CN111485166A - Cold-rolled low-temperature-resistant acid dew point corrosion steel and manufacturing method thereof - Google Patents
Cold-rolled low-temperature-resistant acid dew point corrosion steel and manufacturing method thereof Download PDFInfo
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- 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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- 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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- 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
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- C21D8/0236—Cold rolling
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- 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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- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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- 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
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- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
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- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
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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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- 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
Abstract
A cold rolling low temperature acid dew point corrosion resistant steel and a manufacturing method thereof are disclosed, wherein the steel comprises the following chemical components in percentage by mass: c: 0.04-0.12%, Si: 0.25 to 0.35%, Mn: 0.35-0.65%, P is less than or equal to 0.035%, S: 0.005-0.020%, Cu: 0.25-0.40%, Cr: 0.7-1.2%, Mo: 0.03-0.10%, Sb: 0.06-0.12% of Fe and inevitable impurity elements as the balance; meanwhile, the element content is controlled to satisfy 0.5 ≧ CR ≥ 0.25, CR ═ 0.5w (Cu) + w (Sb) +2w (Mo), and 10w (C) -CR ≤ 0.8. The cold-rolled steel plate strip with excellent low-temperature sulfuric acid and hydrochloric acid mixed acid dew point corrosion resistance is prepared through continuous casting, hot rolling, cold rolling, continuous annealing and flattening, the yield strength is more than or equal to 260MPa, the tensile strength is more than or equal to 400MPa, the elongation is more than or equal to 30%, and the cold-rolled steel plate strip is suitable for systems of low-temperature flue gas treatment, waste heat recovery and the like of thermal power, petrifaction, metallurgy, waste incineration and the like.
Description
Technical Field
The invention relates to cold-rolled low-temperature acid dew point corrosion resistant steel and a manufacturing method thereof, which can ensure excellent corrosion resistance in a low-temperature sulfuric acid and hydrochloric acid mixed acid dew point environment and are suitable for equipment for flue gas treatment, waste heat recovery and the like such as a flue chimney, an air preheater, a heat exchanger, a dust remover, a desulfurizing tower and the like in firepower, petrifaction, metallurgy, garbage incineration and the like.
Background
The combustion exhaust gas from firepower, petrochemical industry, metallurgy and waste incineration mainly contains moisture and Sulfur Oxides (SO)2、SO3)、HCl、NOx、CO2、N2、O2And the like. For flue gas treatment and waste heat recovery system in low temperature environment, SO2、SO3And the HCl and the water are combined to form high-solubility sulfuric acid, hydrochloric acid and the like, so that equipment such as a flue chimney, an air preheater, a heat exchanger, a dust remover, a desulfurizing tower and the like is severely corroded, and dew point corrosion occurs. Such corrosion affects the service life of boilers, flue gas treatment, waste heat recovery, waste incineration furnaces and other facilities. The dew points of the sulfuric acid and the hydrochloric acid are related to the components and the pressure of the flue gas, the dew point of the sulfuric acid is about 100-150 ℃ at normal pressure, and the dew point of the hydrochloric acid is about 50-80 ℃.
China is a country using coal as a main energy source, and dust, sulfide, chloride and nitrogen oxide in coal-fired flue gas are main pollution sources of atmospheric pollution. In recent years, the national environmental governance is strengthened continuously, a series of relevant emission standards are provided, and very strict environmental protection requirements are provided for enterprises such as firepower, petrifaction, metallurgy and waste incineration. Therefore, enterprises need to upgrade and reform the flue gas treatment system, and adopt low-temperature dust removal and waste heat recovery to purify flue gas, improve the energy utilization rate, and realize energy conservation, emission reduction and ultralow emission. The flue gas is processed at low temperature, so that equipment such as a flue chimney, an air preheater, a heat exchanger, a dust remover, a desulfurizing tower and the like in the flue gas processing system generates sulfuric acid and hydrochloric acid dewing corrosion, the service life of the equipment is seriously shortened, and the safety and the stability of production of enterprises are influenced. Therefore, there is an urgent need to improve the sulfuric acid and hydrochloric acid corrosion resistance of steels for these facilities.
At present, acid-resistant steel which is generally applied is mainly designed aiming at the sulfuric acid corrosion resistance, such as Bao steel B485L, NS saddle steel 10Cr1Cu, Jiangyin special steel ND (90CuCrSb) steel, Ji steel 12MnCuCr and the like, in recent years, a plurality of novel sulfuric acid corrosion resistant steels are successively disclosed at home and abroad, for example, a steel which has excellent sulfuric acid dew point corrosion resistance in a wider temperature range is disclosed in a New Japanese iron patent 02800218.0, the steel mainly utilizes the composite action of three elements of Si, Cu and Sb to improve the sulfuric acid corrosion resistance, the new Japanese iron patent 200680006324.X discloses a high-sulfuric acid corrosion resistant steel, the steel focuses on strictly controlling the elements such as C, Si and the like, in addition, the new Japanese iron patent JP 56 discloses a steel which has excellent sulfuric acid and hydrochloric acid mixed acid corrosion resistance, and is mainly characterized in that Sb and Mo are added, the content of C is strictly controlled, and the AI/10000 is 0.× -3925% of Sb ×%.
