Method for manufacture of a pre-coated steel sheet

Patent metadata

Field	Value
Publication number	US-2021395855-A1
Application number	US-202117463187-A
Country	US
Kind code	A1
Filing date	Aug 31, 2021
Priority date	Jul 30, 2015
Publication date	Dec 23, 2021
Grant date	—

Abstract

A method for manufacture of a pre-coated steel sheet includes providing a steel sheet, coating the steel sheet with a metallic coating, the metallic coating including: 2.0 to 24.0% by weight of zinc; 1.1 to 7.0% by weight of silicon; optionally from 0.5 to 3.0% by weight of magnesium when the amount of silicon is between 1.1 and 4.0%, and optionally additional elements chosen from Pb, Ni, Zr or Hf, a content by weight of each additional element being less than 0.3% by weight, a balance of the metallic coating being aluminum, unavoidable impurities and residual elements resulting from feeding ingots or from a passage of the steel sheet in a molten bath; a ratio Al/Zn by weight greater than 2.9, and wherein the metallic coating does not include In and the metallic coating does not include Sn

First claim

What is claimed is:

1 . A method for manufacture of a pre-coated steel sheet, comprising:
providing a steel sheet, wherein the steel sheet has a base with a composition by weight percentage including 0.20%≤C≤0.25%; 0.15%≤Si≤0.35%; 1.10%≤Mn≤1.40%; 0%≤Cr≤0.30%; 0%≤Mo≤0.35%; 0%≤P≤0.025%; 0%≤S≤0.005%; 0.020%≤Ti≤0.060%; 0.020%≤Al≤0.060%; 0.002%≤B≤0.004%, a balance of the steel sheet base composition being iron and unavoidable impurities from the manufacture of steel; and coating the steel sheet with a metallic coating, the metallic coating including: 2.0 to 24.0% by weight of zinc; 1.1 to 7.0% by weight of silicon; optionally from 0.5 to 3.0% by weight of magnesium when the amount of silicon is between 1.1 and 4.0%, and optionally additional elements chosen from Pb, Ni, Zr or Hf, a content by weight of each additional element being less than 0.3% by weight, a balance of the metallic coating being aluminum, unavoidable impurities and residual elements resulting from feeding ingots or from a passage of the steel sheet in a molten bath; a ratio Al/Zn by weight greater than 2.9, and wherein the metallic coating does not include In and the metallic coating does not include Sn.

2 . A method for manufacture of a pre-coated steel sheet, comprising:
providing a steel sheet, wherein the steel sheet has a base with a composition by weight percentage including: 0.24%≤C≤0.38%; 0.40%≤Mn≤3%; 0.10%≤Si≤0.70%; 0.015%≤Al≤0.070%; 0%≤Cr≤2%; 0.25%≤Ni≤2%; 0.020%≤Ti≤0.10%; 0%≤Nb≤0.060%; 0.0005%≤B≤0.0040%; 0.003%≤N≤0.010%; 0.0001%≤S≤0.005%; 0.0001%≤P≤0.025%; it being understood that the contents of titanium and nitrogen satisfy Ti/N>3.42, and that the contents of carbon, manganese, chromium and silicon satisfy 2.6C+Mn/5.3+Cr/13+Si/15≥1.1%, the composition optionally comprising one or more of the following: 0.05%≤Mo≤0.65%; 0.001%≤W≤0.30%; 0.0005%≤Ca≤0.005%, a balance of the steel sheet base composition being iron and unavoidable impurities from manufacture; and coating the steel sheet with a metallic coating, the metallic coating including: 2.0 to 24.0% by weight of zinc; 1.1 to 7.0% by weight of silicon; optionally from 0.5 to 3.0% by weight of magnesium when the amount of silicon is between 1.1 and 4.0%, and optionally additional elements chosen from Pb, Ni, Zr or Hf, a content by weight of each additional element being less than 0.3% by weight, a balance of the metallic coating being aluminum, unavoidable impurities and residual elements resulting from feeding ingots or from a passage of the steel sheet in a molten bath; a ratio Al/Zn by weight greater than 2.9, and wherein the metallic coating does not include In and the metallic coating does not include Sn.

