321 stainless steel tubing

321 stainless steel tubing



Product Description

321 Stainless Steel Tubing

321 Stainless Steel Tubing

Grades 321 and 347 are the basic austenitic 18/8 steel (Grade 304) stabilised by Titanium (321) or Niobium (347) additions. These grades are used because they are not sensitive to intergranular corrosion after heating within the carbide precipitation range of 425-850°C.

 

Grade 321 stainless steel tubing is the grade of choice for applications in the temperature range of up to about 900°C, combining high strength, resistance to scaling and phase stability with resistance to subsequent aqueous corrosion.Grade 321H is a modification of 321 with a higher carbon content, to provide improved high temperature strength.

 

 Applications of 321 stainless steel tubing:

Typical compositional ranges for grade 321 stainless steel tubing are given in table 1.
Table 1. Composition ranges for 321 grade stainless steel

 Grade  C  Mn  Si  P  S  Cr  Mo  Ni  N  Other
 321  min.
max
 –
0.08
 2.00  0.75  0.045  0.030  17.0
19.0
 -  9.0
12.0
 0.10  Ti=5(C+N)
0.70
 321H  min.
max
 0.04
0.10
 2.00 0.75  0.045  0.030  17.0
19.0
 -  9.0
12.0
 -  Ti=4(C+N)
0.70
 347  min.
max
 0.08  2.00  0.75  0.045  0.030  17.0
19.0
 -  9.0
12.0
 - Nb=10(C+N)
1.0

Typical mechanical properties for grade 321 stainless steel tubing are given in table 2.
Table 2. Mechanical properties of 321 grade stainless steel

 Grade  Tensile Strength (MPa) min  Yield Strength 0.2% Proof (MPa) min  Elongation (% in 50mm) min  Hardness
 Rockwell B (HR B) max  Brinell (HB) max
 321  515  205  40  95  217
 321H  515  205  40  95  217
 347  515  205  40  92  201