- steelmaking
- steelmaking deoxidizer
- 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.)
- Pending
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/06—Deoxidising, e.g. killing
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
The invention discloses a steelmaking deoxidizer which comprises the following raw materials in percentage by weight: 35-45% of silicon, 4-6% of strontium and the balance of iron; the preparation method comprises the following steps: (1) weighing quartz stone, celestite and scrap iron according to the weight percentage; (2) sequentially feeding scrap iron, quartz stone and celestite, heating to completely melt, cooling, discharging, and crushing to obtain the final product; the using method comprises the following steps: (1) smelting the molten steel to 1500-; (2) adding slag removing agent to remove dross, adding steel-making deoxidizer, and standing for 3-5 min; (3) and adding a deslagging agent again to remove the scum. The steel-making deoxidizer has thorough deoxidation, can form equiaxial crystals of carbides, spheroidize inclusions and refine steel grains by simple one-time precipitation deoxidation, greatly improves the thermal fatigue property of materials, and has small smoke dust and environmental protection.
Description
Technical Field
The invention relates to the technical field of metal smelting, in particular to a steelmaking deoxidizer, and a preparation method, application and a use method thereof.
Background
According to the development of the automobile industry and the improvement of the energy-saving and environment-friendly requirements in recent years, the automobile engine is required to be updated, the power of the engine is high, and the exhaust emission also meets the requirements of the fifth nation, so that the exhaust pipe turbine shell of the engine is changed from the original gray cast iron to the current heat-resistant steel. The key link of heat-resistant steel smelting is a deoxidation modification technology, effective deoxidation is needed in the smelting process, carbide is needed to be converted from columnar crystal orientation equiaxial crystal in the refining process, and the main problem to be solved at present is how to form the inclusion into spherical inclusion morphology.
The traditional heat-resistant steel smelting process uses rare earth barium calcium magnesium aluminum and other alloys for deoxidation, and has the following defects: firstly, because the evaporation point of calcium is low, a large amount of calcium is evaporated to form smoke after the calcium is added on site, so that the environment is polluted, the visibility on site is reduced, and production safety accidents are easy to happen; secondly, metal aluminum and magnesium are expensive, the steel-making cost is high, aluminum is easy to form alumina inclusions in steel, the performance of the steel is influenced, magnesium belongs to a strong supercooling element, molten steel is easy to supercool to form columnar crystals after being added, the stress of a casting is concentrated, and the fatigue performance after service is reduced; thirdly, the adoption of the deoxidation mode can not effectively solve the problems of thorough deoxidation and spheroidization of inclusions.
At present, silicon-aluminum-barium-iron deoxidizer is widely used, wherein the deoxidizer contains 22-30% of silicon, 30-40% of aluminum, 3-12% of barium and the balance of iron, the alloy prepared by the deoxidizer overcomes the defects of silicon-calcium, pure aluminum and magnesium deoxidization, has the performances of reducing the total amount of non-metallic inclusions, improving the shape, size and distribution of the inclusions and the aluminum-saving effect, but has poor refining effect on steel grains, and the casting is easy to form air holes due to the large amount of residual aluminum in molten steel.
Therefore, it is an urgent need to solve the problem of providing a simple and practical steelmaking deoxidizer by those skilled in the art.
Disclosure of Invention
In view of the above, the present invention aims to provide a steelmaking deoxidizer, a preparation method, an application and a use method thereof, so as to solve the defects in the prior art.
In order to achieve the purpose, the invention adopts the following technical scheme:
a steelmaking deoxidizer comprises the following raw materials in percentage by weight: 35-45% of silicon, 4-6% of strontium and the balance of iron.
The beneficial effects of the invention are that strontium is an alkaline metal, has strong chemical activity and great affinity with oxygen, is added into steel, and most of strontium reacts with oxygen to enter slag, so that the strontium is completely feasible to be used as a deoxidizer; meanwhile, strontium can also be used as a modifier to play a role in refining steel grains, because strontium is a surface active element and can be selectively adsorbed to the surface of a crystal grain-solution from a metal melt, the growth speed of the crystal grain is reduced, and the number of the crystal grains is increased, so that the crystal grains are further refined, in addition, strontium, oxygen and sulfur in molten steel are continuously enriched in the solidification process of the molten steel, and react to a certain saturation degree to generate non-metallic inclusions, so that the number of crystal nuclei is further increased, the crystal structure of the crystal grains is more dispersed, the dispersion degree and the uniformity of the crystal structure of the steel are improved, and the mechanical property of the steel is correspondingly improved; silicon is also a deoxidizer and a reducing agent in the smelting process of the heat-resistant steel, the oxidization of molten steel can be reduced after the silicon is added, the deoxidizing effect is maximum after the silicon and strontium are combined, and in addition, the single strontium is quickly oxidized in the air, so the combination of the silicon and the strontium is also the best choice from the aspect of adding mode; the pure strontium-silicon alloy has lower density, and the density of the strontium-silicon alloy is increased after the strontium-silicon alloy is mixed with iron, so that the strontium-silicon alloy is easier to add into molten steel.