Shenhu Steel making patent 201010162228.2 discloses a steel used in sulfuric acid + hydrochloric acid environment, which is mainly characterized by the following: [C] 0.2 to 5.0, ferrite volume fraction of 20%, and pearlite or bainite phase of 5% or more.
Japanese Steel 201280071581.7 discloses a plain carbon steel-based steel which is free of Sb element, improved in sulfuric acid dew point corrosion resistance by controlling the S content to be 0.005-0.015%, and improved in hydrochloric acid dew point corrosion resistance by adding 0.005-0.03% of Mo.
The coal in China is high-sulfur coal, the smoke components have the characteristics, and the comprehensive cost of the material needs to be reduced as much as possible when the steel plate is designed. Therefore, the low temperature resistant sulfuric acid and hydrochloric acid mixed acid steel needs to be designed specifically, and the foreign related steel types cannot be carried out.
Chinese patent 200910187512.2 discloses a high-sulfur-resistant sulfuric acid corrosion steel, which adopts a composite addition of Cu, Cr and Bi elements to form a dense oxide film rich in Bi, Ti, Cu, Cr and other elements on the surface of the steel. Further, the saddle steel patent 201110418531.9 discloses a Zr-containing sulfuric acid corrosion resistant steel in which 0.01 to 0.0% of Zr is added to a Cu-Cr-Sb systemRefining austenite grains by using ZrN and ZrC with the Zr content of 5% to obtain a fine grain structure; meanwhile, a dense oxide film ZrO is formed on the surface of the steel plate2The steel plate surface is passivated, and the acid resistance of the steel plate is improved by the fine grain structure and the oxidation film.
Chinese patent 201610499180.1 discloses a steel for 09CrCuSb corrosion resistance, which eliminates the hot brittle net cracks caused by Cu and Sb of the traditional 09CrCuSb steel plate by controlling Ni/Cu to be more than or equal to 1, and obtains the corrosion resistance performance of the sulfuric acid equivalent to that of the traditional 09CrCuSb by adding trace Ca element (the content is more than or equal to 0.0005%). However, the above steel sheet is not suitable for a mixed acid corrosive environment in which sulfuric acid and hydrochloric acid coexist at low temperature.
Disclosure of Invention
The invention aims to provide cold-rolled low-temperature acid dew point corrosion resistant steel and a manufacturing method thereof, wherein the steel plate has both sulfuric acid resistance and hydrochloric acid corrosion resistance, and simultaneously has excellent mechanical properties: the yield strength is more than or equal to 260MPa, the tensile strength is more than or equal to 400MPa, and the elongation is more than or equal to 30%, so that the performance requirements of parts such as heat exchange elements of rotary air preheaters, heat exchanger fins or fins, dust remover anode plates and the like in thermal power, petrochemical, metallurgical and waste incineration flue gas treatment and waste heat recovery systems can be met.
In order to achieve the purpose, the technical scheme of the invention is as follows:
the invention is based on Cu-Sb system low-carbon steel, and the steel plate has excellent sulfuric acid and hydrochloric acid mixed acid dew point corrosion resistance by adding a proper amount of Mo element.
Specifically, the cold-rolled low-temperature acid dew point corrosion resistant steel comprises the following chemical components in percentage by mass: c: 0.04-0.12%, Si: 0.20 to 0.40%, Mn: 0.35-0.65%, P is less than or equal to 0.035%, S: 0.005-0.020%, Cu: 0.20-0.50%, Cr: 0.7-1.2%, Mo: 0.03-0.10%, Sb: 0.06-0.12% of Fe and inevitable impurity elements as the balance; and the element content satisfies the following relationship: 0.5. gtoreq.CR.gtoreq.0.25, CR ≧ 0.5w (Cu) + w (Sb) +2w (Mo), 10w (C) -CR ≦ 0.8.
The microstructure of the cold-rolled low-temperature acid dew point corrosion resistant steel of the invention is as follows: ferrite and pearlite, and the pearlite content is more than 5%.
In the chemical composition design of the steel of the invention:
c: the main strengthening elements have low C content, the strength of the steel plate is insufficient, and the smelting cost is increased; too high C content affects the plasticity of the steel sheet and is also detrimental to acid resistance. Therefore, the invention controls the content of C: 0.04-0.12%.
Si: the deoxidizing elements improve the strength of the steel sheet by solid solution strengthening, and Si and Cu are present in the steel sheet to improve the corrosion resistance of the steel sheet, but if the added amount is too high, the hot workability and weldability of the steel sheet deteriorate. Si is controlled in a reasonable range, so that the acid corrosion resistance of the material is improved while the processability is ensured. Therefore, the present invention controls the Si content: 0.20 to 0.40 percent.
