CN115323266A - Economical Q370qE steel plate with yield ratio less than or equal to 0.85 and manufacturing method and application thereof - Google Patents
Economical Q370qE steel plate with yield ratio less than or equal to 0.85 and manufacturing method and application thereof Download PDFInfo
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- CN115323266A CN115323266A CN202210832701.6A CN202210832701A CN115323266A CN 115323266 A CN115323266 A CN 115323266A CN 202210832701 A CN202210832701 A CN 202210832701A CN 115323266 A CN115323266 A CN 115323266A
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 54
- 239000010959 steel Substances 0.000 title claims abstract description 54
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 15
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 13
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 7
- 239000012535 impurity Substances 0.000 claims abstract description 7
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 6
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 4
- 229910052802 copper Inorganic materials 0.000 claims abstract description 4
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 4
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 4
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 4
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 4
- 238000001816 cooling Methods 0.000 claims description 36
- 238000005096 rolling process Methods 0.000 claims description 34
- 238000000034 method Methods 0.000 claims description 14
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 13
- 229910052742 iron Inorganic materials 0.000 claims description 6
- 238000010008 shearing Methods 0.000 claims description 5
- 230000009467 reduction Effects 0.000 claims description 4
- 238000003303 reheating Methods 0.000 claims description 4
- 229910001562 pearlite Inorganic materials 0.000 claims description 3
- 238000002791 soaking Methods 0.000 claims description 3
- 229910000859 α-Fe Inorganic materials 0.000 claims description 3
- 238000005520 cutting process Methods 0.000 abstract description 4
- 239000002699 waste material Substances 0.000 abstract 1
- 239000011572 manganese Substances 0.000 description 8
- 238000003723 Smelting Methods 0.000 description 7
- 238000010438 heat treatment Methods 0.000 description 6
- 230000007704 transition Effects 0.000 description 4
- 238000009851 ferrous metallurgy Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 239000003973 paint Substances 0.000 description 2
- 229910052720 vanadium Inorganic materials 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 206010000496 acne Diseases 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000006356 dehydrogenation reaction Methods 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 238000009440 infrastructure construction Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000010907 mechanical stirring Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000004886 process control Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
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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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
- B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
-
- 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
- C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
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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
-
- 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
-
- 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
- C22C38/20—Ferrous alloys, e.g. steel alloys containing chromium with copper
-
- 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
- C22C38/26—Ferrous alloys, e.g. steel alloys containing chromium with niobium or tantalum
-
- 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
- C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
-
- 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
- C22C38/32—Ferrous alloys, e.g. steel alloys containing chromium with boron
-
- 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
- C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
-
- 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
-
- 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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- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
- E01D2101/00—Material constitution of bridges
- E01D2101/30—Metal
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- 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 Steel (AREA)
Abstract
The invention discloses an economical Q370qE steel plate with a yield ratio less than or equal to 0.85, and a manufacturing method and application thereof. The Q370qE steel plate comprises the following components in percentage by weight: comprises the following components in percentage by weight: 0.05 to 0.08 percent of C, less than or equal to 0.18 percent of Si, 1.50 to 1.60 percent of Mn, 0.020 to 0.05 percent of Al, 0.010 to 0.020 percent of Ti, less than or equal to 0.10 percent of Cu, less than or equal to 0.020 percent of P, less than or equal to 0.005 percent of S, less than or equal to 0.050 percent of N, 0.030 to 0.040 percent of Nb, 0.20 to 0.25 percent of Cr, less than or equal to 0.0005 percent of B, the balance of impurity elements, and the carbon equivalent Ceq is less than or equal to 0.38 percent. The Q370qE steel plate obtained by the invention has excellent mechanical property, the yield ratio is less than or equal to 0.85, the cutting amount is reduced, and the resource waste is low.
Description
Technical Field
The invention belongs to the field of ferrous metallurgy, and particularly relates to an economical Q370qE steel plate with a yield ratio less than or equal to 0.85, and a manufacturing method and application thereof.
