ASTM A312 TP347 347H Stainless Steel Seamless Pipe for Shell and Tube Heat Exchanger and Heat Exchanger Tubesheet
347 Stainless Steel is a variant of the basic austenitic 18/8 Grade 304 with added Columbium (Niobium). The introduction of Columbium stabilizes the steel and eliminates carbide precipitation which subsequently causes intergranular corrosion. The steel has excellent forming and welding qualities and excellent toughness even at cryogenic temperatures.
Alloys 321 (S32100) and 347 (S34700) are stabilized stainless steels which offer as their main advantage an excellent resistance to intergranular corrosion following exposure to temperatures in the chromium carbide precipitation range from 800 to 1500°F (427 to 816°C). Alloy 321 is stabilized against chromium carbide formation by the addition of titanium. Alloy 347 is stabilized by the addition of columbium and tantalum.
Chemical Composition of 347 Stainless Steel Pipes and Tubes (per ASTM A312 / ASME SA312)
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.08 max (347); 0.04–0.10 (347H) |
| Manganese (Mn) | 2.00 max |
| Phosphorus (P) | 0.045 max |
| Sulfur (S) | 0.030 max |
| Silicon (Si) | 0.75 max |
| Chromium (Cr) | 17.00 – 19.00 |
| Nickel (Ni) | 9.00 – 13.00 |
| Columbium + Tantalum (Cb+Ta) | 10 * C min to 1.00 max |
| Iron (Fe) | Balance |
Chemical composition per ASTM A312 / ASME SA312 and ASTM A240 / ASME SA240 specifications.
Mechanical Properties of 347 Stainless Steel Pipes and Tubes
Minimum mechanical properties of the stabilized Alloys 321 and 347 chromium-nickel grades in the annealed condition (2000°F [1093°C], air cooled) are shown below. Elevated temperature tensile properties for Alloys 321 and 347 are distinctly higher than those of non-stabilized 304 alloys at temperatures of 1000°F (538°C) and above. High carbon Alloys 321H and 347H (UNS S32109 and S34709, respectively) have higher strength at temperatures above 1000°F (537°C). ASME maximum allowable design stress data for Alloy 347H reflects the higher strength of this grade in comparison to the lower carbon Alloy 347 grade.
Room Temperature Tensile Properties
| Property | TP347 | TP347H |
|---|---|---|
| Tensile Strength, min | 515 MPa (75 ksi) | 515 MPa (75 ksi) |
| Yield Strength (0.2% offset), min | 205 MPa (30 ksi) | 205 MPa (30 ksi) |
| Elongation in 2″ (50 mm), min | 35% | 35% |
| Hardness (HRB), max | 90 | 90 |
Mechanical properties per ASTM A312 / ASME SA312 specification.
Physical Properties of 347 Stainless Steel Pipes and Tubes
The physical properties of Types 321 and 347 are quite similar and, for all practical purposes, may be considered to be the same. When properly annealed, Alloys 321 and 347 stainless steels consist principally of austenite and carbides of titanium or columbium. Small amounts of ferrite may or may not be present in the microstructure. Small amounts of sigma phase may form during long time exposure in the 1000°F to 1500°F (593°C to 816°C) temperature range.
The stabilized Alloys 321 and 347 stainless steels are not hardenable by heat treatment. The overall heat transfer coefficient of metals is determined by factors in addition to thermal conductivity of the metal. In most cases, film coefficients, scaling, and surface conditions are such that not more than 10 to 15% more surface area is required for stainless steels than for other metals having higher thermal conductivity. The ability of stainless steels to maintain clean surfaces often allows better heat transfer than other metals having higher thermal conductivity.
Heat Treatment of 347 Stainless Steel Pipes and Tubes
The annealing temperature range for Alloys 321 and 347 is 1800 to 2000°F (928 to 1093°C). While the primary purpose of annealing is to obtain softness and high ductility, these steels may also be stress relief annealed within the carbide precipitation range 800 to 1500°F (427 to 816°C), without any danger of subsequent intergranular corrosion. Relieving strains by annealing for only a few hours in the 800 to 1500°F (427 to 816°C) range will not cause any noticeable lowering in the general corrosion resistance, although prolonged heating within this range does tend to lower the general corrosion resistance to some extent. For maximum ductility, the higher annealing range of 1800 to 2000°F (928 to 1093°C) is recommended.
