Metal pipes with anticorrosive polyolefin covering layer

Metal pipe coated on at least a section of the metal pipe with an anti-corrosive polyolefin coating system around said metal pipe, wherein the metal pipe does not comprise an epoxy coating at the section where the anti-corrosive polyolefin coating system is present, the anti-corrosive polyolefin coating system comprising:

• a. a corrosion protective layer of a chromate, phosphate, borate, nitrite or molybdate in a thickness of between 2-200 nm;
• b. a polyolefin based adhesive in direct contact with the metal pipe and the corrosion protective layer;
• c. a PE or PP coating layer;
• wherein the polyolefin based adhesive contains an organic phase consisting of substantially saturated hydrocarbons, and wherein the polyolefin based adhesive contains amorphous polypropylene, ethylene-propylene copolymers or poly(iso)butylene (co)polymers, said polyolefin based adhesive being flowable when a pressure of 10 kgf/mm2 is applied,
• wherein the PE or PP coating layer is a continuous layer over the section where the polyolefin based adhesive is present, and wherein said polyolefin based adhesive adheres to both the metal pipe and to said PE or PP coating layer, wherein the PE or PP coating layer consists substantially of HDPE, MDPE, LLDPE, LDPE or isotactic or syndiotactic PP, and
• wherein the polyolefin based adhesive is present in a thickness of between 0.5 and 5 mm, and the PE or PP coating layer is present in a thickness of between 1-10 mm.