Copper Nickel 70-30

Copper Nickel 70-30

EN 12164 | ASTM B151 | DGS320 | 2.0882 | CuNi30Mn1Fe

The grade Copper Nickel 70/30 is another grade with its base element as copper and major alloying element as nickel. The proportion of the components is 70% and 30% respectively.

The Nickel content has a significant effect on the physical properties of the grade. There might be inclusions of alloying elements like iron and manganese to strengthen the grade with better corrosion and erosion resistance properties.

A small addition of iron (0.5%) gives the grade great resistance to general stress corrosion cracking and stability in various properties.

The content variation in the grade is done to achieve precedence over the 90/10 grade in terms of better strength and stability. The grade is delivered in a very pure form. Like the 90/10 grade, even the copper-nickel 70/30 has alpha phase structure since nickel becomes soluble in the copper phase. Although complete homogeneity is not obtained due to the addition of other alloying elements, the grade almost becomes a balanced compound with a homogenized phase structure. Grade 70/30 has high strength and better ductility. The microstructure of the grade provides it high thermal as well as physical stability.

A considerably high impact strength is obtained from the grade to be used in dynamic applications. After noting its corrosion resistance in polluted and turbulent streams of water, it showed commendable corrosion resistance. The grade is specifically used in imbalanced environments like variable pressures, temperatures, higher velocity flow and turbulence. A high resistance to cracking due to corrosion is obtained. The grade can be used conveniently up to 370°C for relevant applications. The possion's ratio of the grade is slightly higher when compared to standard austenitic steels with exceptional toughness and elastic properties. The grade also has fine electric resistance and electric properties to be used in marine power applications apart from its corrosion resistance underwater.

In fact, it is widely used in electrical engineering space as cables, anodes in TV tubes, and resistors. The grade can be hot worked and cold worked very conveniently. Hot working processes like forging can be carried out at 930-1040°C, with subsequent annealing for grain refinement. The grade comes in the group of corrosion-resistant and moisture-resistant alloys suitably resisting acids, salt solutions, organic solutions and alkalis.

  • Chemical properties
  • Physical properties
  • Mechanical properties
  • Standards Specifications
  • Forms of Supply
  • Corrosion Resistance
  • Heat Treatment
  • Weldability
  • Machining
  • Applications
  • Possible grade alternatives
Grade   Cu Fe Pb Mn Ni Zn
70-30 Min./Max. Rem. 0.4-1.0 0.05 1.0 29.0-33.0 1.0
Nominal 69.5 0.50 - - 30.0 -
Density 8.95 gram/ cm3 or 0.325 ln per inch3
Elastic Modulus 126 000
Poissons Ratio 0.34
Melting Point 1170 to 1240oC or 2140 to 2265 oF
Shears MODULUS (N/MM2) 57.0 GPa 8270 ksi
Specific heat capacity 0.09 cal/goC or 0.09 Btu/lb oF
Thermal conductivity 0.07 cal cm/cm2 s oC or 178 BTU ft/ft2 h oF
Electrical conductivity at -269oC or -452oF (annealed) 0.34 ohm/mm2/m or 207 ohms (circ mil per ft)
Standard 70-30
UNS C71500
EN 12451 CuNi 30 Mnlfe CW354H
BS 2871
DIN 1785 CuNi 30 Mnlfe
AFNOR CuNi 30 Mnlfe
Pipes & Tubes
Summary Standards
Standard Specification for Copper and Copper-Alloy Seamless Condenser Tubes and Ferrule Stock ASTM B111
Standard Specification for Copper and Copper-Alloy Seamless Condenser and Heat Exchanger Tubes With Integral Fins ASTM B359
Standard Specification for U-Bend Seamless Copper and Copper Alloy Heat Exchanger and Condenser Tubes ASTM B395
Standard Specification for Welded Copper-Nickel Pipe ASTM B467
Standard Specification for Welded Copper and Copper-Alloy Heat Exchanger Tube ASTM B543
Standard Specification for Seamless and Welded Copper–Nickel Tubes for Water Desalting Plants ASTM B552

Piping and tubing, fittings and flanges, washers.

The grade delivers exceptional performance in marine service applications and general as well as aggressive attacks in normal seawater. The grade performs well even under polluted water as well as streams of water with higher velocities (up to 4.5 m/s). It can resist moist air or steam efficiently like general copper nickel grades. The grade is almost insensitive to stress corrosion cracking. Acids like phosphoric acid, sulphuric acid, and other mild organic acids can be suitably resisted. It can be attacked by cyanides, halide group acids and nitric acid but can resist alkaline chlorides, sulphates and nitrates. Environments containing wet or dry gases like chlorine, bromine, carbon dioxide can be indisputably resisted.

The grade is normally annealed after procedures to remove internal stresses and refine the grain structure. It is usually done at around 650- 820°C, followed by appropriate quenching. The grade has a wide range of applications under highly uncertain environments. Hence, scrupulous annealing after procedures is required.

The copper-nickel grade has no carbon content, hence its properties and procedures in welding are different from standard stainless steels. It has great welding properties in coated metal arc welding, gas shielded arc welding, seam welding, butt welding, spot welding and satisfactory welding in oxyacetylene.

The grade comes in the category of moderate or sometimes poor machining category alloys. The chips formed while machining are long, hard and tough to remove. Also, sometimes the surface gets damaged while machining. The normal machining rate of the grade is 20%.

Heat exchanger and cooling plant, flexible metal hose, weld wire and boiler parts, pumps and valves, refrigerator and condenser components, pressure vessels, process equipment, evaporator tubes, propeller sleeves, distiller tubes, tube sheets and baffles, tanks, vats, welding backing rings, pump bodies and parts, salt water piping and pipe fittings.

Grade copper nickel 70/30
Grade   Cu Fe Pb Mn Ni Zn
70-30 Min./Max. Rem. 0.4-1.0 0.05 1.0 29.0-33.0 1.0
Nominal 69.5 0.50 - - 30.0 -

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