904L

904L is an austenitic alloy designed for a middle to high level of corrosion resistance. The alloy contains high levels of chromium and nickel with additions of molybdenum and copper to provide added corrosion resistance. The high nickel (25%) and molybdenum (4.5%) contents of 904L provide good resistance to chloride stress corrosion cracking, general and chloride pitting corrosion resistance above the levels of 316 and 317 stainless. The copper addition provides added resistance to hot phosphoric acid and dilute sulfuric acid.

Chemistry

 NiCrMoMnCuSiCSPFe
MIN 23 19 4.0 - 1.0 - - - - -
MAX 28 23 5.0 2.0 2.0 1.0 0.02 0.035 0.045 balance

Specifications

ASME SB-625ASME SB-649
ASME SB-673
ASME SB-674ASME SB-677UNS N08904

Inventory

904L Weld Wire

Common Trade Names

Alloy 904L, 904L Stainless

Features

Critical Crevice Corrosion Temperature*

Alloy 316 317 904L AL-6XN® 625
Temperature, °F 27 35 65 113 113

* ASTM procedure G-48, 10% ferric chloric solution

Applications

  • Tubesheets
  • Acid and fertilizer production
  • Utility scrubbers
  • Pickling equipment

Physical Properties

Density: 0.287 lb/in3
Electrical Resistivity:: 680 Ohm-circ mil/ft

Temperature, °F 70 212 392 750 1475
Coefficient* of Thermal Expansion, in/in°F x 10-6 - 8.5 - 9.2 10.1
Thermal Conductivity
Btu • ft/ft2 • hr • °F
6.6 6.8 8.8 - -

* 70°F to indicated temperature.

Mechanical Properties

Representative Tensile Properties

Ultimate Tensile Strength, ksi 71
0.2% Yield Strength, ksi 31
Elongation, % 35
Hardness, Rockwell B 70 - 90