Steel 08Х18Н5Г12АБ (NN-3B)

Designation

Name The value
Designation GOST Cyrillic 08Х18Н5Г12АБ
Designation GOST Latin 08X18H5G12AB
Transliteration 08H18N5G12AB
By chemical elements 08Cr18Н5Mn12NNb
Name The value
Designation GOST Cyrillic НН-3Б
Designation GOST Latin HH-3B
Transliteration NN-3B
By chemical elements НН-3Nb

Description

08Х18Н5Г12АБ steel is used: for the production of rolled products, forgings and stampings used in the manufacture of parts in shipbuilding and ship repairs; hull structures of ships, vessels and goods marine equipment (propeller shaft low-speed gear, axles, spindles, slides, shafts, couplings, rods, cylinders, brackets).

Note

Corrosion resistant, low steel high-strength austenitic.
When cold deformation is not more than 75%, the magnetic permeability μ ≤ 1,01 GS/C. Heat treatment on the magnetic permeability is not affected.

Standards

Name Code Standards
Processing of metals by pressure. Forgings В03 OST 5Р.9125-84
Castings, non-ferrous metals and alloys В84 RD 9257-76
Bars and shapes В32 TU 14-1-784-73
Blanks. Of the workpiece. Slabs В31 TU 14-1-853-74
Castings with special properties (iron and steel) В83 TU 5.961-11131-79

Chemical composition

Standard C S P Mn Cr Si Ni Fe Cu N V Mo W Co
TU 5.961-11131-79 ≤0.08 ≤0.03 ≤0.045 11.5-13.5 18-19.5 ≤0.8 4.5-5.5 Rest - 0.45-0.52 0.2-0.35 - - -
TU 14-1-784-73 ≤0.08 ≤0.03 ≤0.045 11.5-13.5 18-19.5 ≤0.8 4.5-5.5 Rest ≤0.3 0.45-0.52 0.2-0.35 ≤0.3 ≤0.3 ≤0.3
Fe is the basis.
According to RD 9257-76, TU 14-1-853-74 and TU 5.961-11131-79 the total content of Nb + Ta = 0.80-1.10%.
According to TU 14-1-853-74, deviations from the content of elements according to the chemical composition of steel are possible: 08Х18Н5Г12АБ (НН-3Б): carbon +0.010%, manganese + 0.50%, nickel + 0.50%, chromium + 0.50%, vanadium +0.10%, niobium +0.10%, nitrogen +0.030%, phosphorus +0.0050%, silicon + 0.20%. The residual content of elements in the chemical composition of the steel should not exceed: copper, cobalt, tungsten and molybdenum 0.30% of each element.
According to TU 14-1-784-73, the chemical composition is given for steel grade 08H18N5G12AB (NN-3B). The total content of Niobium (Nb) + Tantalum (Ta) should be in the range of 0.80-1.10%. Deviations in chemical composition are allowed: for carbon +0.010%, for manganese + 0.50%, for nickel + 0.50%, for chromium + 0.50%, for niobium +0.10%, for silicon +0.20 %, in nitrogen +0,030%, in phosphorus +0,0050%, in vanadium +0,10%. The residual content of elements in the chemical composition of the steel should not exceed: copper, cobalt, tungsten and molybdenum 0.30 each.

Mechanical properties

Section, mm sT|s0,2, MPa σU, MPa d5, % KCU, kJ/m2 HB, MPa
Hot rods and forgings of round and square. Quenching in water or air from 950-980 °C
≤180 ≥441 ≥687 ≥25 ≥588 -
Forgings for parts resistant to the ICC. Quenching in oil or air from 950-1050 °C
300 ≥441 ≥687 ≥25 ≥590 187-240
Bars hot rolled and forged, round and square. Quenching in water from 900-1050 °C
≤180 ≥490 ≥736 ≥25 ≥588 -

Description mechanical marks

Name Description
sT|s0,2 Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2%
σU Limit short-term strength
d5 Elongation after rupture
KCU Toughness
HB Brinell hardness number

Physical characteristics

Temperature r, kg/m3 l, W/(m · °C) a, 10-6 1/°C
20 7800 1675 -
100 - - 1670
1000 - - 2100

A description of the physical symbols

Name Description
Е The normal elasticity modulus
r Density
l Coefficient of thermal conductivity
R UD. the resistivity

Technological properties

Name The value
Weldability Welding is not performed.
Machinability Machinability similar to steel grades 12Х18Н12Т and 08KH18N12T.
Macrostructure and pollution Macrostructure of steel bars on the other 14-1-784-73 should not have shrinkage, bubbles, cracks, inclusions, visible without using the magnifying devices.