Production method of high alloy steel and high alloy steel
Through the specific process flow and the use of pickling compound agents, the problem of low pickling efficiency of high alloy steel is solved, and the efficient removal of iron oxide is achieved, and the production efficiency and quality are improved.
Patent Information
- Application Number
- CN202510570966.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-30
- Publication Date
- 2025-07-11
AI Technical Summary
The traditional pickling process is inefficient when processing high-alloy steel, making it difficult to meet the needs of modern and efficient production, especially due to the strong adhesion of the iron oxide sheet and steel matrix caused by high carbon and alloy elements, it is difficult to effectively remove.
Specific process flows include rough rolling, finishing rolling, laminar cooling, winding, slow cooling, flattening, straightening and pickling treatment. Combined with pickling compound, hydrochloric acid and Quekefuton QUAKER INHIBITOR 8905 pickling promoter are used to control the amount of straightening roller pressing and acid concentration, promote the formation of iron oxide cracks, and improve the pickling efficiency and quality.
Through physical pretreatment and chemical synergistic action, the pickling efficiency and pickling quality of high alloy steel are significantly improved, and the efficient removal of iron oxide is achieved and production costs are reduced.
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Figure CN120286502A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of steel plate pickling, and particularly to a production method of high-alloy steel and high-alloy steel. Background Art
[0002] Cold-rolled high-alloy steel products usually use hot-rolled strip as raw materials and are processed through processes such as pickling, cold rolling, and annealing. Due to their relatively high carbon content (usually ≥0.25%) and addition of relatively high alloying elements (such as Cr, Ni, Mo, etc., with a total amount ≥8%), these steel products exhibit superior mechanical properties, including ultra-high strength (yield strength ≥1700 MPa), excellent hardness, and outstanding wear resistance. However, due to the relatively high content of carbon and alloying elements, traditional pickling processes face significant challenges when dealing with such steel products, resulting in low pickling efficiency and difficulty in meeting the requirements of modern high-efficiency production. Summary of the Invention
[0003] The embodiments of this application provide a production method of high-alloy steel and high-alloy steel, which can improve the pickling efficiency and pickling quality of high-alloy steel products.
[0004] In a first aspect, this application provides a production method of high-alloy steel, including rough rolling, finish rolling, laminar cooling, coiling, and slow cooling of a continuous casting slab to obtain a hot-rolled steel coil after slow cooling; leveling the hot-rolled steel coil after slow cooling to obtain a hot-rolled steel coil after leveling; uncoiling and straightening the hot-rolled steel coil after leveling to obtain a hot-rolled strip after straightening, wherein the reduction amount of the straightening rolls used during the straightening process is 8 mm - 15 mm; preparing a pickling compound in a pickling tank, and using the pickling compound to pickle the hot-rolled strip after straightening to obtain high-alloy steel, wherein the pickling compound includes an acid solution and a pickling accelerator, the acid solution includes hydrochloric acid, the pickling accelerator includes pickling accelerator Quaker INHIBITOR 8905, the mass concentration of the acid solution in the pickling compound is 25% - 30%, and the mass concentration of the pickling accelerator in the pickling compound is 2% - 5%.
[0005] In any embodiment of this application, the coiling temperature is 570°C - 640°C.
[0006] In any embodiment of this application, the slow cooling temperature is 80°C - 120°C.
[0007] In any embodiment of this application, the rolling force for leveling is 30 tons - 80 tons.
[0008] In any embodiment of the present application, the temper rolling process for the hot-rolled steel coil after slow cooling treatment includes placing the hot-rolled steel coil after slow cooling treatment on the mandrel of the uncoiler, threading one end of the strip through the temper rolling work rolls to the coiler, and then starting the machine for temper rolling; wherein, the hot-rolled steel coil after slow cooling treatment includes a head strip, a middle strip, and a tail strip in sequence from the outer ring to the inner ring. The temper rolling speeds of the head strip and the tail strip are 50 m / min to 100 m / min respectively, and the tensions are 20 KN to 40 KN respectively. The temper rolling speed of the middle strip is 100 m / min to 150 m / min, and the tension is 35 KN to 55 KN. The head strip is located at the 0 m to 30 m position of the outer ring, the middle strip is located at the 30 m position of the outer ring to 30 m away from the end of the inner ring, and the tail strip is located at 30 m away from the end of the inner ring to the end of the inner ring.
[0009] In any embodiment of the present application, during the pickling treatment process, the temperature of the pickling compounding agent is 70°C to 85°C.
[0010] In any embodiment of the present application, the pickling treatment rate is 60 m / min to 80 m / min.
