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12X18H9 steel

12X18H9 steel

Steel 12Cr18Ni: Handbook of steels and alloys. Below is systematized information on the purpose, chemical composition, types of supply, substitutes, critical point temperatures, physical, mechanical, technological and foundry properties for the grade — Steel 12X18H9.

General information about 12X18H9 steel

12X18H9 steel grade
of steel grades: 20Х13Н4Г9, 12Х17Г9А4, 10Х14Г14Н4Т.
Delivery type
Tape 12х18Н9, bar stock, including shaped: GOST 5949−75, GOST 2590−71, GOST 2591−71, GOST 2879−69. Calibrated bar GOST 7417−75, GOST 8559−75, GOST 8560−78. Grinded rod and silver GOST 14955−77, GOST 18907−73. Sheet thick GOST 7350−77. Thin sheet GOST 5582−75. GOST 4405−75 GOST 103−76 stripe. GOST 18143−72 wire. Forgings and forged blanks GOST 1133−71, GOST 25054−81. Tubes GOST 9940−81, GOST 9941−81, GOST 14162−79.
Application
Cold-rolled high-strength plates and strips for different parts and structures to be spot-welded, as well as for the manufacture of pipes and other parts. The steel is corrosion-resistant and heat-resistant austenitic grade.

Chemical composition of steel 12Х18Н9

Chemical element %
Silicon (Si), not more 0.8
Manganese (Mn), not more than 2.0
Copper (Cu), not more than 0.30
Nickel (Ni) 8.0−10.0
Sulfur (S), not more than 0.020
Titanium (Ti), not more than 0.5
Carbon ©, not more than 0.12
Phosphorus (P), not more than 0.035
Chrome (Cr) 17.0−19.0

Mechanical properties of steel 12Х18Н9

Heat treatment, delivery condition Section, mm σ0, 2, MPa σB, MPa δ5, % δ4, %
Rods. Hardened at 1050−1100°C, air, oil, water. 60 196 490 45  
Grinded bars, machined to the specified strength 1−30   640−880 20  
Hot- and cold-rolled sheets. Hardened 1050−1120°C, water or water shower >4 216 530 38  
Hot- and cold-rolled sheets. Hardened 1050−1080°C, water, air <3,9   540 38  
Electrocoated sheets <3,9   930−1230 13  
Forgings. 1050−1100°C hardening, water. <1000 196 490 35  
Cold-rolled steel tape. Hardened 1050−1080°C, water, air. 0,2−2   540   35
Cold rolled semi-naked tape 0,2−2   800   15
Cold rolled naked steel strip 0,2−2   1000   5
Cold-rolled high-greased tape 0,2−2   1150   3
Seamless hot-deformed pipes without heat treatment 3,5−32   529 40  
Seamless cold- and heat-treated heat-treated pipes 0,2−22   549 37  

Mechanical properties at elevated temperatures

t test,°C σ0, 2, MPa σB, MPa δ5, % ψ, % KCU, J/m2
Bar. Hardened at 1080 °C, air.
20 230 560 46 66 220
200 180 450 36 68 250
300 160 420 29 66 260
400 150 420 26 61 290
500 140 400 30 60 200
550 140 390 31 61 270
600 120 350 28 51 200
650 120 280 27 52 250
700 120 270 20 40 260
Specimen with a diameter of 10 mm and a length of 50 mm, rolled. Deformation rate of 1.1 mm/minute. Strain rate 0.0004 1/s.
700   210 47 76  
800   120 57 70  
900   68 65 66  
1000   38 56 60  
1100   30 64 59  
1200   16 45 71  

Mechanical properties in the long term strength test

Creep strength, MPa Creep rate, %/h t test,°C Ultimate long-term strength, MPa Test duration, h t test, h
118 1/10000 540 127 10 704
48   650 66 10 815
      98 100 704
      43 100 815

Technological properties of steel 12Х18Н9

Forging temperature
Beginning temperature 1200, ending temperature 850. Sections up to 350 mm are cooled in the air.
Weldability
without restriction.

Impact toughness of steel 12X18H9

Impact toughness, KCU, J/cm2

Delivery condition, heat treatment +20 -40 -78
20mm diameter bars. Hardened at 1150 C, water 330 314 307
22 mm diameter bars. Tempering 1100 C, bv = 670 MPa, b0,2 = 245 MPa. 333   333
In delivery condition 183   165

Endurance limit of steel 12Х18Н9

σ-1, MPa n σB, MPa
490 79Е-6 1450

Corrosion properties of 12X18H9 steel

Medium Temperature, °C Test duration, h Depth, mm/year
Water 20   0,1
Air moist+HCl 20 3288 0,075
Seawater 80 142 0,008

Physical properties of steel 12Х18Н9

Test temperature, °C 20 100 200 300 400 500 600 700 800 900
Modulus of normal elasticity, E, GPa 199                  
Torsional shear modulus of elasticity G, GPa 77                  
Steel density, pn, kg/m3 7900 7860 7820 7780 7740 7690 7650 7600 7560 7510
Thermal conductivity coefficient W/(m — °C)   16 18 19 20 22 23 25 26  
Electrical resistivity (p, nominal value — m)   743 819 891 851 1001 1048 1098 1140  
Test temperature,°C 20−100 20−200 20−300 20−400 20−500 20−600 20−700 20−800 20−900 20−1000
Coefficient of linear expansion (a, 10−6 1/°C) 16.5 17.2 17.7 18.1 18.3 18.6 18.9 19.3 19.7 20.2
Specific heat capacity (C, J/(kg -°C)) 504