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Carbon		0.08 max
Chromium		17 - 19
Iron		Balance
Manganese		2 max
Nickel		9 - 13
Niobium		Min:5 x C
Phosphorus		0.045 max
Silicon		1 max
Sulphur		0.03 max

Principal Design Features		Similar to 321 stainless, 347 uses columbium as a stabilizing element to maximize its principal feature: resistance to intergranular corrosion. It can be used in applications requiring repeated heating in the range of 800 and 1650 F (427-899 C).

Applications		High temperature gaskets and expansion joints, rocket engine parts, aircraft collector rings and exhaust manifolds and chemical production equipment.

Machinability		Slightly tougher than 304 stainless, this material will produce the same tough stringy chips. The use of slow speeds and constant positive feeds will minimize this alloy's tendency to work harden.

Welding		347 may be welded by all commonly used fusion and resistance methods. Oxyacetylene welding is not recommended. When necessary, use AWS E/ER347 filler metal.

Hot Working		Working temperatures of 2100-2250 F (1149-1232 C) are recommended for forging, upsetting and other hot work processes. Do not work this alloy at temperatures below 1700 F ( 927 C). Material must be water quenched or fully annealed after working to reattain maximum corrosion resistance.

Cold Working		Although this material requires higher initial forces than 304 stainless, it is quite tough and ductile and can be readily stamped, blanked, spun and drawn.

Annealing		1850-2000 F (1010-1093 C), water quench. This procedure will result in maximum ductility. For maximum corrosion resistance, see the note on stabilizing anneal under corrosion.

Hardening		This alloy does not harden by heat treating. Elevated properties may only be obtained through cold reduction.

Physical Data : [top]

Density (lb / cu. in.)	0.29
Specific Gravity	8.03
Specific Heat (Btu/lb/Deg F - [32-212 Deg F])	0.12
Electrical Resistivity (microhm-cm (at 68 Deg F))	438
Melting Point (Deg F)	2600
Modulus of Elasticity Tension	28

MSO currently has no data available for this grade.