Mn: the steel plate mainly exists in a solid solution state, and has a composite effect with C, so that the strength of the steel plate is improved; mn and S form MnS, so that the hot brittleness tendency of steel is reduced; however, too high Mn content causes center segregation of the cast slab, affects hot workability of the steel sheet, and is disadvantageous in welding performance. Therefore, the present invention controls the Mn content: 0.35-0.65%.
P: if the content of the inevitable inclusion elements in the steel sheet is too high, the center segregation of a casting blank is caused, the hot workability of the steel sheet is affected, and the acid resistance of the steel sheet is reduced. Therefore, the invention controls the content of P: less than or equal to 0.035%.
S: controlling a certain Cu/S ratio to promote the formation of Cu on the surface of the steel plate2S is a passive film, so that the anode reaction and the cathode electrochemical reaction are inhibited, and the acid resistance of the steel plate is improved; however, the S content is too high, which tends to cause center segregation of the cast slab, resulting in hot shortness and unfavorable in steel sheet formability. Therefore, the present invention controls the S content: 0.005-0.020%.
Cu: the active cathode can promote the steel to generate anode passivation under certain conditions, thereby reducing the corrosion rate of the steel. In acid-resistant steel, Cu reacts with S to generate Cu2S protective film for retarding the reaction between anode and cathode to increase the corrosion potential of steel surface, lower Viton current and increase the corrosion resistance of materialAcid resistance. However, the Cu content is too high, and the hot workability of the material is deteriorated. Thus, the present invention controls the Cu content: 0.20 to 0.50 percent.
Cr: the solid solution is carried out in ferrite to inhibit an anode reaction, generate Cr carbide in cementite, inhibit a cathode reaction and improve the corrosion resistance of the material; in addition, Cr forms a dense oxide film on the surface of the steel sheet, thereby improving oxidation resistance. If the amount is excessively added, hot workability of the steel sheet deteriorates. Therefore, the invention controls the Cr content: 0.7 to 1.2 percent.
Mo: the hydrochloric acid resistance dew point corrosion performance of the steel plate is improved. The addition of Mo can promote the passivation of Fe-Cr alloy, and the addition of a proper amount of Mo can move the corrosion potential to the direction which is not easy to corrode, so that the hydrochloric acid resistance dew point corrosion performance of the steel plate is improved under the condition of not damaging the sulfuric acid resistance performance. However, if the amount of the acid is excessively added, the corrosion resistance of the steel sheet to sulfuric acid and hydrochloric acid mixed acid is lowered. Therefore, the present invention controls Mo content: 0.03 to 0.10 percent.
Referring to fig. 2, fig. 2 is a graph showing the relationship between the corrosion resistance to the mixed acid of sulfuric acid and hydrochloric acid and the Mo content according to the present invention.
And (4) testing standard: JBT 7901-.
Corrosion medium: 60 ℃, 11.4 wt.% H2SO4+1.2wt.％HCl+1.0wt.％FeCl3。
Acid resistance was evaluated by measuring the rate of corrosion weight loss of the steel sheet (same below):
wherein, Wt-W0: corrosion weight loss after soaking for t time, unit: mg; a: sample surface area, unit: cm2(ii) a T: sample soaking time, unit: h.
with the addition of Mo element, the weight loss rate of the steel plate is reduced, which shows that the acid resistance is improved; however, when the Mo content exceeds 0.05%, the weight loss rate of the steel sheet increases, indicating a decrease in acid resistance. Therefore, in order to ensure that the steel plate has certain mixed acid resistance, the proper content of the Mo element needs to be selected.
Referring to fig. 3, fig. 3 is a graph showing the relationship between the sulfuric acid resistance and the Mo content of the steel sheet according to the present invention.
And (4) testing standard: JBT 7901-.
Corrosion medium: 50 wt.% H at 70 ℃2SO4。
The acid resistance was evaluated by measuring the rate of corrosion weight loss of the steel sheet.
After the Mo element is added, the weight loss rate of the steel plate is reduced, which shows that the acid resistance is improved. In the initial stage of soaking (24h), the addition of 0.09 wt.% Mo steel sheet had inferior sulfuric acid resistance to 0.01 wt.% Mo steel sheet, but as the corrosion soaking time was further extended (after 48 h), the 0.09 wt.% Mo steel sheet had superior sulfuric acid resistance to 0.01 wt.% Mo steel sheet. Therefore, a higher Mo content should be selected simply from the viewpoint of improving the sulfuric acid resistance.
Referring to fig. 4, fig. 4 is a graph showing the relationship between the corrosion resistance of the steel plate of the present invention to a mixed acid of sulfuric acid and hydrochloric acid and the soaking time.
And (4) testing standard: JBT 7901-.
