Abstract: A steel composition includes, in wt. %: C: 0.25-0.35; Si: 0.20-0.35; Mn: 0.40-0.60; Cr: 1.20-1.70; Ni: 1.40-1.90; Mo: 0.15-0.25; Al: 0.015-0.035; Nb: 0.001-0.040; V: 0.001-0.060; N: 0.0030-0.0120; Ca: 0.0010-0.0030; and Fe. The wrought article made from this composition has a balanced set of mechanical properties including strength, ductility and toughness including resistance to fatigue crack propagation.

Abstract: Equipment for oil and/or gas drilling, completion, storage and transportation, including pressure vessels, tools, pipes, tubes, connections and any other parts is coated with highly structured composite material. Due to its highly structured composition it is a particularly effective barrier to protect metals against attack by corrosive substances such as hydrogen sulfide, carbon dioxide and sea water, if necessary under hydrothermal conditions. At the same time it is also abrasion stable, for example against a grinding effect by sand, as well as resistant to the impact of mechanical load e.g. by tools. This is achieved by a coating comprising a binder comprising at least one cross-linked resin, wherein the resin comprises at least one of polar group; at least one type of hydrophilic flakes with an aspect ratio of more than 10, wherein the surface of the flakes at least partially comprises a metal oxide.