CN109468531A - A kind of low yield strength ratio Q345qNH steel plate and preparation method thereof - Google Patents
A kind of low yield strength ratio Q345qNH steel plate and preparation method thereof Download PDFInfo
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- CN109468531A CN109468531A CN201811306990.6A CN201811306990A CN109468531A CN 109468531 A CN109468531 A CN 109468531A CN 201811306990 A CN201811306990 A CN 201811306990A CN 109468531 A CN109468531 A CN 109468531A
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- 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
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- 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
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0226—Hot rolling
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- 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
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- 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
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
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- 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
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
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- 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
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
-
- 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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/005—Ferrite
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- 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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/009—Pearlite
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- Mechanical Engineering (AREA)
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- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
The present invention provides a kind of low yield strength ratio Q345qNH steel plate and preparation method thereof, the ingredient of the steel plate presses mass percentage are as follows: C:0.04-0.06%, Si:0.20-0.30%, Mn:1.1-1.3%, P :≤0.015%, S :≤0.008%, Nb:0.01-0.02%, Cu:0.25-0.35%, Ni:0.3-0.4%, Cr:0.4-0.5%, Als:0.024-0.034%, surplus are Fe and inevitable impurity.The steel plate that the present invention obtains have low yield strength ratio, good corrosion resistance, low-temperature flexibility, cold forming capability, welding performance, can be in order to avoid coating uses, while its preparation process flow is simple, with short production cycle, production cost is low.
Description
Technical field
The invention belongs to field of steel metallurgy, and in particular to a kind of low yield strength ratio Q345qNH steel plate and preparation method thereof.
Background technique
It is even higher that A3 grade of the bridge steel plate used in China since most has gradually developed to present Q500q, passes
Not only impact flexibility, weldability, fatigability etc. are not ideal for the bridge steel plate of system, but also in the property such as resistance to atmosphere, marine corrosion
It is worse that performance can be gone up.With the development of modern bridge, the security reliability of bridge structure is also increasingly stringenter.This is not only to bridge
The designer of beam is a huge challenge, and to bridge steel plate, higher requirements are also raised, not only to be had high-intensitive with full
The structure lightened requirement of foot, but also should have excellent low-temperature flexibility, weldability, corrosion resistance and fatigue behaviour, have simultaneously
The characteristics such as the standby low, energy conservation and environmental protection of maintenance cost, high performance Weather-resistance bridge with steel because having above-mentioned performance as research hotspot, it is resistance to
The exploitation and application for waiting bridge steel plate become the development trend of bridge steel plate from now on.
Patent CN105331880A discloses a kind of high-strength weathering bridge steel and preparation method thereof, rolls through smelting-continuous casting-
System-stacking slow cooling obtains, and has intensity high and low temperature good-toughness, yield tensile ratio low, and it is excellent that welding performance is excellent and weatherability is good
Point.But alloy content is more in chemical component, and armor plate strength is higher.
Patent CN104711490A discloses a kind of low yield strength ratio high-performance bridge steel plate and its manufacturing method, through rolling-
Ultrafast cold technique obtains the low yield strength ratio bridge steel plate that yield strength is greater than 700MPa.But alloy content is more in chemical component,
Armor plate strength is high.
Patent CN102021495A discloses the preparation side of a kind of 420MPa high tenacity Weather-resistance bridge steel and its hot-rolled sheet coil
Method batches to obtain high tenacity Weather-resistance bridge steel through -7 rack finish rolling of smelting--2 rack roughing of continuous casting-heating-section cooling -.
But contains B element in chemical component, be also easy to produce crack defect, and be only applicable to production roll bending.
The content of background technology part is only the technology that inventor is known, not the existing skill of natural representative this field
Art.
Summary of the invention
For the prior art, there are one or more of problems, and it is an object of the present invention to provide a kind of yield strengths
Greater than 345MPa, with low yield strength ratio, good corrosion resistance, low-temperature flexibility, cold forming capability and welding performance can be with
Exempt from the Weather-resistance bridge steel plate that coating uses.
It is a further object of the present invention to provide the methods for preparing above-mentioned steel plate.
