Explanation of steel a 12 – Steel U12, U12A

Steel U12, U12A – definition of steel grade, GOST, material characteristics

Steel grade – U12, U12A

Standard – GOST 1435

Substitute – U10, U10A

Steel U12

contains an average of 1.2% carbon, the letter
U
indicates that the steel is carbon.

Steel U12A

contains an average of 1.2% carbon, the letter
U
indicates that the steel is carbon, the letter
A
at the end of the brand means that the steel belongs to the high-quality category.

Unalloyed tool steels U12

and
U12A
are used for the manufacture of:

hand taps, files, metalwork scrapers;
cold stamping dies of cut and die-cutting of small sizes and without cross-sectional transitions, cold heading punches and stamps of small sizes, calibers of simple shape and reduced accuracy classes;
tools with reduced wear resistance at moderate and significant specific pressures (without heating the cutting edge): files, razor blades and knives, sharp surgical instruments, scrapers, engraving tools.

Mass fraction of basic chemical elements, %
C – carbon	Si – silicon	Mn – manganese
1,10-1,29	0,17-0,33	0.17-0.33 (U12) 0.17-0.28 (U12A)

Temperature of critical points, °C
Ac1	Ac3	Ar1	Ar3
730	820	700	–

Technological properties
Forging	Forging temperature, °C: beginning 1100, end 750. Slow cooling in air.
Weldability	Not applicable for welded structures. Welding method – resistance welding.
Machinability	Annealed at HB 207: Kv carbide = 1.0 Kv high speed steel = 0.9
Flock sensitivity	Not sensitive
Tendency to temper brittleness	Not inclined

Physical properties	Test temperature, °C
Physical properties	20	100	200	300	400	500	600	700	800	900
Modulus of normal elasticity E, GPa	209	205	200	193	185	178	166	–	–	–
Modulus of elasticity under torsional shear G, GPa	82	80	78	75	72	69	63	–	–	–
Density ρn, kg/m3	7830	7809	7781	7749	7713	7675	7634	7592	7565	7489
Thermal conductivity coefficient λ W/(m*K)	–	45	43	40	37	35	32	28	24	25
Electrical resistivity ρ, nOhm*m	–	252	333	430	540	665	802	964	1152	1196
20-100	20-200	20-300	20-400	20-500	20-600	20-700	20-800	20-900	20-1000
Linear expansion coefficient α*106, K-1	10,5	11,8	12,6	13,4	14,1	14,8	15,3	15,0	16,3	16,8
Specific heat capacity c, J/(kg*K)	469	503	519	536	553	720	611	712	703	699

tekhnar.ru

Structural steel with increased cutting machinability A12 - characteristics, properties, analogues

This page shows the technical, mechanical and other properties, as well as the characteristics of A12 steel.

Classification of material and application of grade A12

Grade: A12 Material classification: Structural steel with increased cutting machinability Additional information about the material: Carbon sulfur steel. According to GOST 1414-75, rolled steel A12 is not allowed for use in newly created and modernized equipment Application: Axles, rollers, bushings, gears, pinions, pins, screws, bolts and other lightly loaded small parts of complex shape processed on automatic machines , and to which increased demands are placed on surface quality and dimensional accuracy.

Chemical composition of material A12 in percentage terms

C	Si	Mn	S	P	Cu
0.08 – 0.16	0.15 – 0.35	0.7 – 1.1	0.08 – 0.2	0.08 – 0.15	up to 0.25

Mechanical properties of A12 at a temperature of 20oC

Assortment	Size	Eg.	sв	sT	d5	y	KCU	Thermal change
–	mm	–	MPa	MPa	%	%	kJ/m2	–
Hot rolled products, GOST 1414-75	410	22	34
The rental is calibrated. cold hardened, GOST 1414-75	460-510	7

Technological properties of A12

Weldability:	not applicable to welded structures.
Flock Sensitivity:	sensitive.
Tendency to temper brittleness:	not inclined.

Foreign analogs of A12

The table shows exact and similar analogues.

USA

Germany

Japan

France

England

European Union

Italy

Spain

China

Sweden

Bulgaria

Poland

Romania

Czech

–

DIN,WNr

JIS

AFNOR

B.S.

UNI

UNE

G.B.