The preparation method of the steelmaking deoxidizer is characterized by comprising the following steps:
(1) weighing quartz stone, celestite and scrap iron according to the weight percentage of the raw materials of the steelmaking deoxidizer;
(2) and sequentially feeding scrap iron, quartz stone and celestite, heating until the scrap iron, the quartz stone and the celestite are completely melted, cooling, discharging, and crushing to obtain the steelmaking deoxidizer.
Further, in the step (2), the temperature is raised to 1550-; crushing until the grain diameter of the steelmaking deoxidizer is 30-50 mm.
The invention also discloses application of the steelmaking deoxidizer in smelting heat-resistant steel.
A use method of a steelmaking deoxidizer specifically comprises the following steps:
(1) smelting the molten steel to 1500-;
(2) adding a slag removing agent into the molten steel A to remove dross, adding the steelmaking deoxidizer, and standing for 3-5min to obtain molten steel B;
(3) and adding the slag removing agent into the molten steel B again to remove the scum.
The using method has the advantages that the deoxidizing process of the steel-making deoxidizing agent is rapid, and the molten steel is not polluted.
Further, in the step (2), the slag removing agent comprises the following raw materials in percentage by weight: si02≥67％，Al203≥11％，Fe203Less than 5 percent, less than 2 percent of CaO and less than 1 percent of water; the dosage of the slag removing agent is 2 per mill of the weight of the molten steel A; the dosage of the steelmaking deoxidizer is 0.65 to 0.80 percent of the weight of the molten steel A.
Further, in the step (3), the amount of the slag removing agent is 1 per mill of the weight of the molten steel A.
According to the technical scheme, compared with the prior art, the invention has the following beneficial effects:
1. the steelmaking deoxidizer has thorough deoxidation, can form equiaxial crystals of carbides through simple one-time precipitation deoxidation, spheroidize inclusions, refine crystal grains of steel, greatly improve the thermal fatigue property of materials, has small smoke dust, and is green and environment-friendly;
2. the heat-resistant steel 1.4837, 1.4848 and 1.4849 turbine shells prepared by smelting the steelmaking deoxidizer can improve the grain size of exhaust pipe steel by 2 levels, the oxygen content of the deoxidized molten steel is less than 40PPm, and the deoxidizing effect is equivalent to that of a barium-calcium-magnesium-aluminum rare earth deoxidizer;
3. the steel-making deoxidizer does not use aluminum, magnesium and rare earth, saves 10 yuan of barium, 15 yuan of magnesium, 10 yuan of aluminum and 58 yuan of rare earth per ton of alloy, and has obvious economic benefit.
Drawings
FIG. 1 is a drawing showing a crystal form of heat-resistant steel of example 3 after being enlarged by 100 times;
FIG. 2 is a drawing showing a crystal form of heat-resistant steel of comparative example 1 enlarged by 100 times;
FIG. 3 is a drawing showing the shape of impurities of heat-resistant steel of example 3 enlarged 500 times;
FIG. 4 is a graph showing the morphology of the inclusions in the heat-resistant steel of comparative example 1 enlarged 500 times.
Detailed Description
The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the following examples, the slag remover was purchased from Shanghai Dan Sancheng (actual industry) Co., Ltd., model number W4.
Example 1
The steel-making deoxidizer contains per 100 kg: 40kg of silicon, 4kg of strontium and 56kg of iron.
The preparation method of the steelmaking deoxidizer specifically comprises the following steps: scrap iron containing 56kg of iron, quartz containing 40kg of silicon and celestite containing 4kg of strontium are fed in sequence, heated to 1550 ℃ to be completely melted, cooled, discharged and crushed into 30mm steel-making deoxidizer.
