Welded blanks made from aluminized steel sheets and having advantageous welded joint characteristics

Patent metadata

Field	Value
Publication number	US-10780529-B2
Application number	US-201916569989-A
Country	US
Kind code	B2
Filing date	Sep 13, 2019
Priority date	Apr 25, 2014
Publication date	Sep 22, 2020
Grant date	Sep 22, 2020

Abstract

A welded blank includes a first pre-coated steel sheet, a second pre-coated steel sheet the first pre-coated steel sheet including a principal first face and an opposite principal first face, the first layer being removed by melting and vaporization in a first peripheral zone of the first pre-coated steel sheet, and the second pre-coated steel sheet including a second principal face and an opposite second principal face, the second layer being removed by melting and vaporization in a second peripheral zone of the second pre-coated steel sheet. At least one welded joint defining a median plane perpendicular to the first and second principal faces. The welded joint area has at least one advantageous characteristic such as a sum of the widths of the first and second peripheral zones of the first and second pre-coated steel sheets varying by less than 10% along the welded joint, the first and second solidification ripples being aligned at the welded joint with respect to the median plane, morphologies of the first and second solidification ripples at the welded joint being identical and symmetrical, and/or an aluminum content in the welded joint being below 0.3%.

First claim

What is claimed is:

1. A welded blank comprising:
a first pre-coated steel sheet including a first steel substrate and a first pre-coating including a first intermetallic alloy layer in contact with the first steel substrate, topped by a first layer of aluminum metal or aluminum alloy or aluminum-based alloy;
a second pre-coated steel sheet including a second steel substrate and a second pre-coating including a second intermetallic alloy layer in contact with the second steel substrate, topped by a second layer of aluminum metal or aluminum alloy or aluminum-based alloy,
the first pre-coated steel sheet including a principal first face and an opposite principal first face, the first layer being removed by melting and vaporization in a first peripheral zone of the first pre-coated steel sheet, and
the second pre-coated steel sheet including a second principal face and an opposite second principal face, the second layer being removed by melting and vaporization in a second peripheral zone of the second pre-coated steel sheet; and
at least one welded joint defining a median plane perpendicular to the first and second principal faces;
a sum of the widths of the first and second peripheral zones of the first and second pre-coated steel sheets varying by less than 10% along the welded joint;
wherein the first and second layers are removed simultaneously in a same melting and vaporization process.

2. The welded blank as recited in claim 1 wherein the first and second layers include, with concentrations expressed by weight, between 8 and 11% silicon and between 2 and 4% iron, the balance of the composition comprising aluminum and unavoidable impurities.

3. The welded blank as recited in claim 1 wherein the first or second steel substrate is a thermal treatment steel.

4. The welded blank as recited in claim 1 wherein a thickness of the first pre-coated steel sheet and the second pre-coated steel sheet is between 0.5 and 4 mm.

5. The welded blank as recited in claim 1 wherein the first and second pre-coated steel sheets have a same thickness.

6. The welded blank as recited in claim 1 wherein the first and second pre-coated steel sheets have different thicknesses.

7. The welded blank as recited in claim 1 wherein the first and second pre-coatings are obtained by hot dip coating.

8. The welded blank as recited in claim 1 wherein, in the first and second peripheral zones, the first and second layers respectively are removed, while the first and second intermetallic alloy layers respectively remain over at least a fraction of an initial thickness.

9. The welded blank as recited in claim 8 , wherein, in the first and second peripheral zones, the first and second intermetallic alloy layers respectively remain over at least 50% of its initial thickness.

10. The welded blank as recited in claim 1 wherein solidification ripples resulting from solidification after melting and vaporization of the first and second pre-coatings in the first and second peripheral zones have identical solidification morphologies at edges facing each other on either side of the median plane.

11. The welded blank as recited in claim 1 wherein solidification ripples resulting from solidification after melting and vaporization of the first and second pre-coatings in the first and second peripheral zones are symmetrical on either side of the median plane.

12. A hot formed part formed by hot forming the welded blank as recited in claim 1 .

13. The hot formed part as recited in claim 12 wherein the first or second steel substrate includes martensite or bainite.

14. A welded blank comprising:
a first pre-coated steel sheet including a first steel substrate and a first pre-coating including a first intermetallic alloy layer in contact with the first steel substrate, topped by a first layer of aluminum metal or aluminum alloy or aluminum-based alloy;
a second pre-coated steel sheet including a second steel substrate and a second pre-coating including a second intermetallic alloy layer in contact with the second steel substrate, topped by a second layer of aluminum metal or aluminum alloy or aluminum-based alloy,
the first pre-coated steel sheet including a principal first face and an opposite principal first face, the first layer being removed by melting and vaporization in a first peripheral zone of the first pre-coated steel sheet, the first peripheral zone having first solidification ripples on the principal first face resulting from solidification after the melting and vaporization, and
the second pre-coated steel sheet including a second principal face and an opposite second principal face, the second layer being removed by melting and vaporization in a second peripheral zone of the second pre-coated steel sheet, the second peripheral zone having second solidification ripples on the second principal face resulting from solidification after the melting and vaporization; and
at least one welded joint defining a median plane perpendicular to the first and second principal faces;
the first and second solidification ripples being aligned at the welded joint with respect to the median plane.

15. The welded blank as recited in claim 14 wherein the first and second solidification ripples are symmetrical and have identical solidification morphologies at the welded joint, a sum of the width of the first and second peripheral zones being greater than a width of the welded joint, the solidification ripples extending on each side of the welded joint.

16. The welded blank as recited in claim 14 wherein the first and second layers include, with concentrations expressed by weight, between 8 and 11% silicon and between 2 and 4% iron, the balance of the composition comprising aluminum and unavoidable impurities.

17. The welded blank as recited in claim 14 wherein the first or second steel substrate is a thermal treatment steel.

18. The welded blank as recited in claim 14 wherein a thickness of the first pre-coated steel sheet and the second pre-coated steel sheet is between 0.5 and 4 mm.

19. The welded blank as recited in claim 14 wherein the first and second pre-coated steel sheets have a same thickness.

20. The welded blank as recited in claim 14 wherein the first and second pre-coated steel sheets have different thicknesses.

21. The welded blank as recited in claim 14 wherein the first and second pre-coatings are obtained by hot dip coating.

22. The welded blank as recited in claim 14 wherein, in the first and second peripheral zones, the first and second layers respectively are removed, while the first and second intermetallic alloy layers respectively remain over at least a fraction of an initial thickness.

23. The welded blank as recited in claim 22 wherein, in the first and second peripheral zones, the first and second intermetallic alloy layers respectively remain over at least 50% of its initial thickness.

24. The welded blank as recited in claim 14 wherein the first and second solidification ripples in both the first and second peripheral zones are a function of a pulse duration and an advancing speed of a same melting and vaporization process.

25. The welded blank as recited in claim 14 wherein the first and second solidification ripples are created in a same melting and vaporization process.

26. A hot formed part formed by hot forming the welded blank as recited in claim 14 .

27. A welded blank comprising

Assignees

• Arcelormittal

Inventors

• Schmit Francis
• Vierstraete Rene
• Yin Qingdong
• Ehling Wolfram

Classifications

• B23K2103/50

  Inorganic materials other than metals or composite materials · CPC title

• B23K2103/04

  Steel {or steel} alloys · CPC title

• B23K2101/34

  Coated articles {; Surface treated articles} · CPC title

• B23K2101/18

  Sheet panels · CPC title

• B23K2101/006

  Vehicles · CPC title