Kochlin SPECIAL ALLOYS · SINCE 2009
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NiCr25FeAlY · UNS N060252.4633 · Alloy 602CA / Inconel 602CA

Oxidation-resistant to 1200 °C with carburisation resistance — furnace rolls, muffles, calciners

InconelNi superalloys
Units
Tensile Rm
680
MPa · ≥ std. min
Yield Rp0.2
270
MPa · ≥ std. min
Elongation A
30
% · ≥ std. min
Service limit
1200
°C · indicative max
Density
8.415
g/cm³

Physical properties

Density7.9g/cm³
Modulus E215GPa
Thermal conductivity11.3W/(m·K)
Thermal expansion13.5×10⁻⁶/K
Specific heat0.45kJ/(kg·K)
Resistivity1.18Ω·mm²/m

Informative values: they vary with composition, condition and test method. Use the governing standard or measured mill data for pressure and heat-transfer calculations.

Chemical composition

Ni 62%Cr 25%Fe 9.5%Al 2.1%C 0.20%Ti 0.15%Y 0.08%Zr 0.06%Minor & residual 0.68%

Nominal: mid-range where both limits are given, the cap where only a maximum is, balance takes the remainder. Exact specified ranges below.

ElementName Content %
Main elements8 elements
Ni NickelBal.
Cr Chromium24 – 26%
Fe Iron8 – 11%
Al Aluminium1.8 – 2.4%
C Carbon0.15 – 0.25%
Ti Titanium0.1 – 0.2%
Y Yttrium0.05 – 0.12%
Zr Zirconium0.01 – 0.1%
ElementName Content %
Minor & residual4 elements
Mn Manganese≤ 0.15%
Si Silicon≤ 0.5%
P Phosphorus≤ 0.02%
S Sulphur≤ 0.01%

Mechanical minima by form

Guaranteed values differ by form, size and delivery condition; quotations confirm the specification, form, size and condition.

FormCondition Rm MPaRp0.2 MPaA ≥ %Other requirements and notes
Bar and forgings
Bar and rodAnnealed after cold working or after hot working ≥ 680 (99 ksi) ≥ 270 (39 ksi) ≥ 30
Forgings, flanges, fittings and valve partsSolution annealed, max section ≤102 mm ≥ 680 (99 ksi) ≥ 270 (39 ksi) ≥ 30
Forgings, flanges, fittings and valve partsSolution annealed, max section >102–305 mm ≥ 580 (84 ksi) ≥ 270 (39 ksi) ≥ 15
Plate, sheet and strip
Hot-rolled plate and sheetAnnealed ≥ 680 (99 ksi) ≥ 270 (39 ksi) ≥ 30
Tube and pipe
Seamless pipe and tubeAnnealed after hot or cold working ≥ 680 (99 ksi) ≥ 270 (39 ksi) ≥ 30
Electric-fusion-welded pipeAnnealed (≥1150 °C) ≥ 680 (99 ksi) ≥ 270 (39 ksi) ≥ 30
Welded heat-exchanger and condenser tubeAnnealed (Class 1 or Class 2 — see note) ≥ 680 (99 ksi) ≥ 270 (39 ksi) ≥ 30 Every piece is leak- or electrically tested (hydrostatic, pneumatic, eddy current or ultrasonic).
Flattening and flange tests required.
Welded pipe (no filler metal)Automatic welded, cold worked after welding, final heat treated (Category 1 or 2) ≥ 680 (99 ksi) ≥ 270 (39 ksi) ≥ 30 Flattening test required.
Every piece is leak- or electrically tested (hydrostatic, pneumatic, eddy current or ultrasonic).
Fittings and flanges
Fittings (factory-made wrought butt-weld / socket)Heat treatment to be agreed between the parties — — — Recommended temperature; tolerance ±15 °C (±25 °F).
Tensile properties follow the starting material.
No tension test on the finished fitting unless agreed.
Heat treatment by agreement.
Several forms
Long products ≤160 mm and flat products ≤20 mm (EN 10302, 2.4633)+AT (solution annealed) ≥ 680 ≥ 270 ≥ 30 Flat products under 3 mm: A five points lower.

Hardness requirement

Required by the standard, conditionally

Form and thicknessHardness max
Sheet; strip >0.25–3.2 mm≤ 86 HRB
Strip 0.13–0.25 mm≤ 88 HRB

Likewise limited to cold-rolled deep-drawing and spinning-quality sheet and strip; ordinary plate, sheet and strip carry NO hardness requirement.

More detail 2

This is a hardness CEILING — deep-drawing material must be soft enough to form — the opposite in kind to the floor carried by age-hardened grades.

Under 1.3 mm the Rockwell B reading is affected by specimen thickness; use superficial Rockwell or Vickers instead.

Creep behaviour

⚠ Scope: these figures apply only to grade 2.4633 (+AT) in EN 10302:2008, as informative guidance; the product standard for this grade specifies no creep data. Use for shortlisting, not for acceptance or design.

Guidance values (MPa) — Mean values of a scatter band. They are neither an acceptance requirement nor a design allowable stress. Figures in parentheses are long-term extrapolations and less reliable than the tested range.