[0011] In a second aspect, the present application provides an alloy steel prepared by the production method described in the first aspect.
[0012] In any embodiment of the present application, the thickness of the high alloy steel is 2.0 mm to 4.5 mm.
[0013] In any embodiment of the present application, the high alloy steel includes, by mass percentage: C: 0.25% to 0.40%, Si: 0.20% to 0.50%, Mn: 0.60% to 1.20%, Cr: 3.00% to 4.50%, Ni: 0.20% to 0.80%, Mo: 1.00% to 2.50%, V: 0.20% to 0.40%, P: ≤0.020%, S: ≤0.010%; the balance is Fe and unavoidable impurities.
[0014] The production method of high-alloy strip steel according to the embodiments of the present application obtains high-alloy strip steel through rough rolling, finish rolling, laminar cooling, coiling, slow cooling, temper rolling, straightening, and pickling of continuous casting slabs. Among them, the reduction of the straightening rolls used in the straightening process is controlled to be 8 mm to 15 mm, which can promote the generation of cracks in the scale on the surface of hot-rolled strip steel; the pickling compound is used to pickle the hot-rolled strip steel after straightening treatment. The pickling compound includes acid solution and pickling accelerator. The acid solution includes hydrochloric acid, and the pickling accelerator includes the pickling accelerator of the type Quaker Inhibitor 8905 produced by Quaker Houghton. The mass concentration of the acid solution in the pickling compound is 25% to 30%, and the mass concentration of the pickling accelerator in the pickling compound is 2% - 5%, which can improve the pickling efficiency and pickling quality of high-alloy steel. Description of the Drawings
[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0016] Figure 1 It is a physical picture of pickled strip steel in Embodiment 1 of the present application.
[0017] Figure 2 It is a physical picture of pickled strip steel in Embodiment 3 of the present application.
[0018] Figure 3 It is a physical picture of pickled strip steel in Comparative Example 1 of the present application.
[0019] Figure 4 It is a physical picture of pickled strip steel in Comparative Example 3 of the present application. Detailed Embodiments
[0020] In order to make the application purpose, technical solutions, and beneficial technical effects of the present application clearer, the following further details the present application in conjunction with embodiments. It should be understood that the embodiments described in this specification are only for explaining the present application and not for limiting the present application.
[0021] For simplicity, the present application only explicitly discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form a range not explicitly recorded; and any lower limit can be combined with other lower limits to form a range not explicitly recorded. Similarly, any upper limit can be combined with any other upper limit to form a range not explicitly recorded. In addition, although not explicitly recorded, each point or single value between the range endpoints is included in this range. Thus, each point or single value can be used as its own lower limit or upper limit and combined with any other point or single value or combined with other lower limits or upper limits to form a range not explicitly recorded.
[0022] It should be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the said element.
[0023] Unless otherwise specified, the values of the various parameters mentioned in this application can be measured by various commonly used measurement methods in the art (for example, they can be tested according to the methods given in the embodiments of this application). Unless otherwise specified, the test temperature for the various parameters mentioned in this application is 25 °C and the test pressure is standard atmospheric pressure.
[0024] The above application content of this application does not intend to describe every disclosed embodiment or every implementation mode in this application. The following description more specifically illustrates exemplary embodiments. Throughout the application, guidance is provided through a series of embodiments, and these embodiments can be used in various combinations. In each instance, the listings are only representative groups and should not be construed as exhaustive.
[0025] X32CrMoV4-1 is an important high-alloy steel for the back material of bimetal saw blades. It has a high carbon content (above 0.25%) and alloy content (above 8%), belongs to the Cr-Ni-Mo-V steel system, and has extremely high strength (yield strength ≥ 1700 MPa), hardness and wear resistance. The final use state of this high-alloy steel is cold rolling, and it is prepared by processes such as pickling, cold rolling, and annealing of hot-rolled strip steel. Since the surface of the hot-rolled steel coil is rich in alloys such as Cr, Ni, and Mo, the adhesion between the scale on the surface of the hot-rolled steel coil and the steel matrix is strong. At the same time, it is difficult to uncoil and thread the ultra-high-strength steel, and annealing and softening treatment are required. However, after annealing, the scale is reduced to iron, which will further increase the difficulty of pickling.
[0026] In traditional pickling processes, mechanical descaling or slow (rate < 15 m / min) multiple pickling methods are mostly used to pickle steel, resulting in low efficiency and high cost of the pickling process.
[0027] In view of the above problems, the inventor has improved the pickling process of high-alloy steel.