The purpose of the present invention is achieved through the following technical solutions:
In one aspect of the invention, the present invention provides a kind of low yield strength ratio Q345qNH steel plate, and the ingredient of the steel plate is pressed
Mass percentage are as follows:
C:0.04-0.06%, Si:0.20-0.30%, Mn:1.1-1.3%, P :≤0.015%, S :≤0.008%, Nb:
0.01-0.02%, Cu:0.25-0.35%, Ni:0.3-0.4%, Cr:0.4-0.5%, Als:0.024-0.034%, surplus are
Fe and inevitable impurity.
Preferably, the ingredient of above-mentioned steel plate presses mass percentage are as follows:
C:0.04-0.06%, Si:0.22-0.26%, Mn:1.21-1.25%, P :≤0.011%, S :≤0.008%,
Nb:0.011-0.015%, Cu:0.30-0.32%, Ni:0.33-0.35%, Cr:0.44-0.46%, Als:0.024-
0.028%, surplus is Fe and inevitable impurity.
Preferably, yield strength >=345MPa of above-mentioned steel plate, tensile strength >=490MPa, elongation percentage >=20%, Qu Qiang
Than≤0.85, -40 DEG C impact of collision function KV2≥120J。
Preferably, welding crack sensibility FACTOR P cm≤0.20% of above-mentioned steel plate, corrosion resistance index I >=6.0.
Preferably, the metallographic structure of above-mentioned steel plate includes ferrite and pearlite.
In another aspect of this invention, the present invention provides the preparation method of above-mentioned low yield strength ratio Q345qNH steel plate, institutes
The method of stating includes: smelting and casting, heating and rolling and cooling；It is wherein described to smelt and cast with above-mentioned ingredient by quality
Proportion carries out vacuum metling, casts after to be melted.
Preferably, in above-mentioned heating and rolling, the heating temperature of the heating is 1200 DEG C -1220 DEG C, the time >=
240min；The rolling includes the rolling of austenite recrystallization area and the rolling of austenite Unhydrated cement, wherein the austenite is again
The temperature of rolling of crystal region rolling is 1130-1180 DEG C, and 1-2 reduction in pass is greater than 10%, then has 1-2 percentage pass reduction big
In 25%；Start rolling temperature≤930 DEG C of the austenite Unhydrated cement rolling, workpiece thickness: 2.0-3.5 times of finished product thickness
Degree, finishing temperature: 830-850 DEG C.
Preferably, above-mentioned cooling uses section cooling first, is cooled to 610-630 DEG C with the cooling velocity of 10-15 DEG C/s
It is cooling using cold bed afterwards.
Based on above technical scheme, the present invention uses Ultra-low carbon composition design, reduces carbon equivalent, ensure that the welding of steel
Performance, the harmful elements contents such as control P, S, improves low-temperature flexibility；Trace alloying element Nb is added, effectively inhibition austenite crystal
Grain length is big, and by the big pressure of high temperature, fining austenite grains finally obtain tiny grain structure, by refined crystalline strengthening and tough
Change effect improves the intensity and low-temperature flexibility of steel；Addition corrosion resistance element Cu, Cr, Ni simultaneously control certain proportion, reach weather-proof
The intensity of steel also can be improved in characteristic；It is controlled by Ni/Cu, can not only reduce slab surface crack, the impact that steel also can be improved is tough
Property.
The invention has the benefit that
By reasonable Design of Chemical Composition, and the available yield strength of aforementioned production method is taken to be greater than 345MPa,
With low yield strength ratio, good corrosion resistance, low-temperature flexibility, cold forming capability and welding performance can be in order to avoid what coating uses
Weather-resistance bridge steel plate, while having that preparation process flow is simple, with short production cycle, the low feature of production cost.
Detailed description of the invention
Attached drawing is used to provide further understanding of the present invention, and constitutes part of specification, with reality of the invention
It applies example to be used to explain the present invention together, not be construed as limiting the invention.In the accompanying drawings:
Fig. 1 is the metallographic structure figure of the steel plate of one embodiment of the invention.
