Heat-resistant austenitic stainless steel with excellent mechanical properties and excellent oxidation resistance at high temperature.

[Chemical Composition 23Cr-11Ni-N-REM-B]
[Corresponding Standard ASTM UNS S31060 / ASME SA-240 (SECTION Ⅰ&Ⅷ Div.1)]
Japan Society of Spring Engineers Excellent paper award(2016)
Sokeizai Industry Technology Award(2010)

Chemical Composition (mass%)

Typical example
Material C Si Mn Cr Ni N REM* B
NSSMC-NAR-AH-4 0.06 0.3 0.8 23.0 11.7 0.21 0.03 addition

* Addition of REM; La+Ce

Mechanical Properties

Typical example
Material Finish 0.2%-Yield Strength
Tensile Strength
Hardness [HV]
NSSMC-NAR-AH-4 Annealed 440 767 42 201
3/4H 1305 1391 4 418



  • Higher oxidation resistance, tensile strength and creep strength at high temperature than SUS310S.
  • Superior phase stability after long-term exposure to high temperature without a drastic drop in toughness such as SUS310S.
  • Lower sensitivity of weld hot cracking than SUS310S.
  • Reasonably designed chemical composition compared with SUS310S or Ni Alloy.

High-temperature mechanical strength

Continious oxidation test result (200 hr)

Creep rupture properties

cold rolled sheets

  • It can be used to raise the strength by cold rolling between the cold sake more as the high-temperature spring material.
  • At higher temperature than 500 ℃, the strength at elevated temperature of NSSMC-NAR-AH-4 is superior to that of SUS301EH.

High temperature vickers' hardness of cold rolled sheets.

Product Form

Strip(Please ask NSSC in the case of the plate)

Examples of use

Vehicle exhaust part, Exhaust gasket, Heat exchanger, Heater part.

Available Size



List of Stainless Steel products for Springs

List of products Heat-resistant and Corrosion-resistant Stainless Steel

Contact Information

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