[0028] The first aspect of the embodiment of the present application provides a production method of high-alloy steel, including rough rolling, finish rolling, laminar cooling, coiling and slow cooling of a continuous casting slab to obtain a hot-rolled steel coil after slow cooling; temper rolling the hot-rolled steel coil after slow cooling to obtain a hot-rolled steel coil after temper rolling; uncoiling and straightening the hot-rolled steel coil after temper rolling to obtain a hot-rolled strip after straightening, wherein the reduction of the straightening roll used in the straightening process is 8 mm to 15 mm; preparing an acid pickling compounding agent in an acid pickling tank, and using the acid pickling compounding agent to pickle the hot-rolled strip after straightening to obtain high-alloy steel, wherein the acid pickling compounding agent includes an acid solution and an acid pickling accelerator, the acid solution includes hydrochloric acid, the acid pickling accelerator includes a QUAKER INHIBITOR 8905 acid pickling accelerator, the mass concentration of the acid solution in the acid pickling compounding agent is 25% to 30%, and the mass concentration of the acid pickling accelerator in the acid pickling compounding agent is 2% to 5%.
[0029] By temper rolling the hot-rolled steel coil first, the flatness of the strip can be improved, which is convenient for threading during subsequent pickling and increases the pickling rate; then straightening it, and controlling the reduction of the straightening roll used in the straightening process to 8 mm to 15 mm can promote the generation of cracks in the scale on the surface of the steel coil. The cracks provide a path for the acid solution to directly contact the inner layer of scale or even the base metal. After the acid solution penetrates through the cracks, it can react with the iron matrix, and the generated hydrogen will further mechanically peel off the scale ("hydrogen explosion" effect), avoiding relying solely on the slow dissolution of the surface layer; moreover, the cracks also increase the reaction area, enabling the acid solution to erode the inside and surface of the scale simultaneously and accelerating the overall peeling; pickling the hot-rolled strip after straightening with an acid pickling compounding agent with a specific formula, hydrochloric acid with a mass concentration of 25% to 30% and QUAKER INHIBITOR 8905 acid pickling accelerator with a mass concentration of 2% to 5% can play a synergistic role, which can promote the dissolution of insoluble oxides on the surface of the strip while inhibiting the over-corrosion of the substrate. Through the above physical pretreatment (temper rolling, straightening) and the chemical synergistic effect of the acid pickling compounding agent (dissolution + complexation), the pickling efficiency and pickling quality of high-alloy steel can be significantly improved.
[0030] As an example, the reduction of the straightening roll used in the straightening process can be 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm or 15 mm.
[0031] If the reduction of the straightening roll is too low, the bending deformation of the strip is small, which is not conducive to the generation of cracks in the oxides on the surface of the strip, thereby reducing the subsequent pickling effect; if the reduction of the straightening roll is too high, the strip is severely deformed, which is likely to cause the breakage of such ultra-high-strength steel.
[0032] As an example, the mass concentration of the acid solution in the pickling compounding agent can be 25%, 26%, 27%, 28%, 29% or 30%.
[0033] As an example, the mass concentration of the pickling accelerator in the pickling compounding agent can be 2%, 3%, 4% or 5%.
[0034] By controlling the mass concentration of the acid solution in the pickling compounding agent to be 25% - 30% and the mass concentration of the pickling accelerator in the pickling compounding agent to be 2% - 5%, the scale on the surface of the strip steel can be removed quickly, and the pickling efficiency can be improved. If the acid solution concentration is too high, it will have a great impact on the environment and high production cost; if it is too low, it is difficult to dissolve the oxides on the surface layer of the strip steel and the pickling is not clean. If the concentration of the pickling accelerator is too high, the pickling efficiency will be reduced instead; if the concentration is too low, it is difficult to play the role of the accelerator.
[0035] In some embodiments, the coiling temperature is 570°C - 640°C.
[0036] As an example, the coiling temperature can be 570°C, 580°C, 590°C, 600°C, 610°C, 620°C, 630°C or 640°C.
[0037] By adopting low-temperature coiling treatment, the thickness of the scale on the surface layer of the strip steel after coiling can be reduced. If the coiling temperature is too high, the strip steel is more likely to undergo an oxidation reaction with air at high temperature, and a thicker scale is formed on the surface layer. If the temperature is too low, the hardness of the strip steel is too high and the brittleness is greater, which is not conducive to subsequent uncoiling.
[0038] In some embodiments, the slow cooling temperature is 80°C - 120°C.
[0039] As an example, the slow cooling temperature can be 80°C, 90°C, 100°C, 110°C or 120°C.
[0040] In some embodiments, the skin pass rolling force is 30 tons - 80 tons.
