阅读说明：本技术 铝组件和具有包含硅、铁、锌和镁，余量为铝的合金涂层的压制硬化钢部件的组合件 (Assembly of an aluminium component and a press hardened steel part with an alloy coating comprising silicon, iron, zinc and magnesium, the balance being aluminium ) 是由 蒂亚戈·马卡多阿莫里姆 斯特凡·莫雷尔 劳伦斯·多斯达 阿斯特丽·格雷瓜尔 于 2020-04-03 设计创作，主要内容包括：本发明涉及基于铝的部件和压制硬化钢部件的组合件,所述压制硬化钢部件在其至少一个表面上设置有按重量百分比计包含0.1％至15.0％的硅、15.0％至70％的铁、0.1％至20.0％的锌、0.1％至4.0％的镁,余量为铝的合金涂层,所述压制硬化钢部件被放置成与基于铝的部件接触。(The invention relates to an assembly of an aluminium-based part and a press hardened steel part provided on at least one of its surfaces with an alloy coating comprising, in weight percent, 0.1% to 15.0% silicon, 15.0% to 70% iron, 0.1% to 20.0% zinc, 0.1% to 4.0% magnesium, the balance being aluminium, the press hardened steel part being placed in contact with the aluminium-based part.)

1. An assembly of at least an aluminium-based element (2) and a press hardened steel part (3) provided on at least one of its surfaces with a coating of an alloy comprising, in weight percent: 0.1 to 15.0% of silicon, 15.0 to 70% of iron, 0.1 to 20.0% of zinc, 0.1 to 4.0% of magnesium, the balance being aluminium, unavoidable impurities and possibly one or more further elements selected from Sb, Pb, Ti, Ca, Mn, Sn, La, Ce, Sr, Cr, Ni or Bi, the hardened steel part (3) being joined to the aluminium-based element (2).

2. The assembly of claim 1, wherein the alloy coating comprises an intermetallic layer of Fe₃Al and an interdiffusion layer Fe-Si-Al.

3. Assembly according to claim 1 or 2, wherein the microstructure of the metal coating comprises Zn₂Mg phase or Mg₂Si phase or both.

4. Assembly according to any one of claims 1 to 3, wherein the press hardened steel part (3) is joined to the aluminium based element (2) by at least one means selected from: adhesive bonding, welding, sealing, crimping, hooking or riveting.

5. A method for manufacturing an assembly according to any of claims 1 to 4, comprising:

A. providing a steel sheet pre-coated on at least one surface with a pre-coating comprising, in weight percent, 0.1% to 20.0% silicon, 0% to 10% iron, 0.1% to 25.0% zinc, 0.1% to 6.0% magnesium, the balance being aluminum, unavoidable impurities and possibly one or more additional elements selected from Sb, Pb, Ti, Ca, Mn, Sn, La, Ce, Cr, Ni or Bi,

B. the pre-coated steel sheet is cut to obtain blanks,

C. the blank is subjected to an austenitizing treatment to obtain a fully austenitic microstructure in the steel,

D. the blank is transferred to a pressing tool,

E. the blank is thermoformed into a shape that is,

F. cooling the blank to obtain a press hardened steel part (3) provided on at least one surface with an alloy coating comprising, in weight percent, 0.1 to 15.0% silicon, 15.0 to 70% iron, 0.1 to 20.0% zinc, 0.1 to 4.0% magnesium, the balance being aluminum, unavoidable impurities and possibly one or more further elements selected from the group consisting of Si, Sb, Pb, Ti, Ca, Mn, Sn, La, Ce, Cr, Ni or Bi, and

G. assembling the press hardened steel component provided with the alloy coating on at least one surface with an aluminium based element.

6. The method according to claim 5, wherein in step C) the austenitizing treatment is carried out between 800 ℃ and 1100 ℃.

7. The method according to claim 5 or 6, wherein in step E) the thermoforming is performed by hot stamping or roll forming.

8. Method according to any one of claims 4 to 7, wherein in step G) the press hardened steel part (3) is joined to the aluminium based element (2) by adhesive bonding, by welding, by sealing, by crimping, clinching or riveting.

9. A component for a vehicle, comprising at least one assembly (1) according to any one of claims 1 to 4 or an assembly (1) obtainable by a method according to any one of claims 5 to 8.

10. The component of claim 9, which is a front cross member, a rear bumper cross member, a door reinforcement, a windshield pillar reinforcement, a B-pillar reinforcement, a floor reinforcement and a roof reinforcement, a roof or a dash cross-member.

11. A vehicle comprising at least one component according to claim 9 or 10.

12. Use of an assembly according to any one of claims 1 to 4 for the manufacture of a component according to any one of claims 9 or 10 or a vehicle according to claim 11.

Examples

ByThe steel sheet produced was coated with a zinc alloy or an aluminum alloy of variable composition as collected in table 1, with a uniform thickness of 20 μm on both sides. Such steel sheet was then press hardened at 900 ℃ for 5 minutes to obtain a member having an alloy composition as described in table 2. The plates made from aluminum AA6061 and those coated press hardened parts were then used to produce assembly samples.

According to specification SEP1160, a plate made of aluminium AA6061 and a coated press hardened steel part were joined with an adhesive tape, leaving a gap of 120 μm in the assembly area. The edges of the plates are then wired together to create the electro-galvanic coupling. No coating is present in the assembly zone.

The assembly samples of aluminium sheet and press hardened steel components were subjected to the VDA 233-:

-cycle a: a cycle comprising a treatment by standing in the presence of a salt spray at 35 ℃ for a period of three hours;

-cycle B: a cycle of 24 hours without salt spray treatment at temperatures varying between 25 ℃ and 50 ℃ and relative humidity varying between 70% and 95%;

-cycle C: there was no 24-hour cycle of salt spray treatment at temperatures varying between-15 ℃ and 50 ℃ and relative humidities varying between 70% and 95%.

The brine solution used was an aqueous solution containing 1% by weight of sodium chloride.

At the end of each cycle, the first sample was subjected to a measurement of the depth of the etching of the aluminum element by laser triangulation mapping over the entire surface of the sample, then extracting the maximum observed value in microns.

The results of the 6 cycles and 12 cycles are summarized and presented in table 3, and the detailed results from cycle to cycle are presented in fig. 2.

TABLE 1 Steel plate coating compositionThe steel sheet before press hardening had the following coating composition:

after press hardening at 900 ℃ for 5 minutes, the steel parts were covered with alloy coatings having the compositions collected in table 2 below.

TABLE 2 Steel parts with alloy coating composition

*: according to the invention

TABLE 3 maximum depth of etch

*: according to the invention

Test 3 according to the present invention shows a high improvement in corrosion resistance compared to tests 1 and 2.