Alloy 68NKHVKTJU (ЭП578)

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