[0041] As an example, the skin pass rolling force is 30 tons, 40 tons, 50 tons, 60 tons, 70 tons or 80 tons.
[0042] In some embodiments, the skin pass treatment of the hot-rolled steel coil after slow cooling treatment includes placing the hot-rolled steel coil after slow cooling treatment on the mandrel of the decoiler, threading one end of the strip through the skin pass work rolls to the coiler, and then starting the machine for skin pass treatment; wherein, the hot-rolled steel coil after slow cooling treatment includes a head strip, a middle strip, and a tail strip in sequence from the outer ring to the inner ring. The skin pass rates of the head strip and the tail strip are 50 m / min to 100 m / min respectively, and the tensions are 20 KN to 40 KN respectively. The skin pass rate of the middle strip is 100 m / min to 150 m / min, and the tension is 35 KN to 55 KN. The head strip is located at the 0 m - 30 m position of the outer ring, the middle strip is located at the 30 m position of the outer ring to 30 m away from the end of the inner ring, and the tail strip is located at 30 m away from the end of the inner ring to the end of the inner ring.
[0043] By performing segmented skin pass treatment on the strip, the mill scale on the head, tail, and middle parts is in the best broken state. The acid solution can quickly penetrate and dissolve the oxides, enabling the pickling speed to be increased to 60 m / min to 80 m / min. After segmented skin pass treatment, the mill scale state of the entire length of the strip is more consistent, and pickling parameters (such as HCl concentration and accelerator addition amount) can be stably controlled, reducing the downtime for adjustment. Thus, the problem of uneven pickling caused by the inherent differences in the rolling process of high-alloy steel is solved, making the acid solution penetrate more efficiently and the process more stable, ultimately achieving the triple effects of increased pickling speed, reduced cost, and improved quality. If the mill scale at the head and tail of the strip is not sufficiently broken, local unclean areas (black spots or residual mill scale) will appear during pickling, requiring a reduction in speed for reverse pickling, which will drag down the overall efficiency.
[0044] In some embodiments, during the pickling treatment process, the temperature of the pickling compound is 70°C to 85°C.
[0045] As an example, the temperature of the pickling compound can be 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C, 80°C, 81°C, 82°C, 83°C, 84°C, or 85°C.
[0046] In some embodiments, the pickling treatment rate is 60 m / min to 80 m / min.
[0047] As an example, the pickling treatment rate can be 60 m / min, 62 m / min, 64 m / min, 66 m / min, 68 m / min, 70 m / min, 72 m / min, 74 m / min, 76 m / min, 78 m / min, or 80 m / min.
[0048] The second aspect of the embodiments of the present application provides an alloy steel prepared according to the production method described in the first aspect.
[0049] In some embodiments, the thickness of the high alloy steel is 2.0 mm to 4.5 mm.
[0050] As an example, the thickness of the high alloy steel can be 2.0 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3.0 mm, 3.2 mm, 3.4 mm, 3.6 mm, 3.8 mm, 4.0 mm, 4.2 mm, 4.4 mm or 4.5 mm.
[0051] In some embodiments, the high alloy steel comprises, by mass percentage: C: 0.25% to 0.40%, Si: 0.20% to 0.50%, Mn: 0.60% to 1.20%, Cr: 3.00% to 4.50%, Ni: 0.20% to 0.80%, Mo: 1.00% to 2.50%, V: 0.20% to 0.40%, P: ≤0.020%, S: ≤0.010%; the balance being Fe and unavoidable impurities.
[0052] Examples
[0053] The following examples more specifically describe the content disclosed in the present application. These examples are for illustrative purposes only, as various modifications and variations within the scope of the present application are obvious to those skilled in the art. Unless otherwise stated, all parts, percentages and ratios reported in the following examples are based on mass, and all reagents used in the examples are commercially available or synthesized by conventional methods and can be used directly without further treatment, and all instruments used in the examples are commercially available.
