CN-122003515-A - Steel sheet and component comprising same

Abstract

The purpose of the present invention is to provide a steel sheet that has excellent post-coating corrosion resistance even when Ni, cu, and Sn are contained, and a member that includes the steel sheet. The steel sheet and the member comprising the steel sheet are characterized in that the steel sheet has a chemical composition comprising, in mass%, 0.30-3.00% of Si, 0.010-1.000% of Ni, 0.010-1.000% of Cu and 0.003-1.000% of Sn, and satisfies Si/(Si+Mn) not less than 0.20, and the strength of Sn, as measured by X-ray photoelectron spectroscopy in the thickness direction from the surface of the steel sheet, satisfies (the outermost surface I 481‑490 )/(the depth of 50nm I 481‑490 ) not more than 0.5 and satisfies (the depth of 50nm I 484.9 )/(the depth of 50nm I 486.5 ) not more than 0.7.

Inventors

• Xilianchuan Naoto
• Light Zai Zai

Assignees

• 日本制铁株式会社

Dates

Publication Date

20260508

Application Date

20250903

Priority Date

20240905

Claims (7)

1. 1. A steel sheet, characterized in that the chemical composition of the steel sheet comprises in mass%: Si:0.30~3.00%、 Ni:0.010~1.000%、 0.010 to 1.000% of Cu, and Sn:0.003~1.000%, And satisfies Si/(Si+Mn) of 0.20 or more, The strength of Sn measured by X-ray photoelectron spectroscopy in the thickness direction from the surface of the steel sheet satisfies (I 481-490 at the outermost surface)/(I 481-490 at a depth of 50 nm). Ltoreq.0.5, And (I 484.9 at a depth of 50 nm)/(I 486.5 at a depth of 50 nm). Ltoreq.0.7.
2. 2. The steel sheet according to claim 1, wherein the strength of Sn measured by X-ray photoelectron spectroscopy from the surface of the steel sheet in the thickness direction satisfies (I 481-490 at the outermost surface)/(I 481-490 at a depth of 50 nm). Ltoreq.0.3.
3. 3. The steel sheet according to claim 1 or 2, wherein the strength of Sn measured by X-ray photoelectron spectroscopy from the surface of the steel sheet in the thickness direction satisfies (I 484.9 at 50nm in depth)/(I 486.5 at 50nm in depth). Ltoreq.0.5.
4. 4. The steel sheet according to any one of claims 1 to 3, wherein the steel sheet has a chemical composition containing, in mass%, 0.50 to 3.00% of Si.
5. 5. The steel sheet according to any one of claims 1 to 4, wherein the steel sheet has a chemical composition comprising, in mass%: Ni:0.040~1.000%、 0.040 to 1.000% of Cu, and Sn:0.004~1.000%。
6. 6. The steel sheet according to any one of claims 1 to 5, wherein the steel sheet has a chemical conversion coating film on a surface thereof.
7. 7. A component comprising the steel sheet according to any one of claims 1 to 6.

Description

Steel sheet and component comprising same Technical Field The present invention relates to a steel sheet and a member including the same. Background In order to improve the corrosion resistance of a steel sheet, it is effective to improve the chemical conversion treatability of the surface of the steel sheet and to uniformly form a chemical conversion coating film on the surface of the steel sheet. In this connection, for example, patent document 1 discloses a method for producing a high-strength cold-rolled steel sheet, which is characterized by continuously annealing a high-strength cold-rolled steel sheet using a continuous annealing furnace or a cold-rolled steel sheet/hot-dip galvanized steel sheet dual-purpose facility having a continuous annealing furnace, wherein the cooling system of a cooling zone including a part or all of a steel sheet temperature range of 600 to 250 ℃ after heating for recrystallization is one or more of gas cooling, diffusion cooling, and cooling tube cooling, and in such a case, the surface of the steel sheet is exposed to an atmosphere in which iron is oxidized in the steel sheet temperature range, and after pickling is performed on the outgoing side of the annealing furnace, 1 to 50mg/m 2 of iron plating or Ni plating is performed. Further, patent document 1 teaches that, in general, oxidation of a steel sheet is prevented by using an inert atmosphere gas having an extremely low concentration of oxygen and/or an extremely low dew point around the steel sheet, and on the contrary, the steel sheet is actively exposed to an oxidizing atmosphere, not only Si and Mn are oxidized to oxidize iron of the steel sheet, but also an oxide film of iron of the steel sheet and an oxide film of Si, mn or the like are eluted by pickling at the time of exiting from an annealing furnace, whereby a high-strength cold-rolled steel sheet excellent in chemical conversion treatability without "uncovered portions" even if the content of Si, mn or the like is high is obtained. Patent document 2 discloses a steel sheet for automobiles, which contains copper (Cu) in an amount of 0.10 mass% or more and 0.50 mass% or less, and has a number of residual oxide scale on the surface of 160,000 pieces/mm 2 or less, and a maximum particle diameter of copper compound particles exposed on the surface of 2 μm or less. Further, patent document 2 teaches that the above-described constitution makes the particle diameter of copper compound particles exposed on the surface of a steel sheet serving as an cathode point 2 μm or less and makes the residual oxide scale a predetermined amount or less in the chemical conversion treatment, and thus can provide a steel sheet excellent in chemical conversion treatability. Prior art literature Patent literature Patent document 1 Japanese patent laid-open publication No. 2008-190030 Patent document 2 Japanese patent application laid-open No. 2020-084238 Disclosure of Invention Problems to be solved by the invention Patent document 2 teaches that, in addition to copper (Cu), elements such as nickel (Ni) and tin (Sn) reduce mechanical properties such as strength and formability required for an automotive steel sheet, and also reduce chemical stability such as corrosion resistance, and particularly that copper compounds present on the surface of the steel sheet reduce chemical conversion treatability for improving corrosion resistance. In general, if the chemical conversion treatability is lowered, a region called an uncovered portion where a chemical conversion coating film is not formed may be generated, and as a result, the post-coating corrosion resistance may be lowered. Accordingly, an object of the present invention is to provide a steel sheet containing Ni, cu and Sn and having excellent post-coating corrosion resistance, and a member including the steel sheet. Means for solving the problems The present invention includes at least the following aspects. (Scheme 1) A steel sheet, characterized in that the steel sheet has a chemical composition comprising, in mass%: Si:0.30~3.00%、 Ni:0.010~1.000%、 0.010 to 1.000% of Cu, and Sn:0.003~1.000%, And satisfies Si/(Si+Mn) of 0.20 or more, The strength of Sn measured by X-ray photoelectron spectroscopy in the thickness direction from the surface of the steel sheet satisfies (I 481-490 at the outermost surface)/(I 481-490 at a depth of 50 nm). Ltoreq.0.5, And (I 484.9 at a depth of 50 nm)/(I 486.5 at a depth of 50 nm). Ltoreq.0.7. (Scheme 2) The steel sheet according to the above-mentioned aspect 1, wherein the strength of Sn measured by X-ray photoelectron spectroscopy from the surface of the above-mentioned steel sheet in the thickness direction satisfies (I 481-490 at the outermost surface)/(I 481-490 at a depth of 50 nm). Ltoreq.0.3. (Scheme 3) The steel sheet according to the above-mentioned aspect 1 or 2, wherein the strength of Sn measured by X-ray photoelectron spectroscopy from the surface of the above-mentioned steel sheet in