WO2022253216A1 - Hot-rolled acid-pickled enameled steel having good deep drawing properties and production method therefor - Google Patents

Abstract

A hot-rolled acid-pickled enameled steel having good deep drawing properties and a production method therefor. The chemical composition of the hot-rolled acid-pickled enameled steel comprises: C, N, S, Al, Mn, Si, P, Ti, and the balance of Fe and inevitable impurities; wherein the weight percentages of C, N, S, Al, and Ti are: C: 0.001-0.006%, N≤0.004%, S≤0.0080%, and Als: 0.015-0.040%, 4[C]+3.42[N]+3[S]≤[Ti]≤0.065%; and the weight percentages of Si, Mn, and P satisfy: Mn: 1.0-1.5%, Si: 0.001-0.03% and P≤0.015%, or Si: 0.4-0.6%, Mn: 0.15-0.3% and P≤0.015%, or Si: 0.001-0.03%, Mn: 0.15-0.3% and P: 0.035-0.055%. The enameled steel of the present invention has a yield strength of 210-245 MPa, a tensile strength of greater than or equal to 320 MPa, an elongation of greater than or equal to 46%, an r value of greater than or equal to 1.3, an n value of greater than or equal to 0.3, a TH value of greater than or equal to 7.0, has good forming properties, especially good deep drawing properties, and further has high tensile strength and fish scaling resistance.

Description

A hot-rolled pickling enamel steel with good drawing performance and its production method technical field

The invention belongs to the technical field of enamel steel production, and in particular relates to a hot-rolled pickling enamel steel with good drawing performance and a production method thereof.

Background technique

Enamel is a composite material in which inorganic vitreous materials are condensed on the base metal by melting and firmly combined with the metal. Enamel products not only have the inherent strength, toughness and machinability of metal materials, but also have the characteristics of corrosion resistance, aging resistance, wear resistance, high temperature resistance, non-toxicity and decorative properties of ceramic materials. advantage. Enamel products with steel plates as metal substrates play a very important role in the national economy and are widely used in light industry, household appliances, metallurgy, chemical industry, construction and other industries.

There are many types of enamelled steel sheets. According to the production process, there are hot-rolled pickled sheets, cold-rolled sheets and clad sheets. Among them, hot-rolled sheets have been more and more widely used due to their good economy, such as for preparing water heaters The thickness of the liner is generally 1.5-2.5mm, and the annual demand exceeds 500,000 tons.

At present, water heater inner tanks are generally produced by rolling and welding, and the production efficiency and yield are low. In order to improve production efficiency and finished product rate, the water heater industry has gradually begun to use the deep drawing process to produce water heater inner tanks, and it is necessary to improve the tensile properties of enamelled steel products.

In the case of relatively stable process conditions, the drawing performance of hot-rolled enamel steel is mainly related to the following performance indicators:

(1) Plastic strain ratio r value: A high plastic strain ratio r value is beneficial to deep drawing.

(2) Hardening index n value: A large n value of the plate indicates that the material has good distribution uniformity in plastic deformation, and it is not easy to produce concentrated deformation, and it is relatively difficult to produce plastic fracture.

(3) Yield ratio: Generally, the lower the yield ratio is, the better it is for the deep drawing of the compressor shell.

(4) Elongation: A high elongation is beneficial to the unidirectional deep drawing deformation of the part. Generally speaking, a high elongation is an important guarantee for the smooth forming of the part.

Chinese patent CN201310547968.1 discloses "Hot-rolled thin plate enamelled steel with a yield strength of 245MPa and its manufacturing method". The thickness of the prepared enamelled steel is 1.0-2.5mm, and the chemical composition is C: 0.001-0.010%, Si≤0.05%, Mn: 0.10-0.50%, P≤0.020%, S≤0.010%, Ti: 0.04-0.10%, Als: 0.02-0.08%, N≤0.008%. The rolling temperature is 1100-1150°C, the final rolling temperature is 860-930°C, and the coiling temperature is 600-700°C. The yield strength of the product is 245-330MPa, the tensile strength is ≥300MPa, and the elongation is 37-42%.

