| All data is for information only------(<---links) | |
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| PRODUCT DATA of AISI 347 |
| Material | AISI 347 |
| General Information | Type 347 is a niobium/tantalum stabilized austenitic chromium-nickel stainless steel which was developed to improve intergranular-corrosion resistance. it is stabilized against chromium carbide formation by the addition of niobium and tantalum. Since niobium and tantalum have a stronger affinity for carbon than chromium, niobiumtantalum carbides precipitate within the grains instead of forming at the grain boundaries. |
| Precautions | Although the alloy is resistant to sensitization and associated intergranualr corrosion, its general corrosion resistance is slightly lowered by prolonged exposures in the sensitization range of 425 to 870 C |
| Effects of Space environment | The natural oxide layer is not repaired in vacuum when damaged. Cold welding might occur in contact to similar materials |
| Chemical Composition | 17-19Cr, 9-13Ni,<2Mn, <0.08C, (10xC)Nb-Ta min, rem Fe |
| EXPERIENCE IN PRACTICE |
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| Development Status | Commercial Product |
| Cost Range | Low |
| Lot Reproducibility | Good |
| Equivalent Designations | S30347, 1.4550, X10,CrNiNb189, 347S17 |
| Space Experience | Good |
| PHYSICAL PROPERTIES |
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| Crystal Structure | Face centered cubic (fcc) |
| Specific Gravity | 7.96 |
| Magnetic Properties | Nonmagnetic |
| ELASTIC PROPERTIES |
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| Tensile Modulus | 195 GPa |
| Shear Modulus | 77 GPa |
| Poisson Ratio | 0.27 |
| THERMAL PROPERTIES |
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| Thermal Conductivity | 16.3 W/m.K |
| Thermal Expansion Coefficient | 17.3 μstrain/°C |
| Melting Range | 1400 to 1430 °C |
| Specific Heat | 0.5 J/g.K |
| RELEVANT PROPERTIES FOR USE IN SPACE COMMUNITY |
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| General Corrosion Status | No specific corrosion protection required |
| Stress Corrosion Status | High Resistance to SCC: Table 1
Remark: acc. to ECSS-Q-ST-70-36C Data Quality: Design Data |
| EMF vs SCE | -0.08 V Remark: Measured in 3.5% NaCl solution. Passive condition Data Quality: Design Data |
| FLUID SYSTEMS COMPATIBILITY |
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| Gaseous Oxygen (GOX) | Meets the mechanical impact requirements. No batch test required. |
| Liquid Oxygen (LOX) | Meets the mechanical impact requirements. No batch test required. |
| Nitrogen Tetroxide (N2O4) | SCC susceptibility is low and no fluid decomposition |
| Hydrazine (HDZE) | SCC susceptibility is low and no fluid decomposition |