CN109082500A - The control method of rail hydrogen content - Google Patents
The control method of rail hydrogen content Download PDFInfo
- Publication number
- CN109082500A CN109082500A CN201810985622.2A CN201810985622A CN109082500A CN 109082500 A CN109082500 A CN 109082500A CN 201810985622 A CN201810985622 A CN 201810985622A CN 109082500 A CN109082500 A CN 109082500A
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- rail
- slow cooling
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- molten steel
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Classifications
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- 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
- C21C7/076—Use of slags or fluxes as treating agents
-
- 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
-
- 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
- C21C7/10—Handling in a vacuum
-
- 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
- C21D1/84—Controlled slow cooling
-
- 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
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/04—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for rails
-
- 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
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
The present invention provides a kind of control methods of rail hydrogen content, comprising: chooses low-sulfur, low-phosphorous molten iron and the steel scrap after overbaking is dry and carries out converter smelting；After molten steel enters LF refining, heat temperature raising, slag making, trimming are carried out；After molten steel goes out LF refining, into double refining VD vacuum outgas；Before molten steel casting, tundish refractory material is sufficiently toasted, in casting process, big water-coating port carries out argon gas-sealed protection；After casting, slab enters burial pit and carries out stacking slow cooling；Entering to cheat temperature is 600-700 DEG C, and slow cooling time is 5 days；Slab enters heating stove heating, and secondary cogging adds insulation cover slow cooling 5 days；Reheating is finally put in storage slow cooling by open rolling, finish to gauge.According to the technical solution of the present invention, the hydrogen content in rail is effectively controlled, the stability and reliability of the toughness of high strength rail, especially rail property are significantly improved, reduces risk of high strength rail during railway is on active service.
Description
Technical field
The present invention relates to metallurgical technology fields, in particular to a kind of control method of rail hydrogen content.
Background technique
As China Railway Freight load-carrying increase and speed are accelerated, in the inclement conditions such as railway line curve section and track switch portion
The failures such as the abrasion of existing pearlite steel rail, peeling that position uses are significantly increased, and production and line upkeep expense is caused to significantly improve,
There is an urgent need to improve rail comprehensive performance.And bainitic steel is as new steel system developed in recent years, intensity, hardness and tough
Property be significantly better than that traditional pearlite-ferrite steel, bainite structure has more preferable comprehensive performance than pearlitic structrure, on an equal basis
Under high intensity, bainite rail has more preferable wearability and contacting fatigue resistance etc. than pearlite steel rail.But due to bainite group
It knits and belongs to metastable state tissue, while is intensity with higher, related studies have shown that such steel may have than pearlite-iron element
The higher environmental cracking sensibility of body steel.
Especially high-strength tenacity bainitic steel is even more serious to the sensibility of hydrogen, when hydrogen content is excessively high in bainitic steel,
Hydrogen meeting segregation through diffusion leads to Delayed hydride cracking at the strong hydrogen trap such as crystal boundary during its military service, and hydrogen content is high
Heavy-loaded line rail for road show impact flexibility in terms of mechanical property and elongation percentage is low, to guarantee to influence the peace of railway operation
Entirely, the comprehensive performance to guarantee heavy-haul line high-strength tenacity rail, it is ensured that its stability and reliability during military service,
Hydrogen content in high-strength tenacity bainite rail need to be controlled.
Summary of the invention
The present invention is directed to solve at least one of the technical problems existing in the prior art or related technologies.
For this purpose, the object of the present invention is to provide a kind of control methods of rail hydrogen content.
