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
  • C22C38/18—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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D51/00—Making hollow objects
  • B21D51/16—Making hollow objects characterised by the use of the objects
  • B21D51/18—Making hollow objects characterised by the use of the objects vessels, e.g. tubs, vats, tanks, sinks, or the like
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D51/00—Making hollow objects
  • B21D51/16—Making hollow objects characterised by the use of the objects
  • B21D51/24—Making hollow objects characterised by the use of the objects high-pressure containers, e.g. boilers, bottles
• • 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 of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
  • C21D8/10—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of tubular bodies

Definitions

• the invention relates to a method for producing seamless corrosion-resistant gas bottles or steel containers, which are used in their further Use in contact with corrosive gases and / or liquids.
• gases are needed that stored in compressed or liquefied form in bottles or containers are. These gases also include hydrogen-containing gases up to pure ones Hydrogen. For example, in the electronics industry, hydrogen is the highest Purity level required. This results in high requirements for the Bottles or containers used material. Possible particle secretions from the bottle inner surfaces often have to be reduced to extremely low values will. In addition, occasionally in the presence of an aqueous phase highly corrosive conditions that do not lead to corrosion on the material may lead.
• the well-known martensitic steel X 20 Cr 13 (material no. 1.4021) lies with a Chromium content of 13% close to the resistance limit, i.e. close to the theoretical Minimum chromium content for the formation of passivity. This is considered to be rustproof Steel is inert to corrosion and would be used to manufacture compressed gas cylinders sufficiently firm. But about the known manufacturing methods of Pressurized gas cylinder manufacture, such as manufacture from the tube Deep drawing from a round blank or by hot extrusion from a block can be done do not process this material. Therefore, only those already mentioned have been mentioned so far welded austenitic stainless steel bottles. It should also be noted that that the material X 20 Cr 13 is by no means a for the intended applications has sufficient corrosion resistance.
• WO 93/11270 discloses a weldable, high-strength structural steel for the production of seamless steel tubes or flat products for tubes or containers which, when further used, come into contact with gaseous or liquid hydrocarbons, the CO 2 and water and possibly small amounts of H 2 S included.
• the objects made from this steel have a 0.2 proof stress of at least 450 N / mm 2 .
• This steel has the following composition: C. 0.015% to 0.035% Si 0.15% to 0.50% Mn 1.0% to 2.0% P Max. 0.020% S Max. 0.003% Cr 12.0% to 13.8% Ni > 0% to 0.25% Mon 0.01% to 1.2% N 0.002% to 0.02% Nb 0.01% to 0.05% Balance iron and usual impurities
• the standard bottle material 34 CrMo 4 has a minimum yield strength of 755 MPa and a minimum tensile strength of 850 MPa.
• the notched impact strength at a test temperature of - 50 ° C must be at least 50 joules / cm 2 (mean value of test direction across).
• the object of the present invention is to provide a method for producing To propose steel bottles or containers to be used in their further use corrosive gases and / or liquids come into contact and thereby are corrosion-resistant and / or are suitable for storing high-purity gases.
• the weight of these bottles or containers is said to be known Stainless steel designs can be significantly lower. Likewise, the production should be less be expensive. A sufficient level of strength and Toughness requirements can be guaranteed.
• the method according to the invention for producing seamless, corrosion-resistant steel bottles which come into contact with highly pure and / or corrosive gases and / or liquids when they are used further, provides for hot extrusion of a heated steel block into a bottle blank.
• a steel alloy with the following composition is used as the raw material (in% by weight): C. 0.02% to 0.06% Si 0.15% to 0.30% Mn 1.60% to 1.80% P Max. 0.035% S Max. 0.008% Al Max. 0.020% Cr 12.5% to 13.5% Ni 0.3% to 0.8% V Max. 0.07% Nb 0.025% to 0.060% W min. 0.03% Ti Max.
• the bottle blank thus produced is then soft-annealed at at least 650 ° C and at most 700 ° C.
• the desired final thickness of the bottle wall is created by subsequent cold flow pressing at room temperature.
• a bottle neck is then formed by rolling at a temperature of 1150 to 1250 ° C.
• a tempering treatment is then carried out to adjust the strength and toughness properties.
