CN-117327969-B - Hot-dip aluminized zinc-plated steel plate with yield strength of 280MPa and manufacturing method thereof

Abstract

The invention discloses a hot dip aluminum zinc plated steel plate with yield strength of 280MPa and a manufacturing method thereof, which mainly solve the technical problem of bending and cracking of the existing 280MPa hot dip aluminum zinc plated steel plate. The technical proposal is that the hot dip aluminum zinc plated steel plate with the yield strength of 280MPa has the chemical components of ：C：0.008％～0.012％,Si≤0.03％,Mn：0.40％～0.60％,P：0.03％～0.05％,S≤0.0050％,Nb：0.005％～0.015％,Ti：0.045％～0.055％,Al：0.08％～0.10％,N：0.0010％～0.0020％, weight percent of the base plate and satisfies the conditions that the ratio of Ti to 3.42 (N-Al/1.92) to C is less than or equal to 16 and less than or equal to 30, and the balance is Fe and unavoidable impurities. The steel plate is mainly used in household appliance industry.

Inventors

• DING ZHILONG
• WANG XIAOJIAN
• WEI BAOMIN
• LU WEIXING
• YAN BINGHAO

Assignees

• 上海梅山钢铁股份有限公司

Dates

Publication Date

20260505

Application Date

20220624

Claims (5)

1. 1. A hot dip aluminum zinc plated steel plate with yield strength of 280MPa grade comprises the chemical components of ：C：0.008%～0.012%,Si≤0.03%,Mn：0.40%～0.60%,P：0.03%～0.05%,S≤0.0050%,Nb：0.005%～0.015%,Ti：0.045%～0.055%,Al：0.08%～0.10%,N：0.0010%～0.0020%, in percentage by weight, and satisfies 16-3.42 (N-Al/1.92)/C-30 in percentage by weight, fe and unavoidable impurities in balance, wherein the yield strength R P0.2 of the hot dip aluminum zinc plated steel plate with thickness of 1.5-2.0 mm is 280-360 MPa, the tensile strength R m is 350-420 MPa, the elongation after breaking A 80 mm is 30-38%, the aging index AI value of the hot dip aluminum zinc plated steel plate is less than or equal to 5 MPa after natural aging of the hot dip aluminum zinc plated steel plate in room temperature environment for 12-14 months, the hot dip aluminum zinc plated steel plate in rolling direction is 180-degree bending test, d=0a is qualified, and the hot dip aluminum zinc plated steel plate in vertical rolling direction is 180-degree bending test, d=0a is qualified.
2. 2. The hot-dip aluminized zinc sheet with yield strength of 280MPa grade according to claim 1, wherein the hot-dip aluminized zinc sheet has a metallographic structure of recrystallized ferrite, and the ferrite grain size grade is I9.0 to I9.5 grade.
3. 3. The hot-dip aluminum-zinc-plated steel sheet with yield strength of 280MPa according to claim 1, wherein after the hot-dip aluminum-zinc-plated steel sheet is subjected to a tensile pre-strain of 8%, a heat treatment is performed for 60 minutes at 100 ℃, an increase in yield stress and a 180 ° bending test of the hot-dip aluminum-zinc-plated steel sheet before and after the heat treatment are detected, d=0a, an aging index AI value of the hot-dip aluminum-zinc-plated steel sheet is not more than 5 MPa, a 180 ° bending test of the hot-dip aluminum-zinc-plated steel sheet in a rolling direction is performed, d=0a is qualified, and a 180 ° bending test of the hot-dip aluminum-zinc-plated steel sheet perpendicular to the rolling direction is performed, d=0a is qualified.
4. 4. A method for manufacturing a hot dip aluminized zinc coated steel sheet having a yield strength of 280MPa grade according to any one of claims 1 to 3, characterized in that the method comprises: continuously casting molten steel to obtain a continuous casting plate blank, wherein the weight percentage of the chemical components of the molten steel is ：C：0.008%～0.012%,Si≤0.03%,Mn：0.40%～0.60%,P：0.03%～0.05%,S≤0.0050%,Nb：0.005%～0.015%,Ti：0.045%～0.055%,Al：0.08%～0.10%,N：0.0010%～0.0020%,, and the chemical components of the molten steel are 16-3.42 (N-Al/1.92) ]/C-30, and the balance of Fe and unavoidable impurities; The continuous casting slab is heated to 1150-1200 ℃ through a heating furnace and then subjected to hot rolling, wherein the hot rolling is a two-stage rolling process, rough rolling is 5-pass continuous rolling, finish rolling is 7-pass continuous rolling, the finish rolling starting temperature is 990-1080 ℃, the finish rolling finishing temperature is 900-940 ℃, the finish rolling reduction is 90-92%, the thickness of a hot rolled steel plate is 3.8-4.1 mm after finish rolling, laminar cooling adopts front-stage cooling, and coiling is performed at 600-640 ℃ to obtain a hot rolled steel coil; And (3) after re-uncoiling the hot rolled steel coil, carrying out acid washing, cold rolling, annealing by a horizontal continuous annealing furnace, hot-dip aluminum-zinc plating, and coiling to obtain a finished hot-dip aluminum-zinc plated steel plate with the thickness of 1.5-2.0 mm, wherein the cold rolling reduction rate is 50% -62%, the heating temperature of the strip steel in a rolled hard state after cold rolling in the horizontal continuous annealing furnace is 630-660 ℃, the soaking section temperature is 731-769 ℃, the annealing time of the strip steel in a soaking section is 50-70 s, and the annealed strip steel is cooled to 590-600 ℃ and is put into an aluminum-zinc pot for hot dip aluminum-zinc plating.
5. 5. The method for producing a hot-dip aluminum zinc plated steel sheet having a yield strength of 280MPa according to claim 4, wherein the hot-rolled steel sheet has a metallographic structure of ferrite, the grain size of the ferrite in the metallographic structure being 10.0 to 11, the hot-rolled steel sheet having a thickness of 3.8 to 4.1 mm has a yield strength R P0.2 to 275 MPa, a tensile strength R m of 387 to 450MPa, and an elongation after break A 80 mm of 31% to 40%.

