321 Stainless Steel Tube Guanyu Tube

ASTM A213 AISI 321 Stainless Steel Tube UNS N32100 EN 10216 – 5 1.4541 is a stabilized stainless steel which offers as its main advantage an excellent resistance to intergranular corrosion following exposure to temperature in the chromium carbide precipitation range from 800 to 1500°F (427 to 816°C). Alloy 321 stainless steel tubing is stabilized against chromium carbide formation by the addition of titanium.

321 321H stainless steel is basically from 304 stainless steel. They different by a very very small addition of Titanium. The real difference is their carbon content. The higher the carbon content the greater the yield strength. 321 stainless steel has advantages in high temperature environment due to its excellent mechanical properties. Compared with 304 alloy, 321 stainless steel has better ductility and resistance to stress fracture. In addition, 304L can also be used for anti-sensitization and intergranular corrosion.A limitation with 321 is that titanium does not transfer well across a high temperature arc, so is not recommended as a welding consumable. In this case grade 347 is preferred – the niobium performs the same carbide stabilisation task but can be transferred across a welding arc. Grade 347 is therefore the standard consumable for welding 321. Grade 347 is only occasionally used as parent plate material.

Like other austenitic grades, 321 and 347 have excellent forming and welding characteristics, are readily brake or roll formed and have outstanding welding characteristics. Post-weld annealing is not required. They also have excellent toughness, even down to cryogenic temperatures. Grade 321 does not polish well, so is not recommended for decorative applications.

ASTM A213 / ASME SA 213 TP321 stainless steel Chemical Composition

Grade	321	321H
UNS Designation	S32100	S32109
Carbon (C) Max.	0.08	0.04–0.10
Manganese (Mn) Max.	2.00	2.00
Phosphorous (P) Max.	0.045	0.045
Sulphur (S) Max.	0.03	0.03
Silicon (Si) Max.	1.00	1.00
Chromium (Cr)	17.0–20.0	17.0–20.0
Nickel (Ni)	9.0–12.0	9.0–12.0
Molybdenum (Mo)	—	—
Nitrogen (N)	–	–
Iron (Fe)	Bal.	Bal.
Other Elements	Ti=5(C+N) to 0.70%	Ti=4(C+N) to 0.70%

Testing is performed on separately solution annealed and quenched test piece. The following figures apply to material in the solution annealed and quenched condition.

At 20°C (68°F) Room Temperature

At 20°C (68°F)

Metric units

Yield Strength	Yield Strength	Tensile strength	Elongation	Contr.	Hardness HBW
Rp0.2a)	Rp1.0 a)	Rm	Ab)	Z
MPa	MPa	MPa	%	%
≥210	≥245	515-700	≥35	≥50	≤192

1 MPa = 1 N/mm2
a) Rp0.2 and Rp1.0 correspond to 0.2% offset and 1.0% offset yield strength respectively.
b) Based on L0 = 5.65 √S0 where L0 is the original gauge length and S0 the original cross-section area.

Impact strength

Due to its austenitic microstructure, 321 has very good impact strength both at room temperature and at cryogenic temperatures.

Tests on bar have demonstrated that the steel fulfils the requirements (60 J (44 ft-lb) at -196 ^oC (-320 ^oF)) according to the European standards prEN13445-2(UFPV-2) and EN 10272.

Physical Properties of 321 Stainless Steel Tube in the Annealed Condition at -20°F to +100°F according to ASTM A213

Alloy	UNS	Spec	Grain Size Req.	Density Specific Gravity g/cm³	Modulus of Elasticity (x106 psi)	Mean Coefficient of Thermal Expansion (IN./IN./°F x 10-6)	Thermal Conductivity (BTU-in/ft2-h-°F)
321	S32100	—	—	7.93	29.0	9.2	—
321H	S32109	—	7 or coarser	7.93	29.0	9.2	—

321 Stainless Steel Tube Recommended Maximum Service Temperature (Oxidising Conditions)

Continuous Service 950 °C
Intermittent Service 870 °C

321 Stainless Steel Tube Thermal Processing

1.    Annealing Heat  from 1050 to 1150°C and cool in air. This ensures maximum ductility of the steel.
2.    Stress Relieving 321 can be stress-relief annealed within the sensitization temperature range
       450-800°C without carbide precipitation occurring, thus avoiding the possibility of intergranular corrosion.
3.     Hot working
        Initial forging and pressing temperature: 1150 – 1250°C
        Finishing temperature: 950°C

Solution Treatment (Annealing) – heat to 950-1120°C and cool rapidly for maximum corrosion resistance.

