Method for producing a steel component provided with a coating, and steel component
The present disclosure provides a steel component produced from a steel substrate coated with anticorrosion coating. The steel component comprises a steel substrate and, at least on one side of the steel substrate, an anticorrosion coating which comprises at least one first and one second silicon-rich layer (Si1, Si2) and also one first and one second low-silicon layer (A, B). A quotient X formed from a thickness (dB) of the second low-silicon layer (B) in μm by a thickness (dA) of the first low-silicon layer (A) in μm is at least 0.4 and at most 1.1.
1 . A steel component comprising a steel substrate and, at least on one side of the steel substrate, an anticorrosion coating, wherein the steel substrate is heat-treated to change the composition of the anticorrosion coating to at least comprise:
a first silicon-rich layer (Si1) which besides unavoidable impurities contains more than 4 and up to 8 wt % of Si, 40-70 wt % of Fe, up to 1 wt % of Mn and 30-60 wt % of aluminum, the sum of the constituents present being 100 wt %, and which is located above a first low-silicon layer (A);
the first low-silicon layer (A) which besides unavoidable impurities contains 1-4 wt % of Si, 30-60 wt % of Fe, up to 1 wt % of Mn and 40-60 wt % of aluminum, the sum of the constituents present being 100 wt %, and which is located between the first silicon-rich layer (Si1) and a second silicon-rich layer (Si2);
the second silicon-rich layer (Si2) which besides unavoidable impurities contains at least 5 and up to 8 wt % of Si, 40-70 wt % of Fe, up to 1 wt % of Mn and 20-50 wt % of aluminum, the sum of the constituents present being 100 wt %, and which is located between the first low-silicon layer (A) and a second low-silicon layer (B);
the second low-silicon layer (B) which besides unavoidable impurities contains 0.5-4 wt % of Si, 40-97 wt % of Fe, 0.5-1.5 wt % of Mn and 2-40 wt % of aluminum, the sum of the constituents present being 100 wt %, and which borders the steel substrate; and
wherein a quotient X formed from the thickness (dB) of the second low-silicon layer (B) in μm by the thickness (dA) of the first low-silicon layer (A) in μm is at least 0.4 and at most 1.1.
2 . The steel component as claimed in 1 , wherein the steel substrate consists of a steel material with 0.10-0.25 wt % of C, 1.0-1.4 wt % of Mn, 0.35-0.4 wt % of Si, up to 0.03 wt % of P, up to 0.01 wt % S, up to 0.040 wt % of Al, up to 0.15 wt % of Ti, up to 0.1 wt % of Nb, up to 0.005 wt % of B, up to 0.5 wt % of Cr, up to 0.5 wt % of Mo, the sum of the amounts of Cr and Mo being at most 0.5 wt %, the balance being iron and unavoidable impurities.
3 . The steel component as claimed in claim 1 , wherein X is at least 0.45 and at most 0.9.
4 . The steel component as claimed in claim 1 wherein the Si content of the first silicon-rich layer (Si1) is 5-8 wt %.
5 . The steel component as claimed in claim 1 wherein the Fe content of the first silicon-rich layer (Si1) and the Fe content of the second silicon-rich layer (Si2) is in each case greater than the Fe content of the first low-silicon layer (A).
6 . The steel component of claim 1 , wherein the anticorrosion coating has a total thickness of 20-55 μm.
7 . The steel component of claim 1 , wherein the steel component has a welding range of at least 0.9 kA, as measured in accordance with SEP 1220-2.
8 . The steel component of claim 1 , wherein the steel component has a fracture area fraction between 75% and 85%.
9 . The steel component of claim 1 , wherein the second silicon-rich layer (Si2) which besides unavoidable impurities contains at least 5.4 and up to 8 wt % of Si.
10 . A steel component comprising a steel substrate and, at least on one side of the steel substrate, an anticorrosion coating, wherein the anticorrosion coating consists of:
an outermost oxide-enriched layer (Ox) in contact with a surrounding atmosphere;
a first silicon-rich layer containing more than 4 and up to 8 wt % of Si, 40-70 wt % of Fe, up to 1 wt % of Mn and 30-60 wt % of aluminum;
a second silicon-rich layer being disposed between the first silicon-rich layer and the steel substrate, and containing more than 4 and up to 8 wt % of Si, 40-70 wt % of Fe, up to 1 wt % of Mn and 20-50 wt % of aluminum;
a first low silicon layer being disposed between the first and second silicon-rich layers, and containing 1-4 wt % of Si, 30-60 wt % of Fe, up to 1 wt % of Mn and 40-60 wt % of aluminum; and
a second low silicon layer being disposed below the second silicon-rich layer and directly on the steel substrate, and containing 0.5-4 wt % of Si, 40-97 wt % of Fe, 0.5-1.5 wt % of Mn and 2-40 wt % of aluminum.
