Copper-Nickel Alloys - Cupronickel (UNS C70600 - C71500)– Wrought Alloys

Topics Covered

Introduction
Alloying Additions
Classification

Introduction

Cu-Ni alloys have a single-phase structure throughout the complete range of compositions and many standard alloys are available with small variations in their element composition for special applications. The earliest application of Cu-Ni alloy was for marine condenser tubes and presently it has many uses. Apart from their usage in coinage and wire mesh, Cu-Ni alloys containing 10 to 30% nickel with iron and manganese additions (C70600 and C71500) are also used for marine applications.

Alloying Additions

Manganese in commercial alloys acts as a de-sulfurizer and de-oxidant. It enhances the working characteristics and anti-corrosiveness in sea-water.

Chromium can also be added instead of iron to increase strength. It is usually added in a 30% nickel casting alloy.

Iron is supplemented (up to about 2%) to the alloys used in marine applications, as it improves the alloy’s strength and provides better resistance to corrosion caused by flowing seawater. Optimum compositions of the copper-nickel-iron alloys offer resistance to corrosion for materials used in making tubes, condensers and other applications which require contact in sea-water. The term "copper-nickel (Cu-Ni)" refers to copper-nickel-iron alloys.

Silicon increases the casting ability of Cu-Ni alloys and is used in combination with either chromium or niobium.

Niobium, when added to cast versions of 10% and 30% nickel alloys, acts as a hardening element. It makes the welding of cast alloys easy.

Addition of tin offers improved resistance to atmospheric tarnishing. The alloy C72500 comprises 2% tin and 9% nickel.

