Corrosion resistant material
AssigneesChoeller-Bleckmann Oilfield Technology GmbH & Co. KG, Kohler Edelstahl GmbH
InventorsHerbert Aigner, Josef Bernauer, Gabriele Saller
Life of this patent
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Abstract
A material which is suitable for equipment in oilfield technology and a process for making the material. The material consist essentially of C, Si, Mn, Cr, Mo, Ni, Cu, N in certain weight percentages, with the balance iron and contaminants due to manufacture. The material is hot formed in a condition free of nitride precipitates and without precipitated associated phases. After a cooling, it is cold formed in a condition free of ferrites. The material has certain values of relative magnetic permeability, yield strength (Rp0.2), notched impact strength, fatigue strength under reversed stresses, and fracture appearance transition temperature.
Claims40
A material suitable for equipment in oilfield technology, consisting essentially of, in percent by weight:
- Carbon (C) ≦0.03 Silicon (Si) ≦0.89 Manganese (Mn) 0.51 to 4.49 Chromium (Cr) 25.1 to 38.9 Molybdenum (Mo) 2.1 to 5.9 Nickel (Ni) 22.9 to 38.9 Copper (Cu) 0.51 to 1.49 Nitrogen (N) 0.17 to 0.29
- with the balance iron and contaminants due to manufacture, which material is hot formed in a condition free of nitride precipitates and without precipitated associated phases and, after a cooling, cold formed in a condition free of ferrites, and having a relative magnetic permeability of less than 1.0048 μr, a yield strength (Rp0.2) of higher than 710 N/mm2, a notched impact strength of higher than 60 J, a fatigue strength under reversed stresses of at least ±310 N/mm2 at N=107 load reversal, and a fracture appearance transition temperature (FATT) of below −28° C.
A process for making a material suitable for equipment in oilfield technology and having a relative magnetic permeability of less than 1.0048 μr, a yield strength (Rp0.2) of higher than 710 N/mm2, a notched impact strength of higher than 60 J, a fatigue strength under reversed stresses of at least ±310 N/mm2 at N=107 load reversal and a fracture appearance transition temperature (FATT) of below −28° C., said process comprising hot forming a material consisting essentially of, in percent by weight:
- Carbon (C) ≦0.03 Silicon (Si) ≦0.89 Manganese (Mn) 0.51 to 4.49 Chromium (Cr) 25.1 to 38.9 Molybdenum (Mo) 2.1 to 5.9 Nickel (Ni) 22.9 to 38.9 Copper (Cu) 0.51 to 1.49 Nitrogen (N) 0.17 to 0.29
- with the balance iron and contaminants due to manufacture, in a condition free of nitride precipitates and without precipitated associated phases and, after a cooling, cold forming the material in a condition free of ferrites.
Dependencies are inferred from the claim text.