Specific embodiment
Hereinafter, certain exemplary embodiments are simply just described.As one skilled in the art will recognize that
Like that, without departing from the spirit or scope of the present invention, described embodiment can be modified by various different modes.
Therefore, attached drawing and description are considered essentially illustrative rather than restrictive.
Following disclosure provides many different embodiments or example is used to realize distinct methods of the invention.In order to
Simplify disclosure of the invention, hereinafter the material of specific examples and step are described.Certainly, they are merely examples, and
And it is not intended to limit the present invention.In addition, the present invention provides various specific techniques and material example, but ability
Domain those of ordinary skill can be appreciated that the application of other techniques and/or the use of other materials.
The object of the present invention is to provide a kind of yield strength be greater than 345MPa, have low yield strength ratio, good corrosion resistance,
Low-temperature flexibility, cold forming capability and welding performance can be in order to avoid the Weather-resistance bridge steel plate that coating uses, will be by detail below
Embodiment is realized:
In the first embodiment of the present invention, the present invention provides a kind of low yield strength ratio Q345qNH steel plate, the steel plate
Ingredient presses mass percentage are as follows:
C:0.04-0.06%, Si:0.20-0.30%, Mn:1.1-1.3%, P :≤0.015%, S :≤0.008%, Nb:
0.01-0.02%, Cu:0.25-0.35%, Ni:0.3-0.4%, Cr:0.4-0.5%, Als:0.024-0.034%, surplus are
Fe and inevitable impurity.
According to a preferred embodiment of the present invention, the ingredient of above-mentioned steel plate presses mass percentage are as follows:
C:0.04-0.06%, Si:0.22-0.26%, Mn:1.21-1.25%, P :≤0.011%, S :≤0.008%,
Nb:0.011-0.015%, Cu:0.30-0.32%, Ni:0.33-0.35%, Cr:0.44-0.46%, Als:0.024-
0.028%, surplus is Fe and inevitable impurity.
According to a preferred embodiment of the present invention, yield strength >=345MPa of above-mentioned steel plate, tensile strength >=
490MPa, elongation percentage >=20%, yield tensile ratio≤0.85, -40 DEG C of impact of collision function KV2≥120J。
According to a preferred embodiment of the present invention, welding crack sensibility FACTOR P cm≤0.20% of above-mentioned steel plate, it is resistance to
Corrosive nature index I >=6.0.
According to a preferred embodiment of the present invention, the metallographic structure of above-mentioned steel plate includes ferrite and pearlite.
The present invention uses Ultra-low carbon composition design, reduces carbon equivalent, ensure that the welding performance of steel, and control P, S etc. have
Evil constituent content, improves low-temperature flexibility；Trace alloying element Nb is added, effectively inhibition Austenite Grain Growth, passes through high temperature
Big pressure, fining austenite grains finally obtain tiny grain structure, improve the strong of steel by refined crystalline strengthening and toughening effect
Degree and low-temperature flexibility；Addition corrosion resistance element Cu, Cr, Ni simultaneously control certain proportion, reach weathering characteristics, steel also can be improved
Intensity；It is controlled by Ni/Cu, can not only reduce slab surface crack, the impact flexibility of steel also can be improved.
In second embodiment of the present invention, the present invention provides the preparations of above-mentioned low yield strength ratio Q345qNH steel plate
Method, which comprises smelt and cast, heat and roll and is cooling；Wherein it is described smelting and casting with it is above-mentioned at
Divide and carry out vacuum metling by quality proportioning, casts after to be melted.In this embodiment, the smelting and casting step are specific
Are as follows: by ready low-phosphorous (≤0.010%), low-sulfur (≤0.005%), hypoxemia (≤0.0040%), low nitrogen (≤
0.0060%) high-quality steel scrap and other alloys for preparing are calculated laboratory 100kg vacuum smelting furnace are added, start after vacuumizing into
Row fusing is smelted, and is cast in rectangle punching block after to be melted, is cast into the rectangle steel billet having a size of 220 × 250 × 300mm.
