Dwyer TIC - Manual (Page 75)

74
Appendix
Emissivity table (continue)
Material Temperature（°C）
Emissivity
approximation
Iron
Polished cast iron
200 0.21
Processed cast iron 20 0.44
Polished tempered
iron
40～250 0.28
Polished steel ingot 770～1040 0.52～0.56
Raw welded steel 945～1100 0.52～0.61
Surface ferric oxide 20 0.69
Completely rusty
surface
22 0.66
Rolled iron plate 100 0.74
Oxidized steel 198～600 0.64～0.78
Cast iron (Oxidizing at
600°C )
198～600 0.79
Steel (Oxidizing at
600°C )
125～520 0.78～0.82
Electrolytic ferric
oxide
500～1200 0.85～0.89
Iron plate 925～1120 0.87～0.95
Cast iron, heavy ferric
oxide
25 0.80
Tempered iron, ferric
oxide
40～250 0.95
Melting surface 22 0.94
Melting cast iron 1300～1400 0.29
Melting mild steel 1600～1800 0.28
Liquid steel 1500～1650 0.42～0.53
Pure liquid iron 1515～1680 0.42～0.45