Equivalent designations

UNS S31254

DIN W. Nr. 1.4547

Form	ASTM
Rod, bar and shape	A 276, A 484
Plate, sheet and strip	A 240, A 480
Seamless and welded pipe	A 312, A 999
Welded pipe	A 814, A 999
Seamless and welded tubing	A 269, A 1016
Fitting	A 403, A 960
Forged or rolled pipe flange and forged fitting	A 182, A 961
Forging	A 473, A 484

Chemical composition

%	Fe	Cr	Ni	Mo	C	Mn	Si	P	S	Cu	N
min	balance	19.5	17.5	6.0						0.50	0.18
max		20.5	18.5	6.5	0.020	1.00	0.80	0.030	0.010	1.00	0.22

Physical properties

Density	7.94 g/cm3
Melting range	1320-1390℃

Features: 254 SMO is a high performance austenitic stainless steel. Its high alloying elements content imparts excellent resistance to uniform, pitting and crevice corrosion, and stress corrosion cracking. It was originally developed to withstand the corrosion of acids, especially in the presence of halide ions, such as hydrochloric acid, hydrofluoric acid, phosphoric acid, and sulphuric acid contaminated with chlorides. In certain environments it is an alternative to more expensive nickel alloys and titanium alloys.

Applications: Chemical processing equipment, pulp and paper industry bleaching equipment, desalination plant seawater piping, food and beverage industry, pharmaceuticals, and hydrometallurgy.