The using method of the steelmaking deoxidizer specifically comprises the following steps: when the molten steel is smelted to 1500 ℃, the power supply is turned off, the molten steel is kept stand at a constant temperature for 3min, then 2kg of slag removing agent is added into each ton of the molten steel to remove dross, 8kg of steelmaking deoxidizer is added into each ton of the molten steel in a precipitation deoxidation mode, the molten steel is kept stand for 3min, and finally 1kg of slag removing agent is added into each ton of the molten steel again to remove dross.
Slag skimming, sampling and analysis, wherein the strontium content is 0.03 percent and the oxygen content is 30PPM by using an American Like oxygen nitrogen hydrogen instrument for measurement. The theory is consistent with the reality, the alkaline earth metal strontium has strong chemical activity and is easy to react with oxygen in molten steel, the grain pair reaches 7 grades through analysis, the grain size of the used barium silicate or rare earth is generally 5-6 grades, the structure is obviously refined, the tensile strength, the yield strength and the elongation are improved, and the requirement of German standard of heat-resistant steel is exceeded.
Example 2
The steel-making deoxidizer contains per 100 kg: 40kg of silicon, 5kg of strontium and 55kg of iron.
The preparation method of the steelmaking deoxidizer specifically comprises the following steps: scrap iron containing 55kg of iron, quartz containing 40kg of silicon and celestite containing 5kg of strontium are sequentially fed, heated to 1650 ℃ and completely melted, cooled, discharged and crushed into a steelmaking deoxidizer of 50 mm.
The using method of the steelmaking deoxidizer specifically comprises the following steps: when the molten steel is smelted to 1700 ℃, the power supply is turned off, the molten steel is kept stand at a constant temperature for 3min, then 2kg of slag removing agent is added into each ton of the molten steel to remove dross, 8kg of steelmaking deoxidizer is added into each ton of the molten steel in a precipitation deoxidation mode, the molten steel is kept stand for 3min, and finally 1kg of slag removing agent is added into each ton of the molten steel again to remove dross.
Slag skimming, sampling and analysis, wherein the strontium content is 0.04 percent and the oxygen content is 35PPM by using an American Like oxygen nitrogen hydrogen instrument for measurement. The theory is consistent with the reality, the alkaline earth metal strontium has strong chemical activity and is easy to react with oxygen in molten steel, the grain pair reaches 8 grades through analysis, the grain size of the used barium silicate or rare earth is generally 5-6 grades, the structure is obviously refined, the tensile strength, the yield strength and the elongation are improved, and the requirement of German standard of heat-resistant steel is exceeded.
Example 3
The steel-making deoxidizer contains per 100 kg: 40kg of silicon, 6kg of strontium and 54kg of iron.
The preparation method of the steelmaking deoxidizer specifically comprises the following steps: scrap iron containing 54kg of iron, quartz containing 40kg of silicon and celestite containing 6kg of strontium are fed in sequence, heated to 1600 ℃, completely melted, cooled, discharged and crushed into a steel-making deoxidizer of 40 mm.
The using method of the steelmaking deoxidizer specifically comprises the following steps: when the molten steel is smelted to 1600 ℃, the power supply is turned off, the molten steel is kept stand at a constant temperature for 3min, then 2kg of slag removing agent is added into each ton of the molten steel to remove dross, 8kg of steelmaking deoxidizer is added into each ton of the molten steel in a precipitation deoxidation mode, the molten steel is kept stand for 3min, and finally 1kg of slag removing agent is added into each ton of the molten steel again to remove dross.
Slag skimming, sampling and analysis, wherein the strontium content is 0.048 percent and the oxygen content is 30PPM by using an American Like oxygen nitrogen hydrogen instrument for measurement. The theory is consistent with the reality, the alkaline earth metal strontium has strong chemical activity and is easy to react with oxygen in molten steel, the grain pair reaches 9 grades through analysis, the grain size of the used barium silicate or rare earth is generally 5-6 grades, the structure is obviously refined, the tensile strength, the yield strength and the elongation are improved, and the requirement of German standard of heat-resistant steel is exceeded.
Comparative example 1
The steel-making deoxidizing agent (rare earth silicon calcium magnesium) contains, per 100 g: 25g of rare earth, 45g of silicon, 17g of calcium, 10g of manganese and 3g of magnesium.
The preparation method and the using method are the same as the example 3.
Comparative example 2
The steel-making deoxidizer (silicon barium) contains per 100 g: 83g of silicon, 14g of barium, 2g of calcium and 1g of aluminum.
The preparation method and the using method are the same as the example 3.