Temp °CCreep strength Rp1.0 (1% plastic strain)Rupture strength Ru
10 000 h100 000 h10 000 h100 000 h
650145115170130
7001027512090
75045266548
80020123525
8501482316
9009.45.61711.5
9506.53.8128.5
10004.32.79.36.4
11002.21.25.13
12001—31.4
1251020501002005001000650700750800850900950100011001200Stress MPa (log)Temperature °C10 000 h100 000 h125102050100200500100065075085095011001200Stress MPa (log)Temperature °C10 000 h100 000 h1251020501002005001000650700750800850900950100011001200Stress MPa (log)Temperature °C10 000 h100 000 h
Logarithmic stress axis. Colour encodes time (1 000 / 10 000 / 100 000 h); solid lines are rupture strength Ru and the dashed line of the same colour is Rp1.0 (1 % plastic elongation). Informative mean values, not acceptance values.

Thermal expansion and elastic modulus

Temperature rangeMean coefficient ×10⁻⁶/K
20–200 °C13.5
20–300 °C14
20–400 °C14.5
20–600 °C14.9
20–800 °C16.6
20–1000 °C17.5
051015202003004006008001000×10⁻⁶/KUpper end of interval °CMean expansion α051015202003004006008001000×10⁻⁶/KUpper end of interval °CMean expansion α051015202003004006008001000×10⁻⁶/KUpper end of interval °CMean expansion α
Each point is the mean from 20 °C to that temperature.

Elastic modulus vs temperature

Temp °CE GPa
20215
100209
200201
300197
400192
500189
600185
700169
800154
900137
1000118
1100102
501001502002502010020030040050060070080090010001100GPaTemperature °CE50100150200250202004006008001100GPaTemperature °CE501001502002502010020030040050060070080090010001100GPaTemperature °CE

Grain size

Required by the standard, conditionally

Form and thicknessASTM micrograin sizeMean grain section dia.
Sheet ≤1.3 mmNo. 4.5 or finer≤ 0.075 mm
Sheet >1.3–6.4 mmNo. 3.5 or finer≤ 0.110 mm
Strip 0.13–0.25 mmNo. 8 or finer≤ 0.022 mm
Strip >0.25–3.2 mmNo. 4.5 or finer≤ 0.075 mm

Applies only to COLD-ROLLED DEEP-DRAWING AND SPINNING QUALITY sheet and strip.

More detail 4

If the order does not call for that quality, this table does not apply.

For this product class, grain size and hardness REPLACE the ordinary tensile minima — the tensile minima do not apply to it, and vice versa.

The direction is "or finer" (a maximum grain diameter), the opposite of 800H's "No. 5 or coarser": deep drawing needs fine grain against orange peel, creep needs coarse grain.

Strip over 3.2 mm thick or over 305 mm wide is judged on the sheet rows; under 0.13 mm, testing is not recommended.

Where this grade is recommended

Matched in 5 service conditions; ranks and scores computed from the condition-scoring matrix.

Service conditionIndustry TemperatureRankScore
Muffles & radiant tubes Furnaces & Vacuum 850 – 1000 °C 1 / 9 94
Furnace internals & fixtures Furnaces & Vacuum 900 – 1150 °C 1 / 12 93
Quench & carburising fixtures Furnaces & Vacuum 950 – 1050 °C 1 / 8 90
Waste-to-energy boilers Environmental & FGD 850 – 1000 °C 2 / 8 87
Hydroprocessing & refinery hot service Oil & Gas 400 – 550 °C 4 / 8 86

Designations & equivalents

W.Nr. (Germany)2.4633
EN designationNiCr25FeAlY
Trade name(s)Inconel 602CA / Nicrofer 6025 HT
ASTM / AISIB163 / B166 / B167 / B168 / B366 / B462 / B516 / B517 / B546 / B564

Cross-references are common near-equivalents for search and shortlisting; substitution across standards requires clause-by-clause verification. All grades in one cross-reference table →

Applicable standards

11 specifications. Name the standard and its edition on the order.

Guaranteed values and required tests differ between specifications — see Mechanical minima by form for the figures per form.

Frequently asked questions

What is Alloy 602CA (Nicrofer 6025 HT) · UNS N06025?

Alloy 602CA (Nicrofer 6025 HT) · UNS N06025 — Ni superalloys. Oxidation-resistant to 1200 °C with carburisation resistance — furnace rolls, muffles, calciners

What is the maximum service temperature of N06025?

Typically about 1200 °C; the practical limit depends on media, stress and design life — acceptance per the governing standard.

What is the tensile strength of N06025?

The specified minimum tensile strength is 680 MPa for the main product form. Minima for other forms and sizes are listed under "Mechanical minima by form" on this page.

Which standards cover N06025?

ASTM B163, ASTM B166, ASTM B167, ASTM B168, ASTM B366 (fittings), ASTM B462, ASTM B516, ASTM B517, ASTM B546, ASTM B564 (forgings), EN 10302 (creep-resisting steels, nickel and cobalt alloys)

Where is N06025 typically used?

Muffles & radiant tubes (Furnaces & Vacuum); Furnace internals & fixtures (Furnaces & Vacuum); Quench & carburising fixtures (Furnaces & Vacuum); Waste-to-energy boilers (Environmental & FGD)

In which forms is N06025 available?

Tube, plate, strip, bar, forgings, wire and other forms — sizes and delivery condition confirmed per order, with EN 10204 3.1 / 3.2 certification.

Same series

Download PDF datasheet

This grade’s datasheet as an A4 PDF — for filing, printing or forwarding to colleagues.

Download PDF datasheet

Supply & enquiry

Tube & pipeφ1 – 219 × 0.25 – 25 mmPlate4.76 – 80 mmBarφ8 – 300 mmWire & filler metalsφ0.01 – 8 mm

For this grade we can supply, against your service conditions:

Or email us: info@kochlin.com