Abstract: The invention relates to a steel substrate coated on at least one of its faces with a metallic coating based on zinc or its alloys wherein the metallic coating is itself coated with a conversion layer comprising: zincsulphate hydrate, aluminium in an amount up to 14 mg·m?2, wherein the conversion layer comprises neither zinc hydroxysulphate, nor free water molecules nor any compounds having free hydroxyl groups, the surface density of sulphur in the conversion layer being greater than or equal to 5.0 mg/m2. The invention also relates to the corresponding treatment method.

Abstract: The present invention relates to a method for the manufacture of a galvannealed steel sheet including the steps of A.) coating of the steel sheet with a first coating consisting of nickel and having a thickness between 150 nm and 650 nm, the steel sheet having the following composition in weight percentage 0.10<C<0.40%, 1.5<Mn<3.0%, 0.7<Si<3.0%, 0.05<Al<1.0%, 0.75<(Si+Al)<3.0%, and on a purely optional basis, one or more elements such as Nb?0.5%, B?0.010%, Cr s 1.0%, Mo?0.50%, Ni?1.0%, Ti?0.5%., the remainder of the composition is made up of iron and inevitable impurities resulting from the elaboration, B.) annealing of the coated steel sheet being annealed at a temperature between 600 to 1200° C., C.) coating of the steel sheet obtained in step B.) with a second coating based on zinc and D.) an alloying heat treatment to form a galvannealed steel sheet.

Abstract: A steel sheet coated with a coating comprising from 10 to 40% of nickel, the balance being zinc, such steel sheet having a microstructure comprising from 1 to 50% of residual austenite, from 1 to 60% of martensite and optionally at least one element chosen from: bainite, ferrite, cementite and pearlite, and the following chemical composition in weight: 0.10<C<0.50%, 1.0<Mn<5.0%, 0.7<Si<3.0%, 0.05<Al<1.0%, 0.75<(Si+Al)<3.0% and on a purely optional basis, one or more elements such as Nb?0.5%, B?0.005%, Cr?1.0%, Mo?0.50%, Ni?1.0%, Ti?0.5%, the remainder of the composition making up of iron and inevitable impurities resulting from the elaboration.

Abstract: A coated metallic substrate including at least a first coating of aluminum, such first coating having a thickness below 5 ?m and being directly topped by a second coating including from 0.5 to 5.9% by weight of magnesium, the balance being zinc.

Abstract: The present invention relates to a method for the manufacture of a galvannealed steel sheet including the steps of A.) coating of the steel sheet with a first coating consisting of nickel and having a thickness between 150 nm and 650 nm, the steel sheet having the following composition in weight percentage 0.10<C<0.40%, 1.5<Mn<3.0%, 0.7<Si<3.0%, 0.05<Al<1.0%, 0.75<(Si+Al)<3.0%, and on a purely optional basis, one or more elements such as Nb?0.5%, B?0.010%, Cr?1.0%, Mo?0.50%, Ni?1.0%, Ti?0.5%, the remainder of the composition is made up of iron and inevitable impurities resulting from the elaboration, B.) annealing of the coated steel sheet being annealed at a temperature between 600 to 1200° C., C.) coating of the steel sheet obtained in step B.) with a second coating based on zinc and D.) an alloying heat treatment to form a galvannealed steel sheet.

Abstract: The present invention relates to a method for the manufacture of a coated steel sheet comprising the following successive steps: A. the coating of the steel sheet with a first coating consisting of nickel and having a thickness between 600 nm and 1400 nm, the steel sheet having the following composition in weight: 0.10<C<0.40%, 1.5<Mn<3.0%, 0.7<Si<3.0%, 0.05<Al<1.0%, 0.75<(Si+Al)<3.0%, and on a purely optional basis, one or more elements such as Nb?0.5%, B?0.010%, Cr?1.0%, Mo?0.50%, Ni?1.0%, Ti?0.5%, the remainder of the composition making up of iron and inevitable impurities resulting from the elaboration, B. the recrystallization annealing at a temperature between 820 to 1200° C., C. the coating with a second coating based on zinc not comprising nickel.

