Economical doped alloys of new generation

Cr20Ni80 (nichromes) were used during many ten years in the whole world for producing heating elements of different domestic appliances and industrial equipments.

However, the high cost of these alloys and not high corrosion resistance in different sulfur content (sulfur fallow, H2S,SO2,SO3), carbonizing, oxidative gases and others mediums insensibly have redirected consumer market of economy countries in the alloys Fe-Cr-Al (fechrals) and nickel economical doped alloys Fe-Ni-Cr.

Approximate pattern of consumption of this alloys is in the picture:




Table1. Chemical composition and physical properties of the most popular heating alloys.

Grade	Chemical composition, %					Удельное сопротивление, Ом*мм2*м-1
	Ni	Cu	Cr	Fe	Прочие
Ni-Cr и Ni-Cr-Fe
Cr20Ni80	78	-	20	-	Si<1,5	1,08
CrNi70Al	68	-	30	-	Si<1,5	1,18
Cr15Ni60	59	-	15	basis	Si<1,75	1,12
Nichrome GS40	30	-	20	basis	Si<3,0	1,04
Fe-Cu-Al
Fechral	-	-	23	basis	6,0Al	1,45
Fechral	-	-	22	basis	5Al+Y	1,39
Fechral	-	-	20	basis	5,25Al	1,35

Grade	Density, gm*сm-3	Coefficient of heat resistance		Thermal conductivity, W*m-1*°C-1
		10-6*°С-1	t °С
Ni-Cr и Ni-Cr-Fe
Cr20Ni80	8,35	17,5	20-1000	15,0
CrNi70Al	8,16	17,5	20-1000	13,7
Cr15Ni60	8,20	17,5	20-1000	13,3
Nichrome	7,90	18	20-1000	13,0
Fe-Cu-Al
Fechral	7,10	15,1	20-1000	16,0
Fechral	7,10	15	20-1000	16,0
FechralТ	7,25	14	20-1000	16,5