According to a preferred embodiment of the present invention, in above-mentioned heating and rolling, the heating temperature of the heating is 1200
DEG C -1220 DEG C, the time >=240min；The rolling includes that the rolling of austenite recrystallization area and austenite Unhydrated cement roll,
Wherein the temperature of rolling of the austenite recrystallization area rolling is 1130-1180 DEG C, and 1-2 reduction in pass is greater than 10%, then
There is 1-2 percentage pass reduction to be greater than 25%；Start rolling temperature≤930 DEG C of the austenite Unhydrated cement rolling, workpiece thickness:
2.0-3.5 times of finished product thickness, finishing temperature: 830-850 DEG C.In this embodiment, the heating and milling step specifically: use
Steel billet is fitted into high temperature resistance furnace by manipulator.1200 DEG C~1220 DEG C of heating temperature, total time inside furnace >=240min, it is ensured that steel
Base temperature is uniform, when steel billet reaches heating requirements, is sent to steel billet with manipulator Experimental mill.Using
The rolling of two-stage control rolling mill practice, i.e. austenite recrystallization area and the rolling of austenite Unhydrated cement.In austenite recrystallization
When area rolls, start rolling temperature is 1130~1180 DEG C, and 1-2 reduction in pass should be greater than 10%, secondly at least 1-2 passage pressure
Lower rate control is 25% or more, sufficiently to refine original austenite grains；In the rolling of austenite Unhydrated cement, this stage
Rolling extend austenite, grain boundary area increases, while deformation causes intra-die to import a large amount of Zona transformans, behind γ
Enhancing Nucleation Density and nucleation point increase when → α phase transformation, and crystal grain further refines.Start rolling temperature≤930 DEG C are set, workpiece thickness:
2.0-3.5 times of finished product thickness, finishing temperature: 830-850 DEG C.
According to a preferred embodiment of the present invention, after controlled rolling, above-mentioned cooling uses section cooling first, with
The cooling velocity of 10-15 DEG C/s is cooling using cold bed after being cooled to 610-630 DEG C.
Hereinafter, preferred embodiments of the present invention will be described, it should be understood that preferred embodiment described herein is only used
In the description and interpretation present invention, it is not intended to limit the present invention.
Embodiment 1:
It is smelted by chemical component shown in table 1, and is cast into steel ingot, by Heating Steel Ingots to 1210 DEG C, total time inside furnace 252
Minute, on experimental mill carry out first stage rolling, i.e., austenite recrystallization area roll, start rolling temperature be 1176 DEG C, the 1st~
2 reductions in pass should be greater than 10%, and secondly the control of at least 1~2 percentage pass reduction is 25% or more, when rolled piece is with a thickness of 45mm
When, to temperature to 930 DEG C on roller-way, second stage rolling is then carried out, i.e. austenite Unhydrated cement rolls.Finishing temperature is
830 DEG C, finished steel plate is with a thickness of 14mm.After rolling, steel plate enters cooling facility for laminar flow, is cooled to the speed of 10 DEG C/s
630 DEG C, the steel plate finally can be obtained.
Embodiment 2:
Method is with embodiment 1, and wherein heating temperature is 1220 DEG C, and total time inside furnace keeps the temperature 256 minutes, first stage rolling
Start rolling temperature be 1175 DEG C, workpiece thickness 60mm, the start rolling temperature of second stage rolling is 925 DEG C, and finishing temperature is
836 DEG C, finished steel plate is with a thickness of 20mm.After rolling, steel plate enters cooling facility for laminar flow, is cooled to the speed of 12 DEG C/s
620 DEG C, the steel plate finally can be obtained.As shown in Figure 1, the metallographic structure of the steel plate of embodiment acquisition is shown, from figure
In it can clearly be seen that the metallographic structure of steel plate that obtains of the present invention is based on ferrite and pearlite, and crystal grain is intensive and thin
Change, so that the steel plate that the present invention is prepared has stronger intensity and low-temperature flexibility.
Embodiment 3:
Method is with embodiment 1, and wherein heating temperature is 1226 DEG C, total time inside furnace 260 minutes；First stage rolling is opened
Rolling temperature is 1180 DEG C, workpiece thickness 80mm；The start rolling temperature of second stage rolling is 930 DEG C, finishing temperature 850
DEG C, finished steel plate is with a thickness of 40mm；After rolling, steel plate enters cooling facility for laminar flow, is cooled to 610 with the speed of 15 DEG C/s
DEG C, the steel plate finally can be obtained.
