CN117925969A - Production method of export H350 grade high-strength heat treatment steel rail - Google Patents
Production method of export H350 grade high-strength heat treatment steel rail Download PDFInfo
- Publication number
- CN117925969A CN117925969A CN202311712108.9A CN202311712108A CN117925969A CN 117925969 A CN117925969 A CN 117925969A CN 202311712108 A CN202311712108 A CN 202311712108A CN 117925969 A CN117925969 A CN 117925969A
- Authority
- CN
- China
- Prior art keywords
- steel rail
- less
- equal
- heat treatment
- rail
- 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
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 78
- 239000010959 steel Substances 0.000 title claims abstract description 78
- 238000010438 heat treatment Methods 0.000 title claims abstract description 39
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 25
- 238000005096 rolling process Methods 0.000 claims abstract description 21
- 239000000126 substance Substances 0.000 claims abstract description 10
- 239000012535 impurity Substances 0.000 claims abstract description 9
- 238000000034 method Methods 0.000 claims abstract description 9
- 238000003723 Smelting Methods 0.000 claims abstract description 6
- 238000001816 cooling Methods 0.000 claims description 27
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 6
- 238000010079 rubber tapping Methods 0.000 claims description 5
- 229910045601 alloy Inorganic materials 0.000 claims description 4
- 239000000956 alloy Substances 0.000 claims description 4
- 229910000599 Cr alloy Inorganic materials 0.000 claims description 3
- 229910052786 argon Inorganic materials 0.000 claims description 3
- 238000009749 continuous casting Methods 0.000 claims description 3
- 238000007670 refining Methods 0.000 claims description 3
- 229910001339 C alloy Inorganic materials 0.000 claims description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 2
- 229910000604 Ferrochrome Inorganic materials 0.000 claims description 2
- 229910000628 Ferrovanadium Inorganic materials 0.000 claims description 2
- 229910000756 V alloy Inorganic materials 0.000 claims description 2
- 229910052799 carbon Inorganic materials 0.000 claims description 2
- 239000002826 coolant Substances 0.000 claims description 2
- 238000005520 cutting process Methods 0.000 claims description 2
- PNXOJQQRXBVKEX-UHFFFAOYSA-N iron vanadium Chemical compound [V].[Fe] PNXOJQQRXBVKEX-UHFFFAOYSA-N 0.000 claims description 2
- 238000004806 packaging method and process Methods 0.000 claims description 2
- 238000010791 quenching Methods 0.000 claims description 2
- 230000000171 quenching effect Effects 0.000 claims description 2
- 239000002918 waste heat Substances 0.000 claims description 2
- 238000005303 weighing Methods 0.000 claims description 2
- 230000008901 benefit Effects 0.000 description 4
- 238000005070 sampling Methods 0.000 description 3
- 238000013461 design Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000007546 Brinell hardness test Methods 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000011031 large-scale manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- -1 silicon-calcium-barium-oxygen Chemical compound 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/005—Modifying the physical properties by deformation combined with, or followed by, heat treatment of ferrous alloys
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/08—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling structural sections, i.e. work of special cross-section, e.g. angle steel
- B21B1/085—Rail sections
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
- B21B37/74—Temperature control, e.g. by cooling or heating the rolls or the product
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/06—Deoxidising, e.g. killing
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/18—Hardening; Quenching with or without subsequent tempering
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/04—Making ferrous alloys by melting
- C22C33/06—Making ferrous alloys by melting using master alloys
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium
-
- 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)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
The invention discloses a production method of an export H350 grade high-strength heat treatment steel rail, which comprises the following steps: a steel smelting production process; rolling a steel rail; an online heat treatment process of a steel rail; the steel rail comprises the following chemical components in percentage by mass: c0.75-0.80%; si 0.50-0.65%; mn 1.00-1.20%; p is less than or equal to 0.020%; s is less than or equal to 0.020%; v is less than or equal to 0.03 percent, cr is less than or equal to 0.15 percent; the balance of Fe and unavoidable impurities, and the mass fraction is 100 percent. The invention aims to provide a production method of an export H350 grade high-strength heat treatment steel rail, which is characterized in that the H350 grade steel rail with good strength and toughness ratio after smelting and heat treatment can meet the European standard technical requirements.