3 . A method for manufacture of a pre-coated steel sheet, comprising:
providing a steel sheet, wherein the steel sheet has a base with a composition by weight percentage including: 0.040%≤C≤0.100%; 0.80%≤Mn≤2.00%; 0%≤Si≤0.30%; 0%≤S≤0.005%; 0%≤P≤0.030%; 0.010%≤Al≤0.070%; 0.015%≤Nb≤0.100%; 0.030%≤Ti≤0.080%; 0%≤N≤0.009%; 0%≤Cu≤0.100%; 0%≤Ni≤0.100%; 0%≤Cr≤0.100%; 0%≤Mo≤0.100%; 0%≤Ca≤0.006%, a balance of the steel sheet base composition being iron and unavoidable impurities from manufacture; and coating the steel sheet with a metallic coating, the metallic coating including: 2.0 to 24.0% by weight of zinc; 1.1 to 7.0% by weight of silicon; optionally from 0.5 to 3.0% by weight of magnesium when the amount of silicon is between 1.1 and 4.0%, and optionally additional elements chosen from Pb, Ni, Zr or Hf, a content by weight of each additional element being less than 0.3% by weight, a balance of the metallic coating being aluminum, unavoidable impurities and residual elements resulting from feeding ingots or from a passage of the steel sheet in a molten bath; a ratio Al/Zn by weight greater than 2.9, and wherein the metallic coating does not include In and the metallic coating does not include Sn.

4 . The method of claim 1 , wherein the ratio is greater than or equal to 5.0.

5 . The method of claim 1 , wherein said coating comprises coating by hot-dip galvanization.

6 . The method of claim 1 , wherein said coating comprises coating by electrogalvanization.

7 . The method of claim 1 , wherein said coating comprises coating by physical vapour deposition.

8 . The method of claim 7 , wherein said physical vapour deposition is jet vapor deposition

9 . The method of claim 7 , wherein said physical vapour deposition is sputtering magnetron.

10 . The method of claim 1 , wherein said coating comprises hot-dip galvanization.

11 . The method of claim 10 , wherein said hot-dip galvanization includes dipping said steel sheet in a molten metal bath.

12 . The method of claim 11 , wherein the molten metal bath comprises zinc, silicon, and aluminum.

13 . The method of claim 12 , wherein the molten metal bath further comprises magnesium.

14 . The method of claim 12 , wherein the molten metal bath further comprises additional elements chosen from Pb, Ni, Zr, or Hf, the content by weight of each additional element being less than 0.3% by weight.

15 . The method of claim 12 , wherein the molten metal bath has a temperature between 580 and 660° C.

16 . The method of claim 1 , wherein after said coating, the method further includes wiping the coated steel sheet with nozzles ejecting gas on both sides of the coated steel sheet.

17 . The method of claim 1 , wherein after said coating and wiping, the method further includes cooling the coated steel sheet.

18 . The method of claim 1 , wherein after said coating, the method further includes cooling the coated steel sheet.

19 . The method of claim 18 , wherein the cooling is at a cooling rate equal or greater than 15° C.s −1 between the beginning of the solidification and the end of the solidification.

20 . The method of claim 19 , wherein the cooling rate is equal to or greater than 20° C.s −1

21 . The method of claim 18 , further including performing a skin-pass on said cooled, coated, steel sheet.

22 . The method according to claim 1 , wherein the metallic coating comprises the magnesium at 0.5 to 3.0% by weight and the silicon between 1.1 and 4.0% by weight.

23 . The method according to claim 1 , wherein the metallic coating comprises at least one of the additional elements chosen from Pb, Ni, Zr, or Hf.

24 . The method according to claim 1 , wherein the ratio Al/Zn is between 5 and 9.

25 . The method according to claim 1 , wherein the metallic coating comprises from 2.0 to 5.0% by weight of silicon.

26 . The method according to claim 1 , wherein the metallic coating comprises from 2.1 to 4.9% by weight of silicon.

27 . The method according to claim 1 , wherein the metallic coating comprises from 1.5 to 3.5% by weight of silicon.

28 . The method according to claim 25 , wherein the metallic coating comprises from 2.0 to 3.5% by weight of silicon.

29 . The method according to claim 1 , wherein the metallic coating comprises from 5.0 to 19.0% by weight of zinc.

30 . The method according to claim 1 , wherein the metallic coating comprises from 5.0 to 15.0% by weight of zinc.

31 . The method according to claim 1 , wherein the metallic coating comprises from 5.0 to 10.0% by weight of zinc.

32 . The method according to claim 25 , where

Assignees

• Arcelormittal

Inventors

• Machado Amorim Tiago
• Allely Christian
• Grigorieva Raisa
• Dussaussois David

Classifications

• C21D8/00

  Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment (hardening articles or materials formed by forging or rolling with no further heating beyond that required for the formation C21D1/02) · CPC title

• C23C2/12 Primary

  Aluminium or alloys based thereon · CPC title

• C21D8/04

  to produce plates or strips for drawing, e.g. for deep-drawing · CPC title

• C21D9/46 Primary

  for sheet metals · CPC title

• C21D6/005

  containing Mn · CPC title