Alloy ХН30МДБ (ЭК77)
Designation
| Name |
The value |
| Designation GOST Cyrillic |
ХН30МДБ |
| Designation GOST Latin |
XH30MDB |
| Transliteration |
HN30MDB |
| The chemical elements |
CrNi30CuДBe |
| Name |
The value |
| Designation GOST Cyrillic |
ЭК77 |
| Designation GOST Latin |
EK77 |
| Transliteration |
EhK77 |
| The chemical elements |
- |
Description
Alloy ХН30МДБ used: for the production of parts and equipment chemical and gas industry with high strength characteristics and high resistance to local corrosion for operation in highly corrosive media; pipes for nuclear power plant equipment welding wire.
Standards
| Name |
Code |
Standards |
| Thermal and thermochemical treatment of metals |
В04 |
STP 26.260.484-2004 |
| Pipes steel and connecting parts to them |
В62 |
TU 1380-001-08620133-05, TU 14-1-5378-99, TU 14-158-135-2003, TU 14-3-1711-90 |
| Bulls. Blanks. Slabs |
В31 |
TU 14-1-1213-75, TU 14-1-4745-89, TU 14-1-4907-90, TU 14-1-5052-91 |
| Welding and cutting of metals. Soldering, riveting |
В05 |
TU 14-1-4998-91 |
| Sheets and stripes |
В33 |
TU 14-134-375-99 |
| Sectional and shaped rolling |
В32 |
TU 14-134-404-2003, TU 14-1-4056-85, TU 14-1-5156-92 |
| Tapes |
В34 |
TU 14-406-1-99 |
Chemical composition
| Standard |
C |
S |
P |
Mn |
Cr |
Si |
Ni |
Fe |
Cu |
B |
Ti |
Mo |
Nb |
| TU 14-1-4745-89 |
≤0.02 |
≤0.02 |
≤0.02 |
0.5-1.8 |
27-29 |
≤0.2 |
29-31 |
The rest |
0.9-1.5 |
0.004 |
≤0.1 |
2.8-3.5 |
0.05-0.2 |
Fe is the basis.
According to TU 14-1-4745-89 and TU 14-1-4907-90, the chemical composition is presented for the alloy grade KhN30MDB (EC77). In the finished metal, deviations from the chemical composition standards are allowed: for carbon +0.010%, for copper -0.10%, for silicon +0.10%, for chromium ± 0.20%, for other elements - in accordance with GOST 5632. The calculated content of modifiers and deoxidizers: boron, cerium, aluminum, magnesium is established by the supplier's technological instructions and their residual content in the metal is not determined by chemical analysis.
Mechanical characteristics
| Section, mm |
sT|s0,2, MPa |
σB, MPa |
d5, % |
y, % |
| Bars hot rolled and forged at STP 26.260.484-2004. Quenching in water or air from 1050-1080 °C |
|
≥300 |
≥540 |
≥35 |
≥40 |
| Pipe forged billet according to TU 14-1-4745-89. Quenching in water with 1090-1110 °C (exposure 40-60 min.) (longitudinal samples of the forge workpieces with a diameter of 80-100 mm) |
| 20-25 |
≥305 |
≥590 |
≥35 |
- |
| Cold-rolled tubes after austenization in the state of delivery on the other 14-158-135-2003 |
|
- |
≥540 |
≥35 |
- |
Description mechanical marks
| Name |
Description |
| Section |
Section |
| sT|s0,2 |
Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2% |
| σB |
Limit short-term strength |
| d5 |
Elongation after rupture |
| y |
The relative narrowing |
Technological properties
| Name |
The value |
| Macrostructure and contamination |
The macrostructure of the metal tube blank on the other 14-1-4745-89 should not have podnasadochnogo looseness, bubbles, cracks, foreign non-metallic inclusions, crusts, visible without using the magnifying devices. The defects allowed must not exceed: - for Central porosity - 2 points; - point heterogeneity - 2 points. Contamination of metal non-metallic inclusions should not exceed average score: oxides of stroke (OS) - 1 point; - point oxides (FROM) - 2 points; - silicates fragile (CX) - 1 point; - for silicates plastic (SP) - 1 point; - for non-deformable silicates (SN) - 1 point; - the sulphides (A) - 1 point; - for nitrides and carbonitrides - 4.5 points. The macrostructure of the billet for rolling on the other 14-1-4907-90 should not have traces of shrinkage, bubbles, cracks, inclusions and delaminations. |
| Features of heat treatment |
Products ХН30МДБ alloy subjected to quenching in water with 1070±10 °C, holding time at the heat for 2-3 minutes per mm of product thickness, but not less than 10 min. |
| Corrosion resistance |
The alloy has high resistance to pitting and crevice corrosion, corrosion cracking, IWC welded joints, stands in the sulfate, phosphate and other harsh environments containing chlorides, fluorides and hydrogen sulfide at elevated temperatures. |