BDS

STAS

CSN

1212

B1112

B1113

B1114

G11080

Gr.1108

10S20

10SPb20

15S20

9S20

Explanation of symbols, abbreviations, parameters

Mechanical properties :
sв	– Short-term strength limit, [MPa]
sT	– Proportional limit (yield strength for permanent deformation), [MPa]
d5	– Elongation at break, [%]
y	– Relative narrowing, [%]
KCU	– Impact strength, [kJ/m2]
HB	– Brinell hardness, [MPa]

Physical properties:
T	– Temperature at which these properties were obtained, [Deg]
E	– Modulus of elasticity of the first kind, [MPa]
a	– Coefficient of thermal (linear) expansion (range 20 o– T), [1/degree]
l	– Thermal conductivity coefficient (heat capacity of the material), [W/(m deg)]
r	– Material density, [kg/m3]
C	– Specific heat capacity of the material (range 20o– T), [J/(kg deg)]
R	– Electrical resistivity, [Ohm m]

Weldability:
no limits	– welding is performed without heating and without subsequent heat treatment
limited weldability	– welding is possible when heated to 100-120 degrees. and subsequent heat treatment
difficult to weld	– to obtain high-quality welded joints, additional operations are required: heating to 200-300 degrees. during welding, heat treatment after welding - annealing

Other brands in this category:

Please note that this information about the A12 brand is provided for informational purposes.
The parameters, properties and composition of real A12 grade material may differ from the values given on this page. More detailed information about the A12 grade can be found on the information resource “Brand of Steel and Alloys”. You can check with our managers for information about the availability, delivery times and cost of materials. If you find inaccuracies in the description of materials or errors found, please inform the site administrators using the feedback form. Thanks in advance for your cooperation! www.c-met.ru

Macrostructure and contamination of steel 12Kh2NVFA

When checking for fractures in the longitudinal direction and transverse templates taken from finished rolled products, the macrostructure of steel should not have shrinkage cavities, friability, bubbles, cracks, delaminations, slag inclusions and flakes, as well as fracture defects listed in Appendix 3 of GOST 10243. Central porosity, point heterogeneity and segregation square should not exceed 1 point; layer-by-layer crystallization and light contour - 3 points of the GOST 10243 standard scales. All other defects provided for by GOST 10243 are not allowed. Contamination of steel with non-metallic inclusions should be no higher than the average score (in points): for point oxides 1.5, for line oxides 2.0, for brittle silicates 1.0, for plastic silicates 1.0, for non-deformable silicates 2.5 , for sulfides 2.5, for nitrides line and dot 1.0.

Steel A12 – State Enterprise Stalmash

reference Information

Material characteristics steel A12

Chemical composition in % of material steel A12

C	Si	Mn	S	P
0.08 – 0.16	0.15 – 0.35	0.7 – 1.1	0.08 – 0.2	0.08 – 0.15

Temperature of critical points of the material steel A12

Ac1 = 735, Ac3(Acm) = 866, Ar3(Arcm) = 840, Ar1 = 685

Mechanical properties at T=20oC of the material steel A12

Assortment	Size	Eg.	sв	sT	d5	y	KCU	Thermal change
–	mm	–	MPa	MPa	%	%	kJ/m2	–
The steel is hot rolled.	100	410	22	34	Delivery status

The hardness of the material is hot-rolled steel A12,	HB 10 -1 = 160 MPa
The hardness of the material is steel A12, calibrated cold-worked,	HB 10 -1 = 217 MPa

Physical properties of the material steel A12

T	E 10– 5	a 10 6	l	r	C	R 10 9
hail	MPa	1/Grad	W/(m deg)	kg/m3	J/(kg deg)	Ohm m
20	1.98	7830
100	1.83	11.9	78	470
200	12.5	67
300	1.66	479
400	13.6	517
500	14.2
600	571
T	E 10– 5	a 10 6	l	r	C	R 10 9

Technological properties of the material steel A12

Weldability:	not applicable to welded structures.
Flock Sensitivity:	sensitive.
Tendency to temper brittleness:	not inclined.

Foreign analogues of the material A12 steel Attention! Both exact and closest analogues are indicated.

USA

Germany

Japan

France

England

European Union

Italy

Spain

China

Sweden

Bulgaria

Poland

Romania

Czech

–

DIN,WNr

JIS

AFNOR

B.S.

UNI

UNE

G.B.

BDS

STAS

CSN

1212

B1112

B1113

B1114

G11080

10S20

10SPb20

15S20

9S20

Designations:

Mechanical properties :
sв	– Short-term strength limit, [MPa]
sT	– Proportional limit (yield strength for permanent deformation), [MPa]
d5	– Elongation at break, [%]
y	– Relative narrowing, [%]
KCU	– Impact strength, [kJ/m2]
HB	– Brinell hardness, [MPa]

Physical properties:
T	– Temperature at which these properties were obtained, [Deg]
E	– Modulus of elasticity of the first kind, [MPa]
a	– Coefficient of thermal (linear) expansion (range 20o – T), [1/degree]
l	– Thermal conductivity coefficient (heat capacity of the material), [W/(m deg)]
r	– Material density, [kg/m3]
C	– Specific heat capacity of the material (range 20o – T), [J/(kg deg)]
R	– Electrical resistivity, [Ohm m]