Description
Technical Field
The invention relates to the field of metallurgical materials, in particular to a production method of an export H350 grade high-strength heat treatment steel rail.
Background
The abrasion of steel rails is very serious on the transportation lines of foreign mines, coal and the like, especially on small radius curves. The paving practice at home and abroad shows that the service life of the full-length quenched steel rail of 1200-1300MPa grade is prolonged by 2-5 times by using the full-length quenched steel rail on a small half-length curve, and the method has remarkable economic benefit. Along with the development of railway construction in China, the steel rail has the advantages that steel rails in European standard, american standard and other standards can be produced, wherein European standard R350HT is a main high-strength heat treatment steel rail purchased by overseas freight lines, and clients obviously put forward the service life requirement of the steel rail.
In addition to the mechanical properties such as tensile strength and hardness, the R350HT steel rail also needs to meet certain cross section hardness requirements, namely, the hardenability and the decreasability of the heat treatment steel rail cross section hardness. The standard components of the steel grade are mainly C-Mn components, and in order to meet the requirements of full standard cross section hardness and service, a heat treatment process with reasonable design is needed, and production components are also needed to be reasonably controlled. Therefore, the development of the R350HT steel rail which has high strength, wear resistance and meets the performance requirements of the European standard cross section has important significance.
Disclosure of Invention
The invention aims to provide a production method of an export H350 grade high-strength heat treatment steel rail, which is characterized in that the H350 grade steel rail with good strength and toughness ratio after smelting and heat treatment can meet the European standard technical requirements.
In order to solve the technical problems, the invention adopts the following technical scheme:
The invention relates to a production method of an export H350 grade high-strength heat treatment steel rail, which comprises the following steps:
the steel production process comprises the following steps: molten iron-converter smelting-LF refining-VD-continuous casting. The converter smelting adopts Si-Ca-Ba deoxidation, and argon is blown normally according to refining in the whole process; vacuum degree is less than or equal to 0.10KPa, deep vacuum time is more than or equal to 18min, superheat degree delta T is less than or equal to 30 ℃, V and Cr alloy are added in an LF station, and the added alloy is medium carbon ferrochrome and ferrovanadium alloy;
The rail rolling process comprises the following steps: square billet sawing, heating, BD1 rolling, BD2 rolling, CCS universal rolling mill continuous rolling, online waste heat quenching, sawing, cooling, head and tail cutting, straightening, checking, packaging, weighing and warehousing; the temperature of a square billet heating preheating section is not more than 900 ℃; heating for a period of time not less than 3 hours and 15 minutes; the tapping temperature is not lower than 1150 ℃, the initial rolling temperature is not lower than 1100 ℃, and the final rolling temperature is 900-940 ℃;
The steel rail on-line heat treatment process comprises the following steps: the cooling medium is mainly natural air medium. The initial cooling temperature of the steel rail is 750-820 ℃, the actual cooling speed of the rail head of the steel rail in the first stage is 3.0 ℃/s-4.6 ℃/s, the steel rail head is cooled to 620-670 ℃ and the steel rail head enters the second stage; the actual cooling speed of the rail head of the second stage rail is 2.1 ℃/s-3.3 ℃/s; the actual cooling speed of the rail head of the steel rail in the third stage is 0.8 ℃/s-1.5 ℃/s, and the steel rail head is cooled to 520 ℃ to 560 ℃ and then is discharged from the heat treatment production line; the cooling time of the heat treatment is 120-150s in total;
The steel rail comprises the following chemical components in percentage by mass: c0.75-0.80%; si 0.50-0.65%; mn1.00-1.20%; p is less than or equal to 0.020%; s is less than or equal to 0.020%; v is less than or equal to 0.03 percent, cr is less than or equal to 0.15 percent; the balance of Fe and unavoidable impurities, and the mass fraction is 100 percent.
