77NMD (EP233, 77NMDP)

For cores of small transformers, chokes and relays, operating in weak fields, magnetic shields. In small thicknesses (0.05 to 0.02 mm) — for cores of pulse transformers, magnetic amplifiers and solid-state relays

Classification

Country Section Category
CIS, Russia, Ukraine Precision alloys Soft Magnetic Precision Alloys

Chemical composition

Standard Fe, % Si, % Mn, % Cu, % Ni, % P, % C, % S, % Mo, %
GOST 10994-74 9.74–15.7 0.1–0.3 < 1.4 4.8–6 75.5–78 < 0.02 < 0.03 < 0.01 3.9–4.5

Information on suppliers

Physical characteristics

Temperature, °C $$\alpha\cdot 10^{6}$$, $$K^{-1}$$ $$\rho$$, $$\frac{kg}{m^3}$$ $$R\cdot 10^{-6}$$, $$\Omega\cdot m$$
20 8600 0.55
100 12.7

Mechanical properties at 20 °C

Rolling Standard Size, mm Tension Classifiers $$\sigma _{U}$$, $$MPa$$ $$\sigma_{P}$$, $$MPa$$ $$\epsilon_L$$, % Treatment
Tape 540 145 40
Tape cold-work 980 980 2

Brinell hardness number

Rolling Standard Classifiers Value, HBW
Tape 110
Tape cold-work 230

Standards

Standard Description
GOST 10994-74

Description of chemical elements

Element Units of measurement Description
Fe % Iron
Si % Silicon
Mn % Manganese
Cu % Copper
Ni % Nickel
P % Phosphorus
C % Carbon
S % Sulfur
Mo % Molybdenum

Description of physical characteristics

Parameter Units of measurement Description
$$\alpha\cdot 10^{6}$$ $$K^{-1}$$ Coefficient of thermal (linear) expansion (range 20°C–T)
$$\rho$$ $$\frac{kg}{m^3}$$ The density of the material
$$R\cdot 10^{-6}$$ $$\Omega\cdot m$$ Electrical resistivity

Description of mechanical properties

Parameter Units of measurement Description
$$\sigma _{U}$$ $$MPa$$ Ultimate tensile strength
$$\sigma_{P}$$ $$MPa$$ Proportionality limit
$$\epsilon_L$$ % Elongation at break (longitudinal)