Background
Q370qE is widely applied to structural and mechanical parts of river-crossing bridges and sea-crossing bridges at present. With the continuous progress of bridge infrastructure construction in China, the demand of Q370qE is increasing, and the Q370qE is one of the steel grades commonly produced in batches by various domestic steel enterprises.
The demand of Q370qE is continuously increased, the mechanical property and the higher low-temperature impact requirement of the product are ensured, the yield ratio requirement is also set to be less than or equal to 0.85, but the abnormal high strength of the head and the tail of the steel plate is caused by the rolling of the blackhead and the tail, and the condition that the strength of the steel plate is not consistent with the strength of the actual whole plate steel plate is finally obtained, so that the loss of yield caused by the extra cutting amount of 1500mm is mostly selected, the cost is increased by phase change in the industrial production, and the development of a production method for resisting low-temperature impact and reducing the yield ratio is urgently needed.
CN110735085A discloses a method for manufacturing thin Q345qE and Q370qE steel plates, belonging to the field of ferrous metallurgy. The method is suitable for the steel plate for the bridge steel with the thickness less than or equal to 10mm, and comprises the following steps: mechanical stirring desulfurization of molten iron KR, oxygen blowing smelting in a converter, refining in an LF furnace, vacuum dehydrogenation treatment in an RH furnace, calcium line feeding, soft stirring, continuous slab casting, slab heating, cogging rolling, reheating of transition slabs, continuous rolling, natural air cooling of steel plates and straightening of steel plates. Wherein the heating temperature of the slab heating stage is 1160-1250 ℃, and the in-furnace time is not less than 1.1min/mm; in the cogging stage, rolling a transition blank with the thickness of 80-100 mm from an original plate blank and naturally cooling, heating the temperature of 1120-1220 ℃ in the reheating stage of the transition blank, continuously rolling without controlled rolling in the rolling stage of the transition blank, and cooling the steel plate by adopting a natural air cooling method without water spraying for accelerated cooling. The method has the advantages of good performance, good plate shape control, reduction of manufacturing difficulty of thin specifications Q345qE and Q370qE, thin applicable thickness specification and the like. However, this technique still requires cogging, with intermediate loss of cogging cost and inability to roll steel plate of too great thickness due to small billet size.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides an economical Q370qE steel plate with the yield ratio less than or equal to 0.85 and a manufacturing method and application thereof.
In order to solve the problems of the prior art, the invention adopts the technical scheme that:
an economical Q370qE steel plate with a yield ratio less than or equal to 0.85, comprising the following components in percentage by weight: 0.05 to 0.08 percent of C, less than or equal to 0.18 percent of Si, 1.50 percent to 1.60 percent of Mn, 0.020 to 0.05 percent of Al, 0.010 to 0.020 percent of Ti, less than or equal to 0.10 percent of Cu, less than or equal to 0.020 percent of P, less than or equal to 0.005 percent of S, less than or equal to 0.050 percent of N, 0.030 to 0.040 percent of Nb, 0.20 to 0.25 percent of Cr, less than or equal to 0.0005 percent of B, and the balance of Fe and inevitable impurity elements, wherein the carbon equivalent Ceq [ = C + Mn/6+ (Cr + Mo + V)/5 + (Cu + Ni)/15 ] of Q370qE is less than or equal to 0.38 percent.
The improved paint comprises the following components in percentage by weight: 0.065% of C, 0.13% of Si, 1.55% of Mn, 0.035% of Al, 0.015% of Ti, less than or equal to 0.10% of Cu, less than or equal to 0.020% of P, less than or equal to 0.005% of S, less than or equal to 0.050% of N, 0.030-0.040% of Nb, 0.022% of Cr, less than or equal to 0.0005% of B, and the balance of iron and inevitable impurity elements; the carbon equivalent Ceq of the Q370qE is less than or equal to 0.38 percent.
As an improvement, the Q370qE steel plate with the economic yield ratio less than or equal to 0.85 is applicable to the thickness of 8-25mm.