Classification

Copper Alloy No. Previous Trade Name Cu(incl Ag) Pb Fe Zn Ni Sn Mn Other Named Elements Status Inactive Date
*C701001 - Rem. - .05 .25 3.0-4.02 - .50 - Active -
*C702001 - Rem. .05 .10 - 2.0-3.02 - .40 - Active -
*C702301 - Rem. - - .50-2.0 2.2-3.2 .10-.50 - .40-.8Si .10Ag Active -
*C702401 - Rem. .05 .10 .30-.8 1.0-4.02 - .01-.20 .40-.8Si .01-.10Ag Active -
*C702501 - Rem. .05 .20 1.0 2.2-4.22 - .10 .05-.30Mg .25- 1.2Si Active -
*C702521 Copper Nickel Rem. .05 .20 1.0 3.0-4.22 - .11 -.20 .05-.30Mg .40-1.2Si Active -
*C702601 - Rem. - - - 1.0-3.02 - - .01P .20 -.7Si Active -
*C702651 - Rem. .05 - .30 1.0-3.02 .05-.8 - .01P .20 -.7Si Active -
*C702701 - Rem. .05 .28-1.0 1.0 1.0-3.02 .10-1.0 .15 .20- 1.0Si Active -
C702751 Copper Nickel Alloy Rem. .01 .25 .30-1.0 .50-1.5 .30-1.0 - .01Ca .06Cr .002-.20Mg .10-.50Si Active -
*C702801 - Rem. .02 .015 .30 1.3-1.72 1.0-1.5 - .02-.04P .22-.30Si Active -
*C702901 - Rem. .02 .015 .30 1.3-1.72 2.1-2.7 - .02-.04P .22-.30Si Active -
C70300 Copper Nickel Alloy Rem. - .05 - 4.7-5.7 - .05 - Inactive 07/01/1974
*C703101 - Rem. .05 .10 2.0 1.0-4.02 1.0 - .01Mg .05P .08- 1.0Si .02-.50Ag .005-.05Zr Active -
C70320 Copper Nickel Rem. - - - 2.5-5.0 - - .20-1.2Al .18-.50Cr .20- 1.2Si Inactive 03/09/1992
*C703501 - Rem. .05 .20 1.0 1.0-2.5 - .20 1.0-2.0Co .04Mg .50- 1.2Si Active -
*C703701 - Rem. .05 .20 1.0 1.0-2.0 - .20 1.0-2.0Co .04Mg .50-1.0Si .20-.70Ag Active -
*C704001 Copper-Nickel, 5% Rem. .05 1.3-1.7 1.0 4.8-6.22 - .30 -.8 - Active -
C704401 95/5 Copper-Nickel Rem. .05 1.0-1.8 1.0 4.5-6.04 - 1.0- 1.5 .05C .35-.45Si .05S Inactive 03/09/1992
*C705001 Copper-Nickel, 7% Rem. .05 .10 .20 5.8-7.82 - .15 - Active -
*C706001 Copper-Nickel, 10% Rem. .05 1.0-1.8 1.0 9.0-11.02 - 1.0 - Active -
*C706101 - Rem. .01 1.0-2.0 - 10.0-11.02 - .50-1.0 .05C .05S Active -
*C706201 - 86.5min .02 1.0-1.8 .50 9.0-11.02 - 1.0 .05C .02S .02P Active -
*C706901 - Rem. .001 .005 .001 9.0-11.02 - .001 5 Active -
*C707001 - Rem. - .05 - 9.5-10.52 - .50 - Active -
*C708001 Copper-Nickel, 11% Rem. .05 .10 .20 10.5-12.52 - .15 - Active -
C70900 Copper Nickel Rem. .05 .6 1.0 13.5-16.5 - .6 - Inactive 03/09/1992
*C710001 Copper-Nickel, 20% Rem. .05 1.0 1.0 19.0-23.02 - 1.0 - Active -
*C711001 - Rem. .05 .10 .20 22.0-24.02 - .15 - Active -
C71110 Copper Nickel Rem. - - - 21.5-23.5 - .35 .008S .05Ti Inactive 03/09/1992
*C713001 - Rem. .05 .20 1.0 23.5-26.52 - 1.0 - Active -
*C715001 Copper-Nickel, 30% Rem. .05 .40-1.0 1.0 29.0-33.02 - 1.0 - Active -
*C715201 - 65.0min .02 .40-1.0 .50 29.0-33.02 - 1.0 .05C .02P .02S Active -
*C715801 - Rem. .05 .50 .05 29.0-33.02 - .30 (6) Active -
*C715811 - Rem. .02 .40-.7 - 29.0-32.02 - 1.0 (7) Active -
*C71590 - Rem. .001 .15 .001 29.0-31.02 .001 .50 (5) Active -
C71600 Copper Nickel Alloy Rem. .05 4.8-5.8 1.0 - - 1.0 29.0- 33.0Si Inactive 05/25/1971
C71630 Copper Nickel Rem. .01 .40-1.0 - 30.0-32.0 - .50-1.5 .06C .08S8 Inactive 03/09/1992
*C716401 - Rem. .058 1.7-2.3 1.08 29.0-32.02 - 1.5-2.5 .06C .03S Active -
*C717001 - Rem. - .40-1.0 1.0 29.0-33.02 - 1.0 .30 -.7Be Active -
C719001 - Rem. .015 .50 .05 28.0-33.02 - .20-1.0 .04C 2.2- 3.0Cr .02P .25Si .015S .01-.20Ti .02-.35Zr Active -
C72000 Copper-Nickel Alloy Rem. .05 1.5-2.5 .30 40.0-43.0 - .8-1.7 - Inactive 02/25/1971
C721501 - Rem. .05 .10 .20 43.0-46.02 - .05 .10C .50Si Active -
C722009 - Rem. .058 .50-1.0 1.08 15.0-18.02 - 1.0 .30-.7Cr .03Si .03Ti8 Active -
C72400 Copper Nickel Rem. .05 .10 .50 11.0-15.0 .05 - 1.5-2.5Al .05-.40Mg 1.0Hg Inactive 03/09/1992
C7242010 - Rem. .02 .7-1.2 .20 13.5-16.52 .10 3.5-5.5 1.0- 2.0Al .05C .50Cr .05Mg .01P .15Si .15S Active -
*C725009 - Rem. .05 .6 .50 8.5-10.52 1.8-2.8 .20 - Active -
C7260010 Copper Nickel 91.0-93.0 - .20 .50 3.5-4.52 3.5- 4.5 .20 .05P Inactive 03/09/1992
*C7265010 - Rem. .01 .10 .10 7.0-8.02 4.5-5.5 .10 - Active -
*C7270010 - Rem. .0211 .50 .50 8.5-9.52 5.5-6.5 .05 -.30 .15Mg .10Nb Active -
*C7280010 - Rem. .005 .50 1.0 9.5-10.52 7.5-8.5 .05 -.30 .10Al .02Sb .001Bi .001B .005-.15Mg .10-.30Nb .005P .05Si .0025S .01Ti Active -
*C7290010 - Rem. .0211 .50 .50 14.5-15.52 7.5- 8.5 .30 .15Mg .10Nb Active -
*C7295010 - Rem. .05 .6 - 20.0-22.02 4.5-5.7 .6 - Active -
C731001 Copper Zinc Nickel Alloy Rem.12 .05 .10 18.0-22.0 4.0- 6.0 .10 .50 - Active -
C73150 Copper Nickel Rem. .10 .25 9.0-15.0 4.0-7.0 - .50 - Inactive 03/09/1992
C73200 Copper Nickel Rem. .05 .6 3.0-6.0 19.0-23.0 - 1.0 - Inactive 03/09/1992

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1Cu + Sum of named elements, 99.5% min.
2Ni value includes Co.
3Ag Includes B
4Includes Co
5The following additional maximum limits shall apply: .02% C, .015% Si, .003% S, .002% Al, .001% P, .0005%Hg, .001% Ti, .001% Sb, .001% As, .001% Bi, .05% Co, .10% Mg and .005% Oxygen. For C70690, Co shall be .02% max.
6The following additional maximum limits shall apply: .07% C, .15% Si, .024% S, .05% Al and .03% P.
7.02% P, max.; .25% Si, max.; .01% S, max.; .02 - .50% Ti.
8The following additional maximum limits shall apply: When the product is for subsequent welding applications and is so specified by the purchaser, .50% Zn, .02% P, .02% Pb, .02%S and .05% C.
9Cu + Sum of named elements, 99.8% min.
10Cu + Sum of named elements, 99.7% min.
11.005% Pb, max., for hot rolling.
12Includes Co

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