In view of this, technical solution of the present invention provides a kind of control method of rail hydrogen content, comprising: choose low
Sulphur, low-phosphorous molten iron and the steel scrap after overbaking is dry carry out converter smelting, in converter steelmaking process, carry out BOTTOM ARGON BLOWING gas mixing
It mixes, in tapping process, the alloy and slag charge of addition carry out baking drying；After molten steel enters LF refining, carries out heat temperature raising, makes
Slag, trimming, melting slag system are calculated as according to wt%: CaO 52-57%, Al2O33.5-6.3%, SiO222-25%, MgO
5-8%, white slag refining time >=20 minute, refining process answer argon flow appropriate；After molten steel goes out LF refining, into secondary fine
Refine VD vacuum outgas, deep vacuum degree≤80Pa, deep vacuum time >=20 minute, soft blow time >=30 minute after deep vacuum, soft blow
Period controls argon flow 200-400Nl/min, forbids molten steel exposed；It is abundant to tundish refractory material before molten steel casting
It toasts, in casting process, big water-coating port carries out argon gas-sealed protection, and coverture, crystallizer submersed nozzle insertion is added in middle packet
Depth 130mm or more fills covering slag；After casting, slab enters burial pit and carries out stacking slow cooling；Entering to cheat temperature is 600-
700 DEG C, slow cooling time is 5 days；Slab enters heating stove heating, and secondary cogging adds insulation cover slow cooling 5 days；Reheating is passed through
Open rolling, finish to gauge roll into qualified rail type, and solid matter cooling is then carried out on cold bed, after aligning processing, are finally put in storage slow cooling.
One or more technical solution provided by the invention, has at least the following technical effects or advantages:
By using converter, LF refining, VD vacuum outgas, molten steel is cast into bloom, and slab carries out stacking slow cooling, through adding
Hot cogging effectively controls the middle hydrogen content of rail, significantly at qualified rail type at intermediate blank, reheating, open rolling, finish to gauge
The toughness of high strength rail, the especially stability and reliability of rail property are improved, product quality is improved, high strength rail is reduced and exists
Risk during railway military service.
A kind of control method of railway high-strength tenacity rail hydrogen content disclosed in technical solution of the present invention, for national item
Mesh is researched and developed programme support, 2017YFB0304500 (National Key R&D Program of China) by state key.
Additional aspect and advantage of the invention will be set forth in part in the description, and will partially become from the following description
Obviously, or practice through the invention is recognized.
Detailed description of the invention
Fig. 1 shows the flow diagram of the control method of the rail hydrogen content of the embodiment of the present invention.
Specific embodiment
In order to be more clearly understood that aforementioned aspect of the present invention, feature and advantage, With reference to embodiment
The present invention is further described in detail.It should be noted that in the absence of conflict, embodiments herein and reality
The feature applied in example can be combined with each other.
In the following description, numerous specific details are set forth in order to facilitate a full understanding of the present invention, still, the present invention may be used also
To be implemented using other than the one described here other modes, therefore, protection scope of the present invention is not by described below
Specific embodiment limitation.
The control method of the rail hydrogen content of embodiment according to the present invention, comprising: (1) choose low-sulfur, low-phosphorous molten iron
Converter smelting is carried out with the steel scrap after overbaking is dry, in converter steelmaking process, carries out argon bottom-blowing stirring, tapping process
In, the alloy and slag charge of addition should carry out baking drying.(2) after molten steel enters LF refining, heat temperature raising, slag making, ingredient are carried out
Fine tuning, melting slag system are CaO 52-57%, Al2O33.5-6.3%, SiO222-25%, MgO 5-8%, control white slag refining
Time >=20 minute, refining process answer argon flow appropriate；(3) it is de- into double refining VD vacuum after molten steel goes out LF refining
Gas, deep vacuum degree≤80Pa keep deep vacuum time >=20 minute, and soft blow time >=30 minute after deep vacuum are controlled during soft blow
Argon flow 200-400NL/min is made, forbids molten steel exposed；(4) before molten steel casting, tundish refractory material is sufficiently dried
Roasting, in casting process, big water-coating port carries out argon gas-sealed protection, and coverture is added in middle packet, and crystallizer submersed nozzle insertion is deep
130mm or more is spent, covering slag is filled, avoids secondary oxidation of steel.(5) after casting, slab enters burial pit and carries out stacking
Slow cooling, further dehydrogenation；Entering to cheat temperature is 600-700 DEG C, and slow cooling time is 5 days.(6) slab enters heating stove heating, secondary
Cogging adds insulation cover slow cooling 5 days.(7) reheating rolls into qualified rail type by open rolling, finish to gauge, then enterprising in cold bed
Row solid matter is cooling, after aligning processing, is finally put in storage slow cooling.