• the steel bottle produced in this way is then descaled inside and out.
• the invention sees the production more seamlessly corrosion-resistant steel bottles by deep drawing before, again the already mentioned material is used as a raw material.
• the primary material consists of soft annealed blanks from a hot-rolled sheet. These blanks will be formed into a bottle sleeve by deep drawing. After warming up then a bottle neck is molded at 1150 to 1250 ° C by rolling. After that there is a remuneration treatment and a final descaling of the interior and Outer surface.
• the one to be used according to the invention for the primary material covers Material not only the required strength spectrum (minimum yield point of 690 MPa) with the greatest manufacturing reliability, but delivers at the same time compared to known materials with 13% Cr improved toughness properties and a improved corrosion resistance. This is achieved without the Significantly increase the manufacturing costs of the alloy.
• the ones taken for this Measures can be seen in particular in the following points:
• the manganese content was set in the narrow range of 1.6 to 1.8%, while the nickel content was raised slightly to a value in the range of 0.3% to 0.8%, preferably 0.4 to 0.6%. This will adjust the ferrite-martensite ratio reached a very favorable value. It also results this increases the basic strength.
• By raising the Minimum niobium content of 0.025% improves the fine grain of the structure with a view to achieving higher strengths and improved toughness values.
• niobium also has a stabilizing effect with a view to achieving one improved corrosion resistance.
• the Alloying of tungsten which is already in very small quantities from 0.03% as a strong carbide former has a stabilizing effect and corrosion resistance improved.
• the tungsten content should not exceed 1.0%, preferably 0.6%.
• the tungsten content is expediently at least 0.1%, preferably at at least 0.15%.
• the addition of molybdenum was completely avoided small amounts of molybdenum are not disturbing.
• the content of vanadium to a maximum of 0.07% and titanium to a maximum 0.01% is to be restricted, the sum of both elements being at most 0.07% may be. It is advisable to change the vanadium content because of its embrittlement To limit the effect even more, preferably to a maximum of 0.03%.
• the tempering treatment after hardening should be at 550 to 700 ° C.
• the appropriate level of temperature depends on the desired properties. The higher the tempering temperature, the better they are Toughness properties. Lower tempering temperatures allow higher temperatures Set strength values. Very good toughness properties result between when hardening and tempering in the temperature range between Ac1 and Ac3 an intermediate annealing with subsequent cooling to below 100 ° C he follows.
• the bottles or containers produced according to the invention can be very electropolish well, so that the requirements with regard to particle freedom Storage of high-purity gases can easily be met.
• Pressurized gas cylinders were produced using the three variants of the method according to the invention, namely by hot extrusion from a steel block, by deep drawing from a sheet metal blank and by hot molding the ends of steel tubes using the spinning method.
• a steel with the following alloy composition (% by weight) was used: C. 0.041% Si 0.199% Mn 1.68% P 0.012% S 0.005% Al 0.003% Cr 13.1% Ni 0.52% V 0.03% Ti 0.005% Nb 0.048% W 0.04% N 0.0162%
• the outer surfaces of the bottles were flawless, the bottoms well pressed and the inner surfaces smooth.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• Organic Chemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Thermal Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Physics & Mathematics (AREA)
• Manufacturing & Machinery (AREA)
• Heat Treatment Of Steel (AREA)
• Preventing Corrosion Or Incrustation Of Metals (AREA)
• Heat Treatment Of Articles (AREA)
• Extrusion Of Metal (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)

Applications Claiming Priority (2)

Publications (3)

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ID=7814891

Family Applications (1)

Country Status (5)

Cited By (5)

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Family Cites Families (5)

• 1996
  • 1996-12-03 DE DE19652335A patent/DE19652335C1/de not_active Expired - Fee Related
• 1997
  • 1997-11-17 DE DE59704363T patent/DE59704363D1/de not_active Expired - Fee Related
  • 1997-11-17 EP EP97250346A patent/EP0848069B1/fr not_active Expired - Lifetime
  • 1997-11-17 AT AT97250346T patent/ATE204611T1/de not_active IP Right Cessation
  • 1997-11-17 ES ES97250346T patent/ES2159809T3/es not_active Expired - Lifetime
  • 1997-11-17 DK DK97250346T patent/DK0848069T3/da active

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