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CN-122013042-A - Hot-rolled pickled steel for ultra-deep drawing and preparation method thereof

CN122013042ACN 122013042 ACN122013042 ACN 122013042ACN-122013042-A

Abstract

The invention relates to the field of metal materials, and discloses hot-rolled pickled steel for ultra-deep drawing and a preparation method thereof. The hot-rolled pickling steel for ultra-deep drawing comprises the following chemical element components in percentage by weight: c is less than or equal to 0.003 percent, si is less than or equal to 0.03 percent, mn: 0.10-0.40%, P is less than or equal to 0.015%, S is less than or equal to 0.010%, al: 0.001-0.06%, ti: 0.01-0.03%, nb: 0.02-0.04%, B:0.0015 to 0.0035%, N: 0.001-0.003%, ca: 0.001-0.003%, al is less than or equal to Ti+0.67Nb+0.01%, and B-0.78N is more than or equal to 0.0005%. According to the invention, through reasonable chemical composition design and matching with steel making, continuous casting, hot rolling, pickling and flattening processes, the hot rolled pickled steel plate with good surface quality and ultra-deep drawing performance is obtained, and the requirements of ultra-deep drawing application are met.

Inventors

  • WANG ZHANYE
  • ZHANG YI
  • WANG TENG
  • TANG HENGQIANG
  • WU HAO
  • MA MINGLU
  • YU BO

Assignees

  • 马鞍山钢铁有限公司

Dates

Publication Date
20260512
Application Date
20260225

Claims (10)

  1. 1. The hot-rolled pickled steel for ultra-deep drawing is characterized by comprising the following chemical element components in percentage by weight ：C≤0.003%,Si≤0.03%,Mn：0.10~0.40%,P≤0.015%,S≤0.010%,Al：0.001~0.06%,Ti：0.01~0.03%,Nb：0.02~0.04%,B：0.0015~0.0035%,N：0.001~0.003%,Ca：0.001~0.003%,Al≤Ti+0.67Nb+0.01%,B-0.78N≥0.0005%.
  2. 2. The hot-rolled pickled steel for ultra-deep drawing according to claim 1, wherein the hot-rolled pickled steel for ultra-deep drawing has a yield strength of 180-240 mpa, a tensile strength of 290-350 mpa, an elongation a 50 of 53% or more, an n value of 0.22 or more, and an r value of 2.2 or more.
  3. 3. The method for producing hot-rolled pickled steel for ultra-deep drawing as claimed in claim 1 or 2, comprising: Pretreating molten iron to obtain pretreated molten iron, smelting the pretreated molten iron in a converter to obtain molten steel, refining and continuously casting the molten steel to obtain a continuous casting slab; Sequentially heating and hot rolling a continuous casting slab, cooling the steel plate obtained after hot rolling to 580-600 ℃ at a cooling speed of 60-120 ℃ per second, coiling, and then pickling to obtain hot-rolled pickled steel for ultra-deep drawing; Heating the continuous casting slab in mixed gas of O 2 and N 2 , wherein the content of O 2 in the mixed gas is less than or equal to 5% by volume; the heating condition comprises 1180-1200 ℃ and 1.5-2.5 hours; The hot rolling comprises rough rolling and finish rolling, wherein the initial rolling temperature of the rough rolling is 1100-1150 ℃, and the final rolling temperature of the finish rolling is 880-900 ℃; And (3) pickling by using a pickling solution, wherein the pickling solution contains 0.1-0.3% by volume of inhibitor.
  4. 4. The method according to claim 3, wherein the content of S element in the pretreated molten iron is controlled to be less than or equal to 0.010% by weight and the content of P element is controlled to be less than or equal to 0.015% by weight.
  5. 5. The preparation method according to claim 3, wherein the weight percentage of the C element is less than or equal to 0.01% and the weight percentage of the P element is less than or equal to 0.012% in the end point control of converter smelting; the tapping temperature of converter smelting is 1650-1680 ℃.
  6. 6. The method according to claim 3, wherein the conditions for refining include a vacuum degree of 67Pa or less for 20 to 30 minutes.
  7. 7. The method according to claim 3, wherein the conditions for continuous casting include a degree of superheat of 15-35 ℃, a drawing speed of 1-1.3 m/min, an aerosol cooling specific water amount of 0.3-0.5L/kg, and a casting blank cooling speed of 20-50 ℃.
  8. 8. The method according to claim 3, wherein the rough rolling is performed in 6-8 rolling passes, the total reduction is not less than 50%, and the single pass reduction is 8-12%.
  9. 9. The method according to claim 3, wherein the finish rolling is performed in 8-10 rolling passes, the single pass reduction is 10-15%, and the total reduction is not less than 70%.
  10. 10. The method according to claim 3, wherein the pickling solution further contains hydrochloric acid and water, and the content of the hydrochloric acid in the pickling solution is 15-20% by volume; The pickling temperature is 70-80 ℃.

