Stainless steel 347 is variation of the fundamental austenitic 18/8 Grade 304 with included Columbium – the presentation of Columbium balances out the steel and wipes out carbide precipitation which accordingly causes intergranular consumption. They are suggested for parts created by welding which can’t be accordingly tempered. These sorts likewise are utilized for parts which are discontinuously warmed and cooled to temperatures somewhere around 800°F and 1600°F. The expansion of columbium creates a stabilized sort of stainless that disposes of carbide precipitation and, thus, intergranular consumption.
FEATURES OF STAINLESS STEEL 347/347H:
- Superior general corrosion resistance over Type 321 due to stabilization with columbium.
- Reduced tendencies to form continuous networks of chromium carbides at the grain boundaries.
- Better high temperature properties than 304 or 304L. Generally used for parts which are intermittently heated up to 1500°F. For continuous service the maximum temperature is 1650°F.
- Type 347 has high carbon (.04 to .10) for better high temperature creep properties.
- Improved intergranular corrosion resistance.
APPLICATIONS OF STAINLESS STEEL 347/347H:
- High temperature chemical processes
- Heat exchanger tubes
- High temperature steam service
- High pressure steam pipes
- Radiant super heaters
- Boiler tubes
- Heavy duty exhaust systems
- General refinery piping
TYPES OF STAINLESS STEEL 347:
- ASTM A312 TP 347 Stainless Steel Seamless Pipes
- SS 347 Welded Pipes
- ASTM A213 TP 347 Stainless Steel Seamless Tubes
- SS 347 Rectangular Pipes
- ASTM A312 TP 347 Stainless Steel Welded Pipes
- SS 347 Seamless Tubes
- ASTM A249 TP 347 Stainless Steel Welded Tubes
- SS 347 ERW Tubes
- SS 347 Seamless Pipes
- SS 347 EFW Tubes
- SS 347 ERW Pipes
- SS 347 Welded Tubes
- SS 347 EFW Pipes
- SS 347 Rectangular Tubes
- Stainless Steel 347 Round Bar
- Stainless Steel 347 plates
- Stainless Steel 347 sheets
- Stainless Steel 347 coil
- Stainless Steel 347 fitting
- Stainless Steel 347 flanges
- Stainless Steel 347 fasteners
CHEMICAL COMPOSITION OF STAINLESS STEEL 347:
| C | Cr | Mn | Ni | P | S | Si | Cb/Ta | |
|---|---|---|---|---|---|---|---|---|
| 347 | 0.08 max |
min: 17.0 |
2.0 max |
min: 9.0 |
0.04 max |
0.30 |
0.75 |
min:10x C |
| 347H |
min: 0.04 |
min: 17.0 |
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 OF STAINLESS STEEL 347:
| 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 |
30 |
40 | 201 | 95 |
PHYSICAL PROPERTIES OF STAINLESS STEEL 347:
| 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 |