Designation
Name |
The value |
Designation GOST Cyrillic |
У8 |
Designation GOST Latin |
U8 |
Transliteration |
U8 |
By chemical elements |
8 |
Description
Steel U8 is used: for the manufacture of tools, working in conditions without heating of cutting edge; the tool for tree processing (milling cutters, countersinks, zekovic, axes, chisels, chisels, longitudinal, and circular saws; rollers, plates and rods for forms of casting of tin and lead metals; calibers simple form and low accuracy classes; cold-rolled heat-treated ribbon with a thickness of from 2.5 to 0.02 mm, intended for manufacturing of flat and wire springs and spring-loaded parts of complex configuration (valves, styli, reeds, slats dolnych knives structural fine details, including hours, etc. (tape is produced according to GOST 2283, GOST 21996 and a number of special technical conditions); the bimetal sheet metal U8/75Н34Х8Г3 for the manufacture of the tuning fork stabilizers and filters.
Standards
Name |
Code |
Standards |
Tape |
В34 |
GOST 10234-77 |
Sheets and strips |
В23 |
GOST 103-2006 |
Bars and shapes |
В22 |
GOST 1133-71, GOST 2590-2006, GOST 2591-2006, GOST 2879-2006 |
Bars and shapes |
В32 |
GOST 1435-99, GOST 5210-95, GOST 7417-75, GOST 8559-75, GOST 8560-78, GOST 14955-77, TU 14-11-245-88, TU 14-1-1271-75 |
Sheets and strips |
В33 |
GOST 4405-75, TU 14-19-81-90, TU 14-131-971-2001, TU 14-1-2198-77 |
Steel wire medium and high carbon |
В72 |
GOST 5468-88, GOST 9389-75 |
Blanks. Of the workpiece. Slabs |
В31 |
TU 14-1-3300-81 |
Chemical composition
Standard |
C |
S |
P |
Mn |
Cr |
Si |
Ni |
Fe |
Cu |
GOST 1435-99 |
0.75-0.84 |
≤0.028 |
≤0.03 |
0.17-0.33 |
≤0.2 |
0.17-0.33 |
≤0.25 |
Rest |
≤0.25 |
Fe is the basis.
According to GOST 1435-99, the mass fraction of chromium, nickel and copper is indicated for 1 group of metal products. The mass fraction of sulfur in steel obtained by the electroslag remelting method should not exceed 0.013%. In the metal products of the third group, the mass fraction of Cr ≤ 0.20-0.40%, Ni ≤ 0.25%, Cu ≤0.25%. In metal products of the 1 st and 3 rd groups, made of steel obtained by scrap-process, the mass fractions of nickel, copper and chromium are increased by 0.05% of each element as compared to those in the table. In a metal designed for the manufacture of cold-rolled strip, an increase in the mass fraction of nickel, copper and chromium is not allowed.
Mechanical properties
Section, mm |
sT|s0,2, MPa |
σU, MPa |
d5, % |
d4 |
y, % |
HB, MPa |
Tape flatted average strength of 0.1-4.0 mm according to GOST 10234-77 in the state of delivery (indicated delivery) |
- |
≤780 |
- |
- |
≥8 |
- |
- |
- |
740-1270 |
- |
- |
- |
- |
- |
Billet. Quenching in oil from 780 °C to + Leave at 400 °C |
6 |
≥1230 |
≥1420 |
≥10 |
- |
≥37 |
- |
Annealed cold-rolled tape of the highest quality |
0.1-1.5 |
- |
≤650 |
- |
≥15 |
- |
- |
Quenching in oil from 780 °C to + Leave at 400 °C (samples a smooth diameter 6.3 mm) |
- |
≥1230 |
≥1420 |
≥10 |
- |
≥37 |
- |
Annealed cold-rolled tape of the highest quality |