[0054] Example 1
[0055] Example 1 provides a method for producing a high alloy steel, comprising the following preparation steps:
[0056] S1. The continuous casting slab is subjected to rough rolling, finish rolling, laminar cooling, coiling and slow cooling treatments to obtain a hot-rolled steel coil after slow cooling;
[0057] The specific steps of S1 include:
[0058] The X32CrMoV4-1 continuous casting slab with a thickness of 230 mm is subjected to rough rolling to form an intermediate billet, and then finish rolling is carried out on 7 stands to form a 4.0 mm strip steel. After laminar cooling, the strip steel is coiled, and medium-temperature coiling is adopted, and the coiling temperature is set at 580 °C. The steel coil is quickly taken offline 108 minutes after rolling and enters a heat preservation pit preset at 100 °C for slow cooling to obtain a hot-rolled steel coil after slow cooling;
[0059] S2. The hot-rolled steel coil after slow cooling is subjected to temper rolling to obtain a hot-rolled steel coil after temper rolling;
[0060] Step S2 specifically includes:
[0061] After the hot-rolled steel coil after slow cooling treatment is cooled to room temperature, it is leveled on a leveler. The leveling rolling force is set to 75 tons. The hot-rolled steel coil cooled to room temperature is placed on the mandrel of the uncoiler, and one end of the strip steel is threaded through the leveling work rolls to the coiler, and then the machine is started for leveling. Among them, the hot-rolled steel coil cooled to room temperature includes a head strip, a middle strip and a tail strip in sequence from the outer ring to the inner ring. The head strip is located at the outer ring at 0m to 30m, the middle strip is located at the outer ring at 30m to the 150m of the inner coil at 30m from the end of the inner ring, and the tail strip is located at 30m from the end of the inner ring to the end of the inner ring. The leveling speeds of the head strip and the tail strip are set to 60m / min respectively, the tensions of the head strip and the tail strip are set to 40KN respectively, the leveling speed of the middle strip is set to 100m / min, and the tension of the middle strip is set to 52KN, obtaining the hot-rolled steel coil after leveling treatment;
[0062] S3. The hot-rolled steel coil after leveling treatment is uncoiled and straightened to obtain the hot-rolled strip after straightening treatment;
[0063] Step S3 specifically includes:
[0064] After the hot-rolled steel coil after leveling treatment is uncoiled, it is put into a 9-roll straightener for straightening. The reduction of the straightening roll is set to 9mm, obtaining the hot-rolled strip after straightening treatment.
[0065] S4. The hot-rolled strip after straightening treatment is pickled with a pickling compound to remove the surface scale, obtaining the hot-rolled strip after pickling treatment;
[0066] Step S4 specifically includes:
[0067] S41. Preparation of the pickling compound: The pickling compound includes an acid solution and a pickling accelerator. Hydrochloric acid is selected as the acid solution, and Quaker Houghton QUAKER INHIBITOR 8905 is selected as the pickling accelerator. The mass concentration of the acid solution in the pickling compound is controlled to be 29%, and the mass concentration of the pickling accelerator in the pickling compound is 4.8%, obtaining the pickling compound.
[0068] S42. Using the aforementioned pickling compound to pickle the hot-rolled strip: During the pickling process, the temperature of the pickling compound is 82°C, and the pickling rate is set to 60m / min, obtaining the hot-rolled strip after pickling treatment.
[0069] S5. The hot-rolled strip after pickling treatment is post-treated to obtain the pickled strip after post-treatment.
[0070] Step S5 specifically includes:
[0071] The pickled hot-rolled strip is rinsed with clean water, and the rinsing temperature is set at 76 °C; the strip after rinsing is dried with hot air, and the temperature of the hot air during hot air drying is about 104 °C, obtaining the pickled strip after post-treatment.
[0072] Figure 1 It is a physical diagram of the pickled strip in Embodiment 1 of this application.
[0073] After treating the X32CrMoV4-1 continuous casting slab according to the above method, there is no residual scale on the surface of the obtained pickled strip, the surface is clean, and the quality is good.
[0074] Embodiment 2
[0075] Embodiment 2 provides a production method of high alloy steel, including the following preparation steps:
[0076] S1. The continuous casting slab is subjected to rough rolling, finish rolling, laminar cooling, coiling and slow cooling treatments to obtain a hot-rolled steel coil after slow cooling treatment;
[0077] Step S1 specifically includes:
[0078] The 230-mm-thick X32CrMoV4-1 continuous casting slab is rough-rolled into an intermediate slab, and then finish-rolled by 7 stands into a 3.0-mm strip. After the strip is cooled by laminar cooling, it is coiled, and medium-temperature coiling is adopted. The coiling temperature is set at 600 °C. The steel coil is quickly taken off the production line 115 minutes after rolling and enters a heat preservation pit preset at 100 °C for slow cooling, obtaining a hot-rolled steel coil after slow cooling treatment;
[0079] S2. The hot-rolled steel coil after slow cooling treatment is leveled to obtain a hot-rolled steel coil after leveling treatment;
[0080] Step S2 specifically includes:
[0081] After the hot-rolled steel coil after slow cooling treatment is cooled to room temperature, it is leveled on a leveler. The leveling rolling force is set at 70 tons. The hot-rolled steel coil cooled to room temperature is placed on the mandrel of the uncoiler, and one end of the strip is threaded through the leveling work rolls to the coiler, and then the machine is started for leveling; among them, the hot-rolled steel coil cooled to room temperature includes a head strip, a middle strip and a tail strip in sequence from the outer circle to the inner circle. The head strip is located at the outer circle from 0 m to 30 m, the middle strip is located at the outer circle from 30 m to 30 m away from the end of the inner circle, and the tail strip is located from 30 m away from the end of the inner circle to the end of the inner circle. The leveling rates of the head strip and the tail strip are set at 70 m / min respectively, the tensions of the head strip and the tail strip are set at 40 KN respectively, the leveling rate of the middle strip is set at 120 m / min, and the tension of the middle strip is set at 50 KN, obtaining a hot-rolled steel coil after leveling treatment;
[0082] S3. Uncoil and straighten the hot-rolled steel coil after leveling to obtain the hot-rolled strip after straightening.
