Abstract: A device for low-temperature plasma surface treatment of a stationary metallic material (8) in plate or sheet form, comprising a sealed enclosure (1) into which a plasma-forming gas is introduced, and a suction device (6) for adjusting the pressure of the gas. The enclosure (1) incorporates a support (7) in contact with the material (8) and at least one fixed or movable electrode (10) having an "active" surface (13) facing the material (8) and defining a space (12) between itself and the surface (9) of the material. The electrode (10) is held at an adjustable distance between its active surface and the surface of the material. A potential difference of given sign and given absolute value is created between the material (8) and the electrode (10), and a low-temperature plasma is generated in the space (12).

Abstract: A subject of the invention is a process for improving the corrosion resistance of a metallic material, characterized in that the metallic material is subjected cold to a surface treatment by a low-temperature plasma, at a pressure of 1 to 10.sup.3 Pa in an atmosphere comprising at least one gas chosen from the following; oxygen, ozone, nitrogen, hydrogen, air, carbon dioxide, carbon monoxide, the oxides of nitrogen, water, combustion gases and mixtures of these with a neutral gas.