11 . The steel component of claim 10 , wherein the steel substrate comprises of a steel material with 0.10-0.25 wt % of C, 1.0-1.4 wt % of Mn, 0.35-0.4 wt % of Si, up to 0.03 wt % of P, up to 0.01 wt % S, up to 0.040 wt % of Al, up to 0.15 wt % of Ti, up to 0.1 wt % of Nb, up to 0.005 wt % of B, up to 0.5 wt % of Cr, up to 0.5 wt % of Mo, the sum of the amounts of Cr and Mo being at most 0.5 wt %, the balance being iron and unavoidable impurities.
12 . The steel component of claim 10 , wherein a quotient X formed from the thickness (dB) of the second low-silicon layer (B) in μm by the thickness (dA) of the first low-silicon layer (A) in μm is at least 0.45 and at most 0.9.
13 . The steel component of claim 10 , wherein the Si content of the first silicon-rich layer (Si1) and/or of the second silicon rich layer (Si2) is 5-8 wt %.
14 . The steel component of claim 10 , wherein the Fe content of the first silicon-rich layer (Si1) and the Fe content of the second silicon-rich layer (Si2) is in each case greater than the Fe content of the first low-silicon layer (A).
15 . The steel component of claim 10 , wherein the second silicon-rich layer (Si2) which besides unavoidable impurities contains at least 5.4 and up to 8 wt % of Si.
16 . A steel component comprising:
a steel substrate;
a heat treated aluminum-based anticorrosion coating disposed on at least one side of the steel substrate;
wherein a composition of the heat treated aluminum-based anticorrosion coating includes a first silicon-rich layer, which contains more than 4 and up to 8 wt % of Si, that is the outermost layer of the aluminum-based anti-corrosion coating, the anticorrosion coating further including a second silicon-rich layer disposed between the first silicon-rich layer and the steel substrate; a first low silicon layer disposed between the first and second silicon-rich layers; and a second low silicon layer disposed between the second silicon-rich layer and the steel substrate,
wherein the second silicon-rich layer contains at least 5 and up to 8 wt % of Si, the first low silicon layer contains 1-4 wt % of Si; and the second low silicon layer contains 0.5-4 wt % of Si.
17 . The steel component of claim 16 , wherein:
the first silicon-rich layer, which besides unavoidable impurities, further contains 40-70 wt % of Fe, up to 1 wt % of Mn and 30-60 wt % of aluminum;
the first low-silicon layer, which besides unavoidable impurities, further contains 30-60 wt % of Fe, up to 1 wt % of Mn and 40-60 wt % of aluminum;
the second silicon-rich layer, which besides unavoidable impurities, further contains 40-70 wt % of Fe, up to 1 wt % of Mn and 20-50 wt % of aluminum; and
the second low-silicon layer, which besides unavoidable impurities, further contains 40-97 wt % of Fe, 0.5-1.5 wt % of Mn and 2-40 wt % of aluminum.
18 . The steel component of claim 17 , wherein the heat treated aluminum-based anticorrosion coating further includes a third low-silicon layer disposed on the first silicon-rich layer such that the third low-silicon layer is the outermost layer of the anticorrosion coating instead of the first silicon-rich layer.
19 . The steel component of claim 18 , wherein the second silicon-rich layer contains at least 5.4 and up to 8 wt % of Si and the third low-silicon layer contains 0-4 wt % Si.
20 . The steel component of claim 17 , wherein the heat treated aluminum-based anticorrosion coating further includes an oxide layer containing silicon oxides and/or aluminum oxides having a thickness of between 50 nm and 250 nm,
wherein the oxide layer is the outermost layer of the anticorrosion coating instead of the first silicon-rich layer, and
wherein a ratio X of a thickness (dB) of the second low-silicon layer in μm to a thickness (dA) of the first low-silicon layer in μm is at least 0.4 and at most 1.1.