Chinese patent CN2013105483 10.2 discloses "hot-rolled thin-plate enameled steel with a yield strength of 330MPa and its manufacturing method", the thickness of the prepared enameled steel is 1.0-2.5mm, and the chemical composition is C: 0.02-0.07% by weight, Si≤ 0.05%, Mn: 0.10-0.50%, P≤0.020%, S≤0.010%, Ti: 0.04-0.10%, Als: 0.02-0.08%, N≤0.008%, the rest is Fe and inevitable inclusions, and Ti /C=1.0～1.5. The manufacturing process is as follows: the heating temperature is 1200-1250°C, the final rolling temperature is 860-930°C, and the coiling temperature is 650-700°C. The yield strength of the product is 330-450MPa, the tensile strength is ≥400MPa, and the elongation is 38-41%.

Chinese patent CN201510280022.2 discloses "a method of manufacturing enamelled steel with excellent scale explosion resistance and its steel plate". The chemical composition of the steel is: C: 0.04-0.10%, Si≤0.10%, Mn : 0.30-1.0%, Ti: 0.03-0.10%, P≤0.015%, S: 0.010-0.045%, N: 0.003-0.009%, Als: 0.005-0.050%, Cr: 0.05-0.25%, and Ti/C : 0.5~1.2. The heating temperature of the continuous casting slab is 1180-1250°C, the finish rolling start temperature is 980-1100°C, and the final rolling temperature is 880-950°C. After rolling, the front-stage cooling method is adopted, and the cooling rate is ≥30°C/s within 6s. Cooled to 630-700°C for coiling, the yield strength of the product is 390-500MPa, the tensile strength is 476-598MPa, and the elongation is 26-38%.

Chinese patent 201510398485.9 patent "thin plate enamel steel for subway decoration and its manufacturing method", the thickness of enamel steel is 1.0~2.0mm, and its chemical composition weight percentage is as follows: C: 0.001-0.003%, Si≤0.10%, Mn: 0.05- 0.10%, P≤0.010%, S≤0.005%, Als: 0.01-0.02%, Ti: 0.20-0.25%, N: 0.010-0.020%. The tapping temperature is 1100-1150°C, the final rolling temperature is 800-850°C, and the coiling temperature is 700-750°C. The yield strength of the product is ≥460MPa, the tensile strength is ≥550Pa, the elongation is 38-42%, the r value is 1-1.5, and the n value is 0.1-0.3.

Chinese patent 201810663362.7 discloses "a low-cost high-oxygen enameled steel produced by CSP process and its manufacturing method", and its chemical composition weight percentage is: C≤0.01%, Mn: 0.10-1.00%, O≤0.0500%, Si ≤0.01%, P≤0.020%, S≤0.030%, Als≤0.01%, and the rest are Fe and unavoidable impurities. This patent increases the oxygen content in the steel to form a large number of oxide inclusions, which serve as hydrogen storage traps and improve the scale explosion resistance of the steel plate. Its manufacturing process is as follows: the furnace temperature is 1160-1200°C, the final rolling temperature is 860-900°C, the coiling temperature is 600-640°C, the yield strength is 151-214MPa, the tensile strength is 256-282MPa, and the elongation is 35.2 ~45.4%.

Chinese patent CN201910697103.0 discloses "a 260MPa grade hot-rolled pickling enamel steel and its production method", and its chemical composition weight percentage is: C: 0.030-0.060%, Si≤0.030%, Mn: 0.30-0.60% , P≤0.020%, S≤0.010%, Als≤0.060%, B: 0.0015-0.0040%, N: 0.0040-0.0100%. The manufacturing method is as follows: the heating temperature of the steel plate before rolling is controlled at 1132-1212°C, the final rolling temperature is controlled at 881-890°C, the coiling temperature is controlled at 687-696°C, and the concentration of free acid in the pickling solution is 105-119g/L , The temperature of the acid solution is 71.4-74°C. The yield strength of the product is ≥260MPa, the tensile strength is ≥360MPa, and the elongation is 33-34%.

Chinese patent CN202010986947.X discloses "Hot-rolled enamelled steel for deep drawing and its manufacturing method", its composition mass percentage is: C<0.01%, Si≤0.05%, Mn 0.10-0.80%, P≤0.030%, S≤ 0.015%, Ti 0.01-0.08%, Al 0.01-0.07%, N≤0.010%, 4≤Ti/N≤10, Ca 0.0010-0.0040%, Ca/S≤1.25. The manufacturing method is as follows: the heating temperature is 1150-1190°C, the final rolling temperature is 800-900°C, the coiling temperature is 710-760°C, the cumulative deformation rate of hot rolling and rough rolling is controlled above 70%, and the cumulative deformation rate of finishing rolling is controlled Above 70%. The leveling pressure is 700-900 tons, and the leveling elongation of the leveling is 7-12%. The yield strength of the product is 359-402MPa, the tensile strength is 447-483MPa, and the elongation is 30-41%.

