Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C9/00—Alloys based on copper
  • C22C9/06—Alloys based on copper with nickel or cobalt as the next major constituent
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C28/00—Alloys based on a metal not provided for in groups C22C5/00 - C22C27/00
• • 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
  • C22C30/02—Alloys containing less than 50% by weight of each constituent containing copper

Definitions

• the present invention relates to an alloy of the system Cu-Fe which is very useful as a material for the structural parts of machines or apparatus used for instance in sea water, such as ships propellers.
• a general object of the present invention is to provide an alloy of the system Cu-Fe that combines the advantages of a copper alloy in the production process and the corrosion resistance, with the advantages of a steel ma terial as to strength and expenses incurred. Therefore, the alloy according to the invention may be produced in a similar technique as copper alloys.
• the cathodic protection is not required for use of the alloy of the invention in sea water, and its strength is far higher than that of the usual copper alloys.
• the alloy of the present invention can be used for ships propellers, impellers, water turbines, condenser tubes, condenser tube plates, and the like.
• the alloy of the present invention is a copperiron base alloy containing Ni, Mn and Cr.
• a simple copper-iron binary alloy it is impossible to produce a solid solution containing a large quantity of copper, because the solubility of copper in the ferrite phase of iron is low.
• the austenite phase of iron containing a certain amount of Ni and Mn is capable of dissolving a large quantity of copper.
• the a phase of the copper rich side of Cu-Fe alloy which has the same [face-centered cubic structure as the austenite phase, precipitates iron as a primary crystal at above 2.8 weight percent Fe so that a solid solution cannot be obtained.
• the copper rich phase of the copper alloy containing Ni and Mn in a certain amount is capable of dissolving a large quantity of iron. That is to say, in a Cu-Fe-Ni-Mn alloy system, solid solutions can be obtained at a proper content of each element, both as the austenite phase of the iron rich region and as the a phase of the copper rich region. Moreover, in order to improve corrosion resistance, CI is added to the Cu-Fe-Ni-Mn alloy. For the same purpose, Al may likewise be added. Therefore the alloy of the present invention contains Cu, Fe, Ni, Mn, Cr and A1 for practical use.
• the invention is preferably concerned with providing a preferred copper alloy composition of the following in percentages by weight:
• the invention is also preferably concerned with providing a second preferred.
• copper alloy compositions having the following in percentages by weight:
• the invention is also concerned with providing articles of manufacture composed of the aforesaid two preferred copper alloy compositions.
• Such articles of manufacture include machine parts exposed to salty water such as propellers, condenser tubes, pipes, impellers and steam turbine parts.
• compositions of Cu-Fe-Ni-Mn-Al alloys and their electric potential In sea water, at the saturated eclomel electrode potential) Chemical compositions (percent) 1 1 Expected compostitions.
• the potentials of Cu-Fe- Ni-Mn base alloys are -0.2 to O.35 volt in sea water at the saturated calomel electrode potential, and are sufficiently nobler than 0.7 volt of ferrous materials.
• the Cu-Fe-Ni-Mn-Cr-Al alloys with Cr added, as shown in Table 3, have superior mechanical properties, especially, a highly improved corrosion fatigue strength and an excellent corrosion resistance.
• addition of Cr which is a powerful element of forming a protective coating
• to the Cu-Fe-Ni-Mn base alloy further improves the corrosion resistance of the alloy.
• Addition of Cr to the Cu-Fe-Ni-Mn base alloy containing a satisfactory quantity of Cu eliminates the incidence of pitting corrosion and makes it possible to obtain desirable corrosion resistant alloy.
• the content of Cu required for the increase of corrosion resistance of the Cu-Fe- Ni-Mn base alloy is in the range of 2 to weight percent.
• the purpose of addition of Al to the alloy is to decrease the density of the material and to produce the coating effect of Al which is similar to Cr.
• the addition of Al is limited to at most 5 weight percent, because, otherwise, the formation of the Ni Al phase would increase so that the mechanical properties of the alloy might be injured.
• the content of Cr is lirnted to 15% at the u o t a d p ds on he desired effects of pro-
• the alloys of the present invention can be melted in a low frequency melting furnace for copper alloys, their melting points being 1250 to 1330 C., and can be cast in cement-sand moulds in conventional use even in the case of casting propellers. Besides, there is little difference between the machinability of the alloys of the invention and that of the usual copper alloys, and the cost of the material is one half of the copper alloys. Consequently, the alloys of the present invention are very useful for industrial purposes.
• the alloys of the present invention also can be used as materials for machine parts requiring corrosion resistance, such as condenser tubes made by plastic Working, forging and rolling.
• the alloy may contain not only the usual impurities such as C, Si, P, S and others, but also stabilizing elements of carbides such as Ti, B and Nb.
• Forming elements of nitrides such as Ti, Zr and V may be added, but the maximum additions of Ti, B, Nb, Zr and V are limited to 0.1 weight percent.
• Mo and Co may be added in view of improving the mechanical properties and the corrosion resistance the maximum additions of Mo and Co are limited to weight percent, in view of the metallographic structures and the material costs.
• Low melting elements such as Zn, Sn, -Pb, which are present in usual Cu alloys, may also be added, but the maximum additions thereof are up to 3 weight percent.
• Copper-iron alloy composition having the following composition in percentages by weight:
• Copper-iron alloy composition having the following composition in percentages by weight:
• Alloy according to claim 1, having the composition in percentages by weight:
• a ship propeller having the composition in percentages by weight: (a) from about 7% to about 1.3% Cr, (b) from about 2% to about 4 Al, (c) from about 20% to about 30% Cu, (d) from about 13% to about 20% Ni, (e) from about 15% to about 22% Mn, and (f) balance Fe, said Fe being in an amount of from about 20% to about 35% Fe.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)
• Prevention Of Electric Corrosion (AREA)
• Preventing Corrosion Or Incrustation Of Metals (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=11929630

Family Applications (1)

Country Status (3)

Cited By (2)

Families Citing this family (1)

Family Cites Families (1)

• 1969
  • 1969-03-14 NL NL6904027A patent/NL6904027A/xx unknown
  • 1969-03-15 DE DE19691913279 patent/DE1913279C2/de not_active Expired
• 1971
  • 1971-11-24 US US00202009A patent/US3740211A/en not_active Expired - Lifetime

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