CN106702118B - Cooling process for reducing work hardening effect of titanium microalloyed high-strength steel - Google Patents
Cooling process for reducing work hardening effect of titanium microalloyed high-strength steel Download PDFInfo
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- CN106702118B CN106702118B CN201611205702.9A CN201611205702A CN106702118B CN 106702118 B CN106702118 B CN 106702118B CN 201611205702 A CN201611205702 A CN 201611205702A CN 106702118 B CN106702118 B CN 106702118B
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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
- C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
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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
- 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
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
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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
- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
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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
- C21D2211/005—Ferrite
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- Heat Treatment Of Sheet Steel (AREA)
- Metal Rolling (AREA)
Abstract
The invention relates to a cooling process for reducing the work hardening effect of titanium microalloyed high-strength steel, which comprises the following steps: after finishing the finish rolling, carrying out air cooling on the strip steel; the air cooling time is 10-20 s; when the air cooling is finished, the temperature of the strip steel is 650-750 ℃; after the air cooling is finished, carrying out water cooling on the strip steel to a target temperature; the target temperature is 610-640 ℃. The cooling process for reducing the work hardening effect of the titanium microalloyed high-strength steel weakens the work hardening effect of the material after cold machining, and improves the plasticity index of cold deformation metal.
Description
Technical Field
The invention relates to the technical field of steel making, in particular to a cooling process for reducing the work hardening effect of titanium microalloyed high-strength steel.
Background
With the rapid development of the microalloying technology and the controlled cooling technology, the Ti microalloying high-strength steel is widely applied, and the strength level can cover 500MPa to 900 MPa. The Ti microalloyed high-strength steel is mainly characterized in that a tissue matrix is mainly composed of fine and uniform ferrite, and a large number of fine Ti precipitates are dispersed on the matrix. The Ti microalloyed high-strength steel has higher yield ratio, generally more than 0.9. In addition, the Ti microalloyed high-strength steel has the characteristics of obvious work hardening effect, greatly improved strength of the material after cold deformation and obviously reduced plasticity. The research on the problem is less at home and abroad.
The cooling process in the prior art causes the steel plate to have remarkable work hardening after cold machining deformation, greatly improves the strength and greatly reduces the plasticity.
Disclosure of Invention
The invention provides a cooling process for reducing the work hardening effect of titanium microalloyed high-strength steel, which solves or partially solves the technical problems that the work hardening effect of a steel plate is obvious after cold machining, the strength is greatly improved and the plasticity is greatly reduced in the prior art, and achieves the technical effects that the work hardening effect of a material is weakened after cold machining, and the plasticity index of cold-deformed metal is improved.
The invention provides a cooling process for reducing the work hardening effect of titanium microalloyed high-strength steel, which comprises the following steps:
after finishing the finish rolling, carrying out air cooling on the strip steel; the air cooling time is 10-20 s;
when the air cooling is finished, the temperature of the strip steel is 650-750 ℃;
after the air cooling is finished, carrying out water cooling on the strip steel to a target temperature; the target temperature is 610-640 ℃.
Preferably, the chemical components of the strip steel comprise: c, by mass percent: 0.04-0.12%, Si: 0.03 to 0.50%, Mn: 0.5 to 2.0%, Mo: 0-0.5%, V: 0-0.1%, Ti: 0.07 to 0.15%, Nb: 0 to 0.09%.
Preferably, the air cooling is performed by laminar cooling water in a front stage of the screen rolling line.
Preferably, the water cooling method is as follows: and carrying out one-stage or multi-stage cooling on the strip steel.
Preferably, after the water cooling is finished, the strength of the strip steel reaches 500MPa-900 MPa.
One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:
because an air cooling process is arranged between the finish rolling and the water cooling process in the production process of the hot rolled strip steel coil, and the air cooling time and the air cooling finishing temperature are reasonably set, the strip steel obtains the final ideal uniform ferrite structure state; the final dislocation state of the material is reduced by reasonably setting the water-cooled target temperature, and the cold deformation work hardening rate of the steel plate is favorably reduced. Therefore, the technical problems that the steel plate is obvious in work hardening after cold machining, the strength is greatly improved, and the plasticity is greatly reduced in the prior art are effectively solved, and the technical effects that the work hardening effect of the material is weakened after the cold machining, and the plasticity index of cold deformation metal is improved are achieved.
Drawings
Fig. 1 is a flowchart of a cooling process for reducing the work hardening effect of titanium microalloyed high strength steel according to an embodiment of the present invention.
Detailed Description
The embodiment of the application provides a cooling process for reducing the work hardening effect of titanium microalloyed high-strength steel, which solves or partially solves the technical problems that the work hardening is obvious after the steel plate is cold-processed, the strength is greatly improved and the plasticity is greatly reduced in the prior art, and an air cooling process is arranged between the finish rolling process and the water cooling process in the production process of a strip steel hot rolled coil, the air cooling time and the air cooling finishing temperature are reasonably set, and the target temperature of water cooling is reasonably set; the technical effects of weakening the work hardening effect of the material after cold machining and improving the plasticity index of the cold deformation metal are achieved.