Performance testing
1. The heat-resistant steels (No. 1.4848) obtained in example 3 and comparative examples 1 to 2 were each subjected to two tests of physical properties (tensile strength, yield strength, elongation and hardness) according to the test method of the national standard GBT 4238-2007 (national standard industrial specifications for heat-resistant steel sheets and steel strips), and the test results are shown in table 1.
Table 1 test results of physical properties of heat resistant steels of example 3 and comparative examples 1 to 2
As can be seen from table 1, compared with the rare earth silicon barium magnesium deoxidizer and the silicon barium deoxidizer, the heat-resistant steel prepared in example 3 of the present invention has excellent tensile strength, yield strength and elongation, and moderate hardness, and all meet the corresponding standards of the national standard GBT 4238-2007 (national standard industrial specifications for heat-resistant steel plates and steel strips).
2. The heat-resistant steels obtained in example 3 and comparative example 1 were each taken and observed under an electron microscope at an enlarged scale, and the results are shown in FIGS. 1 to 4.
Wherein, FIG. 1 is a crystal form of the heat-resistant steel of example 3 amplified by 100 times, which is a typical equiaxed crystal;
FIG. 2 is a crystal form of the heat-resistant steel of comparative example 1 enlarged by 100 times, which is a typical columnar crystal;
FIG. 3 is a spherical shape of the heat-resistant steel of example 3, in which the shape of the inclusions is enlarged 500 times;
FIG. 4 shows the shape of the inclusions of comparative example 1, which are magnified 500 times, and which are rod-shaped.
The tests show that said invented deoxidant can be used for making steel, and can implement deoxidation thoroughly, and can make carbide form equiaxial crystal, make inclusion spherical and refine crystal grain of steel by means of simple one-step precipitation deoxidation, so that it can greatly raise the thermal fatigue property of material.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. The steelmaking deoxidizer is characterized by comprising the following raw materials in percentage by weight: 35-45% of silicon, 4-6% of strontium and the balance of iron.
2. The preparation method of the steelmaking deoxidizer is characterized by comprising the following steps:
(1) weighing quartz stone, celestite and scrap iron according to the weight percentage of the raw materials of the steelmaking deoxidizer of claim 1;
(2) and sequentially feeding scrap iron, quartz stone and celestite, heating until the scrap iron, the quartz stone and the celestite are completely melted, cooling, discharging, and crushing to obtain the steelmaking deoxidizer.
3. The method as claimed in claim 2, wherein the temperature is increased to 1550-1650 ℃ in step (2).
4. The method for preparing a steelmaking deoxidizer of claim 2, wherein in the step (2), the steelmaking deoxidizer is crushed to have a grain size of 30-50 mm.
5. Use of the steelmaking deoxidizer of claim 1 in smelting heat-resistant steel.
6. The use method of the steelmaking deoxidizer as set forth in claim 1 is characterized by comprising the following steps:
(1) smelting the molten steel to 1500-;
(2) adding a deslagging agent into the molten steel A to remove dross, then adding the steelmaking deoxidizer as claimed in claim 1, and standing for 3-5min to obtain molten steel B;
(3) and adding the slag removing agent into the molten steel B again to remove the scum.
7. The use method of steelmaking deoxidizer as claimed in claim 6, wherein in the step (2), the slag remover comprises the following raw materials in percentage by weight: si02≥67％，Al203≥11％，Fe203Less than 5 percent, less than 2 percent of CaO and less than 1 percent of water.
8. The use method of a steelmaking deoxidizer as claimed in claim 7, wherein in the step (2), the amount of the slag remover is 2% by weight of the molten steel A.
9. The use method of the steelmaking deoxidizer of claim 6, wherein in the step (2), the dosage of the steelmaking deoxidizer is 0.65-0.80% of the weight of the molten steel A.
