Abstract: A process for coating metallic substrates in several stages with heat-hardenable synthetic resins having functional groups from the group comprising hydroxyl-containing polyesters, crosslinkable acrylate resins and epoxy resins, thermally stabilized ethylene copolymers and, if appropriate, polyolefins, in which, in the first stage, a powder mixture of these components is applied to a metallic substrate at a preheating temperature which is above the melting point of the (A) resins and which is adequate for their crosslinking, and, in the second stage, an olefin polymer layer is applied to the hot, coated substrate. The metallic substrates are pipes, large moldings, vessels and building elements, the coated pipes being advantageously used as pipelines for petroleum and natural gas.

Abstract: A process for the coating of metal tubes by the application of polyethylene to the preheated tubes, a polyethylene with a melt index of over 1 g/10 minutes being applied first to the pre-heated metal tube and a polyethylene with a low melt index being applied thereupon, the process comprising a first step of applying a polyethylene with a melt index of 1.2 to 70 g/10 minutes (190.degree. C./2.16 kg) to the metal tube which has been pre-heated to a temperature of at least 200.degree. C., a second step in which the coating is cooled to a temperature of about 110.degree. to 170.degree. C. and a third step of applying a self-supporting film of polyethylene with a melt index of 0.1 to 7 g/10 minutes at this temperature so that the total coating has a minimum layer thickness of 1.5 to 4 mm and a coated article coated according to said process.

Abstract: A process for the coating of metal tubes by the application of polyethylene to the preheated tubes, a polyethylene with a melt index of over 1 g/10 minutes being applied first to the pre-heated metal tube and a polyethylene with a low melt index being applied thereupon, the process comprising a first step of applying a polyethylene with a melt index of 1.2 to 70 g/10 minutes (190.degree. C./2.16 kg) to the metal tube which has been pre-heated to a temperature of at least 200.degree. C., a second step in which the coating is cooled to a temperature of about 110.degree. to 170.degree. C. and a third step of applying a self-supporting film of polyethylene with a melt index of 0.1 to 7 g/10 minutes at this temperature so that the total coating has a minimum layer thickness of 1.5 to 4 mm and a coated article coated according to said process.