Steel 70S3A
	
	
Designation
	
		
			| Name | The value | 
	
	
		
			| Designation GOST Cyrillic | 70С3А | 
		
			| Designation GOST Latin | 70C3A | 
		
			| Transliteration | 70S3A | 
		
			| The chemical elements | 70С3 | 
	
	Description
	Steel 70S3A used: for the production of heavily loaded springs responsible and osobochistogo destination.
Note
Steel spring alloy of high quality.
Standards
	
		
			| Name | Code | Standards | 
	
	
		
	| Sheets and stripes | В23 | GOST 103-2006 | 
	| Sectional and shaped rolling | В22 | GOST 1133-71, GOST 2590-2006, GOST 2591-2006, GOST 2879-2006 | 
	| Steel alloy wire | В73 | GOST 14963-78 | 
	| Steel wire medium- and high-carbon | В72 | GOST 26366-84 | 
	| Sheets and stripes | В33 | GOST 4405-75 | 
	| Sectional and shaped rolling | В32 | GOST 7417-75, GOST 7419-90, GOST 8559-75, GOST 8560-78, GOST 14955-77, GOST 14959-79, TU 14-1-2118-77, TU 14-178-179-88, TU 14-11-245-88, TU 14-136-367-2008 | 
	
Chemical composition
	
		
			| Standard | C | S | P | Mn | Cr | Si | Ni | Fe | Cu | 
	
	
		
	| GOST 14959-79 | 0.66-0.74 | ≤0.025 | ≤0.025 | 0.6-0.9 | ≤0.3 | 2.4-2.8 | ≤0.25 | The rest | ≤0.2 | 
	
Fe is the basis. 
Mechanical characteristics
	
		
			
| Section, mm | t отпуска, °C | sT|s0,2, MPa | σB, MPa | d5, % | y, % | kJ/m2, кДж/м2 | Brinell hardness number, MPa | HRC | 
	
	
		
	| Wire with special surface finishes for the manufacture of springs cold-wound in the delivery condition according to GOST 14963-78 | 
	
| 0.5-14 | - | - | ≤1030 | - | - | - | - | - | 
	| Forgings section 16-25 mm. Annealing + Quenching in oil from 900 °C + Vacation | 
	
| - | 250 | ≥1520 | ≥1740 | - | ≥10 | - | - | ≥60 | 
	| Rolled steel. Hardened in oil from 830 °C to + Vacation at 450 °C | 
	
| - | - | ≥1540 | ≥1780 | ≥10 | - | ≥235 | - | - | 
	| Forgings section 16-25 mm. Annealing + Quenching in oil from 900 °C + Vacation | 
	
| - | 350 | ≥1520 | ≥1740 | ≥7 | ≥17 | ≥265 | - | ≥56 | 
	| Rolled steel. Hardened in oil from 830 °C to + Vacation at 450 °C | 
	
| - | - | ≥1440 | ≥1710 | ≥12 | ≥32 | ≥285 | - | - | 
	| Spring. Annealing at 840-850 °C. Wrapped at 850-880 °C. Quenching in oil 850-880 °C + Vacation at 460-470 °C | 
	
| - | - | - | - | - | - | - | 388-445 | - | 
	| Rod forged. Annealing + Isothermal quenching from 900 °C with a hold at 320 °C | 
	
| 15-16 | - | - | ≥1060 | ≥2 | ≥13 | - | - | ≥60 | 
	| Forgings section 16-25 mm. Annealing + Quenching in oil from 900 °C + Vacation | 
	
| - | 450 | ≥1220 | ≥1690 | ≥6 | - | ≥363 | - | ≥49 | 
	| Rolled steel. Hardened in oil from 830 °C to + Vacation at 450 °C | 
	
| - | - | ≥1270 | ≥1620 | ≥16 | ≥32 | - | - | - | 
	| Rod forged. Annealing + Isothermal quenching from 900 °C with a hold at 340 °C | 
	
| 15-16 | - | - | ≥1270 | ≥4 | ≥15 | - | - | ≥49 | 
	| Rolled steel. Hardened in oil from 830 °C to + Vacation at 450 °C | 
	
| - | - | ≥1220 | ≥1400 | ≥20 | ≥65 | - | - | - | 
	| Rolled steel. Steel categories: 3, 3A, 3B, 3C, 3D, 4, 4A, 4B. Quenching in oil from 850 °C + Vacation at 470 °C | 
	
|  | - | ≥1470 | ≥1670 | ≥6 | ≥25 | - | - | - | 
	
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 | 
	| y | The relative narrowing | 
	| kJ/m2 | Toughness | 
	| HRC | Rockwell hardness (indenter diamond spheroconical) | 
	
Physical characteristics
	
		
			| Temperature | Е, ГПа | G, ГПа | l, Вт/(м · °С) | a, 10-6 1/°С | С, Дж/(кг · °С) | 
	
	
		
	| 20 | 214 | 83 | 25 | - | - | 
	| 100 | 208 | 81 | 26 | 114 | 480 | 
	| 200 | 198 | 76 | 27 | 123 | 510 | 
	| 300 | 192 | 79 | 28 | 128 | 520 | 
	| 400 | 185 | 69 | 29 | 133 | 535 | 
	| 500 | 180 | 67 | 29 | 137 | 565 | 
	| 600 | 152 | 57 | 29 | 141 | 585 | 
	| 700 | 139 | 52 | 28 | 143 | 620 | 
	| 800 | 132 | 49 | 27 | 143 | 620 | 
	| 1000 | - | - | - | 128 | 700 | 
	
A description of the physical symbols
	
		
			| Name | Description | 
	
	
		
	| Е | The normal elasticity modulus | 
	| G | Modulus of elasticity shear torsion | 
	| r | Density | 
	| l | Coefficient of thermal conductivity | 
	| R | UD. the resistivity | 
	
Technological properties
	
		
			| Name | The value | 
	
	
		
	| Weldability | Does not apply to welded structures. | 
	| Propensity to temper brittleness | Inclined. | 
	| Forging temperature | Start - 1100 °C, the end - of 800 °C. | 
	| Flock-sensitive sensitivity | not sensitive. |