Steel U8
	
	
Designation
	
		
			| Name | 
			The value | 
		
	
	
		
			| Designation GOST Cyrillic | 
			У8 | 
		
		
			| Designation GOST Latin | 
			U8 | 
		
		
			| Transliteration | 
			U8 | 
		
		
			| The 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 | 
		
	
	
		
	| Tapes | 
	В34 | 
	GOST 10234-77 | 
	| Sheets and stripes | 
	В23 | 
	GOST 103-2006 | 
	| Sectional and shaped rolling | 
	В22 | 
	GOST 1133-71, GOST 2590-2006, GOST 2591-2006, GOST 2879-2006 | 
	| Sectional and shaped rolling | 
	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 stripes | 
	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 | 
	| Bulls. Blanks. 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 | 
The 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 characteristics
	
		
			
| Section, mm | 
 
sT|s0,2, MPa | 
 
σB, MPa | 
 
d5, % | 
 
d4 | 
 
y, % | 
 
Brinell hardness number, 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 | 
		
	
	
		
	| Section | 
	Section | 
	| sT|s0,2 | 
	Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2% | 
	| σB | 
	Limit short-term strength | 
	| d5 | 
	Elongation after rupture | 
	| d4 | 
	Elongation after rupture | 
	| y | 
	The relative narrowing | 
	
Physical characteristics
	
		
			| Temperature | 
			
Е, ГПа | 
 
G, ГПа | 
 
r, кг/м3 | 
 
l, Вт/(м · °С) | 
 
R, НОм · м | 
 
a, 10-6 1/°С | 
 
С, Дж/(кг · °С) | 
		
	
	
		
	| 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 | 
	| 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. | 
	| Propensity to temper brittleness | 
	Tend not. | 
	| Forging temperature | 
	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. | 
	| Workability by cutting | 
	When NV 187-227 Kn TV.SPL.=1,2 Kn b.St.=1,1. | 
	| Grindability | 
	Good. |