[0083] The S3 step specifically includes:
[0084] After uncoiling the hot-rolled steel coil after leveling, feed it into a 9-roll straightening machine for straightening, set the reduction of the straightening rolls to 9 mm, and obtain the hot-rolled strip after straightening.
[0085] S4. Pickle the hot-rolled strip after straightening with a pickling compound to remove the scale on the surface and obtain the pickled hot-rolled strip.
[0086] The S4 step specifically includes:
[0087] S41. Preparation of the pickling compound: The pickling compound includes acid solution and pickling accelerator. Select hydrochloric acid as the acid solution and Quaker Houghton QUAKER INHIBITOR 8905 as the pickling accelerator. Control the mass concentration of the acid solution in the pickling compound to be 30%, and the mass concentration of the pickling accelerator in the pickling compound to be 4.0% to obtain the pickling compound.
[0088] S42. Use the aforementioned pickling compound to pickle the hot-rolled strip: During the pickling process, the temperature of the pickling compound is 80 °C, and set the pickling rate to 70 m / min to obtain the pickled hot-rolled strip.
[0089] S5. Post-treat the pickled hot-rolled strip to obtain the pickled strip after post-treatment.
[0090] The S5 step specifically includes:
[0091] Rinse the pickled hot-rolled strip with clean water, set the rinsing temperature to 75 °C; hot-air dry the strip after rinsing, and the temperature of the hot air during hot-air drying is about 114 °C to obtain the pickled strip after post-treatment.
[0092] After treating the X32CrMoV4-1 continuous casting slab according to the above method, there is no residual scale on the surface of the pickled strip, the surface is clean, and the quality is good.
[0093] Example 3
[0094] Example 3 provides a production method for high-alloy steel, including the following preparation steps:
[0095] S1. Rough roll, finish roll, laminar cooling, coiling and slow cooling the continuous casting slab to obtain the hot-rolled steel coil after slow cooling.
[0096] The S1 step specifically includes:
[0097] The X32CrMoV4-1 continuous casting slab with a thickness of 230 mm is rough rolled into an intermediate billet, and then finish rolled on a 7-stand mill into a 2.6-mm strip steel. After laminar cooling, the strip steel is coiled, with medium-temperature coiling adopted and the coiling temperature set at 640 °C. The steel coil is quickly taken offline 104 minutes after rolling and enters a soaking pit preset at 120 °C for slow cooling, resulting in a hot-rolled steel coil after slow cooling treatment;
[0098] S2. The hot-rolled steel coil after slow cooling treatment is leveled to obtain a hot-rolled steel coil after leveling treatment;
[0099] Step S2 specifically includes:
[0100] After the hot-rolled steel coil after slow cooling treatment is cooled to room temperature, it is leveled on a leveler. The leveling rolling force is set at 70 tons. The hot-rolled steel coil cooled to room temperature is placed on the mandrel of the uncoiler, and one end of the strip steel is threaded through the leveling work rolls to the coiler, and then the machine is started for leveling; among them, the hot-rolled steel coil cooled to room temperature includes a head strip steel, a middle strip steel, and a tail strip steel in sequence from the outer circle to the inner circle. The head strip steel is located at the outer circle from 0 m to 30 m, the middle strip steel is located at the outer circle from 30 m to 30 m away from the end of the inner circle, and the tail strip steel is located from 30 m away from the end of the inner circle to the end of the inner circle. The leveling speeds of the head strip steel and the tail strip steel are set at 90 m / min respectively, the tensions of the head strip steel and the tail strip steel are set at 35 KN respectively, the leveling speed of the middle strip steel is set at 140 m / min, and the tension of the middle strip steel is set at 45 KN, obtaining a hot-rolled steel coil after leveling treatment;
[0101] S3. The hot-rolled steel coil after leveling treatment is uncoiled and straightened to obtain a hot-rolled strip steel after straightening treatment;
[0102] Step S3 specifically includes:
[0103] After the hot-rolled steel coil after leveling treatment is uncoiled, it is fed into a 9-roll straightener for straightening, and the reduction of the straightening rolls is set at 12 mm, obtaining a hot-rolled strip steel after straightening treatment.