Chinese patent CN202010986956.9 discloses "an enamelled steel and its preparation method and application", and its composition mass percentage is: C: 0.01-0.14%, Si≤0.10%, Mn: 0.20-1.6%, P≤0.040%, S≤0.040%, Ti: 0.01-0.12%, Al: 0.01-0.07%, N≤0.010%, Mn/S≥30. Its preparation method is as follows: the heating temperature is 1200-1350°C, the finish rolling temperature is 810-980°C, the coiling temperature is 500-700°C, the cumulative deformation rate of hot-rolled rough rolling is controlled above 70%, and the hot-rolled finish rolling The accumulative deformation rate is controlled above 70%, the leveling pressure is 450-650 tons, and the leveling elongation rate is ≤6%. ~0.85mm, the hardness of shot blasting is 40~52HRC; the concentration of pickling solution is 5~20%. The yield strength of the product is ≥410, the tensile strength is 490MPa, and the elongation is 25-43.5%.

To sum up, the existing disclosed enamel steel has high yield strength, low elongation, poor drawing performance, and quality problems such as napping and cracking are prone to occur in the drawing forming process. Therefore, it is necessary to develop thermal steel with good drawing performance. Rolled enamel steel is of great significance to promote the upgrading of the water heater liner manufacturing industry and the green transformation of the home appliance industry.

Contents of the invention

The object of the present invention is to provide a hot-rolled pickled enamel steel with good drawing performance and its production method. The yield strength of the hot-rolled pickled enamel steel is 210-245MPa, the tensile strength is ≥320MPa, and the elongation is ≥46%. , n value ≥ 0.3, r value ≥ 1.3, TH value ≥ 7.0, has good formability, especially has good deep drawing performance, and also has high strength and anti-scale explosion performance, which meets the production of water heater inner tank Require.

In order to achieve the above object, the technical scheme provided by the invention is:

A hot-rolled pickling enamel steel with good deep-drawing performance, its chemical composition weight percentage is: C: 0.001-0.006%, N≤0.004%, S≤0.0080%, Als: 0.015-0.040%, when it is strengthened with Mn, Mn: 1.0～1.5%, Si: 0.001～0.03%, P≤0.015%; when Si is strengthened, Si: 0.4～0.6%, Mn: 0.15～0.3%, P≤0.015%; when P is strengthened, Si: 0.001～0.03%, Mn: 0.15～0.3%, P: 0.035～0.055%; also includes Ti, and 4[C]+3.42[N]+3[S]≤[Ti]≤0.065%, the rest is Fe and other unavoidable impurities.

In some embodiments, the content of Ti is 0.025-0.065%.

In some embodiments, when Mn is used for strengthening, Mn: 1.0-1.5%, Si: 0.005-0.025%, P≤0.015%.

In some embodiments, when P is used for strengthening, Si: 0.003-0.006%, Mn: 0.15-0.3%, and P: 0.035-0.055%.

The microstructure of the hot-rolled pickling enamelled steel in the present invention is polygonal ferrite grains uniformly having a {111} plane texture, and the grain size does not exceed grade 7.

The yield strength of the hot-rolled pickling enamel steel in the present invention is 210-245MPa, the tensile strength is ≥320MPa, the elongation is ≥46%, the r value is ≥1.3, the n value is ≥0.3, and the TH value is ≥7.0.

In some embodiments, the yield strength of the hot-rolled pickling enamel steel of the present invention is 210-245MPa, the tensile strength is 320-450MPa, the elongation is 46-52%, the r value is 1.3-1.8, and the n value is 0.3~0.4, TH value is 7.0~8.5.

In some embodiments, there are no solid-solution C and N interstitial atoms in the ferrite of the hot-rolled pickling enamel steel of the present invention.