Table 1: the chemical component and mass percentage (%) of 1-3 of the embodiment of the present invention
| Embodiment | C | Si | Mn | P | S | Nb | Cu | Ni | Cr | Als |
| 1 | 0.06 | 0.22 | 1.22 | 0.011 | 0.002 | 0.011 | 0.32 | 0.35 | 0.44 | 0.025 |
| 2 | 0.05 | 0.26 | 1.21 | 0.011 | 0.002 | 0.013 | 0.30 | 0.33 | 0.45 | 0.024 |
| 3 | 0.06 | 0.23 | 1.25 | 0.010 | 0.002 | 0.015 | 0.31 | 0.34 | 0.46 | 0.028 |
Mechanical properties test is carried out to the steel plate of 1-3 of the embodiment of the present invention, inspection result is shown in Table 2.
Table 2: the mechanical property of the steel plate of 1-3 of the embodiment of the present invention
From the data in table 2, it can be seen that steel plate involved in the embodiment of the present invention is all satisfied yield strength >=345MPa, tensile strength
>=490MPa, elongation percentage >=20%, yield tensile ratio≤0.85, -40 DEG C of impact of collision function KV2≥120J。
Table 3 is steel of embodiment of the present invention welding crack sensibility FACTOR P cm and corrosion resistance index I.Wherein welding is split
Line sensitivity coefficient Pcm value is smaller, shows that the welding performance of steel is better, and when welding is not likely to produce welding cold cracking；Corrosion resistance refers to
Number I is bigger, shows that corrosion resistance is better.
Table 3: 1-3 steel plate welding crack sensibility FACTOR P cm and corrosion resistance index I of the embodiment of the present invention
By upper table 3 it is obvious that the weld crack sensitivity coefficient of each steel plate all meets in 1-3 of the embodiment of the present invention
Pcm≤0.20 shows that the welding performance of steel is better, and when welding is not likely to produce welding cold cracking；Corrosion resistance index is all satisfied I
>=6.0, the steel plate corrosion resistance for showing that the present invention obtains is good, and steel plate, which has, exempts from coating use condition.
From above-described embodiment result it is found that the steel plate that can be used for Weather-resistance bridge steel of the invention has excellent mechanical property
Energy, especially its low-temperature flexibility, while there is good welding performance and atmospheric corrosion resistance.
Finally, it should be noted that the foregoing is only a preferred embodiment of the present invention, it is not intended to restrict the invention,
Although the present invention is described in detail referring to the foregoing embodiments, for those skilled in the art, still may be used
To modify the technical solutions described in the foregoing embodiments or equivalent replacement of some of the technical features.
All within the spirits and principles of the present invention, any modification, equivalent replacement, improvement and so on should be included in of the invention
Within protection scope.
Claims (7)
1. a kind of low yield strength ratio Q345qNH steel plate, which is characterized in that the ingredient of the steel plate presses mass percentage are as follows:
C:0.04-0.06%, Si:0.20-0.30%, Mn:1.1-1.3%, P :≤0.015%, S :≤0.008%, Nb:
0.01-0.02%, Cu:0.25-0.35%, Ni:0.3-0.4%, Cr:0.4-0.5%, Als:0.024-0.034%, surplus are
Fe and inevitable impurity.
2. low yield strength ratio Q345qNH steel plate described in claim 1, which is characterized in that the ingredient of the steel plate presses quality percentage
Content are as follows:
C:0.04-0.06%, Si:0.22-0.26%, Mn:1.21-1.25%, P :≤0.011%, S :≤0.008%, Nb:
0.011-0.015%, Cu:0.30-0.32%, Ni:0.33-0.35%, Cr:0.44-0.46%, Als:0.024-0.028%,
Surplus is Fe and inevitable impurity.
