Type 347 / 347H stainless steel is an austenitic grade of chromium
steel, which contains columbium as a stabilizing element. Tantalum
can also be added for achieving stabilization. This eliminates the
carbide precipitation, as well as intergranular corrosion in steel
pipes. Type 347 / 347H stainless steel Coiloffer higher creep and
stress rupture properties than grade 304 and 304L. This makes them
suitable for exposures to sensitization and intergranular
corrosion. Moreover, the inclusion of columbium allows 347 Coil to
have excellent corrosion resistance, even superior to that of 321
stainless steel coils. However, 347H steel is the higher carbon composition substitute of stainless steel coil grade 347.
Therefore, 347H steel coils offer improved high temperature and
creep properties.
With wide experience and expertise, Bozhong Group is one of the
leading 347/347h stainless steel coil/wire/strip manufacturers and
suppliers. We have hundreds of high-qualified workers at your
service. Please rest assured to get the competitive price 347/347h
stainless steel coil/wire/strip for sale with us.
Our range of SS 347 coil is extremely economical, and thus making
our products highly valuable among our clients. Most sizes of SS
347 coil can be cut to exact sizes. Non standard sizes of SS 347
coil can be made to order. SS 347H coil are available in diverse
sizes, grades and shapes, and are quality passed and tested as per
international standards. Bozhong coils as well fabricate and design
these SS 347H coils in different specifications and designs as per
requirements of our customers.
Standard:
| STANDARD | UNS | WERKSTOFF NR. |
| SS 347 | S34700 | 1.4550 |
| SS 347H | S34709 | 1.4961/1.4912 |
Chemical Properties:
| C | Cr | Mn | Ni | P | S | Si | Cb/Ta |
| 347 | 0.08 max | min: 17.0
max: 20.0 | 2.0 max | min: 9.0
max: 13.0 | 0.04 max | 0.30
max | 0.75
max | min:10x C
max: 1.0 |
| 347H | min: 0.04
max: 0.10 | min: 17.0
max: 20.0 | 2.0 max | min: 9.0
max: 13.0 | 0.03 max | 0.30
max | 0.75
max | min:10x C
max: 1.0 |
Mechanical Properties:
| Grade | Tensile Strength ksi (MPa) min | Yield Strength 0.2% ksi offset ksi (MPa) min | Elongation (% in 50mm) min | Hardness (Brinell) MAX | Hardness (Rockwell B) MAX |
| 347/347H | 75
(515) | 30
(205) | 40 | 201 | 95 |
Physical Properties:
Density
lbm/in3 | Coefficient of
Thermal Expansion (min/in)-°F | Thermal Conductivity BTU/hr-ft-°F | Specific Heat BTU/lbm -°F | Modules of Elasticity (annealed)2-psi |
| at 68 °F | at 68 – 212°F | at 68 – 1832°F | 68-932°F | at 32 – 212°F | in tension (E) |
| 0.288 | 9.2 | 11.4 | 14.7 | 0.12 | 28 x 106 |
Corrosion Resistance:
1, Offers similar resistance to general, overall corrosion as Alloy
304
2, Used for applications where alloys such as Alloy 304 are
vulnerable to intergranualr corrosion
3, Generally used for heavy welded equipment which cannot be
annealed and for equipment which is operated between 800 to 150°F
(427 TO 816°C)
4, Alloy 347 is preferred over Alloy 321 for aqueous and other low
temperature environments
5, Primarily used in high temperature environments where resistance
to sensitization is necessary, in turn preventing intergranualr
corrosion at lower levels
6, Susceptible to stress corrosion cracking
7, Exhibits oxidation resistance similar to all other 18-8
austenitic stainless steels
Weldability
1, Austenitic stainless steels are considered to be the most
weldable out of all high alloy steels
2, Can be welded by all fusion and resistance welding processes
Heat Treatment
1, Annealing temperature range is 1800 to 2000°F
2, May be stress relief annealed within the carbide precipitation
range of 800 to 1500°F without any danger of subsequent
intergranualr corrosion
3, Cannot be hardened by heat treatment