Corrosion medium: 60 ℃, 11.4 wt.% H2SO4+1.2wt.％HCl+1.0wt.％FeCl3
The acid resistance was evaluated by measuring the rate of corrosion weight loss of the steel sheet.
With the increase of the soaking time, the weight loss rate of the steel plate tends to decrease, and especially for 0.09 wt.% Mo steel plate, the weight loss rate decreases by about 50% in 72h compared with 24 h.
Sb: the element for effectively improving the sulfuric acid resistance and the hydrochloric acid resistance of the steel plate can generate Sb on the surface of the steel plate by adding the Sb2O5The oxide inhibits anodic reactions, thereby reducing the corrosion rate. In addition, the high Sb addition can promote the formation of the Cu-containing compound with high corrosion resistance and inhibit the occurrence of cathode reaction. However, Sb and Cu are low-melting elements, and when added in excess, the hot workability of the steel sheet deteriorates. Therefore, the present invention controls the Sb content: 0.06-0.12%.
In order to ensure that the steel plate has the sulfuric acid resistance and the hydrochloric acid resistance, the following requirements are met: 0.5. gtoreq.CR.gtoreq.0.25, CR ≧ 0.5w (Cu) + w (Sb) +2w (Mo), 10w (C) -CR ≦ 0.8.
In addition, the invention provides a manufacturing method of cold-rolled low-temperature acid dew point corrosion resistant steel, wherein during hot rolling, the heating temperature of a steel billet is 1200-1250 ℃, the finishing temperature is 850-950 ℃, the coiling temperature is 600-680 ℃, the cold rolling reduction rate is 50-80%, the continuous annealing temperature is 720-840 ℃, and the leveling rate is 0.8-1.6%.
The production method of the present invention is explained below.
Hot rolling heating temperature: the continuous casting slab is heated to dissolve second phase particles such as AlN and Ti (C, N), the particles are re-precipitated in the hot rolling and coiling process, but the particles are smaller in size and more dispersed in distribution compared with a continuous casting slab, and the mechanical and acid resistance of a steel plate is improved. When the heating temperature is too low, the dissolution degree of the second phase particles is reduced, the precipitation in the post-processing process is influenced, and the mechanical property and the acid resistance are not facilitated; when the heating temperature is too high, the crystal grains are coarsened, the generated oxide skin is thick, and the subsequent procedures are difficult to remove; and the mechanical property of the steel plate is low. Therefore, the present invention controls the hot rolling heating temperature: 1200-1250 ℃.
Hot rolling finishing temperature: when the finishing temperature is too low, the hot rolling in the all-austenite region can not be realized, so that mixed crystals appear in steel, and the stability of the structure and the performance is influenced; when the finishing rolling temperature is too high, crystal grains are easy to coarsen, and the mechanical property of the steel plate is reduced. Therefore, the invention controls the finishing temperature: 850-950 ℃.
Hot rolling coiling temperature: and coiling is carried out in a proper temperature interval, fine and dispersed cementite precipitation can be realized in the interval, the cementite is easy to dissolve in the subsequent continuous annealing process, a ferrite and pearlite structure is favorably formed, and the influence of carbide particles on the corrosion performance of the material is reduced. Therefore, the present invention controls the coiling temperature: 600-680 ℃.
Cold rolling reduction: the r value of the cold-rolled steel sheet generally increases along with the increase of the cold rolling reduction, the cold rolling reduction is increased, the deformation energy in the steel is increased, and the recrystallization driving force is improved, so that the recrystallization temperature is reduced, and the {111} texture is formed after annealing; however, when the reduction rate exceeds 85%, the load of the rolling mill is significantly increased, the production efficiency of the cold rolling mill train is reduced, and the manufacturing cost is increased. Therefore, the invention controls the cold rolling reduction rate: 50-85%.
Annealing temperature and holding time: the continuous annealing process is a process of recovery and recrystallization of deformed grains, and needs a certain time to guarantee in terms of kinetics. If the temperature is too low and the heat preservation time is too short, the recrystallization of the rolled hard plate is insufficient, the plasticity of the material is low, and the processability is poor; if the annealing temperature is too high and the heat preservation time is too long, the grain size of the steel plate is too large, and the strength of the finished steel plate is low. Therefore, the annealing temperature is controlled to be 720-780 ℃ and the heat preservation time is controlled to be 80-120 s.
As shown in figure 1, when the annealing temperature is 720-780 ℃, the mechanical properties of the steel plate can meet the requirements that the yield strength is more than or equal to 260MPa, the tensile strength is more than or equal to 400MPa, and the elongation is more than or equal to 30%.
Leveling rate: leveling is an important process for producing cold-rolled steel sheets, and the required surface roughness, plate shape and mechanical property of the products are realized. Therefore, the invention controls the leveling rate to be 0.8-1.6%.