Stabilising – heat to 870-900°C for 1 hour per 25mm of thickness and air cool. Stabilisation is recommended for most severe service conditions (above 425°C) and particularly for material annealed at the upper side of the annealing temperature range.

Stress Relief – Heat to 700°C for 1 to 2 hours and air cool.

These grades cannot be hardened by thermal treatment.

321 Stainless Steel Tubing Corrosion Resistance

Equivalent to Grade 304 in the annealed condition, and superior if a weldment in these grades has not been post-weld annealed or if the application involves service in the 425-900°C range. Subject to pitting and crevice corrosion in warm chloride environments, and to stress corrosion cracking above about 60°C. Considered resistant to potable water with up to about 200mg/L chlorides at ambient temperatures, reducing to about 150mg/L at 60°C.321 Stainless Steel Tube Heat Resistance

Good oxidation resistance in intermittent service to 900°C and in continuous service to 925°C. These grades perform well in the 425-900°C range, and particularly where subsequent aqueous corrosive conditions are present. 321H has higher hot strength, and is particularly suitable for high temperature structural applications.321 Stainless Steel Pipe Heat Treatment

Typical Applications include:

• Stainless Steel Reheater Tubes and Superheater Tubes for Boiler

• Aircraft exhaust manifolds

• Expansion joints

• Bellows

• Furnace parts

• Heating element tubing

• Heat Exchanger

• Woven or welded screens for high temperature mineral processing

• Spiral Welded tube for burner pipes and flues

321 Stainless Steel Welding

Excellent weldability by all standard fusion methods, both with and without filler metals. AS 1554.6 pre-qualifies welding of 321 and 347 with Grade 347 rods or electrodes; high silicon version of 347 is also pre-qualified for welding of 321.321 Stainless Steel Tube and Pipe Applications

321 Stainless Steel Tube Range

Alloy	UNS Designation	Werkstoff NR.	Specifications*
321	S32100	EN 10216 – 5 1.4541	A269, A/SA249, A/SA312, A/ SA 213
321H	S32109	EN 10216 – 5 1.4878	A269, A/SA249, A/SA312, A/ SA 213

Intergranular-Corrosion-Test — Intergranular Corrosion Test

Referenced Documents

1 Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.10 on Stainless and Alloy Steel Tubular Products. Current edition approved April 1, 2009. Published April 2009. Originally approved in 1939. Last previous edition approved in 2009 as A 213/A 213M – 09.

2 For ASME Boiler and Pressure Vessel Code applications see related Speciﬁcation SA-213 in Section II of that Code.

ASTM A262 Practices for Detecting Susceptibility to Intergranu lar Attack in Austenitic Stainless Steel
A 941 Terminology Relating to Steel, Stainless Steel, Re lated Alloys, and Ferroalloys
A 1016/A 1016M Speciﬁcation for General Requirements for Ferritic Alloy Steel, Austenitic Alloy Steel, and Stainless Steel Tubes
ASTM E112 Test Methods for Determining Average Grain Size

Nominal Pipe Size (NPS): 1/8, 1/4, 3/8, 1/2, 3/4, 1, 1 1/4, 1 1/2, 2, 2 1/2 inch
Outside Diameter: 10,3 – 73 mm (0,405 – 2,875 inch)
Wall Thickness: 1,24 – 7,01 (0,049 – 0,276 inch)