Further, the steel rail comprises the following chemical components in percentage by mass: c0.79%; si 0.54%; mn 1.05%; p0.003%; s0.003%; v0.017% and Cr 0.11%; the balance of Fe and unavoidable impurities, and the mass fraction is 100 percent.
Further, the steel rail comprises the following chemical components in percentage by mass: c0.78%; si 0.58%; mn 1.09%; p0.011%; s0.004%; v0.018% and Cr 0.09%; the balance of Fe and unavoidable impurities, and the mass fraction is 100 percent.
Further, the steel rail comprises the following chemical components in percentage by mass: c0.79%; si 0.57%; mn 1.11%; p0.010%; s0.004%; v0.016% and Cr 0.09%; the balance of Fe and unavoidable impurities, and the mass fraction is 100 percent.
Further, the tensile strength of the produced steel rail is more than 1250MPa, and the elongation is more than 14%.
Compared with the prior art, the invention has the beneficial technical effects that:
By reasonably designing components and adding trace V, cr alloy elements into the steel rail, the invention can improve the performances of the steel rail such as tensile strength, elongation, tread hardness, cross section hardness, wear resistance and the like under the rolling process. The steel rail has the advantages of unique production process, high production efficiency, energy conservation, environmental protection and good economic benefit, is suitable for large-scale production, and has good popularization value.
Detailed Description
A production method of a high-strength heat-treated steel rail with an outlet H350 level comprises the following steps: molten iron-converter smelting-LF refining-VD-continuous casting. The converter smelting adopts silicon-calcium-barium-oxygen alloying, and argon is blown normally according to refining in the whole process; the vacuum degree is less than or equal to 0.10KPa, the deep vacuum time is more than or equal to 18min, and the superheat degree delta T is less than or equal to 30 ℃. The chemical compositions of the examples are shown in Table 1.
Table 1 the components (mass% of each example)
The temperature of a steel rail square billet heating preheating section in the embodiment 1 is 770 ℃; heating for 3 hours and 25 minutes; tapping temperature is 1180 ℃, and initial rolling temperature: 1120 ℃, and the finishing temperature is 937 ℃; the initial cooling temperature of the steel rail is 770 ℃, the actual cooling speed of the rail head of the steel rail in the first stage is 4.0 ℃/s, the steel rail head is cooled to 630 ℃ and enters the second stage; the actual cooling speed of the rail head of the second stage rail is 3.0 ℃/s; the actual cooling speed of the rail head of the steel rail in the third stage is 0.9 ℃/s, and the steel rail head is cooled to 525 ℃ and then is discharged from the heat treatment production line; the heat treatment cooling time was 139s in total.
Example 2 rail billet heating preheating section temperature 840 ℃; heating for 3 hours and 35 minutes; tapping temperature is 1190 ℃, and initial rolling temperature is as follows: 1125 ℃, and the final rolling temperature is 942 ℃; the initial cooling temperature of the steel rail is 783 ℃, the actual cooling speed of the rail head of the steel rail in the first stage is 4.2 ℃/s, the steel rail head is cooled to 637 ℃ and then the steel rail head enters the second stage; the actual cooling speed of the rail head of the second stage rail is 3.2 ℃/s; the actual cooling speed of the rail head of the steel rail in the third stage is 0.87 ℃/s, and the steel rail head is cooled to 528 and then is discharged from the heat treatment production line; the heat treatment cooling time was 125 seconds in total.