10. The use method of the deoxidizing agent for steel making as claimed in claim 6, wherein in the step (3), the amount of the deslagging agent is 1 ‰ of the weight of the molten steel A.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010954297.0A CN112063799A (en) | 2020-09-11 | 2020-09-11 | Steelmaking deoxidizer, preparation method, application and use method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010954297.0A CN112063799A (en) | 2020-09-11 | 2020-09-11 | Steelmaking deoxidizer, preparation method, application and use method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112063799A true CN112063799A (en) | 2020-12-11 |
Family
ID=73696414
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010954297.0A Pending CN112063799A (en) | 2020-09-11 | 2020-09-11 | Steelmaking deoxidizer, preparation method, application and use method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112063799A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1226738A (en) * | 1968-10-14 | 1971-03-31 | ||
| CN1097808A (en) * | 1994-05-04 | 1995-01-25 | 本溪冶炼厂 | Be used as silicon-barium-strontium-iron alloy of steel liquid deoxidizing agent and preparation method thereof |
| CN101353714A (en) * | 2007-07-23 | 2009-01-28 | 才会成 | Aluminum-free deoxidizing agent |
| CN102876998A (en) * | 2012-09-29 | 2013-01-16 | 西峡县众德汽车部件有限公司 | Heat-resistant steel, turbocharger conjoined casing and preparation method of turbocharger conjoined casing |
| CN109234640A (en) * | 2018-11-16 | 2019-01-18 | 泉州市恒通机械配件有限公司 | A kind of cast steel and its production technology |
-
2020
- 2020-09-11 CN CN202010954297.0A patent/CN112063799A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1226738A (en) * | 1968-10-14 | 1971-03-31 | ||
| CN1097808A (en) * | 1994-05-04 | 1995-01-25 | 本溪冶炼厂 | Be used as silicon-barium-strontium-iron alloy of steel liquid deoxidizing agent and preparation method thereof |
| CN101353714A (en) * | 2007-07-23 | 2009-01-28 | 才会成 | Aluminum-free deoxidizing agent |
| CN102876998A (en) * | 2012-09-29 | 2013-01-16 | 西峡县众德汽车部件有限公司 | Heat-resistant steel, turbocharger conjoined casing and preparation method of turbocharger conjoined casing |
| CN109234640A (en) * | 2018-11-16 | 2019-01-18 | 泉州市恒通机械配件有限公司 | A kind of cast steel and its production technology |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111593257A (en) | High-toughness and high-thermal-stability hot-work die steel and preparation method thereof | |
| CN106312000A (en) | 18CrNiMo7-6 round billet continuous casting method for vertical type continuous casting production gear steel | |
| WO2022110982A1 (en) | Preparation method for low-temperature impact toughness-resistant wind power steel | |
| CN108330245A (en) | A kind of high-purity smelting process of stainless steel | |
| CN109750210A (en) | The production method of hypoxemia, hydrogen content potassium steel | |
| WO2023056792A1 (en) | Magnesium-containing steel 45 and preparation process therefor | |
| CN110117748B (en) | Cutting steel wire, steel material for cutting steel wire, and method for producing same | |
| CN112981249B (en) | Smelting method of electrode bar base material for protective atmosphere electroslag remelting H13 steel | |
| CN106544594A (en) | Carbon vanadium steel and preparation method thereof in a kind of drill steel | |
| WO2019120122A1 (en) | HIGH STRENGTH AND HIGH TOUGHNESS SPHEROIDIZING GRAPHITE CAST IRON AT LOW TEMPERATURE OF -40ºC AND PREPARATION METHOD THEREOF AND RAILWAY LOCOMOTIVE PARTS | |
| CN107460403A (en) | A kind of effective steel round blank of high-pressure boiler, the effective steel of high-pressure boiler and preparation method thereof | |
| WO2012079415A1 (en) | Steel used for railway locomotive axle and the manufacturing method thereof | |
| CN114645208B (en) | Tellurium-treated non-quenched and tempered steel for connecting rod and production method thereof | |
| CN104862450A (en) | Method for enabling nano molten iron purifying modifier to be used in austenite ductile cast iron wear-resistant casting | |
| CN117230360B (en) | Preparation method of single-vacuum 300M steel | |
| CN110565030A (en) | low-silicon low-aluminum martensitic stainless steel containing rare earth elements and smelting method thereof | |
| CN112410573B (en) | Slag system for smelting Ce-containing Fe-Ni soft magnetic alloy and use method thereof | |
| CN109487036A (en) | 18 potassium steel of high-purity manganese and preparation method thereof | |
| CN112063799A (en) | Steelmaking deoxidizer, preparation method, application and use method thereof | |
| CN103243195B (en) | Smelting process of steel ingot for wind power generating motor shaft with high performance | |
| CN108570599A (en) | A kind of high-strength high hard narrow quenching degree oil 4145H steel ingots and its production method | |
| CN112680656B (en) | Boron-containing steel for motor claw pole and low-cost smelting process thereof | |
| CN101565792B (en) | Method for smelting boron steel | |
| CN109762959B (en) | Smelting method of special steel and special steel | |
| CN103233095A (en) | Complex deoxidizer as well as preparation method and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |