Stainless Steel Plate

Sandmeyer Steel Company stocks Alloy 321 stainless steel plate in thicknesses from 3/16" through 4". A high carbon version, Alloy 321H (UNS S32109) stainless steel plate, can also be ordered in the same thickness range.

Available thicknesses for Alloy 321/321H:

3/16" 1/4" 5/16" 3/8" 1/2" 5/8" 3/4" 7/8" 1" 1 1/8"
4.8mm 6.3mm 7.9mm 9.5mm 12.7mm 15.9mm 19mm 22.2mm 25.4mm 28.6mm
 
1 1/4" 1 1/2" 1 3/4" 2" 2 1/4" 2 1/2" 2 3/4" 3" 3 1/2" 4"
31.8mm 38.1mm 44.5mm 50.8mm 57.2mm 63.5mm 69.9mm 76.2mm 88.9mm 101.6mm

Alloy 321 (UNS S32100) is stabilized stainless steel plate which offers as its main advantage an excellent resistance to intergranular corrosion following exposure to temperatures in the chromium carbide precipitation range from 800 to 1500°F (427 to 816°C). Alloy 321 stainless steel plate is stabilized against chromium carbide formation by the addition of titanium.

Alloy 321 stainless steel plate is also advantageous for high temperature service because of its good mechanical properties. Alloy 321 stainless steel plate offers higher creep and stress rupture properties than Alloy 304 and, particularly, Alloy 304L, which might also be considered for exposures where sensitization and intergranular corrosion are concerns.

General Properties

Alloy 321 (UNS S32100) is titanium stabilized austenitic stainless steel plate with good general corrosion resistance. It has excellent resistance to intergranular corrosion after exposure to temperatures in the chromium carbide precipitation range of 800 - 1500°F (427 - 816°C). The alloy resists oxidation to 1500°F (816°C) and has higher creep and stress rupture properties than alloys 304 and 304L. It also possesses good low temperature toughness.

Alloy 321H (UNS S 32109) stainless steel plate is the higher carbon (0.04 - 0.10) version of the alloy. It was developed for enhanced creep resistance and for higher strength at temperatures above 1000oF (537°C). In most instances, the carbon content of the plate enables dual certification.

Alloy 321 stainless steel plate cannot be hardened by heat treatment, only by cold working. It can be easily welded and processed by standard shop fabrication practices.


Corrosion Resistance

Alloy 321 stainless steel plate exhibits good general corrosion resistance that is comparable to 304. It was developed for use in the chromium carbide precipitation range of 1800 – 1500°F (427 – 816°C) where un-stabilized alloys such as 304 are subject to intergranular attack.

The alloy can be used in most diluted organic acids at moderate temperatures and in pure phosphoric acid at lower temperatures and up to 10% diluted solutions at elevated temperatures. Alloy 321 resists polythionic acid stress corrosion cracking in hydrocarbon service. It can also be utilized in chloride or fluoride free caustic solutions at moderate temperatures.

Alloy 321 stainless steel plate does not perform well in chloride solutions, even in small concentrations, or in sulfuric acid service.

Chemical Analysis

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

Element 321 321H
Chromium 17.00 min.-19.00 max. 17.00 min.-19.00 max.
Nickel 9.00 min.-12.00 max. 9.00 min.-12.00 max.
Carbon 0.08 0.04 min.-0.14 max.
Manganese 2.00 2.00
Phosphorus 0.045 0.045
Sulfur 0.03 0.03
Silicon 0.75 0.75
Titanium 5 x (C + N) min.-0.70 max. 4 x (C + N) min.-0.70 max.
Nitrogen 0.10 0.10
Iron Balance Balance

Physical Properties

Density

0.286 lbs/in3
7.920 g/cm3

Specific Heat

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

Modulus of Elasticity

28.0 x 106 psi
193 GPa

 

Thermal Conductivity 200°F (100°C)

9.3 BTU/hr/ft2/ft/°F
16.0 W/m-°K

Melting Range

2550 – 2635°F
1398 – 1446°C

Electrical Resistivity

72 Microhm-cm at 20°F
Mean Coefficient of Thermal Expansion
Temperature Range  
°F °C in/in °F cm/cm °C
68-212 20-100 9.2 x 10-6 16.0 x 10-6
68-1112 20-600 10.5 x 10-6 18.9 x 10-6
68-1832 20-1000 11.4 x 10-6 20.5 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
psi (min.) (MPa) psi (min.) (MPa) % (min.) (max.)
30,000 205 75,000 515 40 217 Brinell

Fabrication Data

 

Alloy 321 stainless steel plate can be easily welded and processed by standard shop fabrication practices.

Cold Forming

The alloy is quite ductile and forms easily.

Hot Forming

The high sulfur content of Alloy 303 also has a detrimental impact on hot workability. If hot forming is required, once again, 304 should be considered as an alternate selection.

Machining

The cold work hardening rate of 321 stainless steel plate makes it less machinable than 410 stainless steel, but similar to 304. 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 12-16 39-52
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 23-28 75-92
Turning Carbide Dry or Cutting Oil 6 .23 0.5 .019 67-76 220-249
Turning Carbide Dry or Cutting Oil 3 .11 0.4 .016 81-90 226-295
Turning Carbide Dry or Cutting Oil 1 .04 0.2 .008 99-108 325-354
      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 9-13 29-42
Drilling High Speed Steel Cutting Oil 3 .11 0.05-0.06 .0020-.0024 11-15 36-49
Drilling High Speed Steel Cutting Oil 6 .23 0.08-0.09 .0031-.0035 11-15 36-49
Drilling High Speed Steel Cutting Oil 12 .48 0.09-0.10 .0035-.0039 11-15 36-49
          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 11-21 36-69

Welding

Alloy 321 stainless steel plate can be readily welded by most standard processes. 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.

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