Example 3 rail billet heating preheating section temperature 780 ℃; heating for 3 hours and 23 minutes; tapping temperature is 1183 ℃, and initial rolling temperature: 1122 ℃, and the final rolling temperature is 932 ℃; the initial cooling temperature of the steel rail is 768 ℃, the actual cooling speed of the rail head of the steel rail in the first stage is 4.1 ℃/s, the steel rail head is cooled to 637 ℃ and then enters the second stage; the actual cooling speed of the rail head of the second stage rail is 3.0 ℃/s; the actual cooling speed of the rail head of the steel rail in the third stage is 0.9 ℃/s, and the steel rail head is cooled to 523 and then is discharged from the heat treatment production line; the heat treatment cooling time was 127s in total.
Rolled steel sample performance after heat treatment: the tensile test piece specification is that the diameter d0=10 mm, and the gauge length lo=5do. Randomly sampling tread hardness on a steel rail, grinding the top surface of a rail head by 0.5mm with the length of a sample being 250mm, carrying out Brinell hardness test on 5 test points, and calculating an average value; the cross section hardness is measured according to the standard, 8 points of data are measured, and the sampling method and the sampling position of the above sample are according to the EN 13674-2011 standard; the results of the production test are shown in Table 2.
Table 2 mechanical properties of the examples
The above embodiments are only illustrative of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art to the technical solutions of the present invention should fall within the protection scope defined by the claims of the present invention without departing from the design spirit of the present invention.
Claims (5)
1. The production method of the export H350 grade high-strength heat treatment steel rail is characterized by comprising the following steps of:
the steel production process comprises the following steps: molten iron-converter smelting-LF refining-VD-continuous casting; the converter smelting adopts Si-Ca-Ba deoxidation, and argon is blown normally according to refining in the whole process; vacuum degree is less than or equal to 0.10KPa, deep vacuum time is more than or equal to 18min, superheat degree delta T is less than or equal to 30 ℃, V and Cr alloy are added in an LF station, and the added alloy is medium carbon ferrochrome and ferrovanadium alloy;
The rail rolling process comprises the following steps: square billet sawing, heating, BD1 rolling, BD2 rolling, CCS universal rolling mill continuous rolling, online waste heat quenching, sawing, cooling, head and tail cutting, straightening, checking, packaging, weighing and warehousing; the temperature of a square billet heating preheating section is not more than 900 ℃; the heating time is not less than 3 hours and 15 minutes, the tapping temperature is not less than 1150 ℃, the initial rolling temperature is not less than 1100 ℃, and the final rolling temperature is 900-940 ℃;
The steel rail on-line heat treatment process comprises the following steps: the cooling medium is mainly natural air medium, the initial cooling temperature of the steel rail is 750-820 ℃, the actual cooling speed of the rail head of the steel rail in the first stage is 3.0 ℃/s-4.6 ℃/s, the steel rail head is cooled to 620-670 ℃ and the steel rail head enters the second stage; the actual cooling speed of the rail head of the second stage rail is 2.1 ℃/s-3.3 ℃/s; the actual cooling speed of the rail head of the steel rail in the third stage is 0.8 ℃/s-1.5 ℃/s, the steel rail head is cooled to 520 ℃ to 560 ℃ and then is discharged from a heat treatment production line, and the total cooling time of the heat treatment is 120 to 150s;
The steel rail comprises the following chemical components in percentage by mass: c0.75-0.80%; si 0.50-0.65%; mn1.00-1.20%; p is less than or equal to 0.020%; s is less than or equal to 0.020%; v is less than or equal to 0.03 percent, cr is less than or equal to 0.15 percent; the balance of Fe and unavoidable impurities, and the mass fraction is 100 percent.
2. The method for producing the high-strength heat-treated steel rail at the outlet H350 level according to claim 1, wherein the steel rail comprises the following chemical components in percentage by mass: c0.79%; si 0.54%; mn 1.05%; p0.003%; s0.003%; v0.017% and Cr 0.11%; the balance of Fe and unavoidable impurities, and the mass fraction is 100 percent.