The manufacturing method of the Q370qE steel plate with the economic yield ratio less than or equal to 0.85 comprises the following steps:
step 1, heating of the slab
The temperature is controlled to be 1180-1200 ℃, the temperature of the soaking section is controlled to be 1140-1160 ℃, and the furnace time is not less than 300min;
step 2, rolling stage
The rolling stage comprises two stages of rough rolling and finish rolling, wherein the rough rolling reduction is 60-80%, and the finish rolling temperature is 850 +/-20 ℃;
step 3, rapidly cooling the steel plate
When t is more than or equal to 8mm and less than 10mm, the final cooling temperature is 680 +/-20 ℃; when t is less than 16mm and the thickness of the finished product is less than or equal to 10mm, the final cooling temperature is 660 +/-20 ℃; when t is more than or equal to 16mm and less than 25mm, the final cooling temperature is 650 +/-20 ℃;
and 4, hot straightening of the steel plate, cooling on a cooling bed, shearing and warehousing.
The improvement is that the cooling rate is air cooling rate.
As a modification, the cooling rate in step 3 is controlled to be 15-20 ℃/s.
As a modification, the final structure of the obtained Q370qE steel plate is a ferrite + pearlite structure, and the head part only needs to be cut off by 300-500mm.
The application of the Q370qE steel plate with the economic yield ratio less than or equal to 0.85 in bridge steel.
Has the advantages that:
compared with the prior art, the invention relates to an economical Q370qE steel plate with the yield ratio less than or equal to 0.85, and a manufacturing method and application thereof, and is particularly suitable for preparing the Q370qE steel plate with the thickness of 8-25mm, wherein the yield strength of the obtained Q370qE steel plate is more than or equal to 370MPa, the tensile strength is more than or equal to 510MPa, the elongation (A) is more than or equal to 20%, the Charpy impact power at 40 ℃ below zero is more than or equal to 120J, and the yield ratio is less than or equal to 0.85. In addition, other precious elements such as V, cu and the like are not added in the components, so that the production cost is low, and the method is suitable for industrialization.
Drawings
FIG. 1 is a 1/2 thickness of 15mm tissue;
FIG. 2 is a 1/4 thickness of the tissue of 15 mm;
FIG. 3 is a 15mm surface texture;
FIG. 4 is a 15mm finish rolling temperature profile;
FIG. 5 is a 15mm final cooling temperature plot.
Detailed Description
The following examples are presented to enable one of ordinary skill in the art to more fully understand the present invention and are not intended to limit the invention in any way.
An economical Q370qE steel plate with a yield ratio of less than or equal to 0.85 comprises the following components in percentage by weight: 0.05 to 0.08 percent of C, less than or equal to 0.18 percent of Si, 1.50 to 1.60 percent of Mn, 0.020 to 0.05 percent of Al, 0.010 to 0.020 percent of Ti, less than or equal to 0.10 percent of Cu, less than or equal to 0.020 percent of P, less than or equal to 0.005 percent of S, less than or equal to 0.050 percent of N, 0.030 to 0.040 percent of Nb, 0.20 to 0.25 percent of Cr, less than or equal to 0.0005 percent of B, and the balance of iron and inevitable impurity elements, wherein the carbon equivalent Ceq [ = C + Mn/6+ (Cr + Mo + V)/5 + (Cu + Ni)/15 ] of Q370qE is less than or equal to 0.38 percent.
The paint comprises the following components in percentage by weight: 0.065% of C, 0.13% of Si, 1.55% of Mn, 0.035% of Al, 0.015% of Ti, less than or equal to 0.10% of Cu, less than or equal to 0.020% of P, less than or equal to 0.005% of S, less than or equal to 0.050% of N, 0.030-0.040% of Nb, 0.022% of Cr, less than or equal to 0.0005% of B, and the balance of iron and inevitable impurity elements; the carbon equivalent Ceq of the Q370qE is less than or equal to 0.38 percent.