The cold-rolled low-temperature acid dew point corrosion resistant steel prepared by the components and the process has excellent sulfuric acid and hydrochloric acid mixed acid corrosion resistance, the yield strength is more than or equal to 260MPa, the tensile strength is more than or equal to 400MPa, and the elongation is more than or equal to 30%, so that the performance requirements of parts such as rotary air preheater heat exchange elements, heat exchanger fins or fins, dust remover anode plates and the like in thermal power, petrochemical, metallurgical and waste incineration flue gas treatment and waste heat recovery systems are met.
The difference of the invention from Chinese patent 201010162228.2 is that the latter obtains ferrite, pearlite or bainite content required by the target by controlling the content ratio of [ C ]/[ Cr ], thereby ensuring the sulfuric acid resistance and the hydrochloric acid resistance of the steel plate, and the invention adopts the addition of 0.03-0.10% of Mo on the basis of Cu-Sb, and the design ideas of the components of the two are different.
The difference of the invention from the Chinese patent 201280071581.7 is that the latter is based on plain carbon steel, Sb element is not added, the sulfuric acid resistance is improved by controlling the S content in a certain range, and the hydrochloric acid resistance is improved by adding certain Mo element. The invention discloses a Cu-Sb system, and finds that a proper Mo element content interval exists in the system, so that the sulfuric acid resistance and the hydrochloric acid resistance of a steel plate can be effectively improved.
The invention is different from Japanese patent JP2002251787A in that the latter requires strict control of the contents of Sb, Mo and C, and requires control of AI/10000 ═ 0.0005+0.045 × Sb% -C% × Mo% ≥ 0 to ensure that the sulfuric acid corrosion resistance is not damaged.
The steel plate disclosed by the invention has both low-temperature sulfuric acid resistance and hydrochloric acid resistance, and has excellent mechanical properties: the yield strength is more than or equal to 260MPa, the tensile strength is more than or equal to 400MPa, and the elongation is more than or equal to 30%, so that the performance requirements of parts such as heat exchange elements of rotary air preheaters, heat exchanger fins or fins, dust remover anode plates and the like in thermal power, petrochemical, metallurgical and waste incineration flue gas treatment and waste heat recovery systems can be met.
Drawings
FIG. 1 is a graph showing the relationship between mechanical properties and annealing temperature of the steel sheet of the present invention.
FIG. 2 is a relationship between the corrosion resistance to a mixed acid of sulfuric acid and hydrochloric acid and the Mo content.
FIG. 3 is a graph showing the relationship between the sulfuric acid resistance and Mo content of the steel sheet of the present invention.
FIG. 4 is a graph showing the relationship between the corrosion resistance of the steel sheet according to the present invention to sulfuric acid and hydrochloric acid mixed acid and the soaking time.
FIG. 5 is a photograph of a metallographic structure of a sample in example 1 of the present invention.
FIG. 6 is a depth distribution of elements in a surface corrosion layer after 72h soaking in example 1 of the present invention.
FIG. 7 is the distribution of elements of the cross-section corrosion layer after 72h soaking in example 1 of the present invention.
Detailed Description
The invention is further described below by way of examples and figures.
Example 1
Chemical components (wt%): c: 0.086, Si: 0.30, Mn: 0.48, S: 0.006, Cu: 0.26, Cr: 0.97, Mo: 0.09, Sb: 0.079.
the manufacturing method comprises the following steps: the hot rolling heating temperature of the billet is 1230 ℃, the final rolling temperature is 880 ℃, the coiling temperature is 660 ℃, the cold rolling reduction rate is 50%, the continuous annealing temperature is 800 ℃, the heat preservation time is 90s, and the leveling rate is 1.2%.
Microstructure: ferrite + pearlite, with a pearlite content of about 10%, granular cementite is distributed at the ferrite phase boundary as shown in fig. 5.
Mechanical properties: yield strength 289MPa, tensile strength 451MPa, and elongation 38.3%.
50 wt.% H at 70 ℃2SO4Soaking for 24h, the corrosion rate of sulfuric acid is as follows: 5.73mg/cm2·h。
11.4 wt.% H at 60 ℃2SO4+1.2wt.％HCl+1.0wt.％FeCl3Soaking for 24h, the mixed acid corrosion resistance rate: 1.02mg/cm2·h。
The surface corrosion layer has Cu and Sb oxides through SEM and EDS analysis, and is shown in figure 6. The surface layer is rich in Cu, Sb and O elements.
The GDS analysis shows that the surface layer is enriched with Cu, S, Si, Mo and other elements, as shown in FIG. 7.
Example 2
Chemical components (wt%): c: 0.076, Si: 0.31, Mn: 0.44, S: 0.008, Cu: 0.24, Cr: 0.94, Mo: 0.05, Sb: 0.077.
the manufacturing method comprises the following steps: during hot rolling, the heating temperature of a steel billet is 1220 ℃, the finish rolling temperature is 920 ℃, the coiling temperature is 640 ℃, the cold rolling reduction rate is 66.7%, the continuous annealing temperature is 760 ℃, the heat preservation time is 95s, and the leveling rate is 1.4%.