3. The method for producing the high-strength heat-treated steel rail at the outlet H350 level according to claim 1, wherein the steel rail comprises the following chemical components in percentage by mass: c0.78%; si 0.58%; mn 1.09%; p0.011%; s0.004%; v0.018% and Cr 0.09%; the balance of Fe and unavoidable impurities, and the mass fraction is 100 percent.
4. The method for producing the high-strength heat-treated steel rail at the outlet H350 level according to claim 1, wherein the steel rail comprises the following chemical components in percentage by mass: c0.79%; si 0.57%; mn 1.11%; p0.010%; s0.004%; v0.016% and Cr 0.09%; the balance of Fe and unavoidable impurities, and the mass fraction is 100 percent.
5. The method for producing high-strength heat-treated steel rail at H350 grade outlet according to claim 1, wherein the tensile strength of the produced steel rail is more than 1250MPa and the elongation is more than 14%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311712108.9A CN117925969A (en) | 2023-12-13 | 2023-12-13 | Production method of export H350 grade high-strength heat treatment steel rail |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311712108.9A CN117925969A (en) | 2023-12-13 | 2023-12-13 | Production method of export H350 grade high-strength heat treatment steel rail |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117925969A true CN117925969A (en) | 2024-04-26 |
Family
ID=90751445
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311712108.9A Pending CN117925969A (en) | 2023-12-13 | 2023-12-13 | Production method of export H350 grade high-strength heat treatment steel rail |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117925969A (en) |
-
2023
- 2023-12-13 CN CN202311712108.9A patent/CN117925969A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104480390A (en) | High-impact-toughness steel rail and production method thereof | |
| CN109518090B (en) | Bainite steel for frog point rail and manufacturing method thereof | |
| CN111041350A (en) | Rolled steel rail with high low-temperature impact performance and production method thereof | |
| CN112877586A (en) | Production method of high-strength and high-toughness American-standard steel rail for CR175 crane | |
| CN114774663A (en) | Production method of Baimi fixed-length 75kg/m bainite steel rail for heavy haul railway through online heat treatment | |
| CN114480987A (en) | Rare earth-containing NM600 wear-resistant steel plate and preparation method thereof | |
| CN115921524A (en) | Production process of export hot-rolled high-strength steel rail | |
| CN114941101B (en) | Steel for bearing shaft of automobile engine and production method thereof | |
| CN115466904A (en) | Production method of wear-resistant corrosion-resistant steel rail for low-temperature area railway | |
| CN111485171A (en) | Steel rail material for heavy haul railway and production method thereof | |
| CN114635072A (en) | Production method of low-temperature-resistant steel rail in alpine region | |
| CN115125448A (en) | Non-quenched and tempered steel for cold machining of hydraulic piston rod and preparation method | |
| CN117925969A (en) | Production method of export H350 grade high-strength heat treatment steel rail | |
| CN116623098A (en) | Steel suitable for wheels of passenger locomotives in alpine regions, production method, wheels and production method | |
| CN112501417B (en) | Steel rail for heavy haul railway and preparation method thereof | |
| CN112322979B (en) | Steel for subway wheels and wheel production method | |
| CN112281058B (en) | Steel for large forklift goods fork and production process thereof | |
| CN115233503A (en) | Medium-strength steel rail with high yield strength and production method thereof | |
| CN113957348A (en) | Steel for long-life hydraulic breaking hammer drill rod and preparation method thereof | |
| CN113999962A (en) | High-toughness bainite steel rail and production method thereof | |
| CN114015944A (en) | Bainite steel rail with low rail top surface hardness fluctuation and production method thereof | |
| CN113235019A (en) | Fe-Mn-Al-N-S series high-nitrogen low-density free-cutting steel bar and preparation method thereof | |
| CN116479322B (en) | Steel for high-speed motor train gear box bearing and manufacturing method thereof | |
| CN116254403A (en) | Preparation process of export high-strength heat-treated steel rail | |
| CN114086061B (en) | 6.8-grade corrosion-resistant cold forging steel and production method 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 |