Referring to the attached drawing 1, the cooling process for reducing the work hardening effect of the titanium microalloyed high-strength steel provided by the invention comprises the following steps:
s1: after finishing the finish rolling, carrying out air cooling on the strip steel; the air cooling time is 10-20 s; the shielding front-section laminar cooling water can be adopted for realization, and the guarantee of the air cooling time is realized by controlling the group number of the shielding cooling water. After finish rolling, the strip steel is air-cooled, on one hand, the rolled deformation dislocation is recovered, and the number of high-temperature dislocation reserved to a final product is reduced; meanwhile, high-temperature deformation induced precipitation can be increased, and the increase of high-temperature precipitation can reduce the amount of low-temperature precipitation after cooling and coiling, namely the hot rolling state strength can be controlled and the proportion of fine precipitates can be reduced; further, since water cooling is not performed immediately after finish rolling, the number of nucleation points of the rolling deformation band decreases, and anisotropy of the ferrite structure after transformation weakens.
The air cooling time of 10-20 seconds is obtained through a large amount of experimental data, so that uniform ferrite grains can be obtained, the ferrite grains are prevented from being elongated seriously along the rolling direction, and more high-temperature precipitates can be obtained. If the air cooling time is less than 10 seconds, the control on the organization and the precipitation cannot reach an ideal state, and the reduction effect on the subsequent cold deformation work hardening rate is not obvious; and the air cooling time is more than 20 seconds, the low-temperature nano-scale precipitation is too little due to too much high-temperature precipitation, and meanwhile, the material strength is greatly reduced due to too coarse crystal grains, so that the risk that the technical standard cannot be reached exists.
S2: when the air cooling is finished, the temperature of the strip steel is 650-750 ℃; through a large number of experimental researches, water cooling is started within the temperature range, and the final ideal uniform ferrite structure state can be obtained. If the initial cooling temperature is too high and exceeds 750 ℃, the control on the structure and the precipitation cannot reach an ideal state, and the reduction effect on the subsequent cold deformation work hardening rate is not obvious; if the initial cooling temperature is too low, below 650 ℃, in the case of a high Ti steel having a partial composition, transformation may occur or a pearlite structure may appear, affecting the mechanical properties of the final material.
S3: after the air cooling is finished, carrying out water cooling on the strip steel to a target temperature; the target temperature is 610-640 ℃. The target temperature in this range is set in order to obtain a uniform ferrite structure and a certain amount of nano-scale precipitates to improve the strength of the material. And the higher final cooling temperature is adopted, so that the final dislocation state of the material is reduced, and the reduction of the cold deformation work hardening rate of the steel plate is facilitated.
The steel strip has a target structure of ferrite, and a large amount of Ti precipitates are present in the steel, so that the strength of the material is improved by means of fine-grain strengthening and precipitation strengthening. The cooling process comprises the following steps: an air cooling process is arranged between the finish rolling and the water cooling in the production process of the hot rolled coil, and the air cooling time and the air cooling finishing temperature are reasonably set, so that the strip steel obtains the final ideal uniform ferrite structure state; the final dislocation state of the material is reduced by reasonably setting the water-cooled target temperature, and the cold deformation work hardening rate of the steel plate is favorably reduced.
The cooling process is suitable for the steel grade of the whole low-titanium microalloyed high-strength steel system, and as a preferred embodiment, the chemical components of the strip steel comprise: c, by mass percent: 0.04-0.12%, Si: 0.03 to 0.50%, Mn: 0.5 to 2.0%, Mo: 0-0.5%, V: 0-0.1%, Ti: 0.07 to 0.15%, Nb: 0 to 0.09%.
Furthermore, the air cooling is completed through front section laminar cooling water of a shielding rolling production line. The water cooling mode is as follows: and carrying out one-stage or multi-stage cooling on the strip steel, namely, continuously finishing the water cooling process of the whole rolling plate, or dividing the whole rolling plate into a plurality of sections for respectively carrying out water cooling. After the water cooling is finished, the strength of the strip steel reaches 500MPa-900 MPa.
The cooling process for reducing the work hardening effect of the titanium microalloyed high strength steel provided by the invention is described in detail by combining the table and the embodiment as follows:
the test selects the strip steel of six component systems for comparison.