In some embodiments, the present invention provides a water heater inner tank, the steel part of the water heater inner tank is the hot-rolled pickled enamelled steel with good drawing performance described in any embodiment of the present invention. In some embodiments, the inner tank of the water heater of the present invention is produced from the hot-rolled pickled enamelled steel with good drawing performance described in any embodiment of the present invention through deep drawing.

In the composition design of the hot-rolled pickling enamelled steel of the present invention:

C: Solid solution C will increase the yield strength and tensile strength of steel, but the plasticity will decrease, and solid solution C is not conducive to the formation of {111} texture, reducing the r value of the product. Materials with a higher limit drawing ratio require low yield strength, high elongation, and high {111} texture strength. Therefore, the smaller the solid solution C, the better, but the lower the C content, the lower the refining cost required for the C content The higher the value, the longer the refining time. In order to balance the mechanical properties and production costs, the C content in the steel of the present invention is controlled at 0.001-0.006%.

N: It is a strong solid-solution strengthening element, which is not conducive to the formation of {111} texture, and will cause aging to affect the stamping quality of the steel plate, but the low N content will increase the production cost. Comprehensive consideration, the N content in the steel of the present invention is controlled Below 0.004%. In some embodiments, the N content is 0.002-0.004%.

S: It is a harmful impurity element in steel. S in steel is easy to form segregation in steel, which reduces the toughness and welding performance of steel. S is easy to form plastic sulfide, which causes delamination of steel plate and deteriorates the performance of steel plate. Therefore, the lower the S content The better, considering comprehensively, the S content in the steel of the present invention is controlled below 0.008%.

Als: Al is a strong deoxidizer, which can reduce oxide inclusions in steel and make the steel pure. However, if the Al content is too high, it will easily produce grain refinement and increase the yield strength and yield ratio. Considering comprehensively, the steel of the present invention Als control is 0.015-0.040%.

Ti: Ti has a strong affinity with C and N in the steel. By forming TiC and TiN to fix C and N interstitial atoms, reducing the content of C and N in solid solution in the steel is beneficial to promote the formation of {111} texture, Increase the r value. In addition, since the binding capacity of Ti and S is greater than that of Ti and C, in order to ensure that Ti can remove solid-dissolved C atoms, according to the mass percentage of TiC, TiN and Ti ₄ C ₂ S ₂ , it should be ensured that 4 [C]+3.42[N]+3[S]≤[Ti]≤0.065%. The formed TiC, TiN and Ti ₄ C ₂ S ₂ can be used as traps for hydrogen storage and improve the scale explosion resistance of the steel plate.

Si, Mn, P: Solid solution in ferrite and austenite can increase the strength, but at the same time it will reduce the plasticity. Considering comprehensively, when Mn is used for strengthening, the Mn content is controlled at 1.0-1.5%, and Si≤ 0.03%, such as 0.005-0.025%, P≤0.015%, such as 0.005-0.013%; when using Si strengthening, the Si content is controlled at 0.4-0.6%, the Mn content is controlled at 0.15-0.3%, P≤0.015%, such as, Such as 0.005-0.015%; when P is used for strengthening, the P content is controlled at 0.035-0.055%, Si≤0.03%, such as ≤0.01%, and the Mn content is controlled at 0.15-0.3%.

The invention adopts ultra-low C and microalloying (addition of Ti) to realize no solid-solution C and N interstitial atoms in ferrite, lubricated rolling and high-temperature coiling under low temperature and high pressure, and obtains coarse, uniform size and {111 }Ferrite grains with surface texture can improve the deep-drawing performance of the product, and further, the tensile strength and elongation of the product can be improved through solid solution strengthening of Si, Mn and P. In addition, control the composition ratio of Ti, C, N, and S to form coarse ferrite grains (TiC, TiN, and Ti ₄ C ₂ S ₂ ), which serve as traps for hydrogen storage, improve the scale explosion resistance of the steel plate, and realize the product The yield strength is 210-245MPa, the tensile strength is ≥320MPa, the elongation is ≥46%, the n value is ≥0.3, the r value is ≥1.3, and the TH value is ≥7.0. The product has good formability, especially good deep drawing Formability, at the same time, has high tensile strength and anti-scale explosion performance.

