Classifications

• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
  • C21D8/005—Modifying the physical properties by deformation combined with, or followed by, heat treatment of ferrous alloys
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C30/00—Alloys containing less than 50% by weight of each constituent
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
  • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
  • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
  • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
  • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
  • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
  • C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
  • C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
  • C21D8/065—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires of ferrous alloys

Definitions

• the invention relates to a material with high corrosion resistance in media with high chloride concentration, suitable for facilities in oilfield technology, in particular for drill string components consisting of the elements Carbon (C), silicon (Si), manganese (Mn), chromium (Cr), molybdenum (Mo), nickel (Ni), copper (Cu), nitrogen (N), iron (Fe) and production-related Impurities, which material thermoformed and after cooling cold-worked.
• drill string components consisting of the elements Carbon (C), silicon (Si), manganese (Mn), chromium (Cr), molybdenum (Mo), nickel (Ni), copper (Cu), nitrogen (N), iron (Fe) and production-related Impurities, which material thermoformed and after cooling cold-worked.
• Corrosion resistant materials showing paramagnetic behavior and high strength are for facilities in the oil field technology, in particular for drill string components, usable. However, they are getting higher Parts requirements and stricter standards of materials gestelit or created.
• the material For directional measurements when drilling or sinking a hole with to perform a necessary accuracy, the material must have a Permeability of less than 1.005.
• a high mechanical strength in particular a high 0.2% elongation value, is in the With regard to an advantageous plant engineering conception and a high Operational safety of the parts required because the stresses of the same up provided for the limits of the respective material load capacity and always larger drilling depths are required. Furthermore, a notched impact strength of Material important because often abrupt or jerky high loads from the Parts have to be endured.
• the parts are often mounted or used at low temperatures, so that also the toughness transition temperature (FATT) of the material a high Significance.
• FATT toughness transition temperature
• the invention sets itself the goal of a paramagnetic material with high Yield point, high notched impact strength and high permanent fatigue strength as well to create a low toughness transition temperature at the same time corrosion resistant, in particular resistant to pitting, in chloride-containing media.
• the advantages achieved by the invention are in particular in the alloying effect of a balanced nitrogen concentration. It It has surprisingly been found that in the production of parts a particular high output can be achieved. Although in a hot deformation no nitride precipitations can be given, the deformability of the Material at fluctuating forging heat at contents above 0.29 wt .-% Nitrogen leaps and bounds. Also can in the narrow concentration range of 0.17 to 0.29 wt.% N is an excretion of dissociated phases be prevented easily when the other alloying elements in the salary ranges. Nitrogen, nickel and molybdenum synergistically provide an extremely high resistance Pitting.
• the carbon content of the alloy is of a corrosion-chemical Limited reasons, with a further reduction of the same Corrosion resistance of the material, especially the hole and Stress corrosion cracking, increase.
• the silicon content in the material according to the invention 0.89 wt .-%, from corrosion-chemical reasons and in particular the low magnetic Because of permeability, do not exceed.
• the nitrogen solubility of the alloy and austenite stabilization are achieved Promoted manganese.
• the manganese content with 4.49 wt .-% limited to the top and for nickel are introduced into the alloy.
• a minimum content of 0.51% by weight Manganese is needed for effective sulfur fixation.
• chromium is the basis for the formation of a Passive layer on the surface of the parts represents.
• Alloy elements in particular Mo and N to prevent a large extent, are Contents of at least 25.1 wt.% Cr required. Due to higher contents than 38,9 Wt .-% increases the risk of excretion of intermetallic phases.
• the alloying element nickel is important in the intended concentrations Stabilization of the cubic face-centered atomic lattice, ie for small ones Permeability, and interactive with chromium and molybdenum effective for one Prevention of pitting corrosion. Up to 38.9 wt .-% are the toughness, the FATT and the fatigue strength advantageously increased. When falling below of 22.9% by weight, the stabilizing effect is increasingly reduced with regard to corrosion, in particular stress corrosion cracking, in chloride-containing media and regarding the magnetic values in the Cold deformation; So it increases the tendency to form zones with Verformungsmartentsit.
• the nitrogen content is synergistic to the rest Alloy composition matched.
• This content of 0.17 to 0.29% by weight has the further advantage that a block solidify under atmospheric pressure can be left without gas bubbles by exceeding the Solubility limit in the solidification are formed in this.
• High mechanical property values at a relative magnetic Permeability of 1.004 and smaller are achieved when the material is in the precipitation-free state at least 3.6 times hot-formed and at one Temperature of 100 to 590 ° C, preferably from 360 to 490 ° C, with a Forming degree of less than 38%, preferably from 6 to 19%, cold-worked.
• the material has a hole corrosion potential in neutral Solution at room temperature greater than 1100 mVH / 1000 ppm chlorides and / or 1000 mVH / 80000 ppm chlorides.
• Table 1 shows the chemical composition of the alloys according to the invention and of the comparative materials. Furthermore, the figures for the hot deformation and the cold deformation of the forgings of this table can be removed. Table 2 shows the magnetic and mechanical characteristics of these materials. With the sample designation 1 to 5 are comparative alloys and with the sample designation A to E, alloys composed according to the invention are summarized in Table 1. The test results of the materials are shown in Table 2, which will be briefly described below.
• the alloys 1 to 3 have low nitrogen contents , therefore show no desired solidification in a cold molding , as can be seen from the R p0,2 values, and also for the permanent fatigue strength were low numerical values (not shown in the table) of ⁇ 270, 210 and 290 N / mm 2 determined. Corrosion-wise, neither the SCC nor the CPT values are sufficient, which is due in particular to low Mo contents and, in the case of material 2, to a low Cr content. Alloys 4 and 5 have a not sufficiently high and an excessive nitrogen concentration, which leads to higher yield strength values and also raises the value of flexural fatigue strength ( ⁇ 308, 340 N / mm 2 ).

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Metallurgy (AREA)
• Mechanical Engineering (AREA)
• Crystallography & Structural Chemistry (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Heat Treatment Of Steel (AREA)
• Glass Compositions (AREA)
• Earth Drilling (AREA)
• Heat Treatment Of Articles (AREA)
• Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
• Hard Magnetic Materials (AREA)
• Powder Metallurgy (AREA)
• Soft Magnetic Materials (AREA)

Applications Claiming Priority (3)

Publications (2)

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• 2000
  • 2000-06-30 AT AT0113300A patent/AT408889B/de not_active IP Right Cessation
• 2001
  • 2001-06-08 CA CA002396207A patent/CA2396207C/en not_active Expired - Lifetime
  • 2001-06-08 US US10/182,725 patent/US6764647B2/en not_active Expired - Lifetime
  • 2001-06-08 AT AT01942857T patent/ATE284979T1/de active
  • 2001-06-08 ES ES01942857T patent/ES2231505T3/es not_active Expired - Lifetime
  • 2001-06-08 AU AU2001265657A patent/AU2001265657A1/en not_active Abandoned
  • 2001-06-08 DE DE50104841T patent/DE50104841D1/de not_active Expired - Lifetime
  • 2001-06-08 WO PCT/AT2001/000188 patent/WO2002002837A1/de active IP Right Grant
  • 2001-06-08 EP EP01942857A patent/EP1294956B1/de not_active Expired - Lifetime
• 2002
  • 2002-06-18 NO NO20022917A patent/NO330002B1/no not_active IP Right Cessation

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