The chemical composition (in weight percent) of each group of steel strips is shown in Table 1
TABLE 1
The Ti microalloyed high-strength steel of the six component systems is respectively subjected to a front-stage cooling process of the conventional process and an air cooling process after rolling to produce the steel plate, and the specific test processes are shown in the table 2:
TABLE 2
The steel plate produced by the test steel is subjected to cold deformation, and the adopted cold deformation test method is that strip steel is continuously rolled and formed into a round pipe and then flattened into a square pipe, and the plastic deformation rate is about 3 percent. And (3) taking a tensile sample in the longitudinal direction of the square pipe, comparing the work hardening effect of the material produced by the two processes of each component after cold deformation, and mainly comparing the strength index with the elongation index. The comparative results are shown in Table 3:
TABLE 3
From the above examples, it can be seen that the Ti microalloyed high strength steel produced by the inventive process has a small strength increase after cold deformation and a small elongation index decrease compared to the conventional process, indicating that the work hardening effect is significantly reduced compared to the product produced by the conventional process.
One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:
because an air cooling process is arranged between the finish rolling and the water cooling process in the production process of the hot rolled strip steel coil, and the air cooling time and the air cooling finishing temperature are reasonably set, the strip steel obtains the final ideal uniform ferrite structure state; the final dislocation state of the material is reduced by reasonably setting the water-cooled target temperature, and the cold deformation work hardening rate of the steel plate is favorably reduced. Therefore, the technical problems that the steel plate is obvious in work hardening after cold machining, the strength is greatly improved, and the plasticity is greatly reduced in the prior art are effectively solved, and the technical effects that the work hardening effect of the material is weakened after the cold machining, and the plasticity index of cold deformation metal is improved are achieved.
The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only illustrative of the present invention and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (4)
1. A cooling process for reducing the work hardening effect of titanium microalloyed high-strength steel is characterized by comprising the following steps of:
after finishing the finish rolling, carrying out air cooling on the strip steel; the air cooling time is 10-20 s; the chemical components of the strip steel comprise: c, by mass percent: 0.04-0.12%, Si: 0.03 to 0.50%, Mn: 0.5 to 2.0%, Mo: 0-0.5%, V: 0-0.1%, Ti: 0.07 to 0.15%, Nb: 0 to 0.09 percent;
when the air cooling is finished, the temperature of the strip steel is 650-750 ℃;
after the air cooling is finished, carrying out water cooling on the strip steel to a target temperature; the target temperature is 610-640 ℃.
2. The cooling process for reducing the work hardening effect of titanium micro-alloyed high strength steel as claimed in claim 1,
and cooling water by front-section laminar flow of a shielding rolling production line to finish the air cooling.
3. The cooling process for reducing the work hardening effect of titanium micro-alloyed high strength steel as claimed in claim 1,
the water cooling mode is as follows: and carrying out one-stage or multi-stage cooling on the strip steel.
4. The cooling process for reducing the work hardening effect of titanium micro-alloyed high strength steel as claimed in claim 1,
after the water cooling is finished, the strength of the strip steel reaches 500MPa-900 MPa.
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| CN201611205702.9A CN106702118B (en) | 2016-12-23 | 2016-12-23 | Cooling process for reducing work hardening effect of titanium microalloyed high-strength steel |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101082104A (en) * | 2006-05-30 | 2007-12-05 | 宝山钢铁股份有限公司 | Nickel-free micro-alloy low-temperature pressure vessel steel and manufacturing method thereof |
| CN103103458A (en) * | 2013-02-17 | 2013-05-15 | 武汉钢铁(集团)公司 | High strength weathering resistant steel and preparation method |
| CN104789863A (en) * | 2015-03-20 | 2015-07-22 | 宝山钢铁股份有限公司 | X80 pipeline steel with good anti-strain aging property, pipeline pipe and manufacturing method of pipeline pipe |
| CN105779904A (en) * | 2014-12-23 | 2016-07-20 | 鞍钢股份有限公司 | Low-cost X80 straight welded pipe and preparation method thereof |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103882327B (en) * | 2012-12-21 | 2016-01-20 | 鞍钢股份有限公司 | Steel plate for pipeline with excellent strain aging performance and manufacturing method thereof |
| EP3686292A4 (en) * | 2017-09-20 | 2020-11-11 | Baosteel Zhanjiang Iron & Steel Co., Ltd. | Production method for inline increase in precipitation toughening effect of ti microalloyed hot-rolled high-strength steel |
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- 2016-12-23 CN CN201611205702.9A patent/CN106702118B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101082104A (en) * | 2006-05-30 | 2007-12-05 | 宝山钢铁股份有限公司 | Nickel-free micro-alloy low-temperature pressure vessel steel and manufacturing method thereof |
| CN103103458A (en) * | 2013-02-17 | 2013-05-15 | 武汉钢铁(集团)公司 | High strength weathering resistant steel and preparation method |
| CN105779904A (en) * | 2014-12-23 | 2016-07-20 | 鞍钢股份有限公司 | Low-cost X80 straight welded pipe and preparation method thereof |
| CN104789863A (en) * | 2015-03-20 | 2015-07-22 | 宝山钢铁股份有限公司 | X80 pipeline steel with good anti-strain aging property, pipeline pipe and manufacturing method of pipeline pipe |
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