UNS N08367/AL-6XN/25-6HN Stainless Steel

UNS N08367 is a type of high Molybdenum containing super austenitic stainless steel that has nickel as the base metal. This alloy has nickel-chromium-iron as the primary constituents. By varying the other elements, it can be designed to resist attacks from specific chemical reagents. This alloy exhibits high strength even at high temperatures. 6% Mo, high Ni, and N alloyed austenitic grade with extremely high resistance to both uniform and localized corrosion. Commonly used in applications to withstand chlorinated sea water and also used in flue gas cleaning.

UNS N08367 Chemical Composition:

23.5-25.520-226.0- 7.00.03 Max0.18-0.252.00 Max1.00 Max0.040 Max0.030 Max0.75 MaxRem.

UNS N08367 Mechanical Properties:

Temp. °F (°C)Ultimate Tensile Strength, psi0.2% Yield Strength, psiElongation in 2”, percentCharpy V-Notch Toughness, ft-lb
-450 (-268)218,000142,00036353*
-320 (-196)196,000107,0004985
-200 (-129)100
70 (21)108,00053,00047140
200 (93)99,90049,40047
400 (204)903,00040,40046
600 (316)86,00036,30047
800 (427)87,00036,00048

UNS N08367 is also known as super-austenitic stainless steel. This alloy contains a higher content of Molybdenum and Nitrogen (so it is also called 6% Mo Super Austenitic Stainless Alloy, AL-6XN, NAS 254NM, INCOLOY alloy 25-6HN, F62). These additions enhance the thermal stability and corrosion resistance of the alloy. Among super austenitic stainless steels, UNS N08367 offers a higher degree of corrosion resistance and strength.

UNS N08367 Specifications:

Metal TypeUNS N08367
BarASTM B691 / ASME SB691
WireASTM B691 / ASME SB691
SheetASTM B688, A240 / ASME SB688, SA240
PlateASTM B688, A240 / ASME SB688, SA240
FittingASTM B366 / ASME SB366 / ASTM B462 /   ASME SB462
ForgingASTM B472 / ASTM B462 / ASME SB462


Machining of UNS N08367 should be done at a slightly lower speed when compared to 316 stainless steel, as it has high strength.


UNS N08367 can be welded by shielded metal arc welding, gas tungsten arc welding, submerged arc welding, plasma arc welding and gas metal arc welding. The filler metal and electrodes are usually made of INCONEL alloy.


UNS N08367 can be hot worked at temperature ranges of 982-1232°C (1800-2250°F).


UNS N08367 should be annealed at temperatures greater than 1121°C (2050°F).


In applications to withstand chlorinated sea water
Flue gas cleaning
Process equipment in chemical industry
Bleaching equipment in the pulp and paper industry
Seawater handling
Food and beverage
Heat exchangers