Microstructure: ferrite + pearlite, with a pearlite content of about 10%.
Mechanical properties: the yield strength is 283MPa, the tensile strength is 445MPa, and the elongation is 36.5 percent.
50 wt.% H at 70 ℃2SO4Soaking for 24h, the corrosion rate of sulfuric acid is as follows: 5.53mg/cm2·h。
11.4 wt.% H at 60 ℃2SO4+1.2wt.％HCl+1.0wt.％FeCl3Soaking for 24h, the mixed acid corrosion resistance rate: 0.67mg/cm2·h。
Example 3
Chemical components (wt%): c: 0.053, Si: 0.27, Mn: 0.59, S: 0.015, Cu: 0.35, Cr: 0.86, Mo: 0.03, Sb: 0.067.
the manufacturing method comprises the following steps: during hot rolling, the heating temperature of a steel billet is 1200 ℃, the finish rolling temperature is 860 ℃, the coiling temperature is 620 ℃, the cold rolling reduction rate is 75%, the continuous annealing temperature is 740 ℃, the heat preservation time is 110s, and the leveling rate is 0.8%.
Microstructure: ferrite + pearlite, with a pearlite content of about 10%.
Mechanical properties: the yield strength is 273MPa, the tensile strength is 431MPa, and the elongation is 37%.
50 wt.% H at 70 ℃2SO4Soaking for 24h, the corrosion rate of sulfuric acid is as follows: 5.31mg/cm2·h。
11.4 wt.% H at 60 ℃2SO4+1.2wt.％HCl+1.0wt.％FeCl3Soaking for 24h, the mixed acid corrosion resistance rate: 0.97mg/cm2·h。
Example 4
Chemical components (wt%): c: 0.087, Si: 0.38, Mn: 0.41, S: 0.005, Cu: 0.26, Cr: 0.96, Mo: 0.072, Sb: 0.078.
the manufacturing method comprises the following steps: during hot rolling, the heating temperature of a steel billet is 1200 ℃, the finish rolling temperature is 880 ℃, the coiling temperature is 650 ℃, the cold rolling reduction rate is 75%, the continuous annealing temperature is 780 ℃, the heat preservation time is 110s, and the leveling rate is 0.8%.
Mechanical properties: the yield strength is 290MPa, the tensile strength is 456MPa, and the elongation is 37.7%.
50 wt.% H at 70 ℃2SO4Soaking for 24h, the corrosion rate of sulfuric acid is as follows: 5.58mg/cm2·h。
11.4 wt.% H at 60 ℃2SO4+1.2wt.％HCl+1.0wt.％FeCl3Soaking for 24h, the mixed acid corrosion resistance rate: 1.16mg/cm2·h。
Example 5
Chemical components (wt%): c: 0.086, Si: 0.30, Mn: 0.48, S: 0.007, Cu: 0.45, Cr: 0.97, Mo: 0.093, Sb: 0.079.
the manufacturing method comprises the following steps: during hot rolling, the heating temperature of a steel billet is 1200 ℃, the finish rolling temperature is 880 ℃, the coiling temperature is 650 ℃, the cold rolling reduction rate is 75%, the continuous annealing temperature is 780 ℃, the heat preservation time is 110s, and the leveling rate is 0.8%.
Mechanical properties: the yield strength is 288MPa, the tensile strength is 445MPa, and the elongation is 36.7 percent.
50 wt.% H at 70 ℃2SO4Soaking for 24h, the corrosion rate of sulfuric acid is as follows: 5.67mg/cm2·h。
11.4 wt.% H at 60 ℃2SO4+1.2wt.％HCl+1.0wt.％FeCl3Soaking for 24h, the mixed acid corrosion resistance rate: 0.98mg/cm2·h。
Example 6
Chemical components (wt%): c: 0.076, Si: 0.31, Mn: 0.44, S: 0.008, Cu: 0.24, Cr: 0.94, Mo: 0.05, Sb: 0.077.
the manufacturing method comprises the following steps: during hot rolling, the heating temperature of a steel billet is 1200 ℃, the finish rolling temperature is 880 ℃, the coiling temperature is 650 ℃, the cold rolling reduction rate is 75%, the continuous annealing temperature is 780 ℃, the heat preservation time is 110s, and the leveling rate is 0.8%.
Mechanical properties: the yield strength is 271MPa, the tensile strength is 433MPa, and the elongation is 32.5 percent.
50 wt.% H at 70 ℃2SO4Soaking for 24h, the corrosion rate of sulfuric acid is as follows: 6.16mg/cm2·h。
11.4 wt.% H at 60 ℃2SO4+1.2wt.％HCl+1.0wt.％FeCl3Soaking for 24h, the mixed acid corrosion resistance rate: 0.73mg/cm2·h。
Example 7
Chemical components (wt%): c: 0.11, Si: 0.25, Mn: 0.48, S: 0.01, Cu: 0.25, Cr: 0.95, Mo: 0.10, Sb: 0.079.
the manufacturing method comprises the following steps: during hot rolling, the heating temperature of a steel billet is 1200 ℃, the finish rolling temperature is 880 ℃, the coiling temperature is 650 ℃, the cold rolling reduction rate is 75%, the continuous annealing temperature is 820 ℃, the heat preservation time is 110s, and the leveling rate is 0.8%.