Description

Hot-rolled pickled steel for ultra-deep drawing and preparation method thereof Technical Field The invention relates to the field of metal materials, in particular to hot-rolled pickled steel for ultra-deep drawing and a preparation method thereof. Background With the development of industries such as automobiles, home appliances and the like, there is an increasing demand for steels having excellent deep drawing properties. In the deep drawing process, the steel needs to have good plasticity so as to ensure that the defects such as cracking and the like do not occur under the complex deformation condition. The conventional hot-rolled pickled steel plate has certain limitations in deep drawing performance, such as higher yield ratio, lower elongation and the like, and is difficult to meet the manufacturing requirements of high-end products. The development of a hot-rolled pickled steel plate with excellent ultra-deep drawing performance and a high-efficiency production method thereof has important practical significance. Currently, a great deal of research has been carried out for optimizing the deep drawing performance of hot-rolled pickled steel plates at home and abroad, but the following technical bottlenecks still exist: The prior art generally adopts a traditional low-carbon steel component system (C is less than or equal to 0.015 percent), but the synergistic effect of microalloy elements is not controlled systematically. For example, the titanium content is controlled to be 0.01-0.03% by partial technology, but the nitrogen fixation effect of boron element is not combined, so that the solid solution nitrogen content is higher (N is more than 0.006%), and the ageing sensitivity is obviously increased. Boron element, wherein boron (0.0005-0.002%) is tried to be added in the prior art, but hot rolling process parameters are not optimized, so that the precipitation behavior of boron is difficult to regulate and control, and the ferrite grain refinement effect is not obvious. Aluminum content most of the techniques control aluminum to 0.02-0.04%, but the binding efficiency of aluminum and nitrogen is not considered, and the size distribution of AlN precipitates is uneven, so that the strain timeliness is affected. The prior art has the defects that the thickness of a hot rolling intermediate billet is generally lower than 40mm in the conventional process, the final rolling temperature is fluctuated (+ -30 ℃), particularly the temperature of the edge is excessively reduced, the rolling of an austenite and ferrite two-phase region is easy to form, and the forming performance is deteriorated. Coiling temperature-coiling temperature in the prior art is controlled to be 620-650 ℃ so as to lead to coarse ferrite grain size (> 8.0 grade). The patent application with publication number CN 111926252A relates to a hot-rolled pickled steel plate for deep drawing and a production method thereof. In view of the problems that users require hot-rolled pickled steel plates to have deep drawing performance and higher strength, but the traditional IF steel cannot meet the fatigue performance requirement due to lower strength, and the common aluminum killed steel has higher strength but cannot meet the deep drawing requirement, the hot-rolled pickled steel plates for deep drawing and the production method thereof are provided, wherein the steel plates comprise the following chemical components in percentage by mass, and the balance of ：C：0.005％～0.010％,Si≤0.02％,Mn：0.25％～0.45％,P≤0.020％,S≤0.015％,Als：0.025％～0.050％,N≤0.0020％,Ti：0.030％～0.080％,Cu：0.025％～0.055％,B：0.0005％～0.0015％, is Fe and unavoidable impurities. By reasonably proportioning key elements such as carbon, manganese, titanium, copper, boron and the like and matching with a reasonable production process, the steel plate which not only meets the deep drawing purpose, but also has higher tensile strength is produced, and simultaneously meets the requirements of users on the deep drawing purpose and fatigue performance. According to the patent, the Cu element is added, so that a certain strength can be improved, the Mn content is higher, the strength can be improved, the forming performance can be reduced, the elongation is mainly between 40% and 50%, the requirement of deep-drawing parts can be met, and the cracking risk still exists when the ultra-deep-drawing parts are punched. The patent application publication No. CN 107779743A relates to a micro-carbon hot-rolled pickled steel plate with good deep drawability and a manufacturing method thereof. The hot-rolled pickled steel plate comprises the following chemical components in percentage by weight ：C:0 .006-0 .020％,Si≤0.035％,Mn:0.10-0 .20％,P≤0.018％ ,S≤0.010％ ,Ti:0.01-0.02％ ,B:0.0005-0.002％,N≤0.0050％ ,Al:0.020-0.055％, and the balance of iron and unavoidable impurities. The yield strength Rp0.2 of the steel plate is 165-225 MPa, the tensile strength Rm is 280-340 MPa, the elongation after fracture A50 is 47-58%, and the