Abstract: The present invention relates to a method for the manufacture of a coated steel sheet comprising the following successive steps: A. the coating of the steel sheet with a first coating consisting of nickel and having a thickness between 600 nm and 1400 nm, the steel sheet having the following composition in weight: 0.10<C<0.40%, 1.5<Mn<3.0%, 0.7<Si<3.0%, 0.05<Al<1.0%, 0.75<(Si+Al)<3.0%, and on a purely optional basis, one or more elements such as Nb?0.5%, B?0.010%, Cr?1.0%, Mo?0.50%, Ni?1.0%, Ti?0.5%, the remainder of the composition making up of iron and inevitable impurities resulting from the elaboration, B. the recrystallization annealing at a temperature between 820 to 1200° C., C. the coating with a second coating based on zinc not comprising nickel.

Abstract: A rolled steel sheet, for press hardening is provided, having a chemical composition where Ti/N>3.42, and the carbon, manganese, chromium and silicon contents satisfy: 2.6 C + Mn 5.3 + Cr 13 + Si 15 ? 1.1 % . The sheet has a nickel content Nisurf at any point of the steel in the vicinity of the surface over a depth ?, such that: Nisurf>Ninom, Ninom denoting the nominal nickel content of the steel, and such that, Nimax denoting the maximum nickel content within ?: ( Ni max + Ni nom ) 2 × ( ? ) ? 0.6 , and such that: ( Ni max - Ni nom ) ? ? 0.01 and the surface density of all of the particles Di , and the surface density of the particles D(>2 ?m) larger than 2 micrometers satisfy, at least to a depth of 100 micrometers in the vicinity of the surface of said sheet: Di+6.

Abstract: A hardened part coated with a phosphatable coating is provided. The part is made by a method that includes providing a steel sheet pre-coated with a metallic coating including from 4.0 to 20.0% by weight of zinc, from 1.0 to 3.5% by weight of silicon, optionally from 1.0 to 4.0% by weight of magnesium, and optionally additional elements chosen from Pb, Ni, Zr, or Hf, the content by weight of each additional element being less than 0.3% by weight, the balance being aluminum and unavoidable impurities and residuals elements. The steel sheet is cut to obtain a blank, the blank is thermally treated at a temperature between 840 and 950° C. to obtain a fully austenitic microstructure in the steel, the blank is transferred into a press tool and hot-formed to obtain a part. The part is cooled to obtain a martensitic or martensitic-bainitic microstructure or made of at least 75% of equiaxed ferrite, from 5 to 20% of martensite and bainite in amount less than or equal to 10%.

Abstract: A rolled steel sheet, for press hardening is provided, having a chemical composition where Ti/N>3.42, and the carbon, manganese, chromium and silicon contents satisfy: 2.6 ? C + Mn 5.3 + Cr 13 + Si 15 ? 1.1 ? % . The sheet has a nickel content Nisurf at any point of the steel in the vicinity of the surface over a depth ?, such that: Nisurf >Ninom, Ninom denoting the nominal nickel content of the steel, and such that, Nimax denoting the maximum nickel content within ?: ( Ni max + Ni nom ) 2 × ( ? ) ? 0.6 , and such that: ( Ni max - Ni nom ) ? ? 0.01 and the surface density of all of the particles Di and the surface density of the particles D(>2 ?m) larger than 2 micrometers satisfy, at least to a depth of 100 micrometers in the vicinity of the surface of said sheet: Di+6.

Abstract: A steel sheet with a metallic coating is provided. A composition of the metallic coating includes from 2.0 to 24.0% by weight of zinc, from 7.1 to 12.0% by weight of silicon, optionally from 1.1 to 8.0% by weight of magnesium, and optionally additional elements chosen from Pb, Ni, Zr, or Hf. The content by weight of each additional element is less than 0.3%. A balance of the composition is aluminum, unavoidable impurities and residual elements. A ratio Al/Zn is from 4.0 to 6.0.

