Stainless Steel AL-6XN®

  • UNS N08367
  • ASTM B 688, B 691, B 675 / 676
  • B 462, B 366, B 564, B 804

Forms of AL-6XN Available at Mega Mex

  • Sheet
  • Plate
  • Bar
  • Pipe & Tube (welded & seamless)
  • Fittings (i.e. flanges, slip-ons, blinds, weld-necks, lapjoints, long welding necks, socket welds, elbows, tees, stub-ends, returns, caps, crosses, reducers, and pipe nipples)
Forms of 330 Stainless Steel available at Mega Mex​

AL6XN Overview

AL6XN is a superaustenitic stainless steel with outstanding resistance to chloride pitting, crevice corrosion and stress corrosion cracking. AL6XN is a 6 moly alloy that was developed for and is used in highly aggressive environments.  It has high nickel (24%), molybdenum (6.3%), nitrogen and chromium contents that give it excellent resistance to chloride stress corrosion cracking, chloride pitting, and exceptional general corrosion resistance. AL6XN is primarily used for its improved pitting and crevice corrosion resistance in chlorides. It is a formable and weldable stainless steel.

Because of its nitrogen content, AL6XN has greater tensile strength than common austentitic stainlesses, while retaining high ductility and impact strength.

Corrosion Resistance

Chromium, molybdenum, nickel and nitrogen all contribute to overall resistance to corrosion by various media. Chromium is the principal agent for conferring corrosion resistance in neutral or oxidizing environments. Chromium, molybdenum and nitrogen increase resistance to pitting corrosion. Nickel imparts the austenitic structure. Nickel and molybdenum both provide increased resistance to chloride stress corrosion cracking in reducing environments.

What are the characteristics of AL-6XN?

  • Excellent resistance to pitting and crevice corrosion in chloride solutions
  • Practical immunity to stress corrosion in NaCl environments
  • High Strength and toughness

Chemical Composition, %

Ni Cr Mo C N Mn Si P S Cu Fe
23.5-25.5
20.00-22.00
6.00-7.00
0.03 Max
0.18-0.25
2.0 Max
1.00 Max
.040 Max
0.03 Max
0.75 Max
Remainder

In what applications is AL-6XN used?

  • Reverse osmosis desalination equipment and pumps
  • FGD Scrubbers
  • Chemical process tanks and pipelines
  • Seawater heat exchangers
  • Tall oil distillation columns and packing
  • Offshore oil and gas production equipment
  • Pulp bleaching plant washers, vats, press rolls and pipelines

ASTM Specifications

Pipe Welded Tube Welded Sheet/Plate Bar Flanges & Fittings
B675, A312
B676, A249
B688, A240
B691, A479
B462, A182

Mechanical Properties

Representative Tensile and Impact Properties, Plate

Temp. °F (°C) Ult. Tensile Strength, psi .2% Yield Strength, psi Elongation in 2”, percent Charpy V-Notch Toughness, ft-lb
-450 (-268)
218,000
142,000
36
353*
-320 (-196)
196,000
107,000
49
85
-200 (-129)
-
-
-
100
70 (21)
108,000
53,000
47
140
200 (93)
99,900
49,400
47
-
400 (204)
903,000
40,400
46
-
600 (316)
86,000
36,300
47
-
800 (427)
87,000
36,000
48
-

*For welded pipe and tube, a joint efficiency factor of .85 must be applied.

* AL-6XN® is a registered trademark of the Allegheny Ludlum Corporation