Weldability:
no limits	– welding is performed without heating and without subsequent heat treatment
limited weldability	– welding is possible when heated to 100-120 degrees. and subsequent heat treatment
difficult to weld	– to obtain high-quality welded joints, additional operations are required: heating to 200-300 degrees. during welding, heat treatment after welding - annealing

Brand of steel and alloys
yaruse.ru

Steel 12ХН3А – definition of steel grade, GOST, material characteristics

Steel grade – 12ХН3А

Standard – GOST 4543

Substitute – 12ХН2, 20ХН3А, 25ХГТ, 12Х2Н4А, 20ХНР

Steel 12ХН3А

contains an average of 0.12% carbon,
X
- indicates the chromium content in steel is approximately 1%,
H3
- indicates the nickel content in steel is about 3%, the letter
A
at the end of the brand means that the steel belongs to the high-quality category.

Steel 12ХН3А is used for the manufacture of large critical parts. Steel products are subjected to carburization followed by heat treatment; sometimes this steel is used for non-cemented parts. Steel with high strength, toughness and hardenability.

Gears, axles, shafts, worms, claw couplings, piston pins and other parts are made from steel 12ХН3А

Mass fraction of basic chemical elements, %
C – carbon	Si – silicon	Mn – manganese	Cr – chromium	Ni – nickel
0,09-0,16	0,17-0,37	0,30-0,60	0,60-0,90	2,75-3,15

Temperature of critical points, °C
Ac1	Ac3	Ar1	Ar3
715	773	659	726

Technological properties
Forging	Forging temperature, °C: beginning 1220, end 800. Sections up to 100 mm are cooled in air, sections 101-300 mm are cooled in a pit.
Weldability	Limited weldability. Welding methods: manual arc welding, automatic arc welding, resistance welding.
Machinability	In the hot-rolled state at HB 183-187 and σв = 590 MPa: Kv hard alloy = 1.25 Kv high-speed steel = 0.95
Flock sensitivity	Sensitive
Tendency to temper brittleness	Inclined

Physical properties	Test temperature, °C
Physical properties	20	100	200	300	400	500	600	700	800	900
Modulus of normal elasticity E, GPa	200	–	–	–	–	–	–	–	–	–
Modulus of elasticity under torsional shear G, GPa	–	–	–	–	–	–	–	–	–	–
Density ρn, kg/m3	7850	7830	7800	7760	7720	7680	7640	–	–	–
Thermal conductivity coefficient λ W/(m*K)	–	31	–	–	26	–	–	–	–	–
Electrical resistivity ρ, nOhm*m	–	–	–	–	–	–	–	–	–	–
20-100	20-200	20-300	20-400	20-500	20-600	20-700	20-800	20-900	20-1000
Linear expansion coefficient α*106, K-1	11,8	13,0	14,0	14,7	15,3	15,6	–	–	–	–
Specific heat capacity c, J/(kg*K)	–	–	–	528	540	565	–	–	–	–

tekhnar.ru

Production of metal structures at the North-West plant

ZMK "North-West" is a metal structures plant in St. Petersburg. The company's products are widely used in construction, the oil and gas industry, and the automotive industry. We produce metal products for retail and wholesale sales. We produce serial products and accept orders for individual production of non-standard designs. The product range includes metal foundations and trusses, mooring and port structures, lighting towers, containers and other products. The plant performs all types of metalworking - cutting, chopping, bending, rolling, galvanizing, milling and turning.

properties and characteristics of the brand, application. Steel A and its chemical composition.

Group A steels are classified as structural carbon steels of ordinary quality, but, most often, endowed with increased machinability. Strictly regulated mechanical characteristics and properties play a role here against the background of relative freedom in terms of the chemical composition of the metal. As a rule, steel A is used to create components and entire structures without initially undergoing forging, stamping or other hot or heat treatment. As a result, hot-rolled steel grade A always retains its original properties.

Steel A12 and A20

The most popular materials of this class are considered to be alloys A12 and A20, which are actually analogues of each other. These are structural materials of increased machinability, characterized by low cost and high manufacturability. This alloy is supplied to industrial enterprises in the following form (in accordance with GOST):

GOST 1414-75, GOST 2879-2006, GOST 2590-2006, GOST 2591-2006 – long and shaped rolled products
GOST 1414-75 and GOST 14955-77 – silver and ground rods.
GOST 8559-75, GOST 1414-75, GOST 8560-78 – calibrated rods

Mechanical and physical properties of A12 steel

The hardness of this alloy is HB 10-1 = 160 MPa. The material is flake-sensitive and therefore requires strict adherence to smelting technology. However, it is not prone to temper brittleness and is not used as part of welded structures. The basic mechanical and physical properties of A12 steel can be found here:

Chemical composition of the alloy

The number 12 in the brand designation traditionally indicates the average percentage of carbon, expressed in hundredths of a percent. The chemical composition of A12 steel is the following set of elements:

Application of grade A steels

A12 (A20) steel is widely used in the creation of industrial equipment: bushings, rollers and axles are cast from it, and gears and gears are made from it. In general, this material is excellent for the manufacture of small bolts, screws and other small parts - complex shapes, lightly loaded, intended for processing using automatic machines. A rather important characteristic of the alloy can be considered its compliance with increased requirements for the dimensional accuracy of the resulting parts and the quality of their surfaces. In other words, this steel is a material with increased machinability.

fx-commodities.ru

Supply of 12X2NVFA

Sheets and strips	GOST 11268-76, GOST 11269-76
Steel pipes and connecting parts for them	GOST 21729-76, TU 14-3-967-80, TU 14-3-463-2005, TU 14-3-975-80
Sheets and strips	GOST 82-70
Classification, nomenclature and general norms	OST 1 90005-91
Blanks. Blanks. Slabs	OST 1 90280-79, TU 1-92-156-90, TU 14-1-1278-75
Long and shaped rolled products	OST 1 92049-76, TU 14-1-1885-85, TU 14-1-2854-79, TU 14-1-950-74, TU 14-1-3238-81, TU 14-1-3238-2006 , TU 14-1-1271-75
Long and shaped rolled products	TU 14-2-490-82

Steel A12 - characteristics, chemical composition, properties, hardness

Bulletin board

Steel A12 - characteristics, chemical composition, properties, hardness

Steel A12

General information

Substitute

Steel A20.

Type of delivery

Long products, including shaped steel: GOST 1414-75, GOST 2590-71, GOST 2591-71, GOST 2879-69. Calibrated rod GOST 1414-75, GOST 8559-78, GOST 8560-78. Polished rod and silver steel GOST 1414-75, GOST 14955-77.

Purpose

axles, rollers, bushings, gears, pinions, pins, screws, bolts and other lightly loaded small parts of complex shapes, processed for surface quality and dimensional accuracy.

Chemical composition

Chemical element	%
Silicon (Si)	0.15-0.35
Manganese (Mn)	0.70-1.10
Phosphorus (P)	0.08-0.15
Sulfur (S)	0.08-0.2

Mechanical properties

Heat treatment, delivery condition	Section, mm	s0.2, MPa	sB, MPa	d5, %	y, %	HB	HRСе
Hot rolled steel	100	410	22	34	160
Calibrated, hard-worked steel	30	510	7	217
Calibrated, hard-worked steel	30-100	460	7	217
Deformation degree – 5\%	450	550	50	159
Deformation degree – 10\%	530	600	47	189
Deformation degree – 20\%	640	680	43	229
Deformation degree – 25%	680	710	42	235
Liquid cementation 860-880 °C. Quenching 860-880 °C, water. Vacation 180-220 °C, air.
15	290	440	36	57
Cyanidation 820-860 °C. Quenching 820-860 °C, water. Vacation 180-220 °C, air.
15	290	440	36	57

Mechanical properties at elevated temperatures

test t, °C	s0.2, MPa	sB, MPa	d5, %
Annealing 840 °C.
20	290	440	36
400	170	400	34
480	165	315	38
535	140	255	42
590	98	185	56

Mechanical properties depending on the degree of deformation

Heat treatment, delivery condition	s0.2, MPa	sB, MPa	d4, %	y, %	HB
Hot rolled steel	410	34	160
Calibrated, hard-worked steel	510	217
Calibrated, hard-worked steel	460	217
Deformation degree – 5\%	450	550	21	50	159
Deformation degree – 10\%	530	600	17	47	189
Deformation degree – 20\%	640	680	14	43	229
Deformation degree – 25%	680	710	13	42	235

Technological properties

Forging temperature

Started at 1200, ended at 850.

Weldability

not applicable for welded structures

Machinability

HB 167-217, Ku TV.all. = 1.6

Tendency to release ability

not inclined

Flock sensitivity

sensitive

Critical point temperature

Critical point	°C
Ac1	735
Ac3	866
Ar3	840
Ar1	685

Physical properties

Test temperature, °C	20	100	200	300	400	500	600	700	800	900
Modulus of normal elasticity, E, GPa	198	183	166
Density, pn, kg/cm3	7830
Thermal conductivity coefficient W/(m °C)	78	67
Test temperature, °C	20- 100	20- 200	20- 300	20- 400	20- 500	20- 600	20- 700	20- 800	20- 900	20- 1000
Linear expansion coefficient (a, 10-6 1/°С)	11.9	12.5	13.6	14.2
Specific heat capacity (C, J/(kg °C))	470	479	517	571

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