Abstract: A method for the manufacture of a hardened part coated with a phosphatable coating is provided. The method includes providing a steel sheet pre-coated with a metallic coating including from 4.0 to 20.0% by weight of zinc, from 1.0 to 3.5% by weight of silicon, optionally from 1.0 to 4.0% by weight of magnesium, and optionally additional elements chosen from Pb, Ni, Zr, or Hf, the content by weight of each additional element being less than 0.3% by weight, the balance being aluminum and unavoidable impurities and residuals elements. The steel sheet is cut to obtain a blank, the blank is thermally treated at a temperature between 840 and 950° C. to obtain a fully austenitic microstructure in the steel, the blank is transferred into a press tool and hot-formed to obtain a part. The part is cooled to obtain a martensitic or martensitic-bainitic microstructure or made of at least 75% of equiaxed ferrite, from 5 to 20% of martensite and bainite in amount less than or equal to 10%.

Abstract: An Al-steel assembly is provided. The assembly includes an aluminum-based element and a steel element on at least one surface of the aluminum-based element. The steel element has a metal coating made of a zinc-aluminum-magnesium alloy and includes from 2.3% to 3.3% by weight of magnesium and from 3.6% to 3.9% by weight of aluminum. A coated surface of the steel element is in contact with the aluminum-based element in an assembly zone and a protective coating coats the assembly around and adjacent the assembly zone. A body-in-white, further assembly and method are also provided.

Abstract: A painted steel part includes a steel sheet precoated with a metallic coating and hot formed, the 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 being aluminum, unavoidable impurities and residual elements resulting from feeding ingots or from a passage of the steel sheet in a molten bath; and a ratio Al/Zn by weight greater than 2.9; and a paint layer.

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.

Abstract: A pre-coated steel sheet includes a steel sheet precoated with a metallic coating, the 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 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, wherein the coating does not include In and the coating does not include Sn.

Abstract: A hot formed pre-coated steel part includes a steel sheet precoated with a metallic coating and hot formed, the 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 being aluminum, unavoidable impurities and residual elements resulting from feeding ingots or from a passage of the steel sheet in a molten bath; and a ratio Al/Zn by weight greater than 2.9, where a microstructure in the steel after said hot forming being martensitic or martensitic-bainitic or made of at least 75% of equiaxed ferrite, 5 to 20% of martensite and bainite in an amount less than or equal to 10%.

Abstract: The present invention provides a method for the manufacture of a hardened part. The method includes the provision of a steel sheet pre-coated with a metallic coating including from 2.0 to 24.0% by weight of zinc, from 1.1 to 7.0% by weight of silicon, optionally from 1.1 to 8.0% 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, the content by weight of each additional element being less than 0.3% by weight, the balance being aluminum and unavoidable impurities and residuals elements, wherein the ratio Al/Zn is above 2.9. The method further includes the cutting of the coated steel sheet to obtain a blank, the thermal treatment of the blank at a temperature between 840 and 950° C.

Abstract: A method for the production of metal sheet including a substrate having two faces, at least one of which is coated with a metal coating including between 0.1 and 10% by weight of Mg and optionally between 0.1 and 20% by weight of Al, the remainder of the metal coating being Zn. The method includes at least the steps of providing a steel substrate having two faces, depositing a metal coating on at least one face hot dipping of the substrate, solidifying the metal coating, applying onto the outer surfaces of the metal coating an aqueous solution having a pH of 7 to 13 and including a magnesium ion complexing agent, for which the dissociation constant pKd of the complexing reaction of the agent with the magnesium is greater than or equal to 2, and to the metal sheet obtainable with this method.

Abstract: A steel sheet coated with a metallic coating is provided. The coating includes from 1.0 to 22.0% by weight of zinc, from 0.1 to 1.0% by weight of titanium, from 1.6 to 15.0% by weight of silicon, below 0.5% by weight of magnesium, below 0.05% by weight of La or Ce or both, below 0.2% by weight of Sn and optionally, less than 0.3% by weight of additional elements chosen from Sb, Pb, Ca, Mn, Cr, Ni, Zr, In, Hf or Bi. A balance of the coating includes aluminum and optionally unavoidable impurities and residual elements. A microstructure of the coating does not include Al—Zn binary phases. A coated part is also provided.