U9 (U9A)

Steel is not used for welded structures, not inclined. to temper embrittlement. Flock sensitivity: not sensitive. Temperature of critical points of steel: Ac1 = 740, Ac3 (Acm) = 760, Ar1 = 700, Mn = 190. Hardness U9 after annealing, (GOST 1435−99): HB 10 -1 = 192 MPa.

tool, working in conditions that do not cause heating of the edges: a tool for working wood, hand tools, calibers simple form and the downgrading of accuracy.

Classification

Country Section Category
CIS, Russia, Ukraine Tool steel Carbon Tool Steel

Chemical composition

Standard Fe, % Si, % Mn, % Cr, % Cu, % Ni, % P, % C, % S, %
GOST 1435-99 97.642–98.81 0.17–0.33 0.17–0.33 < 0.2 < 0.25 < 0.25 < 0.03 0.85–0.94 < 0.028

Information on suppliers

Physical characteristics

Temperature, °C $$E\cdot 10^{9}$$, $$MPa$$ $$\alpha\cdot 10^{6}$$, $$K^{-1}$$ $$\varkappa$$, $$\frac{W}{m\cdot K}$$ $$\rho$$, $$\frac{kg}{m^3}$$ $$R\cdot 10^{-6}$$, $$\Omega\cdot m$$
20 207 7745
100 11.3 49 7726 0.253
200 12.1 48 7717 0.329
300 12.9 46 7690 0.418
400 13.6 43 7686 0.525
500 14.2 40 7655 0.646
600 14.7 37 7622 0.789
700 15.2 33 7586 0.943
800 14 7568 1.155
900 7523 1.198

Mechanical properties at 20 °C

Rolling Standard Size, mm Tension Classifiers $$\sigma _{U}$$, $$MPa$$ $$\epsilon_L$$, % Treatment
Tape < 4 cold rolling 750 10 delivery condition

Brinell hardness number

Rolling Standard Classifiers Value, HBW
Alloy GOST 1435-99 annealing 192

Technological Properties

Weldability Flake Susceptibility Propensity to temper brittleness
Not applicable for welded structures not sensitive not inclined

Critical point temperatures

Ac1, K Ac3(Acm), K Ar1, K Mn, K
740 760 700 190

Analogues

USA Germany Japan France United Kingdom Italy Bulgaria Hungary Poland
W1-8 1.1525 (C80W1) SK5 C90E2U BW1A C90KU U9 S91 N9

Standards

Standard Description
GOST 1435-99

Description of chemical elements

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

Description of physical characteristics

Parameter Units of measurement Description
$$E\cdot 10^{9}$$ $$MPa$$ Elastic modulus
$$\alpha\cdot 10^{6}$$ $$K^{-1}$$ Coefficient of thermal (linear) expansion (range 20°C–T)
$$\varkappa$$ $$\frac{W}{m\cdot K}$$ Coefficient of thermal conductivity (the heat capacity of the material)
$$\rho$$ $$\frac{kg}{m^3}$$ 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
$$\epsilon_L$$ % Elongation at break (longitudinal)

Designation of types of weldability

Parameter Units of measurement Description
no limits Welding is performed without heating and without subsequent heat treatment
Boundedly welded Welding is possible with heating up to 100–120 °C and subsequent heat treatment
Difficult to weld For obtaining quality welded joints, additional operations are required: heating up to 200–300 °C for welding, heat treatment after welding — annealing
Not applicable for welded structures

Description of temperatures of critical points

Parameter Units of measurement Description
Ac1 K
Ac3(Acm) K
Ar1 K
Mn K