The production method of the hot-rolled pickling enamelled steel with good drawing performance of the present invention comprises the following steps:

1) Smelting and casting;

Smelting, refining and continuous casting according to the above composition;

2) rolling

The final rolling temperature is 750-800°C, the total reduction ratio of the rolling temperature ≤840°C is ≥60%, and the rolling temperature ≤840°C is put into the lubricating emulsion during the rolling process, and the oil-water ratio of the lubricating emulsion is 1-5% ;

3) cooling

Cooling rate≤6℃/s;

4) coiling

The coiling temperature is 720～780℃;

5) slow cooling

Slowly cool the steel plate after coiling;

6) pickling

Pickling after slow cooling to remove scale on the surface of the steel plate.

Preferably, in step 2), the finish rolling temperature is 750-780°C.

Preferably, in step 4), the coiling temperature is 730-760°C.

Preferably, in step 5), the slow cooling is the slow cooling of the stack or the slow cooling of the insulation cover, and hot coils are stacked around the stack during the slow cooling.

In some embodiments, in the rolling of step 2), the total reduction rate at the rolling temperature ≤ 840°C is 60-85%.

In some embodiments, the cooling rate in step 3) is 1-6°C/s.

In the production method of hot-rolled pickling enamel steel of the present invention:

Controlling the final rolling temperature at 750-800°C during the rolling process can promote the formation of {111} texture, increase the r value of the product, and coarsen the ferrite grains; if the final rolling temperature is higher than 800°C, the ferrite The grain becomes finer, the {111} texture decreases, the product strength increases, and the elongation, n value, and r value will all decrease. If the final rolling temperature is lower than 750°C, it will not be possible to ensure that the coiling temperature is ≥720°C, and the deformed ferrite Sufficient recovery cannot be achieved, but the formability of the product will be deteriorated.

The rolling process of the present invention adopts low-temperature lubricated rolling, ferrite rolling occurs on the steel plate below 840°C, and the rolling temperature is controlled in the ferrite phase region to control the total reduction rate to ≥60%, which promotes the formation of {111} texture , Obtain ferrite grains with {111} surface texture, and improve the r value of the product. The purpose of lubricated rolling during rolling temperature ≤ 840°C during ferrite rolling is to obtain a uniform {111} texture in the thickness direction, avoid the formation of {110} texture on the surface, and improve the r value of the product. When lubricating rolling, control the oil-water ratio of the milk lubricant emulsion to 1-5%. If the oil-water ratio is less than 1%, the friction coefficient between the steel plate and the roll will be large, and it is easy to form a shear texture that is not conducive to forming. If the oil-water ratio is greater than 5 %, it is easy to slip during rolling, the rolling stability is poor, and the product yield is low. The oil used in the lubricating emulsion of the present invention may be the oil conventionally used in rolling in the art.

In order to promote the full recovery of ferrite, the cooling rate should be controlled to be ≤6°C/s.

The coiling adopts high-temperature coiling, and the coiling temperature is controlled at 720-780 ° C. Combined with the slow cooling of the steel coil, the ferrite extending along the rolling direction at the end of rolling can be fully recovered to form a coarse and uniform ferrite. grains to obtain the desired performance. If the coiling temperature is lower than 720°C, the deformed ferrite cannot be fully recovered, which will deteriorate the formability of the product. Under the conditions of the existing process equipment, the temperature will decrease during the cooling process. Under the set final rolling temperature, 780°C is the highest temperature that the ferrite can fully recover and the coarse and uniform ferrite grains can be achieved. If the temperature is higher than 780°C, on the one hand, it will not have a significant impact on performance, and on the other hand, it will be more difficult to implement.

In some embodiments, the present invention provides a method for manufacturing a water heater liner, the method includes the step of manufacturing the hot-rolled pickled enamelled steel with good drawing performance by using the method described in any embodiment of the present invention , and the step of deep-drawing the hot-rolled pickling enamel steel with good drawing performance to form the inner tank of the water heater. The deep drawing method known in the art can be used to prepare the water heater liner of the present invention.

Beneficial effects of the present invention:

1. The composition design of the present invention adopts ultra-low carbon, Ti micro-alloy chemical composition design, and further through Si, Mn, P solid solution strengthening, realizes that there are no solid solution C and N interstitial atoms in the ferrite, so that the hot-rolled pickling enamelled steel The microstructure obtains coarse, uniform size and polygonal ferrite grains with {111} surface texture, which improves the deep-drawing performance of the product. In addition, by controlling the composition ratio of Ti, C, N, and S, irreversible hydrogen storage traps such as TiC, TiN, and Ti ₄ C ₂ S ₂ are formed to reduce the dissolved hydrogen in the matrix, reduce the risk of scale explosion, and improve the scale resistance of the steel plate. The hot-rolled pickled enamelled steel products have good forming properties, especially good drawing and forming properties, and also have high tensile strength and good anti-scale cracking properties.

