6 Moly - 6% Molybdenum Stainless Steels

UNS S31254 - UNS N08925 - UNS N08926

6 Moly Plate/Sheet
6 Moly Seamless & Welded Tube
6 Moly Seamless & Welded Pipe
6 Moly Round Bar
6 Moly Flanges F44
6 Moly Specialty Forgings

Trade Name	UNS	6Moly Industry Specifications	Chemical Composition	Min.Tensile (KSI)	Min.Yield (KSI)	Elongation %
254SMO® 6moly, 6MO	UNS S31254	ASME SA-182, SA-240, SA-249, SA-312, SA-358, SA-409, SA-479, SA-480, SA-813, SA-814, SA-988 ASTM A182 (F44), A193, A240, A249, A269, A270, A276, A312, A358, A403, A409, A473, A479, A480, A813, A814, A988 SAE J405	C 0.020 max Cr 19.50-20.5 Cu 0.50-1.00 Mn 1.00 max Mo 6.00-6.50 N 0.18-0.220 Ni 17.50-18.50 P 0.030 max S 0.010 max Si 0.80 max	94	44	35
N/A	UNS N08925	ASME SB-366,SB-625, SB-649, SB-673, SB-674 ASTM B366, B625, B649, B673, B674, B677	C 0.020 max Cr 19.0-21.0 Cu 0.80-1.50 Fe rem Mn 1.00 max Mo 6.00-7.00 N 0.10-0.20 Ni 24.0-26.0 P 0.045 max S 0.030 max Si 0.50 max	94	43	35
Alloy 25-6MO/ Alloy 926	UNS N08926	ASME SB-366, SB-625, SB-649, SB-673, SB-674, SB-677 ASTM A240, A249, A269, A270, A314, A358, A480, A688, A959, B366, B472, B625, B649, B673, B674, B677, B804 SAE J405	C 0.020 max Cr 19.0-21.0 Cu 0.50-1.5 Fe rem Mn 2.00 max Mo 6.00-7.00 N 0.15-0.25 Ni 24.0-26.0 P 0.030 max S 0.010 max Si 0.50 max	94	43	35

254SMO® is a registered trademark for Outokumpu

Moldydenum General Information

Molybdenum is a lustrous, silvery colored metal which has an abundance of 1.5 ppm in the earth's crust. In many instances, it shows a resemblance to tungsten with which it tends to be paired in the transition series in the periodic table, but their chemistries tend to show more distinct differences than might be expected.

Molybdenum has a high melting point and applications for the pure metal take advantage of this; for example, the pure material is used as resistance heating elements in furnaces, as filament supports in electric lamps, and as electrodes for mercury vapor lamps. Molybdenum is used as an alloying agent in certain grades of steel, Permalloys and Stellites (a series of alloys which contain varying proportions of Cr, Co, W and Mo, are very hard and are used in cutting tools and to protect surfaces subject to heavy wear).

Molybdenum Key Properties

Low co-efficient of thermal expansion (5.1x10-6 m/m/°C) which is about half that of most steels,
Good thermal conductivity,
Good electrical conductivity,
Good stiffness, greater than that of steel (Young’s Modulus 317MPa),
High melting point (2615°C),
Good hot strength,
Good strength and ductility at room temperature,
High density (10.2 g/cm3)

Molybdenum's ability to withstand high temperatures and maintain strength under these conditions are responsible for the fact that molybdenum finds most of its application at elevated temperatures. In fact, it can work at temperatures above 1100°C (in non-oxidizing conditions), which is higher than steels and nickel-based superalloys.

When exposed to temperatures in excess of 760°C in air rapid oxidation can result. Under these conditions, the oxide layer sublimes and the base metal is attacked. Thus, molybdenum performs best in inert of vacuum environments.

Molybdenum Applications

Seawater Handling Equipment
Pulp Mill Bleach Systems
Tall Oil Distillation Columns and Equipment
Chemical Processing Equipment
Food Processing Equipment
Desalination Equipment
Flue Gas Desulfurization Scrubbers
Oil and Gas Production Equipment