Eleatric Heating alloy

Nickel-chromium (NiCr) alloys

Nickel-chromium (NiCr) alloys' chemical composition is nickel,chromium and ferrum, it used at operating temperatures up to 1200 degree. Its chemical composition gives good oxidation resistance especially under conditions of frequent switching or wide temperature fluctuations.They are used for electric resistances of appliances or for application of industrial furnaces. Compare to ferrtic alloy, it has better resistance to oxidation，low embrittlement at high temperature, good plasticity (easier to give them a shape compared with FeCrAl. But the price is very more expensive than FeCrAl alloy.

Chemical Composition and Main Properties of Nickel-chromium (NiCr) alloys

Chemical Composition and Main Properties of Nickel-chromium (NiCr) alloys

Properties / Grade

NiCr 80/20

NiCr 70/30

NiCr 60/15

NiCr 35/20

NiCr 30/20

 Main Chemical Composition(%)

Ni

Rest

Rest

Rest

34.0-37.0

30.0-34.0

Cr

20.0-23.0

28.0-31.0

15.0-18.0

18.0-21.0

18.0-21.0

Fe

≤1.0

≤1.0

 Rest

Rest

Rest

Max Work Temp(℃)

1200

1250

1150

1100

1100

Resisivity 20(Ωmm2/m)

1.09

1.18

1.12

1.04

1.04

Density(g/cm3)

8.4

8.1

8.2

7.9

7.9

ThermalConductivity(KJ/m·h·℃)

60.3

45.2

45.2

43.8

43.8

Coefficient of Thermal Expansion(α×10-6/℃)

18

17

17

19

19

Melting Point(℃)

1400

1380

1390

1390

1390

Elongation(%)

>20

>20

>20

>20

>20

Micrographic Structure

austenite

austenite

austenite

austenite

austenite

Magnetic Property

nonmagnetic

nonmagnetic

nonmagnetic

Weak magnetic

Weak magnetic

A series of Ni-Cr,Ni-Cr-Fe alloys with their diameters and characteristics (Conversion Table)