Description

Hot-dip aluminized zinc-plated steel plate with yield strength of 280MPa and manufacturing method thereof Technical Field The invention relates to a cold-rolled hot-dip aluminum-zinc plated steel plate, in particular to a hot-dip aluminum-zinc plated steel plate with yield strength of 280MPa and a manufacturing method thereof, in particular to a hot-dip aluminum-zinc plated steel plate with thickness of 1.5-2.0 mm and yield strength of 280MPa for household appliance industry, and belongs to the technical field of iron-based alloy. Background Aluminum-zinc-plated steel sheets are widely used in various industries such as home appliances due to their excellent corrosion resistance and beautiful appearance. The thickness of an aluminized zinc product used in the household appliance industry is 1.5 mm-2.0 mm of a cold-rolled hot-dip aluminized zinc steel plate, and the yield strength of the steel plate is 200-300MPa. With the continuous upgrading of household appliances, aluminum-zinc plated products for household appliances need products with higher yield strength. In order to meet the requirements of the household appliance industry, aluminum-zinc plated steel plates with yield strength of 280-360 MPa and steel plate effect index of less than or equal to 5MPa need to be developed, and bending and cracking caused by overlong standing time are avoided. The Chinese patent document of application publication number CN 105441795A discloses a low-carbon cold-rolled steel plate for an LED lead frame and a production method thereof, and mainly solves the technical problems of uneven hardness, high surface roughness and poor aging resistance of the low-carbon cold-rolled steel plate for the traditional LED lead frame. The low-carbon cold-rolled steel plate for the LED lead frame comprises the following components in percentage by weight (wt%) ：C：0.025％～0.05％,Si≤0.03％,Mn：0.15％～0.25％,P≤0.020％,S≤0.010％,Alt：0.025％～0.048％,B：0.001％～0.0014％,N≤0.0035％,, fe and unavoidable impurity elements as the rest, wherein the lower yield strength Rel of the low-carbon cold-rolled steel plate for the LED lead frame is 200-250 MPa, the tensile strength Rm is 270-340 MPa, the elongation after break A 50mm is more than or equal to 40%, the hardness value HRB is 40-52, the roughness Ra is less than or equal to 0.5, and the aging index AI is 26-30. The yield strength and the aging index of the steel do not meet the requirements of household steel. The Chinese patent document of application publication No. CN112442577A discloses a cold-rolled steel sheet with excellent ageing resistance for double-layer coiled welded pipe and a manufacturing method thereof, and solves the technical problem that the ageing resistance of the welded pipe is poor when the conventional cold-rolled steel sheet produced by a continuous annealing mode is used for continuous brazing type double-layer coiled welded pipe. The chemical components comprise, by weight, 0.03-0.07% of C, less than or equal to 0.05% of Si, 0.10-0.30% of Mn, less than or equal to 0.025% of P, less than or equal to 0.020% of S, 0.03-0.06% of Alt, less than or equal to 0.003% of N, 0.05-0.15% of Cr, and the balance of Fe and unavoidable impurities. The ageing index AI is 15-20. The aging index of the steel does not meet the requirements of household appliances. The Chinese patent of application publication No. CN 103510001A discloses a cold-rolled steel sheet for double-layer coil welded pipe and a production method thereof, which mainly solves the problem that the cold-rolled steel sheet has timeliness because the cold-rolled steel sheet is required to be annealed when the double-layer coil welded pipe is produced in the prior art. The chemical components comprise, by weight, 0.0010% -0.0035% of C, less than or equal to 0.05% of Si, 0.10% -0.25% of Mn, less than or equal to 0.020% of P, less than or equal to 0.015% of S, 0.04% -0.07% of Ti, less than or equal to 0.0035% of N, and the balance of Fe and unavoidable inclusion elements, wherein the yield strength of the cold-rolled steel plate is 180-240 mpa. The yield strength of the product does not meet the requirements of household steel. The Chinese patent with the application publication number CN 103938077A discloses a cold-rolled steel plate for a double-layer coil welded pipe and a production method thereof, wherein the cold-rolled steel plate comprises the following chemical components, by mass, less than or equal to 0.008% of C, 0.3-0.5% of Mn, less than or equal to 0.01% of Si, less than or equal to 0.015% of P, 0.012-0.018% of S, 0.03-0.06% of Als, 0.05-0.10% of Ti, less than or equal to 0.003% of N, and the balance of Fe and unavoidable impurities, and chemical component content is controlled to control compound precipitates to avoid timeliness. The yield strength of the product does not meet the requirements of household steel. The existing hot dip aluminum zinc plated steel plate has the technical problems of low yield strength, poor