Classifications

• • 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
  • C22C38/04—Ferrous alloys, e.g. steel alloys containing 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
  • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
  • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
  • C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling
• • 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
  • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
  • C21D9/42—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for armour plate
• • 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
  • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
• • 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
  • C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
• • 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
  • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
  • C21D1/18—Hardening; Quenching with or without subsequent tempering
• • 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
  • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
  • C21D1/78—Combined heat-treatments not provided for above

Definitions

• the invention relates to a hot-rolled armored sheet with a tempering structure with a yield strength> 1100 N / mm 2 and a hardness> 400 HB from a low-alloy steel and a method for its production.
• the slabs After heating to a temperature of> 1150 ° C, the slabs, which are preferably produced in a continuous casting process, are hot-rolled into coarse strips or sheets.
• the armored sheet which was rolled to its final thickness, is hardened after cooling to room temperature by reheating to above Ac 3 and quenching at a rate of> 1 K / s in oil or water.
• the sheet can then be tempered in the temperature range of 180 to 250 ° C if necessary.
• a high hardness is set which is as little as possible below the starting hardness.
• These well-known armor plates are characterized by a homogeneous structure as well as high hardness and bullet resistance even in the case of large thicknesses. The penetration depth of projectiles can usually be reduced by 30%.
• an armor plate made of steel is included 0.25 - 0.45% C, 0.08 - 0.50% Si, 0.30 - 1.50% Mn, ⁇ 0.02% P, ⁇ 0.02% S, 0.60 - 1.80% Cr, 0.20-0.60% Mo, ⁇ 0.006% B, 0.02-0.15% Al and / or Ti and 0.005 - 0.03% Nb known from CA 1 266 760 C1, which austenitizes at 860 to 960 ° C, then quenched and tempered at 160-550 ° C.
• the invention has for its object a armor plate to propose which, on the one hand, with regard to the Bullet resistance at least equally good properties like armored sheets of the type explained above on the other hand, however, improved material properties, like a higher yield strength, a higher strength at the same time higher toughness and an improved Has weldability.
• a hot-rolled and tempered armor plate made of a steel alloy which has the following chemical composition (in% by mass):
• the steel alloy can additionally contain up to 0.005% boron contain.
• the nitrogen content of the steel alloy should preferably limited to 0.004 to 0.008%.
• the new steel alloy stands out from the Known steel alloy explained at the beginning on the one hand through a lower carbon content and secondly by the carbonitride former vanadium as precipitation-hardening element. Surprisingly achieved one from the steel alloy according to the invention produced armored sheet in the tempered condition despite the lower carbon content compared to known Armor plates have a significantly higher yield strength and Strength, but also a higher toughness and one higher elongation at break.
• the yield strength of the armor plate according to the invention is over 1100 N / mm 2 compared to only 950 N / mm 2 of the known armor plate.
• the minimum tensile strength is 1200 N / mm 2 , in particular 1250 N / mm 2 , and is consequently significantly higher than the minimum tensile strength of 1150 N / mm 2 achieved in the prior art.
• the toughness of armor sheets according to the invention measured on an ISO-V transverse sample at -40 ° C., is A v ⁇ 27 joules. Their elongation at break is more than 10%.
• Armor plate according to the invention preferably has a predominantly martenistic structure with a fine Grit. Result in particularly good material properties itself when the proportion of the martensitic structure is at least 98%.
• room temperature i.e. to a well below the martensite start temperature fine-grained martensitic structure.
• Whose Fine grain can be further improved in that the quench to room temperature after the second Austenitization in the temperature range of 800 - 500 ° C with one related to the sheet metal core Cooling rate of at least 5 K / s takes place, whereby preferably for the rapid cooling Pressurized water is used.
• a melt of the composition shown in Table 1 was poured into a 260 mm thick slab.
• the slab was based on a furnace temperature of 1250 ° C, with a piercing temperature of about 1100 ° C at a final rolling temperature of 950 ° C to a final thickness of 10, 40 and 50 mm hot rolled. Then the Compensation treatment.
• sheets 1, 3 and 4 in Table 2 consisted of austenitizing (940 ° C / water) with subsequent tempering 320 ° C / air. Sheet 2 was austenitized twice, quenched and tempered.
• the samples of the like Properties obtained from armored sheet metal are in Table 2 compiled.
• the yield strength and tensile strength are well above the aforementioned minimum limits.
• the elongation values are approx. 11 to 12% is extraordinarily good, and the notched impact strength values are also significantly above the aforementioned minimum limit of 27 J.
• the hardness values are all above 400 HB.
• the double austenitized sheet 2 again achieved increased values of the mechanical properties.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Heat Treatment Of Steel (AREA)
• Aiming, Guidance, Guns With A Light Source, Armor, Camouflage, And Targets (AREA)
• Laminated Bodies (AREA)
• Securing Of Glass Panes Or The Like (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (3)

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ID=7907466

Family Applications (1)

Country Status (5)

Cited By (8)

Families Citing this family (3)

Citations (5)

• 2000
  • 2000-05-08 ES ES00109687T patent/ES2234476T3/es not_active Expired - Lifetime
  • 2000-05-08 DE DE50008938T patent/DE50008938D1/de not_active Expired - Lifetime
  • 2000-05-08 DK DK00109687T patent/DK1052296T3/da active
  • 2000-05-08 AT AT00109687T patent/ATE284977T1/de active
  • 2000-05-08 EP EP00109687A patent/EP1052296B1/fr not_active Expired - Lifetime

Patent Citations (5)

Non-Patent Citations (3)

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