Steel U12
	
	
Designation
	
		
			| Name | The value | 
	
	
		
			| Designation GOST Cyrillic | У12 | 
		
			| Designation GOST Latin | U12 | 
		
			| Transliteration | U12 | 
		
			| The chemical elements | 12 | 
	
	Description
	Steel U12 is used: for the manufacture of hand taps, files, metal scrapers; parts dies of cold forming, trimming and punching of small size and no transitions in the cross section; cold forging punches and dies for small sizes; calibers simple form and low accuracy classes; tools with low wear resistance at moderate and high specific pressure (without heating the cutting edge): nail files, razor blades and knives, sharp surgical tools, scrapers, engraving tools.
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 | 
	| 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 | 
	| Steel wire medium- and high-carbon | В72 | GOST 5468-88, GOST 9389-75 | 
	
Chemical composition
	
		
			| Standard | C | S | P | Mn | Cr | Si | Ni | Fe | Cu | 
	
	
		
	| GOST 1435-99 | 1.1-1.29 | ≤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 | t отпуска, °C | sT|s0,2, MPa | σB, MPa | d5, % | d4 | y, % | kJ/m2, кДж/м2 | HRC | 
	
	
		
	| Annealed cold-rolled tape of the highest quality | 
	
| 0.08-3 | - | - | ≤750 | - | ≥10 | - | - | - | 
	| Samples section 21-30 mm. Quenching in water 810-830 °C + Vacation | 
	
| - | 400 | ≥1370 | ≥1570 | ≥9 | - | ≥24 | ≥200 | ≥52 | 
	| 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 | ≥60 | - | ≥68 | - | - | 
	| Samples section 21-30 mm. Quenching in water 810-830 °C + Vacation | 
	
| - | 500 | ≥880 | ≥1040 | ≥11 | - | ≥30 | ≥290 | ≥40 | 
	| Rolled steel. Annealing | 
	
| - | - | ≥325 | 590-690 | ≥28 | - | ≥50 | ≥270 | - | 
	| 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 | 
	
| - | - | - | ≥100 | ≥52 | - | ≥96 | - | - | 
	| Samples section 21-30 mm. Quenching in water 810-830 °C + Vacation | 
	
| - | 600 | ≥650 | ≥760 | ≥18 | - | ≥52 | ≥440 | ≥26 | 
	| 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 | 
	
| - | - | - | ≥60 | ≥40 | - | ≥100 | - | - | 
	
| - | - | - | ≥34 | ≥65 | - | ≥100 | - | - | 
	
| - | - | - | ≥18 | ≥74 | - | ≥100 | - | - | 
	
| - | - | - | ≥15 | ≥92 | - | ≥100 | - | - | 
	| Rolled steel. Annealing (at 20 °C HB=207) | 
	
| - | - | ≥325 | 590-690 | ≥28 | - | 45-55 | - | - | 
	
| - | - | ≥320 | ≥570 | ≥23 | - | ≥47 | - | - | 
	
| - | - | ≥310 | ≥450 | ≥41 | - | ≥60 | - | - | 
	
| - | - | ≥110 | ≥140 | ≥56 | - | ≥74 | - | - | 
	
| - | - | ≥59 | ≥76 | ≥56 | - | ≥82 | - | - | 
	
| - | - | ≥53 | ≥72 | ≥59 | - | ≥85 | - | - | 
	
| - | - | ≥34 | ≥40 | ≥52 | - | ≥91 | - | - | 
	
| - | - | ≥20 | ≥28 | ≥55 | - | ≥98 | - | - | 
	
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 | 
	| kJ/m2 | Toughness | 
	| HRC | Rockwell hardness (indenter diamond spheroconical) | 
	
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) | 
	
	
		
	| 0 | 209 | 82 | 7830 | - | - | - | - | 
	| 20 | 209 | - | 7830 | - | - | - | - | 
	| 100 | 205 | 80 | 7809 | 45 | 252 | 105 | 469 | 
	| 200 | 200 | 78 | 7781 | 43 | 333 | 118 | 503 | 
	| 300 | 193 | 75 | 7749 | 40 | 430 | 126 | 519 | 
	| 400 | 185 | 72 | 7713 | 37 | 540 | 134 | 536 | 
	| 500 | 178 | 69 | 7675 | 35 | 665 | 141 | 553 | 
	| 600 | 166 | 63 | 7634 | 32 | 802 | 148 | 720 | 
	| 700 | - | - | 7592 | 28 | 964 | 153 | 611 | 
	| 800 | - | - | 7565 | 24 | 1152 | 15 | 712 | 
	| 900 | - | - | 7489 | 25 | 1196 | 163 | 703 | 
	| 1000 | - | - | - | - | - | 163 | 703 | 
	| 1200 | - | - | - | - | - | 168 | 699 | 
	
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 | 
	| 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 - 1100 °C, the end - 750 °C. slow Cooling in air. | 
	| Flock-sensitive sensitivity | not sensitive | 
	| Workability by cutting | In the annealed condition with HB 207 Kn TV.SPL.=1.0 Kn b.St.=0.9 | 
	| Grindability | good |