The composition of 439 stainless steel has been balanced to provide a completely ferritic structure
at all temperatures, to avoid the loss of ductility after welding and to provide resistance to intergranular corrosion.
Similar ferritic stainless steels such as 430 and 434 alloys are susceptible to brittle martensite formation after welding
and to intergranular corrosion sensitivity in the as-welded condition.
439 stainless does not require annealing after welding to restore ductility or to provide intergranular corrosion resistance.
Excellent resistance to stress corrosion cracking, good weldability, high thermal conductivity and low thermal expansion
characteristics make 439 stainless steel an ideal consideration
for many applications. For shell and tube heat exchangers where carbon steel shells are used with 439 tubes,
the close match of thermal expansion coefficients may possibly eliminate the need for an expansion joint in the
heat exchanger. 439 stainless has a low cobalt content, compared to Type 304, making it an attractive consideration
for nuclear applications. When aplication temperatures are too high
for 409 stainless, 439 stainless provides good oxidation and corrosion resistance for many automotive exhaust
system components and residential furnace primary heat exchangers.
Chemical composition of stainless 439
| Grade |
C |
Si |
Mn |
P |
S |
Cr |
Ti |
| 439 |
0.070 |
1.00 |
1.00 |
0.040 |
0.030 |
17.00~19.00 |
≥ 0.20+4(C+N)min - 0.50 max |
Typical annealed state mechanical properties
| Tensile strength |
Yiled strength |
Elongation |
Hardness |
| 455 |
290 |
34 |
78 HB |
Product forms
Hot-rolled wide strip, cold-rolled wide strip, slit strip, cut sheets, precision strip
We stock 439 hot and cold rolled stainless steel sheet, plate, strip and coil.
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