1.5-4 |
- |
≤750 |
- |
≥10 |
- |
- |
Quenching in oil from 780 °C to + Leave at 400 °C (samples a smooth diameter 6.3 mm) |
- |
≥1270 |
≥1450 |
≥11 |
- |
≥36 |
- |
Cold-rolled steel strip sagatovna (specified strength class) |
0.1-4 |
- |
750-900 |
- |
- |
- |
- |
Quenching in oil from 780 °C to + Leave at 400 °C (samples a smooth diameter 6.3 mm) |
- |
≥1300 |
≥1470 |
≥12 |
- |
≥35 |
- |
Cold-rolled steel strip sagatovna (specified strength class) |
0.1-4 |
- |
900-1050 |
- |
- |
- |
- |
A sample with a diameter of 5 mm and a length of 25 mm, the deformed and annealed. The rate of deformation of 10 mm/min strain Rate 0,007 1/C |
- |
- |
≥105 |
≥58 |
- |
≥91 |
- |
Cold-rolled steel strip sagatovna (specified strength class) |
0.1-4 |
- |
1050-1200 |
- |
- |
- |
- |
A sample with a diameter of 5 mm and a length of 25 mm, the deformed and annealed. The rate of deformation of 10 mm/min strain Rate 0,007 1/C |
- |
- |
≥91 |
≥58 |
- |
≥100 |
- |
- |
- |
≥55 |
≥62 |
- |
≥100 |
- |
- |
- |
≥33 |
≥62 |
- |
≥100 |
- |
- |
- |
≥21 |
≥80 |
- |
≥100 |
- |
- |
- |
≥15 |
≥69 |
- |
≥100 |
- |
Annealing or normalizing |
- |
- |
≤710 |
≥17 |
- |
≥24 |
≤195 |
- |
- |
≤640 |
≥15 |
- |
≥15 |
≤205 |
- |
- |
≤580 |
≥17 |
- |
≥16 |
≤205 |
- |
- |
≤540 |
≥19 |
- |
≥23 |
≤190 |
- |
- |
≤500 |
≥23 |
- |
≥29 |
≤170 |
- |
- |
≤370 |
≥28 |
- |
≥39 |
≤150 |
- |
- |
≤255 |
≥33 |
- |
≥50 |
≤120 |
Description mechanical marks
Name |
Description |
sT|s0,2 |
Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2% |
σU |
Limit short-term strength |
d5 |
Elongation after rupture |
d4 |
Elongation after rupture |
y |
The relative narrowing |
HB |
Brinell hardness number |
Physical characteristics
Temperature |
Е, HPa |
G, HPa |
r, kg/m3 |
l, W/(m · °C) |
R, Mr. · m |
a, 10-6 1/°C |
С, J/(kg · °C) |
20 |
209 |
81 |
7839 |
- |
- |
- |
- |
100 |
205 |
80 |
7817 |
49 |
230 |
114 |
477 |
200 |
199 |
77 |
7786 |
46 |
305 |
122 |
511 |
300 |
192 |
74 |
7752 |
42 |
395 |
13 |
528 |
400 |
185 |
71 |
7714 |
38 |
491 |
137 |
548 |
500 |
175 |
67 |
7676 |
35 |
625 |
143 |
565 |
600 |
166 |
62 |
7638 |
33 |
769 |
148 |
594 |
700 |
- |
- |
7600 |
30 |
931 |
152 |
624 |
800 |
- |
- |
7852 |
24 |
1129 |
145 |
724 |
900 |
- |
- |
- |
25 |
1165 |
- |
- |
1000 |
- |
- |
- |
- |
- |
152 |
724 |
1200 |
- |
- |
- |
- |
- |
157 |
703 |
A description of the physical symbols
Name |
Description |
Е |
The normal elasticity modulus |
r |
Density |
l |
Coefficient of thermal conductivity |
R |
UD. the resistivity |
a |
The coefficient of linear expansion |
Technological properties
Name |
The value |
Weldability |
Does not apply to welded structures. Method of welding - CCC. |
Склонность к отпускной хрупкости |
Tend not. |
The temperature of forging |
Start - 1180 °C, the end - of 800 °C. the cooling of the workpiece cross-section up to 100 mm in the air, 101-300 mm in the pit. |
Flock-sensitive sensitivity |
not sensitive. |
Machinability |
When NV 187-227 Kn TV.SPL.=1,2 Kn b.St.=1,1. |
Sanding behaviour |
Good. |