The economic Q370qE steel plate with the yield ratio less than or equal to 0.85 is applicable to the thickness of 8-25mm.
The specific route of the method for manufacturing the Q370qE steel plate with the economic yield ratio less than or equal to 0.85 is as follows: reheating a plate blank, rough rolling, finish rolling, rapidly cooling a steel plate, thermally straightening the steel plate, cooling on a cooling bed, shearing, warehousing,
step 1, heating of slab
The temperature is controlled to be 1180-1200 ℃, the temperature of a soaking section is controlled to be 1140-1160 ℃, and the time in the furnace is not less than 300min;
step 2, rolling stage
The rolling stage comprises two stages of rough rolling and finish rolling, wherein the rough rolling reduction is 60-80%, and the finish rolling temperature is 850 +/-20 ℃;
step 3, rapidly cooling the steel plate
When the thickness of the finished product is not less than 8mm and t is less than 10mm, the final cooling temperature is 680 +/-20 ℃; when t is less than 16mm and the thickness of the finished product is less than or equal to 10mm, the final cooling temperature is 660 +/-20 ℃; when t is more than or equal to 16mm and less than 25mm, the final cooling temperature is 650 +/-20 ℃;
and 4, hot straightening of the steel plate, cooling on a cooling bed, shearing and warehousing.
Wherein the cooling rate is an air cooling rate.
The cooling speed in the step 3 is controlled to be 15-20 ℃/s.
The final structure of the obtained Q370qE steel plate is a ferrite plus pearlite structure, and the head part only needs to be cut off by 300-500mm.
The economic Q370qE steel plate with the yield ratio less than or equal to 0.85 is applied to bridge steel.
In the embodiment, the control parameters of the smelting heat and the mother plate rolling process are shown in the table 1, the smelting components of the smelting heat are shown in the table 2, and the mechanical properties of the hot rolling mother plate are shown in the table 3.
Table 1: example smelting heat and mother plate rolling technological process control parameters
Table 2: EXAMPLES smelting compositions of smelting furnace
Table 3: mechanical properties of hot-rolled mother plate of examples (cutting allowance 300 mm): inspection according to GBT 228
The method is particularly suitable for preparing the Q370qE steel plate with the thickness of 8-25mm, the Q370qE steel plate is sampled by shearing 300-500mm after rolling, the yield strength of the obtained Q370qE steel plate is more than or equal to 370MPa, the tensile strength is more than or equal to 510MPa, the elongation (A) is more than or equal to 20 percent, the Charpy impact work at minus 40 ℃ is more than or equal to 120J, the yield ratio is less than or equal to 0.85, the method is economically realized by low-carbon high-manganese components and a rolling process, the temperature uniformity of the whole plate is better by controlling the rolling pass and the opening times of rolling descaling water, the additional cutting amount of 800-1000mm is reduced compared with the medium-carbon low-manganese components, and the method is not worthy of economic development. In addition, other precious elements such as V, cu and the like are not added into the components, so that the production cost is low, and the method is suitable for industrialization.
Claims (8)
1. An economical Q370qE steel plate with a yield ratio less than or equal to 0.85, characterized by comprising the following components in percentage by weight: 0.05 to 0.08 percent of C, less than or equal to 0.18 percent of Si, 1.50 to 1.60 percent of Mn, 0.020 to 0.05 percent of Al, 0.010 to 0.020 percent of Ti, less than or equal to 0.10 percent of Cu, less than or equal to 0.020 percent of P, less than or equal to 0.005 percent of S, less than or equal to 0.050 percent of N, 0.030 to 0.040 percent of Nb, 0.20 to 0.25 percent of Cr, less than or equal to 0.0005 percent of B, and the balance of iron and inevitable impurity elements, wherein the carbon equivalent Ceq [ = C + Mn/6+ (Cr + Mo + V)/5 + (Cu + Ni)/15 ] of Q370qE is less than or equal to 0.38 percent.