Mechanical properties: the yield strength is 292MPa, the tensile strength is 439MPa, and the elongation is 33.3%.
50 wt.% H at 70 ℃2SO4Soaking for 24h, the corrosion rate of sulfuric acid is as follows: 6.12mg/cm2·h。
11.4 wt.% H at 60 ℃2SO4+1.2wt.％HCl+1.0wt.％FeCl3Soaking for 24h, the mixed acid corrosion resistance rate: 1.31mg/cm2·h。
Example 8
Chemical components (wt%): c: 0.048, Si: 0.27, Mn: 0.35, S: 0.005, Cu: 0.38, Cr: 0.77, Mo: 0.08, Sb: 0.12.
the manufacturing method comprises the following steps: during hot rolling, the heating temperature of a steel billet is 1200 ℃, the finish rolling temperature is 860 ℃, the coiling temperature is 660 ℃, the cold rolling reduction rate is 70%, the continuous annealing temperature is 740 ℃, the heat preservation time is 110s, and the leveling rate is 1.0%.
Mechanical properties: the yield strength is 277MPa, the tensile strength is 442MPa, and the elongation is 33.9 percent.
50 wt.% H at 70 ℃2SO4Soaking for 24h, the corrosion rate of sulfuric acid is as follows: 5.88mg/cm2·h。
11.4 wt.% H at 60 ℃2SO4+1.2wt.％HCl+1.0wt.％FeCl3Soaking for 24h, the mixed acid corrosion resistance rate: 0.82mg/cm2·h。
Comparative example 1
Chemical components (wt%): c: 0.15, Si: 0.31, Mn: 0.61, S: 0.005, Cu: 0.45, Cr: 0.81, Mo: 0.097, Sb: 0.11.
the manufacturing method comprises the following steps: during hot rolling, the heating temperature of a steel billet is 1200 ℃, the finish rolling temperature is 900 ℃, the coiling temperature is 660 ℃, the cold rolling reduction rate is 67%, the continuous annealing temperature is 760 ℃, the heat preservation time is 80s, and the leveling rate is 1.0%.
Mechanical properties: the yield strength is 317MPa, the tensile strength is 476MPa, the elongation is 28.5 percent, and the elongation is insufficient.
50 wt.% H at 70 ℃2SO4Soaking for 24h, the corrosion rate of sulfuric acid is as follows: 6.97mg/cm2·h。
11.4 wt.% H at 60 ℃2SO4+1.2wt.％HCl+1.0wt.％FeCl3Soaking for 24h, the mixed acid corrosion resistance rate: 1.21mg/cm2·h。
Comparative example 2
Chemical components (wt%): c: 0.08, Si: 0.24, Mn: 0.37, S: 0.007, Cu: 0.34, Cr: 0.73, Mo: 0.02, Sb: 0.02.
the manufacturing method comprises the following steps: during hot rolling, the heating temperature of a steel billet is 1200 ℃, the finish rolling temperature is 900 ℃, the coiling temperature is 660 ℃, the cold rolling reduction rate is 70%, the continuous annealing temperature is 740 ℃, the heat preservation time is 80s, and the leveling rate is 1.0%.
Mechanical properties: yield strength 270MPa, tensile strength 431MPa, and elongation 35.7%.
50 wt.% H at 70 ℃2SO4Soaking for 24h, the corrosion rate of sulfuric acid is as follows: 7.03mg/cm2·h。
11.4 wt.% H at 60 ℃2SO4+1.2wt.％HCl+1.0wt.％FeCl3Soaking for 24h, the mixed acid corrosion resistance rate: 1.88mg/cm2·h。
The corrosion resistance is deteriorated.
Comparative example 3
Chemical components (wt%): c: 0.11, Si: 0.25, Mn: 0.39, S: 0.006, Cu: 0.25, Cr: 0.77, Mo: 0.2, Sb: 0.096.
the manufacturing method comprises the following steps: during hot rolling, the heating temperature of a steel billet is 1200 ℃, the finish rolling temperature is 880 ℃, the coiling temperature is 660 ℃, the cold rolling reduction rate is 67%, the continuous annealing temperature is 760 ℃, the heat preservation time is 100s, and the leveling rate is 1.0%.
Mechanical properties: the yield strength is 305MPa, the tensile strength is 478MPa, and the elongation is 30.4%.
50 wt.% H at 70 ℃2SO4Soaking for 24h, the corrosion rate of sulfuric acid is as follows: 8.25mg/cm2·h。
11.4 wt.% H at 60 ℃2SO4+1.2wt.％HCl+1.0wt.％FeCl3Soaking for 24h, the mixed acid corrosion resistance rate: 2.19mg/cm2H. The corrosion resistance is deteriorated.
