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
  • C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten

Definitions

• This invention relates to machine parts and apparatus intended for operation upon metals heated to a high temperature, which causes the machine parts to be subjected in use to considerable variations in temperature.
• machine parts are centrifugal casting moulds, and matrices, swaging sockets, rollers, pressing plungers and dies for use at high temperatures.
• chromium nickel or chromium molybdenum steel alloys of somewhat the following composition have hitherto been regarded as the most suitable materials:
• Chromium-nickel steel alloys containing about 0.3% carbon, about 1.5 to 2% nickel and about 0.5 to 1% chromium, and.
• Chromium-molybdenum steel alloys containing about 0.3% carbon, about 1.0 to 1.3% chromium and about 0.35% molybdenum.
• centrifugal casting moulds can be increased up to 100% if they are made of steel alloys which contain up to about 0.3% carbon, more than about 2.1% chromium, more than about 0.15% molybdenum with or without an amount of nickel up to about 2%. Some or all of the molybdenum may be replaced by about twice as much tungsten.
• the improvement in the durability of the centrifugal casting moulds is believed to be due to the fact that on account of the increased chr0- mium and reduced carbon content the occurrence on the surface of a network of cracks due to stresses set up by heat is retarded and reduced.
• the occurrence of these cracks in existing centrifugal casting moulds is a source of anxiety.
• the improvement is believed to be also due to the fact that even after the formation of the cracks they are practically prevented from spreading and enlarging themselves by virtue of the substantially higher yield point due to the higher chromium content and the addition of molybdenum. It is found that particularly durable centrifugal casting moulds can be produced if the moulds'during the process for improving their properties, i. e.
• a steel alloy may be mentioned which contains about 0.16% carbon, about 2.4% chromium and 0.38% molybdenum with or without an amount of nickel up to about 0.5%.
• the addition of molybdenum can be replaced by an addition of tungsten twice as large, 1. e. by about 0.76% tungsten; it is also found to be advantageous to add up to about 0.4% vanadium for the purpose of further increasing the yield point.
• the steel alloys mentioned above are not only suitable for the production of centrifugal casting moulds but also for the production of all those machine parts or apparatus which have to work at high temperatures and aresubjected to considerable temperature variations, that is to say for the production of such articles as pressing matrices, swaging sockets, rollers, pressing plungers and pressing dies for use at high temperatures.
• a steel alloy which contains about 0.21% carbon, about 2.53% chromium, about 0.42% molybdenum and about 0.28% vanadium.
• a steel alloy is particularly suitable for example which contains about 0.28% carv bon, about 2.01% chromium, about 1.08% nickel and about 0.48% molybdenum.
• centrifugal casting mould made from a steel alloy containingabout, 0.16% carbon, about 2.4% chromium, about 0.38% molybdenumand up to about 0.5% nickel. 5.
• a centrifugal casting mould composed of a steel alloy containing up to about 0.3% of car-,
• a centrifugal casting mould composed of a steel alloy containing up to about 0.3% of carbon
• a centrifugal casting mould composed of a steel alloy containing up to about 0.3% carbon, about 2.1 to 4.5% of chromium, about 0.15 to 0.8%

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Heat Treatment Of Articles (AREA)
• Reduction Rolling/Reduction Stand/Operation Of Reduction Machine (AREA)
• Forging (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=7981801

Family Applications (1)

Country Status (4)

Cited By (3)

Families Citing this family (6)

• 1931
  • 1931-05-12 US US536940A patent/US2031904A/en not_active Expired - Lifetime
  • 1931-05-15 CH CH158001D patent/CH158001A/de unknown
  • 1931-05-15 GB GB14428/31A patent/GB371633A/en not_active Expired
  • 1931-05-15 AT AT134828D patent/AT134828B/de active

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