Dia
mm

Cross sectional area
Mm2

Weight per Meter（kg/m）

Resistance per meter at 20℃（Ω/m）

OCr13Al4

OCr25Al5
OCr21Al6
OCr21Al6Nb
OCr27Al7MO2

Cr15Ni60

Cr20Ni80

Cr20Ni30

OCr13Al4

OCr25Al5
OCr21Al6

OCr27Al7
MO2

OCr21Al6
Nb

Cr15Ni60

Cr20Ni80

Cr20Ni30
0.1 0.0079 0.00006 0.00006 0.00006 0.00007 0.00006 160.4 178.3 191 183.5 131.6 140.1 141.3
0.2 0.0314 0.00023 0.00022 0.00026 0.00026 0.00025 40.13 44.59 44.77 46.17 33.12 35.01 35.33
0.3 0.0707 0.00052 0.0005 0.00058 0.00059 0.00056 17.82 19.8 21.22 20.5 14.71 15.56 15.7
0.4 0.01257 0.00093 0.00089 0.00103 0.00106 0.00099 10.02 11.14 11.93 11.53 8.27 8.75 8.83
0.5 0.1964 0.0015 0.0014 0.00161 0.00165 0.0016 6.416 7.128 7.638 7.382 5.295 5.604 5.655
0.6 0.2827 0.0021 0.002 0.00232 0.00237 0.0022 4.457 4.952 5.306 5.129 3.678 3.891 3.926
0.8 0.5027 0.0037 0.0036 0.00412 0.00422 0.0039 2.507 2.785 2.984 2.884 2.068 2.188 2.208
1 0.7854 0.0058 0.0056 0.0064 0.0066 0.0062 1.604 1.872 1.91 1.846 1.324 1.401 1.413
1.2 1.131 0.0084 0.008 0.0092 0.0095 0.0089 1.114 1.238 1.326 1.282 0.919 0.972 0.9814
1.4 1.539 0.011 0.011 0.0126 0.0129 0.0122 0.8187 0.9097 0.9747 0.9421 0.6757 0.7147 0.7212
1.6 2.011 0.015 0.014 0.0164 0.0169 0.0159 0.6266 0.6962 0.7459 0.721 0.5171 0.547 0.522
1.8 2.545 0.019 0.018 0.0209 0.0214 0.0201 0.4951 0.5501 0.5894 0.5697 0.4086 0.4322 0.4361
2 3.142 0.023 0.22 0.0257 0.0264 0.0248 0.401 0.4456 0.4775 0.4614 0.3309 0.3501 0.3533
2.2 3.801 0.028 0.027 0.0312 0.0319 0.03 0.3315 0.3683 0.3946 0.3814 0.2736 0.2894 0.292
2.4 4.524 0.033 0.032 0.037 0.038 0.036 0.2785 0.3095 0.3316 0.3205 0.2298 0.2431 0.2454
2.6 5.309 0.039 0.038 0.044 0.045 0.042 0.2373 0.2637 0.2825 0.2731 0.1958 0.2027 0.2091
2.8 6.158 0.046 0.044 0.05 0.052 0.049 0.2046 0.2273 0.2436 0.2354 0.1688 0.1786 0.1803
3 7.069 0.052 0.05 0.058 0.059 0.056 0.1782 0.198 0.2122 0.2051 0.1471 0.1556 0.157
3.2 8.043 0.06 0.057 0.066 0.068 0.064 0.1576 0.1741 0.1856 0.1802 0.1293 0.138 0.1386
3.5 9.621 0.071 0.068 0.079 0.081 0.076 0.131 0.1455 0.1559 0.1507 0.108 0.1143 0.1154
4 12.57 0.093 0.089 0.103 0.105 0.099 0.1002 0.1114 0.1193 0.1153 0.0827 0.0875 0.0883
4.5 15.9 0.118 0.113 0.13 0.134 0.126 0.0792 0.0881 0.0943 0.0911 0.0654 0.0691 0.0698
5 19.64 0.145 0.139 0.161 0.165 0.155 0.0642 0.0713 0.0764 0.0738 0.0529 0.056 0.0565
5.5 23.76 0.175 0.168 0.195 0.199 0.188 0.053 0.0589 0.0631 0.061 0.0437 0.0463 0.0467
6 28.27 0.209 0.201 0.232 0.237 0.223 0.0446 0.0495 0.0531 0.0512 0.0367 0.0389 0.0396
6.5 33.17 0.245 0.235 0.272 0.279 0.262 0.0376 0.0428 0.0461 0.0437 0.0313 0.034 0.0343
7 38.48 0.284 0.273 0.315 0.323 0.303 0.0327 0.0364 0.039 0.0376 0.027 0.0293 0.0296
8 50.24 0.371 0.36 0.36 0.422 0.397 0.0248 0.0282 0.0304 0.0288 0.0207 0.0224 0.0226

Temperature Factor of the Resistivity

Grade

20℃

100℃

200℃

300℃

400℃

500℃

600℃

700℃

800℃

900℃

1000℃

1100℃

1200℃

1Cr13A14

1

1.005

1.014

1.028

1.044

1.064

1.09

1.12

1.132

1.164

1.172

1.18

1.186

0Cr25A15

1

1.002

1.005

1.008

1.013

1.021

1.03

1.038

1.04

1.042

1.044

1.049

1.047

0Cr21A16

1

1

1.002

1.006

1.011

1.02        

1.037

1.043

1.046

1.049

1.052

1.055

1.058

0Cr21A16Nb

1

0.997

0.996

0.994

0.991

0.99

0.99

0.99

0.99

0.99

0.99

0.99

0.99

0Cr27A17Mo2

1

0.992

0.986

0.981

0.978

0.976

0.974

0.972

0.97

0.969

0.968

0.968

0.967

Cr20Ni80

1

1.006

1.012

1.018

1.025

1.026

1.018

1.01

1.008

1.01

1.014

1.021

1.025

Cr15Ni60

1

1.011

1.024

1.038

1.052

1.064

1.069

1.073

1.078

1.088

1.095

1.109

 

Cr20Ni30

1

1.023

1.052

1.079

1.103

1.125

1.141

1.158

1.713

1.187

1.201

1.214

1.226