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Nitronic 60 Chemical Composition (UNS S21800 Element Ranges)

Nitronic 60 chemical composition per UNS S21800 element ranges
Nitronic 60 chemical composition per UNS S21800 element ranges

Nitronic 60 chemical composition per UNS S21800 specifies the element-range envelope that defines the alloy. 17 percent chromium, 8 percent manganese, 8.5 percent nickel, 4 percent silicon, and 0.13 percent nitrogen are the typical values that produce the anti-galling, high-yield, austenitic-stable behavior that distinguishes Nitronic 60 from 304 / 316L. This page covers the full element envelope, mill heat analysis, residual element limits, and certification requirements.

TorqBolt stocks Nitronic 60 (UNS S21800) at our Mumbai head office and Rajkot production plant. Each consignment ships with EN 10204 3.1 mill test certification by default and 3.2 dual-witnessed inspection (Lloyds, TUV, DNV, BV) on request. Contact info@torqbolt.com or +91-22-66157017 for sized stock and lead time.

Element Range Analysis

The chemistry envelope is specified in ASTM A276 / A479 with mill heat analysis verifying compliance per element. Mill QA-QC reports values to four-decimal precision for C, P, S, N (low-percent elements) and two-decimal precision for major elements (Cr, Mn, Ni, Si, Fe).

Residual elements (Cu, Mo, Co, Cb, Al, Ti, V, B) are typically below 0.50 percent each and not specified in the UNS S21800 standard, but mill heat analysis reports them anyway. Customer specifications for aerospace and nuclear service may add explicit residual limits.

The Mn-Si-N combination is the active anti-galling chemistry. Removing or reducing any one of these elements toward a 300-series-equivalent composition collapses the anti-galling property. Substitution mills must hit the full Mn-Si-N envelope.

For element compliance details and certification samples see the UNS S21800 designation matrix and the ASTM A276 standard summary.

Nitronic 60 Chemistry (UNS S21800 Element Ranges)

All Nitronic 60 product forms share the UNS S21800 chemistry envelope per ASTM A276 / A479 specification:

ElementMin %Max %Typical %
Carbon (C)-0.100.05
Manganese (Mn)7.09.08.0
Phosphorus (P)-0.0600.025
Sulfur (S)-0.0300.010
Silicon (Si)3.54.54.0
Chromium (Cr)16.018.017.0
Nickel (Ni)8.09.08.5
Nitrogen (N)0.080.180.13
Iron (Fe)Balance

The Mn-Si-N combination is the active anti-galling chemistry. See detailed chemical composition for residuals and trace-element envelope.

Nitronic 60 Mechanical Properties

Solution-annealed and cold-worked condition mechanical properties per ASTM A276, ASTM A479, and AMS 5848:

PropertySolution AnnealedCold-Worked HS
Yield Strength (0.2% offset)380 MPa (55 ksi) min620 MPa (90 ksi) min
Tensile Strength655 MPa (95 ksi) min860 MPa (125 ksi) min
Elongation (in 4D)35% min15% min
Hardness95 HRB max (~210 HB)30 HRC max
Impact (Charpy V at -196 C)54 J min-
Density7.62 g/cc7.62 g/cc

See yield strength, tensile properties, hardness, and density for cold-work curves and temperature-derated allowables.

Galling Resistance vs 304 / 316L (ASTM G98)

The primary reason buyers specify Nitronic 60. Threshold galling stress per ASTM G98 button-on-block self-mated test:

Self-Mated PairThreshold Galling Stress (ASTM G98)Relative
304 / 30435 to 70 MPa1x baseline
316L / 316L35 to 70 MPa1x baseline
Nitronic 50 / Nitronic 50175 to 275 MPa3-5x
Nitronic 60 / Nitronic 60350 to 500 MPa5-10x

Where threshold stress exceeds the applied contact stress, galling does not initiate. For 316L bolted joints at typical preload, contact stress routinely exceeds 70 MPa, so galling DOES initiate. Nitronic 60 raises the threshold above typical preload contact stress, so galling does NOT initiate. See galling resistance and galling failure mechanism for the full mechanism.

Heat Treatment

Nitronic 60 is austenitic and NOT precipitation-hardenable. Standard heat treatment cycle is solution anneal only:

  • Solution Anneal, 1010 to 1120 C (1850 to 2050 F) for 30 to 60 minutes, water quench.
  • Stress Relief (optional), 450 to 480 C (840 to 900 F) for 2 to 4 hours, air cool.
  • Avoid 540 to 815 C range during cooldown, risk of sigma-phase precipitation. Quench fast through this range.
  • Cold work is the only strengthening mechanism, HS condition reaches ~30 HRC with retained ductility.

Welding

Nitronic 60 is weldable by GTAW, GMAW, SMAW, and PAW processes. Nitronic 60 welding procedure uses matching filler ER218 per AMS 5847 (UNS S21880, cast variant). Key parameters:

  • Matching filler ER218 preserves anti-galling chemistry in the weld bead.
  • Preheat NOT required (austenitic).
  • Interpass temperature below 150 C (300 F) to avoid sigma precipitation.
  • Post-weld solution anneal for critical service; as-welded adequate for general.
  • ER309L is a non-matching emergency substitute; expect reduced galling resistance in the weld bead.

Material Selection: Nitronic 60 vs 316L vs 304 vs Stellite 6

Property304316LNitronic 50Nitronic 60Stellite 6
UNSS30400S31603S20910S21800R30006
Yield (MPa)205170380380620
Galling (G98)PoorPoorModerateExcellentOutstanding
PREN19243618N/A
Cost (relative)1x1.2x2.5x2x15-25x
Cryogenic to -196 CYesYesYesYesYes

Detailed pair-wise comparisons: Nitronic 60 vs 316L, Nitronic 60 vs 304, Nitronic 60 vs Nitronic 50, Nitronic 60 vs 17-4 PH, Nitronic 60 vs Stellite 6, Nitronic 60 vs Inconel 718, and Nitronic 60 vs duplex 2205.

Nitronic 60 Applications by Industry

Related Nitronic 60 Forms and Fasteners

Request a Quote

For Nitronic 60 stock with verified chemical composition certification, Contact the TorqBolt QA-QC team at info@torqbolt.com or +91-22-66157017. We respond within 24 hours with sized stock availability, lead time, and EN 10204 3.1 / 3.2 MTC documentation samples.

Frequently Asked Questions

What is the Nitronic 60 chemical composition?

See the values in the table above. The chemical composition of Nitronic 60 is one of the property metrics that distinguishes it from 304 / 316L.

Why does Nitronic 60 chemical composition matter?

For design engineering decisions, chemical composition directly affects component sizing, service envelope, and material substitution choices.

How is chemical composition verified?

Standard test methods per ASTM. Mill test certificate (EN 10204 3.1) reports the measured value for the heat lot.

What is the temperature dependence?

Nitronic 60 retains useful properties from -196 C cryogenic to ~815 C upper service temperature. Above 540 C check sigma-phase precipitation envelope.