Stainless Steel Plate

A Corrosion Resistant Austenitic Stainless Steel with a High Molybdenum and Nitrogen Content Developed for Use in Chloride Containing Environments.

Available thicknesses for Alloy 317LMN:

3/16" 5/16" 3/8" 1/2" 5/8" 3/4"
4.8mm 7.9mm 9.5mm 12.7mm 15.9mm 19mm
 

Alloy 317LMN (UNS S31726) is an austenitic chromium-nickel-molybdenum stainless steel with corrosion resistance superior to 316L and 317L. The higher molybdenum content, combined with an addition of nitrogen, provides the alloy with its enhanced corrosion resistance, especially in acidic chloride containing service. The combination of molybdenum and nitrogen also improves the alloys resistance to pitting and crevice corrosion.

The nitrogen content of Alloy 317LMN acts as a strengthening agent giving it a higher yield strength than 317L .Alloy 317LMN is also a low carbon grade which enables it to be used in the as-welded condition free from chromium carbide precipitation on the grain boundaries.

Alloy 317LMN is non-magnetic in the annealed condition. It cannot be hardened by heat treatment, only by cold working. The alloy can be easily welded and processed by standard shop fabrication practices.

Applications

  • Air Pollution Control—flue gas desulfurization systems, stack liners, absorbers, ducts, dampers, and fans
  • Chemical and Petrochemical Processing
  • Food and Beverage Processing
  • Pharmaceutical Equipment

Standards

ASTM........A 240
ASME........SA 240

Corrosion Resistance

The higher molybdenum and nitrogen content of Alloy 317LMN assures superior general and localized corrosion resistance in most media when compared with 304/304L, 316/316L and even 317L stainless steels. Environments that don’t attack 304/304L stainless steel will normally not corrode 317LMN. One exception, however, are strongly oxidizing acids such as nitric acid. Alloys that contain molybdenum generally do not perform as well in these environments.

Alloy 317LMN has excellent corrosion resistance in a wide range of chemicals. It resists attack in sulfuric acid, hydrochloric acid, acidic chlorine and phosphoric acid. It is used in handling hot organic and fatty acids often present in food and pharmaceutical processing applications.

Because of its low carbon content, Alloy 317LMN should be utilized when it will be exposed to temperatures in the chromium carbide precipitation range of 800-1500°F (427-816°C). The higher nitrogen content of 317LMN further retards the precipitation of sigma phase as well as carbides.

In general, austenitic stainless steels are subject to chloride stress corrosion cracking in halide service. Although 317LMN is somewhat more resistant to stress corrosion cracking than 304/304L stainless steels, because of its higher molybdenum content, it is still susceptible.

The higher chromium, molybdenum and nitrogen content of 317LMN enhance its ability to resist pitting and crevice corrosion in the presence of chlorides and other halides. The Pitting Resistance Equivalent including Nitrogen number (PREN) is a relative measure of pitting resistance. The following chart offers a comparison Alloy 317LMN and other austenitic stainless steels.

ALLOY PRE ALLOY PRE
316 25 317LMN 38
317L 30 SSC-6MO 48
317LM 34 625 52
904L 36 276 69

PRE = Cr + 3.3Mo + 30N

317 corrosion resistance

Chemical Analysis

Weight % (all values are maximum unless a range is otherwise indicated)

Chromium 17.0 min.-20.0 max. Manganese 2.00
Nickel 13.5 min.-17.5 max. Phosphorus 0.045
Molybdenum 4.0 min.-5.0 max. Sulfur 0.030
Nitrogen 0.10 min.-0.20 max. Silicon 0.75
Carbon 0.030 Iron Balance

Physical Properties

Density

0.290 lbs/in3
8.0 g/cm3

Specific Heat

0.12 BTU/lb-°F (32 – 212°F)
502 J/kg-°K (0 – 100°C)

Modulus of Elasticity

29.0 x 106 psi
200 GPa

 

Thermal Conductivity 212°F (100°C)