3. low yield strength ratio Q345qNH steel plate of any of claims 1 or 2, which is characterized in that the yield strength of the steel plate >=
345MPa, tensile strength >=490MPa, elongation percentage >=20%, yield tensile ratio≤0.85, -40 DEG C of impact of collision function KV2≥120J；
Welding crack sensibility FACTOR P cm≤0.20% of the steel plate, corrosion resistance index I >=6.0.
4. low yield strength ratio Q345qNH steel plate of any of claims 1 or 2, which is characterized in that the metallographic structure of the steel plate includes
Ferrite and pearlite.
5. the preparation method of low yield strength ratio Q345qNH steel plate of any of claims 1-4, which is characterized in that described
Method includes: smelting and casting, heating and rolling and cooling；Wherein the smelting and casting are with any in claim 1-4
Ingredient described in carries out vacuum metling by quality proportioning, casts after to be melted.
6. method described in claim 5, which is characterized in that in the heating and rolling, the heating temperature of the heating is
1200 DEG C -1220 DEG C, the time >=240min；The rolling includes that the rolling of austenite recrystallization area and austenite Unhydrated cement roll
System, wherein the temperature of rolling of austenite recrystallization area rolling is 1130-1180 DEG C, 1-2 reduction in pass is greater than 10%, with
After have 1-2 percentage pass reduction be greater than 25%；Start rolling temperature≤930 DEG C of the austenite Unhydrated cement rolling, intermediate base are thick
Degree: 2.0-3.5 times of finished product thickness, finishing temperature: 830-850 DEG C.
7. method described in claim 5, which is characterized in that the cooling uses section cooling first, with the cold of 10-15 DEG C/s
But it is cooling using cold bed after speed is cooled to 610-630 DEG C.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115074620A (en) * | 2022-05-18 | 2022-09-20 | 包头钢铁（集团）有限责任公司 | Q345qENH high-performance weather-proof bridge steel and production method thereof |
| CN115323286A (en) * | 2022-07-12 | 2022-11-11 | 包头钢铁（集团）有限责任公司 | Rare earth microalloyed Q345 qDNH-grade weather-proof seamless steel tube for bridge and manufacturing method thereof |
| CN115449716A (en) * | 2022-10-08 | 2022-12-09 | 包头钢铁（集团）有限责任公司 | Smelting and continuous casting method of Q420-grade hot-rolled H-shaped steel for bridge structure |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107557665A (en) * | 2017-08-30 | 2018-01-09 | 包头钢铁（集团）有限责任公司 | A kind of yield strength 345MPa levels rare earth Weather-resistance bridge steel plate and its production method |
| CN107574374A (en) * | 2017-08-30 | 2018-01-12 | 包头钢铁（集团）有限责任公司 | A kind of yield strength 420MPa levels rare earth Weather-resistance bridge steel plate and its production method |
| CN107686943A (en) * | 2017-08-30 | 2018-02-13 | 包头钢铁（集团）有限责任公司 | A kind of yield strength 370MPa levels rare earth Weather-resistance bridge steel plate and preparation method thereof |
-
2018
- 2018-11-05 CN CN201811306990.6A patent/CN109468531A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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| CN107574374A (en) * | 2017-08-30 | 2018-01-12 | 包头钢铁（集团）有限责任公司 | A kind of yield strength 420MPa levels rare earth Weather-resistance bridge steel plate and its production method |
| CN107686943A (en) * | 2017-08-30 | 2018-02-13 | 包头钢铁（集团）有限责任公司 | A kind of yield strength 370MPa levels rare earth Weather-resistance bridge steel plate and preparation method thereof |
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| CN115323286A (en) * | 2022-07-12 | 2022-11-11 | 包头钢铁（集团）有限责任公司 | Rare earth microalloyed Q345 qDNH-grade weather-proof seamless steel tube for bridge and manufacturing method thereof |
| CN115449716A (en) * | 2022-10-08 | 2022-12-09 | 包头钢铁（集团）有限责任公司 | Smelting and continuous casting method of Q420-grade hot-rolled H-shaped steel for bridge structure |
| CN115449716B (en) * | 2022-10-08 | 2023-12-08 | 包头钢铁（集团）有限责任公司 | Smelting continuous casting method of Q420-grade hot rolled H-shaped steel for bridge structure |
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