2. On the basis of composition design, in the rolling process, the rolling temperature is controlled in the range of ferrite phase region to have a total reduction rate greater than 60%, combined with lubricated rolling, to obtain iron with {111} surface texture Ferrite grains, followed by slow cooling and high-temperature coiling to fully recover the ferrite and form coarse and uniform polygonal ferrite grains, so that the yield strength of hot-rolled pickling enamel steel is 210-245MPa, and the tensile strength ≥320MPa, elongation ≥46%, n ≥ 0.3, r ≥ 1.3, the product not only has good deep drawing performance, but also has high tensile strength, in addition, TH value ≥ 7.0, has good scale resistance Explosive performance.

3. Lubricated rolling is adopted in the low-temperature ferrite rolling process of the present invention, and the oil-water ratio of the lubricating emulsion is controlled at 1 to 5%, so as to avoid the formation of shear texture that is not conducive to forming, and the ferrite phase accumulates at a certain reduction rate, forming The {111} surface texture, which is conducive to stamping, combined with subsequent slow cooling and high-temperature coiling, forms coarse and uniform ferrite grains, thereby obtaining the required mechanical properties.

4. The hot-rolled pickled enamelled steel obtained by the present invention has better drawing performance, and can be used in the production of water heater liners by drawing and forming, replacing the rolling and welding forming methods with low production efficiency and low yield, and has a great impact on promoting water heaters. The upgrading of the liner manufacturing industry and the green transformation of the home appliance industry are of great significance.

Detailed ways

The present invention will be further described below in conjunction with embodiment.

The specific components of the examples of the present invention are shown in Table 1, the process parameters of the examples are shown in Table 2, and the properties of the hot-rolled pickling enamelled steels of each example are shown in Table 3.

After the sample is processed into a standard size, the yield strength, tensile strength, n value, and r value are tested on a tensile testing machine with reference to the standard EN10002. The hydrogen permeation test method is used to detect the explosive sensitive TH value of the enamel scale with reference to the standard EN10209.

The microstructure of the hot-rolled pickling enamel steel obtained by the present invention is coarse, uniform in size and polygonal ferrite grains with {111} plane texture, with a tensile strength of 210 to 245 MPa, a tensile strength of ≥320 MPa, and an elongation of ≥46%. , n value ≥ 0.3, r value ≥ 1.3, TH value ≥ 7.0, has good formability, especially has good deep drawing performance, also has high tensile strength and good anti-scale explosion performance, can be used in The production of water heater inner tank by deep drawing can replace the rolling and welding forming methods with low production efficiency and low yield rate, which is of great significance to promote the upgrading of the water heater inner tank manufacturing industry and the green transformation of the home appliance industry.

Table 1 (unit: weight percentage)

the	C	Si	mn	als	P	S	N	Ti
Example 1	0.0011	0.025	1.02	0.039	0.011	0.006	0.0034	0.040
Example 2	0.0010	0.008	1.31	0.034	0.013	0.004	0.0030	0.030
Example 3	0.0059	0.010	1.47	0.030	0.012	0.007	0.0029	0.055
Example 4	0.0029	0.456	0.28	0.040	0.014	0.007	0.0036	0.045
Example 5	0.0015	0.584	0.16	0.028	0.010	0.001	0.0039	0.029
Example 6	0.0032	0.418	0.19	0.027	0.009	0.005	0.0025	0.045

Example 7	0.0036	0.003	0.30	0.035	0.039	0.007	0.0040	0.065
Example 8	0.0040	0.006	0.17	0.020	0.055	0.008	0.0036	0.059
Example 9	0.0039	0.005	0.24	0.016	0.043	0.002	0.0039	0.040

Table 2

table 3

Claims (15)