[0104] S4. The hot-rolled strip steel after straightening treatment is pickled with a pickling compound to remove the surface scale, obtaining a hot-rolled strip steel after pickling treatment;
[0105] Step S4 specifically includes:
[0106] S41, Preparation of pickling compound: The pickling compound includes acid solution and pickling accelerator. Hydrochloric acid is selected as the acid solution, and Quaker INHIBITOR 8905 is selected as the pickling accelerator. The mass concentration of the acid solution in the pickling compound is controlled at 26%, and the mass concentration of the pickling accelerator in the pickling compound is 2.5% to obtain the pickling compound.
[0107] S42, Pickling the hot-rolled strip with the aforementioned pickling compound: During the pickling process, the temperature of the pickling compound is 84°C, and the pickling rate is set at 80 m / min to obtain the pickled hot-rolled strip.
[0108] S5, Post-treating the pickled hot-rolled strip to obtain the post-treated pickled strip.
[0109] Step S5 specifically includes:
[0110] Rinsing the pickled hot-rolled strip with clean water, and setting the rinsing temperature at 70°C; drying the rinsed strip with hot air. The temperature of the hot air during hot air drying is about 118°C to obtain the post-treated pickled strip.
[0111] Figure 2 It is a physical diagram of the pickled strip in Example 3 of this application.
[0112] After treating the X32CrMoV4-1 continuous casting slab according to the above method, there is no residual scale on the surface of the obtained pickled strip, the surface is clean, and the quality is good.
[0113] Comparative Example 1
[0114] The difference between Comparative Example 1 and Example 1 is only that the reduction amount of the leveling roll in step S3 is 7 mm.
[0115] Figure 3 It is a physical diagram of the pickled strip in Comparative Example 1 of this application.
[0116] After pickling the X32CrMoV4-1 steel coil according to the above method, there is residual scale on the surface of the obtained strip, and the pickling surface quality is unqualified.
[0117] Comparative Example 2
[0118] The difference between Comparative Example 2 and Example 1 is only that the reduction amount of the leveling roll in step S3 is 16 mm.
[0119] After pickling the X32CrMoV4-1 steel coil according to the above method, there is residual scale on the surface of the obtained strip, and the pickling surface quality is unqualified.
[0120] Comparative Example 3
[0121] The difference between Comparative Example 3 and Example 1 is only that the pickling accelerator in step S4 - QUAKER INHIBITOR8905 is adjusted to 1.5%.
[0122] Figure 4 This is a physical picture of the pickled strip steel in Comparative Example 3 of this application.
[0123] After pickling the X32CrMoV4 - 1 steel coil according to the above method, obvious scale residues exist on the surface of the obtained strip steel, and the pickling surface quality is unqualified.
[0124] Comparative Example 4
[0125] The difference between Comparative Example 4 and Example 1 is only that the pickling accelerator in step S4 - QUAKER INHIBITOR8905 is adjusted to 5.5%.
[0126] After pickling the X32CrMoV4 - 1 steel coil according to the above method, partial scale residues exist on the surface of the obtained strip steel, and the pickling surface quality is unqualified.
[0127] Comparative Example 5
[0128] The difference between Comparative Example 5 and Example 1 is only that the mass concentration of hydrochloric acid in step S4 is adjusted to 32%.
[0129] After pickling the X32CrMoV4 - 1 steel coil according to the above method, the surface of the obtained strip steel is pickled clean, but the surface is severely blackened, showing characteristics of over - pickling.
[0130] Comparative Example 6
[0131] The difference between Comparative Example 6 and Example 1 is only that the mass concentration of hydrochloric acid in step S4 is adjusted to 22%.
[0132] After pickling the X32CrMoV4 - 1 steel coil according to the above method, slight scale residues exist on the surface of the obtained strip steel, and the pickling surface quality is unqualified.
[0133] Comparative Example 7
[0134] The difference between Comparative Example 7 and Example 1 is only that the tensions of the head strip steel and the tail strip steel in step S2 are both adjusted to 45 KN.
[0135] When leveling the X32CrMoV4 - 1 steel coil according to the above method, the tail part has strip breakage and surface abrasion.
