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US-12624409-B2 - Steel for high-strength aluminum clad substrate and manufacturing method therefor

US12624409B2US 12624409 B2US12624409 B2US 12624409B2US-12624409-B2

Abstract

A steel for high-strength aluminum clad substrate, comprising the following chemical elements by mass percent: C: 0.008-0.02%, 0<Si≤0.005%, Mn: 0.25-0.5%, P: 0.018-0.03%, Al≤0.005%, N: 0.0040-0.010%, Ti: 0.02-0.04%, O: 0.02-0.050%, and the balance being Fe and other inevitable impurities. The manufacturing method therefor comprises the steps of: (1) smelting and casting; (2) reheating: reheating a casting blank to 1180° C.-1250° C.; (3) rough rolling; (4) finish rolling; (5) coiling; and (6) cooling to room temperature. The steel for high-strength aluminum clad substrate has good strength and good plasticity.

Inventors

  • Fengming Song
  • Wei Wang
  • Xiaoping Hu
  • Donghui Wen
  • Yunhua Liu
  • Junkai WANG

Assignees

  • BAOSHAN IRON & STEEL CO., LTD.

Dates

Publication Date
20260512
Application Date
20191224
Priority Date
20181224

Claims (10)

  1. 1 . A steel plate, comprising a substrate and an aluminum layer covering the substrate, wherein the substrate comprises the following chemical elements by mass percent: C: 0.008-0.02%, 0<Si<0.005%, Mn: 0.25-0.5%, P: 0.018-0.03%, Al≤0.005%, N: 0.0040-0.010%, Ti: 0.02-0.04%, O: 0.02-0.050%, and the balance being Fe and other inevitable impurities; wherein the mass percent of each of Ti, N, and C elements in the substrate satisfies Ti/(3.42N+4C)≥0.3, and the mass percent of each of O, Al, and Si elements satisfies O/(0.9Al+1.2Si)≥3.0; wherein the substrate has a tensile strength of 320 MPa-420 MPa and an elongation greater than or equal to 40%; and wherein a steel-aluminum interface compound layer has a thickness≤5 μm.
  2. 2 . The steel plate according to claim 1 , wherein the substrate has the mass percent of each of Ti, N, and C elements satisfying 0.3≤Ti/(3.42N+4C)≤0.88, and the mass percent of each of O, Al, and Si elements satisfying 3.0≤O/(0.9Al+1.2Si)≤10.0.
  3. 3 . The steel plate according to claim 1 , wherein each C, P, N, and O of the substrate by mass percent is: C: 0.008-0.015%, P: 0.018-0.024%, N: 0.004-0.008%, O: 0.02-0.04%.
  4. 4 . The steel plate according to claim 1 , wherein among the inevitable impurities, the mass percent of S of the substrate is less than or equal to 0.005%.
  5. 5 . The steel plate according to claim 1 , wherein a matrix of the substrate is an equiaxed ferrite, a grain size of which is 10-50 microns.
  6. 6 . The steel plate according to claim 1 , wherein the substrate has a yield strength of 210-290 MPa.
  7. 7 . The steel plate of claim 2 , wherein the substrate has a yield strength of 210-290 MPa.
  8. 8 . The steel plate of claim 3 , wherein the substrate has a yield strength of 210-290 MPa.
  9. 9 . The steel plate of claim 4 , wherein the substrate has a yield strength of 210-290 MPa.
  10. 10 . The steel plate of claim 5 , wherein the substrate has a yield strength of 210-290 MPa.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a 371 U.S. National Phase of PCT International Application No. PCT/CN2019/128006 filed on Dec. 24, 2019, which claims priority to a Chinese Application No. 201811580436.7, filed on Dec. 24, 2018, the contents of both are incorporated by reference herein in their entireties. TECHNICAL FIELD The present invention relates to steel and a manufacturing method therefor, and particularly relates to steel for a substrate and a manufacturing method for the steel. BACKGROUND OF THE INVENTION With the development of technology and economy, the requirements on the property of a metal material are getting higher and higher, and it is often difficult for a single-composition metal material to simultaneously meet the requirements on various properties in an actual use process. A composite board made of two or more metal materials by various different processes can meet a special comprehensive property requirement. Aluminum clad steel is a composite sheet strip having an aluminum surface and a steel sandwich layer and formed by cladding the surface of strip steel with an aluminum film through rolling under a room temperature condition. It has the strength of steel, and also has the characteristics of good heat dissipating performance, erosion resistance, lightweight and aesthetics of aluminum. Particularly, the cost is greatly reduced. The aluminum clad steel is widely applied to the fields of household appliance panels, heat dissipating components, decoration and the like. A substrate for producing aluminum clad strip steel deforms together with the aluminum film on the surface in the production process of the composite strip, so that the substrate is required to have equivalent strength and plasticity to aluminum. Therefore, the substrate is generally low in strength and good in plasticity. However, the aluminum clad substrate is also required to have good steel-aluminum cladding property, and it is difficult for steel with low yield strength in the usual sense to produce aluminum clad steel. The Chinese patent document with the publication number CN102019727A and the publication date of Apr. 20, 2011 and entitled “Aluminum Clad Strip Steel for Cooler and Preparation Method Therefor, and Strip Steel and Aluminum Alloy Strip Used in Method” discloses aluminum clad strip steel and a preparation method therefor, and strip steel and an aluminum alloy strip used in the preparation method. In the technical solution disclosed in the Chinese patent document, although the substrate used is involved, it is mainly used to produce thicker aluminum clad strip steel, has low plastic deformation capacity, and is difficult to meet a large deformation requirement. The Chinese patent document with the publication number CN101525720 and the publication date of Sep. 9, 2009 and entitled “Novel Matrix Strip Steel Special for Preparing Aluminum Clad Strip Steel” discloses novel matrix strip steel special for preparing aluminum clad strip steel. In the technical solution disclosed in the Chinese patent document, the steel involved is a high alloy composition in which the Mn content is 15-30%. The Chinese patent document with the publication number CN107881427A and the publication date of Apr. 6, 2018 and entitled “Aluminum Clad Substrate with Excellent Plasticity and Low Yield Strength” discloses an aluminum clad substrate with low yield strength. It is required that the content of P must be controlled at 0.01% in order to guarantee the steel-aluminum bonding property and other mechanical property indicators. This obviously increases the production difficulty of a steel plate. It can be seen from this that, on the one hand, the steel grades involved in the prior art do not have the steel-aluminum bonding property, and only have strength and plasticity that are equivalent to those of Al; on the other hand, the prior art that involves an aluminum clad substrate generally limits the content of P, which greatly increases the production difficulty of an aluminum clad substrate. SUMMARY OF THE INVENTION One objective of the present invention is to provide steel for a high-strength aluminum clad substrate. The steel for a high-strength aluminum clad substrate uses extremely low C and Si compositions, so that P does not need to be regarded as impurities to be controlled below 0.015%; the restriction to the content of P is relaxed, thereby significantly lowering the production difficulty and improving the production efficiency; and moreover, on the basis of guaranteeing the steel-aluminum bonding property, appropriate strength and good plasticity are achieved. In order to achieve the above-mentioned objective, the present invention provides steel for a high-strength aluminum clad substrate, comprising chemical elements by mass percent: C: 0.008-0.02%, 0<Si≤0.005%, Mn: 0.25-0.5%, P: 0.018-0.03%, Al≤0.005%, N: 0.0040-0.010%, Ti: 0.02-0.04%, O: 0.02-0.050%, and the balance being Fe and other inev