1. A hot-rolled pickling enamel steel with good drawing performance, its chemical composition is C, N, S, Al, Mn, Si, P, Ti and the balance of Fe and unavoidable impurities; wherein, C, N, The weight percentage of S, Al, and Ti is: C: 0.001～0.006%, N≤0.004%, S≤0.0080%, Als: 0.015～0.040%, 4[C]+3.42[N]+3[S]≤ [Ti]≤0.065%; the weight percentage of Si, Mn and P satisfies: Mn: 1.0～1.5%, Si: 0.001～0.03% and P≤0.015%, or Si: 0.4～0.6%, Mn: 0.15～0.3% and P≤0.015%, or Si: 0.001-0.03%, Mn: 0.15-0.3% and P: 0.035-0.055%.
2. The hot-rolled pickling enamel steel with good drawing performance according to claim 1, characterized in that the content of Ti is 0.025-0.065%.
3. The hot-rolled pickling enamel steel with good drawing performance according to claim 1, characterized in that the weight percentages of Si, Mn and P satisfy: Mn: 1.0-1.5%, Si: 0.005-0.025%, P≤0.015 %.
4. The hot-rolled pickling enamel steel with good drawing performance according to claim 1, characterized in that the weight percentages of Si, Mn and P satisfy: Si: 0.003-0.006%, Mn: 0.15-0.3%, P: 0.035 ~0.055%.
5. The hot-rolled pickled enamel steel with good drawing performance according to claim 1, characterized in that the microstructure of the hot-rolled pickled enamel steel is uniform polygonal ferrite with {111} plane texture grains, and the grain size does not exceed grade 7.
6. The hot-rolled pickled enamel steel with good drawing performance according to any one of claims 1-5, characterized in that the yield strength of the hot-rolled pickled enamel steel is 210-245 MPa, and the tensile strength is ≥ 320MPa, elongation ≥ 46%, r value ≥ 1.3, n value ≥ 0.3, TH value ≥ 7.0.
7. The hot-rolled pickled enamel steel with good drawing performance as claimed in claim 6, characterized in that the yield strength of the hot-rolled pickled enamel steel is 210-245MPa, the tensile strength is 320-450MPa, and the elongation is 46-52%, r value 1.3-1.8, n value 0.3-0.4, TH value 7.0-8.5.
8. The production method of hot-rolled pickling enamelled steel with good drawing performance as described in any one of claims 1-7, characterized in that it comprises the steps of:

   1) Smelting and casting

   Smelting, refining, and continuous casting of components according to any one of claims 1-4;

   2) rolling

   The final rolling temperature is 750-800°C, the total reduction ratio of the rolling temperature ≤840°C is ≥60%, and the rolling temperature ≤840°C is put into the lubricating emulsion during the rolling process, and the oil-water ratio of the lubricating emulsion is 1-5% ;

   3) cooling

   Cooling rate≤6℃/s;

   4) coiling

   The coiling temperature is 720～780℃;

   5) slow cooling

   Slowly cool the steel plate after coiling;

   6) pickling

   Pickling after slow cooling to remove scale on the surface of the steel plate.
9. The production method of hot-rolled pickling enamel steel with good drawing performance according to claim 8, characterized in that, in step 2), the finish rolling temperature is 750-780°C.
10. The production method of hot-rolled pickling enamel steel with good drawing performance according to claim 8, characterized in that, in step 4), the coiling temperature is 730-760°C.
11. The production method of hot-rolled pickling enamelled steel with good drawing performance as claimed in claim 8, characterized in that, in step 5), the slow cooling is stacking slow cooling or insulation cover slow cooling, and the stacking Stack hot rolls around while cooling slowly.
12. The production method of hot-rolled pickling enamelled steel with good drawing performance as claimed in claim 8, characterized in that, in the rolling of step 2), the total reduction rate at the rolling temperature ≤ 840°C is 60-85% .
13. The production method of hot-rolled pickled enamel steel with good drawing performance as claimed in claim 8, characterized in that the cooling rate in step 3) is 1-6°C/s.
14. A water heater liner, which is produced from the hot-rolled pickled enamelled steel with good drawing performance according to any one of claims 1-7 through deep drawing.
15. A method for manufacturing an inner tank of a water heater, characterized in that the method includes the step of manufacturing the hot-rolled pickled enamel steel with good drawing performance by the method described in any one of claims 8-13, and The step of deep-drawing the hot-rolled acid-washed enamel steel with good drawing performance to form the inner tank of the water heater.