Embodiment 1:
Heavy haul railway high duty rails, molten steel hydrogen content are detected as 1.0ppm, using production technology road shown in FIG. 1
Line, it is 630 DEG C that casting blank stacking slow cooling, which enters to cheat temperature, and covering soaking time 5 days, secondary heat preservation slow cooling temperature was 860 DEG C, when holding
Between 5 days, the results are shown in Table 1 for the rail hydrogen content tested.
1 high duty rails hydrogen content testing result of table.
The results are shown in Table 2 for every mechanical properties test of measured high duty rails.
Table 2
Embodiment 2:
Heavy haul railway high duty rails, molten steel hydrogen content are detected as 0.8ppm, using production technology road shown in FIG. 1
Line, it is 650 DEG C that casting blank stacking slow cooling, which enters to cheat temperature, and covering soaking time 5 days, secondary heat preservation slow cooling temperature was 850 DEG C, when holding
Between 5 days, the results are shown in Table 3 for the rail hydrogen content tested.
3 high duty rails hydrogen content testing result of table.
The results are shown in Table 4 for every mechanical properties test of measured high duty rails.
Table 4
Embodiment 3:
Heavy haul railway high duty rails, rail water content are detected as 0.7ppm, using production technology road shown in FIG. 1
Line, it is 680 DEG C that casting blank stacking slow cooling, which enters to cheat temperature, and covering soaking time 5 days, secondary heat preservation slow cooling temperature was 890 DEG C, when holding
Between 5 days, the results are shown in Table 5 for the rail hydrogen content tested.
5 high duty rails hydrogen content testing result of table.
The results are shown in Table 6 for every mechanical properties test of measured high duty rails.
Table 6
Technical solution of the present invention is explained above, according to the technical solution of the present invention, by using converter, LF refining,
VD vacuum outgas, molten steel are cast into bloom, and slab carries out stacking slow cooling, and heated cogging is opened at intermediate blank, reheating
Roll, finish to gauge is at qualified rail type, the effective middle hydrogen content for controlling rail significantly improves the toughness of high strength rail, especially steel
The stability and reliability of rail performance improve product quality, reduce risk of high strength rail during railway is on active service.
In the description of this specification, the description of term " one embodiment ", " some embodiments ", " specific embodiment " etc.
Mean that particular features, structures, materials, or characteristics described in conjunction with this embodiment or example are contained at least one reality of the invention
It applies in example or example.In the present specification, schematic expression of the above terms are not necessarily referring to identical embodiment or reality
Example.Moreover, description particular features, structures, materials, or characteristics can in any one or more of the embodiments or examples with
Suitable mode combines.
The foregoing is only a preferred embodiment of the present invention, is not intended to restrict the invention, for the skill of this field
For art personnel, the invention may be variously modified and varied.All within the spirits and principles of the present invention, made any to repair
Change, equivalent replacement, improvement etc., should all be included in the protection scope of the present invention.
