The present invention provides a deformed part created by forming a coated metal sheet into a part, the coated metal sheet comprising a steel substrate, at least one face of which is coated with a metal coating deposited by dipping the substrate in a bath, said coating comprising between 0.2 and 0.7% by weight of Al, the remainder of the metal coating being Zn and inevitable impurities, wherein an outer surface of a metal coating of the deformed part has a waviness Wa0.8 of less than or equal to 0.43 ?m.

A high-strength, manganese-containing steel, in particular for producing a flexibly rolled flat steel product in the form of a hot or cold strip, includes the following chemical composition (in wt. %): C: 0.005 to 0.6; Mn: 4 to 10; Al: 0.005 to 4; Si: 0.005 to 2; P: 0.001 to 0.2; S: up to 0.05; N: 0.001 to 0.3; with the remainder being iron including unavoidable steel-associated elements, with optional alloying of one or more of the following elements (in wt. %): Sn: 0 to 0.5; Ni: 0 to 2; Cu: 0.005 to 3; Cr: 0.1 to 4; V: 0.005 to 0.9; Nb: 0.005 to 0.9; Ti: 0.005 to 0.9; Mo: 0.01 to 3; W: 0.1 to 3; Co: 0.1 to 3; B: 0.0001 to 0.05; Zr: 0.005 to 0.5; Ca: 0.0002 to 0.1 which has a good combination of strength, expansion and deformation properties.

The present invention provides a method for manufacturing a metal sheet. In this method, at least one of the following equations is satisfied: $\begin{array}{cc}\frac{Z}{d}+18\ln \left(\frac{Z}{d}\right)<8\ln \left(\frac{P}{V}\right)-27.52& \left(A\right)\\ {\mathrm{fO}}_2<\frac{2.304.Math.{10}^{-3}}{{(27.52+\frac{Z}{d}+8\ln (\frac{V}{P}}^{}}\end{array}$

The present invention provides a deformed part created by forming a coated metal sheet into a part, the coated metal sheet comprising a steel substrate, at least one face of which is coated with a metal coating deposited by dipping the substrate in a bath, said coating comprising between 0.2 and 0.7% by weight of Al, the remainder of the metal coating being Zn and inevitable impurities, wherein an outer surface of a metal coating of the deformed part has a waviness Wa0.8 of less than or equal to 0.43 m.

The present invention provides a method for manufacturing a metal sheet. In this method, at least one of the following equations is satisfied:

[00001]$\begin{array}{cc}\frac{Z}{d}+18.Math..Math.\ln \left(\frac{Z}{d}\right)<8.Math..Math.\ln \left(\frac{P}{V}\right)-27.52& \left(A\right)\\ f.Math..Math.O_2<\frac{2.304.Math.{\mathrm{.10}}^{-3}}{{\left(27.52+\frac{Z}{d}+8.Math..Math.\ln \left(\frac{V}{P}.Math.{\left(\frac{Z}{d}\right)}^{2.25}\right)\right)}^2}& \left(B\right)\end{array}$

wherein: Z is the distance between the metal sheet and the nozzle along the main ejection direction (E), Z being expressed in mm, d is the average height of the outlet of the nozzle along with the running direction of the metal sheet in front of the nozzle, d being expressed in mm, V is the running speed of the metal sheet in front of the nozzle, V being expressed in m.Math.s.sup.1, P is the pressure of the wiping gas in the nozzle, P being expressed in N.Math.m.sup.2, and fO.sub.2 is the volume fraction of oxygen in the wiping gas. A metal sheet, part and land motor vehicle are also provided.

A steel part includes a steel sheet substrate and a coating on at least one surface of the steel sheet substrate. The coating includes between 0.2 and 0.7% by weight of Al, with a remainder of the metal coating being Zn and inevitable impurities. The steel sheet substrate and the coating have at least one deformation. An outer surface of the coating has a waviness Wa.sub.0.8 of less than or equal to 0.43 m.