[0136] Comparative Example 8
[0137] The difference between Comparative Example 8 and Example 1 is only that the tension of the middle strip steel in step S2 is adjusted to 60 KN.
[0138] When the X32CrMoV4-1 steel coil is leveled according to the above method, the surface quality of the middle part of the coil is downgraded due to surface scratches.
[0139] Comparative Example 9
[0140] The difference between Comparative Example 9 and Example 1 is only that the coiling temperature in Step S1 is adjusted to 650 °C.
[0141] When the strip steel obtained by pickling the X32CrMoV4-1 steel coil according to the above method is pickled, some scale remains on the surface, the pickling surface quality is unqualified, and the pickling rate needs to be reduced to pickle it clean.
[0142] Comparative Example 10
[0143] The difference between Comparative Example 10 and Example 1 is only that the coiling temperature in Step S1 is adjusted to 560 °C.
[0144] When the X32CrMoV4-1 hot-rolled steel coil is leveled and pickled according to the above method, the shape of the strip is poor, it is difficult to uncoil, it is difficult to thread the strip during pickling, and surface scratches are generated.
[0145] As mentioned above, the above is only the specific implementation manner of the present application. Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working process described above can refer to the corresponding process in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present application.
Claims
1. A method for producing a high alloy steel, characterized in that, including performing rough rolling, finish rolling, laminar cooling, coiling and slow cooling on a continuous casting slab to obtain a hot-rolled steel coil after slow cooling; performing temper rolling on the hot-rolled steel coil after slow cooling to obtain a hot-rolled steel coil after temper rolling; performing uncoiling and straightening on the hot-rolled steel coil after temper rolling to obtain a hot-rolled strip after straightening, wherein the reduction of the straightening roll used in the straightening process is 8 mm - 15 mm; preparing an acid pickling compounding agent in an acid pickling tank, and performing acid pickling on the hot-rolled strip after straightening with the acid pickling compounding agent to obtain a high-alloy steel, wherein the acid pickling compounding agent includes an acid solution and an acid pickling accelerator, the acid solution includes hydrochloric acid, the acid pickling accelerator includes an acid pickling accelerator of the type Quaker Houghton QUAKER INHIBITOR 8905, the mass concentration of the acid solution in the acid pickling compounding agent is 25% - 30%, and the mass concentration of the acid pickling accelerator in the acid pickling compounding agent is 2% - 5%.
2. The production method according to claim 1, characterized in that, The coiling temperature is 570 °C - 640 °C.
3. The production method according to claim 1, characterized in that, The slow cooling temperature is 80 °C - 120 °C.
4. The production method according to claim 1, characterized in that, The temper rolling force is 30 tons - 80 tons.
5. The production method according to claim 1, characterized in that, Performing temper rolling on the hot-rolled steel coil after slow cooling includes placing the hot-rolled steel coil after slow cooling on the mandrel of an uncoiler, threading one end of the strip through the temper work rolls to a coiler, and then starting the machine for temper rolling; wherein the hot-rolled steel coil after slow cooling includes a head strip, a middle strip and a tail strip in sequence from the outer circle to the inner circle, the temper rolling speeds of the head strip and the tail strip are 50 m / min - 100 m / min respectively, and the tensions are 20 KN - 40 KN respectively, and the temper rolling speed of the middle strip is 100 m / min - 150 m / min and the tension is 35 KN - 55 KN; The head strip is located at the 0 m - 30 m position of the outer circle, the middle strip is located at the 30 m position of the outer circle to 30 m away from the end of the inner circle, and the tail strip is located at 30 m away from the end of the inner circle to the end of the inner circle.
6. The production method according to claim 1, characterized in that, During the acid pickling process, the temperature of the acid pickling compounding agent is 70 °C - 85 °C.
7. The production method according to claim 1, characterized in that, The acid pickling rate is 60 m / min - 80 m / min.
8. A high-alloy steel, characterized in that, Prepared by the production method according to any one of claims 1 - 7.
9. The high alloy steel according to claim 8, characterized in that, The thickness of the high-alloy steel is 2.0 mm - 4.5 mm.
10. The high-alloy steel according to claim 8, wherein, The high-alloy steel includes, by mass percentage: C: 0.25% - 0.40%, Si: 0.20% - 0.50%, Mn: 0.60% - 1.20%, Cr: 3.00% - 4.50%, Ni: 0.20% - 0.80%, Mo: 1.00% - 2.50%, V: 0.20% - 0.40%, P: ≤0.020%, S: ≤0.010%; the balance is Fe and unavoidable impurities.