Resistance to Corrosion of 347 Stainless Steel Pipes and Tubes
General Corrosion – Alloys 321 and 347 offer similar resistance to general, overall corrosion as the unstabilized chromium nickels Alloy 304. Heating for long periods of time in the chromium carbide precipitation range may affect the general resistance of Alloys 321 and 347 in severe corrosive media. In most environments, both alloys will show similar corrosion resistance; however, Alloy 321 in the annealed condition is somewhat less resistant to general corrosion in strongly oxidizing environments than annealed Alloy 347. For this reason, Alloy 347 is preferable for aqueous and other low temperature environments. Exposure in the 800°F to 1500°F (427°C to 816°C) temperature range lowers the overall corrosion resistance of Alloy 321 to a much greater extent than Alloy 347. Alloy 347 is used primarily in high temperature applications where high resistance to sensitization is essential, thereby preventing intergranular corrosion at lower temperatures.
Intergranular Corrosion – The stabilized Alloys 321 and 347 stainless steels offer excellent resistance to intergranular corrosion following exposure to temperatures in the chromium carbide precipitation range. The addition of columbium and tantalum in Alloy 347 stabilizes the steel and eliminates carbide precipitation which subsequently causes intergranular corrosion.
Product Range and Specifications
Specifications: ASTM A/ASME SA213/A249/A269/A312/A358 CL. I to V, ASTM A789/A790
Sizes (Seamless): 1/2″ NB – 24″ NB
Sizes (ERW): 1/2″ NB – 24″ NB
Sizes (EFW): 6″ NB – 100″ NB
Wall Thickness available: Schedule 5S – Schedule XXS (heavier on request)
Size Range
Production Outside Diameter: 6.00 mm to 830 mm
Wall Thickness: 0.5 mm to 48 mm
Length: 6M, or 20ft, or Random Length, up to 27m/pc
Other Materials Testing
NACE MR0175, H2 SERVICE, OXYGEN SERVICE, CRYO SERVICE, etc.
Dimensions
All pipes are manufactured and inspected/tested to the relevant standards including ASTM, ASME and API.
Typical Uses
Heat exchangers
High temperature steam service
High temperature chemical process
Electric power plant
Both 347 and 347H are used primarily in elevated temperature applications.
Standard Specification References
ASTM A213/A213M: Standard Specification for Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes
ASTM A269: Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubing for General Service
ASTM A312/A312M: Standard Specification for Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes
ASTM A511/A511M: Standard Specification for Seamless Stainless Steel Mechanical Tubing
ASTM A789/A789M: Standard Specification for Seamless and Welded Ferritic/Austenitic Stainless Steel Tubing for General Service
ASTM A790/A790M: Standard Specification for Seamless and Welded Ferritic/Austenitic Stainless Steel Pipe
DIN 17456-2010: General Purpose Seamless Circular Stainless Steel Tubes
DIN 17458-2010: Seamless Circular of Austenitic Stainless Steel Tube
EN10216-5 CT 1/2: Stainless Steel Seamless Pipe & Tube
GOST 9941-81: Seamless Cold- and Warm-Worked Tubes Made of Corrosion Resistant Steel
ANSI B16.10: B16.19 SCH 5S, SCH 10S, SCH 20, SCH 30, SCH 40S, SCH 60, SCH 80S, XS, SCH 100, SCH 120, SCH 160, XXS
Available Material Grades
American Standard Austenitic Steel: TP304, TP304L, TP304H, TP304N, TP310S, TP316, TP316L, TP316Ti, TP316H, TP317, TP317L, TP321, TP321H, TP347, TP347H, 904L
Duplex Steel: S32101, S32205, S31803, S32304, S32750, S32760
Others: TP405, TP409, TP410, TP430, TP439
European Standard: 1.4301, 1.4307, 1.4948, 1.4541, 1.4878, 1.4550, 1.4401, 1.4404, 1.4571, 1.4438, 1.4841, 1.4845, 1.4539, 1.4162, 1.4462, 1.4362, 1.4410, 1.4501
GOST: 08Х17Т, 08Х13, 12Х13, 12Х17, 15Х25Т, 04Х18Н10, 08Х20Н14С2, 08Х18Н12Б, 10Х17Н13М2Т, 10Х23Н18, 08Х18Н10, 08Х18Н10Т, 08Х18Н12Т, 08Х17Н15М3Т, 12Х18Н10Т, 12Х18Н12Т, 12Х18Н9, 17Х18Н9, 08Х22Н6Т, 06ХН28МДТ
For a rapid quotation on ASTM A312 TP347 347H Stainless Steel Seamless Pipe, please provide the following information:
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