Designation
Name |
The value |
Designation GOST Cyrillic |
68НХВКТЮ |
Designation GOST Latin |
68HXBKTJu |
Transliteration |
68NHVKTYu |
By chemical elements |
68NiCrВCoTeAl |
Name |
The value |
Designation GOST Cyrillic |
ЭП578 |
Designation GOST Latin |
EP578 |
Transliteration |
EhP578 |
By chemical elements |
- |
Description
Alloy 68NKHVKTJU used: for the manufacture of elastic sensing elements, operating at temperatures from -196 °C to +500 °C; details provocatively elements Aviapribor and automatic aviation systems.
Note
Alloy non-magnetic corrosion-resistant dispersion-hardened with a temporary resistance 1375- 1570 MN/m2 (140−160 kgf/mm2), with the normal elasticity modulus 196000- 216000 MN/m2 (20000- 22000 kgf/mm2).
Standards
Name |
Code |
Standards |
Classification, nomenclature and General rules |
В30 |
GOST 10994-74 |
Tape |
В34 |
TU 14-1-4456-88 |
Bars and shapes |
В32 |
TU 14-1-4470-88, TU 14-11-245-88 |
Wire, steel, alloy |
В73 |
TU 14-1-4488-88 |
Chemical composition
Standard |
C |
S |
P |
Mn |
Cr |
Si |
Ni |
Fe |
Cu |
Al |
V |
B |
Ti |
Nb |
W |
Ce |
Co |
GOST 10994-74 |
≤0.05 |
≤0.01 |
≤0.015 |
≤0.4 |
18-20 |
≤0.4 |
Rest |
≤1 |
≤0.07 |
1.3-1.8 |
≤0.2 |
0.003 |
2.7-3.2 |
≤0.2 |
9-10.5 |
0.05 |
5.5-6.7 |
Ni is the basis.
According to GOST 10994-74, the calculated content of boron and cerium is indicated.
According to TU 14-1-4470-88 and TU 14-1-4456-88 the chemical composition is given for the alloy 68NHVKTYU-VI (EP578-VI). The residual content of niobium and vanadium is not more than 0.20% of each. Boron and cerium are introduced by calculation.
Mechanical properties
Section, mm |
sT|s0,2, MPa |
σU, MPa |
d5, % |
d4 |
y, % |
KCU, kJ/m2 |
HB, MPa |
HRC |
HV, MPa |
Cold-rolled steel strip on the other 14-1-4456-88. Delivery condition - Dispersion hardening in a stepwise mode: 800 °C for 1 hour, 700 °C - 2 hours, air cooling |
- |
- |
≥1470 |
- |
≥1 |
- |
- |
- |
≥46 |
≥460 |
- |
- |
≥1370 |
- |
≥1.5 |
- |
- |
- |
≥43 |
≥430 |
The bars as supplied on the other 14-1-4470-88. Quenching in water from 1060-1100 °C + the Dispersion hardening at 790-810 °C (aging for 3.0-4.5 hours) + Dispersion hardening at 690-710 °C (extract 4-6 hours) |
60, 65, 70 |
≥785 |
≥1180 |
≥15 |
- |
≥20 |
≥396 |
321-415 |
- |
- |
8-55 |
≥835 |
≥1230 |
≥18 |
- |
≥25 |
≥539 |
321-415 |
- |
- |
60-100 |
≥785 |
≥1180 |
≥15 |
- |
≥20 |
≥396 |
321-415 |
- |
- |
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 |
d4 |
Elongation after rupture |
y |
The relative narrowing |
KCU |
Toughness |
HB |
Brinell hardness number |
HRC |
Rockwell hardness (indenter diamond spheroconical) |
HV |
The Vickers hardness |