Claims (5)
1. The cold-rolled low-temperature acid dew point corrosion resistant steel comprises the following chemical components in percentage by mass: c: 0.04-0.12%, Si: 0.20 to 0.40%, Mn: 0.35-0.65%, P is less than or equal to 0.035%, S: 0.005-0.020%, Cu: 0.20-0.50%, Cr: 0.7-1.2%, Mo: 0.03-0.10%, Sb: 0.06-0.12% of Fe and inevitable impurity elements as the balance; and the element content satisfies the following relationship: 0.5. gtoreq.CR.gtoreq.0.25, CR.gtoreq.0.5 w (Cu) + w (Sb) +2w (Mo), and 10w (C) -CR.gtoreq.0.8.
2. The cold rolled low temperature acid dew point corrosion resistant steel of claim 1, wherein the microstructure of the cold rolled low temperature acid dew point corrosion resistant steel is: ferrite and pearlite, and the pearlite content is more than 5%.
3. The cold-rolled low-temperature acid dew point corrosion-resistant steel as claimed in claim 1, wherein the yield strength of the cold-rolled low-temperature acid dew point corrosion-resistant steel is equal to or more than 260MPa, the tensile strength of the cold-rolled low-temperature acid dew point corrosion-resistant steel is equal to or more than 400MPa, and the elongation of the cold-rolled low-temperature acid dew point corrosion-resistant steel is equal to or.
4. The method for manufacturing cold-rolled low-temperature acid dew point corrosion-resistant steel according to claim 1, comprising: smelting and casting into a casting blank according to the components of claim 1, hot rolling, coiling, cold rolling, continuous annealing and flattening; wherein the heating temperature of a casting blank is 1200-1250 ℃, the finishing temperature is 850-950 ℃ and the coiling temperature is 600-680 ℃ during hot rolling; the cold rolling reduction rate is 50-80%; the continuous annealing temperature is 720-840 ℃, and the leveling rate is 0.8-1.6%.
5. The method for manufacturing the cold-rolled low-temperature acid dew point corrosion-resistant steel as claimed in claim 3, wherein the yield strength of the cold-rolled low-temperature acid dew point corrosion-resistant steel is equal to or more than 260MPa, the tensile strength of the cold-rolled low-temperature acid dew point corrosion-resistant steel is equal to or more than 400MPa, and the elongation of the cold-rolled low-temperature acid dew point corrosion-resistant steel is.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112662856A (en) * | 2020-12-04 | 2021-04-16 | 安阳钢铁股份有限公司 | Production method of cold-rolled acid-resistant steel 09CrCuSb |
| CN114214558A (en) * | 2021-11-16 | 2022-03-22 | 马鞍山钢铁股份有限公司 | Ultra-strong low alloy steel resistant to corrosion of sulfuric acid and hydrochloric acid and preparation method thereof |
| CN114807760A (en) * | 2022-04-28 | 2022-07-29 | 湖南华菱湘潭钢铁有限公司 | Tungsten-containing sulfuric acid dew point corrosion resistant steel and production method thereof |
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| CN1123845A (en) * | 1994-12-26 | 1996-06-05 | 郑文龙 | Corrosionproof steel against sulfuric acid at dew point |
| EP2878687A1 (en) * | 2012-07-26 | 2015-06-03 | JFE Steel Corporation | Method for producing oriented electromagnetic steel sheet |
| CN106414784A (en) * | 2014-03-28 | 2017-02-15 | 日新制钢株式会社 | Steel plate having excellent acid dew point corrosion resistance, method of production, and exhaust gas channel constituent member |
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| CN1123845A (en) * | 1994-12-26 | 1996-06-05 | 郑文龙 | Corrosionproof steel against sulfuric acid at dew point |
| EP2878687A1 (en) * | 2012-07-26 | 2015-06-03 | JFE Steel Corporation | Method for producing oriented electromagnetic steel sheet |
| CN106414784A (en) * | 2014-03-28 | 2017-02-15 | 日新制钢株式会社 | Steel plate having excellent acid dew point corrosion resistance, method of production, and exhaust gas channel constituent member |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN112662856A (en) * | 2020-12-04 | 2021-04-16 | 安阳钢铁股份有限公司 | Production method of cold-rolled acid-resistant steel 09CrCuSb |
| CN114214558A (en) * | 2021-11-16 | 2022-03-22 | 马鞍山钢铁股份有限公司 | Ultra-strong low alloy steel resistant to corrosion of sulfuric acid and hydrochloric acid and preparation method thereof |
| CN114807760A (en) * | 2022-04-28 | 2022-07-29 | 湖南华菱湘潭钢铁有限公司 | Tungsten-containing sulfuric acid dew point corrosion resistant steel and production method thereof |
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