2. The economical Q370qE steel sheet according to claim 1 having a yield ratio ≦ 0.85, characterized by comprising the following components in weight percent: 0.065% of C, 0.13% of Si, 1.55% of Mn, 0.035% of Al, 0.015% of Ti, less than or equal to 0.10% of Cu, less than or equal to 0.020% of P, less than or equal to 0.005% of S, less than or equal to 0.050% of N, 0.030-0.040% of NbB, 0.022% of Cr, less than or equal to 0.0005% of B, and the balance of iron and inevitable impurity elements; the carbon equivalent Ceq of the Q370qE is less than or equal to 0.38 percent.
3. The Q370qE steel plate with the economic yield ratio less than or equal to 0.85 as claimed in claim 1, wherein the Q370qE steel plate with the economic yield ratio less than or equal to 0.85 is suitable for the thickness of 8-25mm.
4. The method for manufacturing the Q370qE steel plate with the economic yield ratio of less than or equal to 0.85 according to claim 1, which comprises the following steps:
step 1, slab reheating
The temperature is controlled to be 1180-1200 ℃, the temperature of the soaking section is controlled to be 1140-1160 ℃, and the furnace time is not less than 300min;
step 2, rolling stage
The rolling stage comprises two stages of rough rolling and finish rolling, wherein the rough rolling reduction is 60-80%, and the finish rolling temperature is 850 +/-20 ℃;
step 3, rapidly cooling the steel plate
When the thickness of the finished product is not less than 8mm and t is less than 10mm, the final cooling temperature is 680 +/-20 ℃; when t is more than or equal to 10mm and less than 16mm of the thickness of the finished product, the final cooling temperature is 660 +/-20 ℃; when t is less than 25mm and the thickness of the finished product is less than or equal to 16mm, the final cooling temperature is 650 +/-20 ℃;
and 4, hot straightening of the steel plate, cooling on a cooling bed, shearing and warehousing.
5. The method of claim 4, wherein the cooling rate is an air cooling rate.
6. The method of claim 4, wherein the cooling rate in step 3 is controlled to 15-20 ℃/s.
7. The method for manufacturing the Q370qE steel plate with the economic yield ratio less than or equal to 0.85 according to claim 4, wherein the final structure of the obtained Q370qE steel plate is a ferrite + pearlite structure, and the head part only needs to be cut off by 300-500mm.
8. Application of the Q370qE steel plate based on any one of claims 1 or 4 on bridge steel.
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| CN202210832701.6A CN115323266A (en) | 2022-07-14 | 2022-07-14 | Economical Q370qE steel plate with yield ratio less than or equal to 0.85 and manufacturing method and application thereof |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103981452A (en) * | 2014-05-28 | 2014-08-13 | 江苏省沙钢钢铁研究院有限公司 | Economical air-cooling double-phase low-yield-ratio steel plate and production process thereof |
| WO2018036382A1 (en) * | 2016-08-23 | 2018-03-01 | 南京钢铁股份有限公司 | Method for preparing stainless steel composite plate for tmcp bridge |
| CN108914007A (en) * | 2018-08-10 | 2018-11-30 | 武汉钢铁集团鄂城钢铁有限责任公司 | A kind of the low yield strength ratio high-performance bridge steel plate plate and its manufacturing method of low-carbon and low-alloy |
| WO2020158228A1 (en) * | 2019-01-29 | 2020-08-06 | Ｊｆｅスチール株式会社 | High-strength steel sheet and method for producing same |
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| WO2018036382A1 (en) * | 2016-08-23 | 2018-03-01 | 南京钢铁股份有限公司 | Method for preparing stainless steel composite plate for tmcp bridge |
| CN108914007A (en) * | 2018-08-10 | 2018-11-30 | 武汉钢铁集团鄂城钢铁有限责任公司 | A kind of the low yield strength ratio high-performance bridge steel plate plate and its manufacturing method of low-carbon and low-alloy |
| WO2020158228A1 (en) * | 2019-01-29 | 2020-08-06 | Ｊｆｅスチール株式会社 | High-strength steel sheet and method for producing same |
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