Claims (1)
1. a kind of control method of rail hydrogen content characterized by comprising
It chooses low-sulfur, low-phosphorous molten iron and the steel scrap after overbaking is dry and carries out converter smelting, in converter steelmaking process, carry out
Argon bottom-blowing stirs, and in tapping process, the alloy and slag charge of addition carry out baking drying；
After molten steel enters LF refining, heat temperature raising, slag making, trimming are carried out, melting slag system is calculated as according to wt%: CaO 52-
57%, Al2O33.5-6.3%, SiO222-25%, MgO 5-8%, white slag refining time >=20 minute, refining process should fit
When argon flow；
After molten steel goes out LF refining, into double refining VD vacuum outgas, deep vacuum degree≤80Pa, deep vacuum time >=20 minute,
Soft blow time >=30 minute after deep vacuum, control argon flow 200-400Nl/min during soft blow, forbid molten steel exposed；
Before molten steel casting, tundish refractory material sufficiently to be toasted, in casting process, big water-coating port carries out argon gas-sealed protection,
Coverture is added in middle packet, and crystallizer submersed nozzle insertion depth 130mm or more fills covering slag；
After casting, slab enters burial pit and carries out stacking slow cooling；Entering to cheat temperature is 600-700 DEG C, and slow cooling time is 5 days；
Slab enters heating stove heating, and secondary cogging adds insulation cover slow cooling 5 days；
Reheating rolls into qualified rail type by open rolling, finish to gauge, and solid matter cooling is then carried out on cold bed, is processed through aligning
Afterwards, finally it is put in storage slow cooling.
Priority Applications (1)
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| CN201810985622.2A CN109082500A (en) | 2018-08-28 | 2018-08-28 | The control method of rail hydrogen content |
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| CN201810985622.2A CN109082500A (en) | 2018-08-28 | 2018-08-28 | The control method of rail hydrogen content |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN110923405A (en) * | 2019-10-31 | 2020-03-27 | 邯郸钢铁集团有限责任公司 | Process control method for reducing hydrogen hazard in steel rail |
| CN111020102A (en) * | 2019-12-25 | 2020-04-17 | 芜湖新兴铸管有限责任公司 | Molten steel hydrogen content control method |
| CN111485066A (en) * | 2020-04-10 | 2020-08-04 | 包头钢铁（集团）有限责任公司 | Method for controlling inclusions in heavy rail steel by adopting refining slag |
| CN111545717A (en) * | 2020-06-30 | 2020-08-18 | 新余钢铁股份有限公司 | Pouring method of rare earth steel |
| CN111733310A (en) * | 2020-06-29 | 2020-10-02 | 包头钢铁（集团）有限责任公司 | Control method for effectively controlling inclusion components of heavy rail steel |
| CN115125367A (en) * | 2022-06-20 | 2022-09-30 | 河北普阳钢铁有限公司 | Production method for reducing H content in bridge steel without vacuum refining |
| CN117305536A (en) * | 2023-09-28 | 2023-12-29 | 河北普阳钢铁有限公司 | Method for producing ultralow hydrogen content steel under non-vacuum condition |
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110923405A (en) * | 2019-10-31 | 2020-03-27 | 邯郸钢铁集团有限责任公司 | Process control method for reducing hydrogen hazard in steel rail |
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| CN111485066A (en) * | 2020-04-10 | 2020-08-04 | 包头钢铁（集团）有限责任公司 | Method for controlling inclusions in heavy rail steel by adopting refining slag |
| CN111733310A (en) * | 2020-06-29 | 2020-10-02 | 包头钢铁（集团）有限责任公司 | Control method for effectively controlling inclusion components of heavy rail steel |
| CN111545717A (en) * | 2020-06-30 | 2020-08-18 | 新余钢铁股份有限公司 | Pouring method of rare earth steel |
| CN115125367A (en) * | 2022-06-20 | 2022-09-30 | 河北普阳钢铁有限公司 | Production method for reducing H content in bridge steel without vacuum refining |
| CN117305536A (en) * | 2023-09-28 | 2023-12-29 | 河北普阳钢铁有限公司 | Method for producing ultralow hydrogen content steel under non-vacuum condition |
| CN117305536B (en) * | 2023-09-28 | 2024-06-07 | 河北普阳钢铁有限公司 | Method for producing ultralow hydrogen content steel under non-vacuum condition |
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