8.7 BTU/hr/ft2/ft/°F
1.26 W/m-°K

Melting Range

2540 – 2630°F
1393 – 1443°C

Electrical Resistivity

33.5 Microhm-in at 68°C
85.1 Microhm-cm at 20°C
Mean Coefficient of Thermal Expansion
Temperature Range  
°F °C in/in °F cm/cm °C
68-212 20-100 8.9 x 10-6 16.03 x 10-6

 

Mechanical Properties

Typical Values at 68°F (20°C)

Yield Strength
0.2% Offset
Ultimate Tensile
Strength
Elongation
in 2 in.
Hardness Reduction
in Area
psi (min.) (MPa) psi (min.) (MPa) % (min.) (max.) %
35,000 205 80,000 550 40 96 Rockwell B 69

Fabrication Data

 

Alloy 317LMN can be easily welded and processed by standard shop fabrication practices.

Cold Forming

The cold formability of Alloy 303 is adversely impacted by the high sulfur content. The alloy may be bent with a generous bend radius, however, when cold forming is required, 304 should be utilized.

Hot Forming

The alloy is quite ductile and forms easily. The addition of molybdenum and nitrogen implies more powerful processing equipment may be necessary when compared with the standard 304/304L grades.

Machining

The cold work hardening rate of Alloy 317LMN makes it less machinable than 410 stainless steel. The table below provides relevant machining data.

Operation Tool Lubrication CONDITIONS
      Depth-mm Depth-in Feed-mm/t Feed-in/t Speed-m/min Speed-ft/min
Turning High Speed Steel Cutting Oil 6 .23 0.5 .019 11-16 36-52
Turning High Speed Steel Cutting Oil 3 .11 0.4 .016 18-23 59-75
Turning High Speed Steel Cutting Oil 1 .04 0.2 .008 25-30 82-98
Turning Carbide Dry or Cutting Oil 6 .23 0.5 .019 70-80 230-262
Turning Carbide Dry or Cutting Oil 3 .11 0.4 .016 85-95 279-313
Turning Carbide Dry or Cutting Oil 1 .04 0.2 .008 100-110 328-361
      Depth of cut-mm Depth of cut-in Feed-mm/t Feed-in/t Speed-m/min Speed-ft/min
Cutting High Speed Steel Cutting Oil 1.5 .06 0.03-0.05 .0012-.0020 16-21 52-69
Cutting High Speed Steel Cutting Oil 3 .11 0.04-0.06 .0016-.0024 17-22 56-72
Cutting High Speed Steel Cutting Oil 6 .23 0.05-0.07 .0020-.0027 18-23 59-75
      Drill ø mm Drill ø in Feed-mm/t Feed-in/t Speed-m/min Speed-ft/min
Drilling High Speed Steel Cutting Oil 1.5 .06 0.02-0.03 .0007-.0012 10-14 33-46
Drilling High Speed Steel Cutting Oil 3 .11 0.05-0.06 .0020-.0024 12-16 39-52
Drilling High Speed Steel Cutting Oil 6 .23 0.08-0.09 .0031-.0035 12-16 39-52
Drilling High Speed Steel Cutting Oil 12 .48 0.09-0.10 .0035-.0039 12-16 39-52
          Feed-mm/t Feed-in/t Speed-m/min Speed-ft/min
Milling Profiling High Speed Steel Cutting Oil     0.05-0.10 .002-.004 10-20 33-66

Welding

Alloy 317LMN can be readily welded by most standard processes including TIG/GTAW, MIG/GMAW, MMAW and SAW. A post weld heat treatment is not necessary.

NOTE: The information and data in this product data sheet are accurate to the best of our knowledge and belief, but are intended for informational purposes only, and may be revised at any time without notice. Applications suggested for the materials are described only to help readers make their own evaluations and decisions, and are neither guarantees nor to be construed as express or implied warranties of suitability for these or other applications.

Associations and Accreditations

ASME
Metals Service Center Institute Member 2016
NIAC
SSINA
Quality System Certificate
Pennsylvania Prosperity Project
Proud Member of the National Association of Manufacturers