Sidmar N.v.

Arcelormittal France

Serge Claessens

Sven Vandeputte

Marijke De Meyer

Dirk Vanderschueren

Franz Horzenberger

The present invention is related to a method for the production of metal coated steel products including steps of: providing a steel product with a metal coating; adding an additional metallic element to the metal coating; subjecting the metal coated steel product to a thermal treatment. The method is characterized in that: prior to the addition of the additional element, the steel product is subjected to a plasma treatment via a dielectric barrier discharge, for cleaning and activating the surface of the metal coating; the additional element is added through a physical vapor deposition technique; the thermal treatment is applied by directing high energy infra red radiation towards the outer surface of the metal coating. The present invention is further related to an apparatus including: a component for performing a plasma treatment on a metal coated product; a component for adding an additional element to the metal coating by using a physical vapor deposition technique; a component for directing high energy infra red radiation towards the outer surface of the metal coating.

Method and apparatus for the production of metal coated steel products

The present invention aims to produce a cold rolled metal coated multi-phase steel, characterized by a tensile strength of at least 500 MPa, a yield ratio (Re/Rm) lower than 0.65 in skinned conditions, lower than 0.60 in unskinned conditions, and with good metal coating adhesion behavior. In the case of the aluminized steel according to the invention, the steel also has superior resistance to temperature corrosion up to 900&deg; C. and excellent mechanical properties at this high temperature. The hot metal coated steel product having a steel composition with a manganese content lower than 1.5%, chrome content between 0.2 and 0.5%, molybdenum content between 0.1 and 0.25%, and a relation between the chrome and molybdenum content as follows Cr&plus;2 Mo higher than or equal to 0.7%, undergoes a thermal treatment in the hot dip metal coating line defined by a soaking temperature between Ac1 and Ac3, a primary cooling speed higher than 25&deg; C./sec and a secondary cooling speed higher than 4&deg; C./sec.

Method of production of cold-rolled metal coated steel products, and the products obtained, having a low yield ratio

The present invention describes an ultra-low carbon bake hardenable galvanized or galvannealed steel product, having a higher yield strength at the temperature of the molten zinc bath while maintaining a low yield strength and excellent bake hardening properties in a skinpassed condition, BH being higher than 35 MPa and BH higher than 40 MPa (GI) and BH >20 MPa and BH >30 MPa (GA), as well as having a superior paint appearance after stamping and painting. The content in the steel composition of the Ti is comprised between 3.42 N and 3.42 N&plus;60 ppm for a fixed nitrogen content (N), and the Nb-content, comprised between 50 ppm and 100 ppm, is fixed so that no substantial precipitation of niobium carbides will occur during the process.

Growing community of inventors

Deurne, Belgium

Serge Claessens