Tensile Requirements

Grade	UNS	Tensile Strength, Min. Ksi [MPa]	Yield Strength, min. Ksi [MPa]	Elongation in 2 in. or50 mm, min, % A, B	Hardness, Max
Designation	Brinell / Vickers	Rockwell
TP304	S30400	75 [515]	30 [205]	35	192HBW/200Hv	90HB
TP304L	S30403	70 [485]	25 [170]	35	192HBW/200Hv	90HB
TP304H	S30409	75 [515]	30 [205]	35	192HBW/200Hv	90HB
TP304N	S30415	80 [550]	35 [240]	35	192HBW/200Hv	90HB
TP310S	S31008	75 [515]	30 [205]	35	192HBW/200Hv	90HB
TP310H	S31009	75 [515]	30 [205]	35	192HBW/200Hv	90HB
TP316	S31600	75 [515]	30 [205]	35	192HBW/200Hv	90HB
TP316L	S31603	70 [485]	25 [170]	35	192HBW/200Hv	90HB
TP316H	S31609	75 [515]	30 [205]	35	192HBW/200Hv	90HB
TP316Ti	S31635	75 [515]	30 [205]	35	192HBW/200Hv	90HB
TP317	S31700	75 [515]	30 [205]	34	192HBW/200Hv	90HB
TP317L	S31703	75 [515]	30 [205]	35	192HBW/200Hv	90HB
TP321	S32100	75 [515]	30 [205]	35	192HBW/200Hv	90HB
TP321H	S32109	75 [515]	30 [205]	35	192HBW/200Hv	90HB
TP347	S34700	75 [515]	30 [205]	35	192HBW/200Hv	90HB
TP347H	S34709	75 [515]	30 [205]	35	192HBW/200Hv	90HB
TP444	S44400	60 [415]	40 [275]	20	217 HBW/230HV	96 HB

Heat Treatment Requirements

Grade	UNS Designation	Heat Treat Type	Austenitizing/ Solutioning Temperature, min or range °F [°C]	Cooling Media	ASTM Grain Size No. B
TP304	S30400	Solution treatment	1900 °F [1040 °C]	water or another rapid cool	. . .
TP304L	S30403	Solution treatment	1900 °F [1040 °C]	water or another rapid cool	. . .
TP304H	S30409	Solution treatment	1900 °F [1040 °C]	water or another rapid cool	7
TP309S	S30908	Solution treatment	1900 °F [1040 °C]	water or another rapid cool	. . .
TP309H	S30909	Solution treatment	1900 °F [1040 °C]	water or another rapid cool	7
TP310S	S31008	Solution treatment	1900 °F [1040 °C]	water or another rapid cool	. . .
TP310H	S31009	Solution treatment	1900 °F [1040 °C]	water or another rapid cool	7
TP316	S31600	Solution treatment	1900 °F [1040 °C]	water or another rapid cool	. . .
TP316L	S31603	Solution treatment	1900 °F [1040 °C]	water or another rapid cool	. . .
TP316H	S31609	Solution treatment	1900 °F [1040 °C]	water or another rapid cool	7
TP317	S31700	Solution treatment	1900 °F [1040 °C]	water or another rapid cool	. . .
TP317L	S31703	Solution treatment	1900 °F [1040 °C]	water or another rapid cool	. . .
TP321	S32100	Solution treatment	1900 °F [1040 °C]	water or another rapid cool	. . .
TP321H	S32109	Solution treatment	cold worked:2000[1090] hot rolled: 1925 [1050]H	water or another rapid cool	7
TP347	S34700	Solution treatment	1900 °F [1040 °C]	water or another rapid cool	. . .
TP347H	S34709	Solution treatment	cold worked:2000[1100] hot rolled: 1925 [1050]H	water or another rapid cool	7
TP444	S44400	subcritical anneal	. . .	. . .	. . .

Flattening Test

One flattening test shall be made on specimens from each end of one finished tube, not the one used for the flaring test, from each lot.

Flaring Test

One flaring test shall be made on specimens from each end of one finished tube, not the one used for the flattening test, from each lot.

Hydrostatic or Nondestructive Testing

Each pipe shall be subjected to the nondestructive electric test or the hydrostatic test, the type of test to be used shall be at the option of the manufacturer, unless otherwise specified in the purchase order.

Markings

Markings will adhere to prescribed specifications in A999/A999M and shall include the NPS or OD and schedule number or average wall thickness, heat number, and NH (when hydrotesting is not performed) and ET (when eddy-current testing is performed) or UT (when ultrasonic testing is performed). The marking shall also include the manufacturer’s private identifying mark, the marking requirement of section 12.3 on Hydrostatic or Nondestructive Electric Test, if applicable, and whether seamless (SML), welded (WLD), or heavily cold-worked (HCW). For Grades TP304H, TP316H, TP321H & TP347H, the marking shall also include the heat number and heat-treatment lot identification.

Note:

Mill test certificates will be issued according to EN10204.3.
All tubes shall be supplied as per applicable ASTM A213 /A213M Specification.

Notes:

Steel Grades – TP 304, TP 304L, TP 316, TP 316L, TP 321
Technical requirements acc. to ASTM A 450.
Size of pipes in accordance with ANSI/ASME B36.19M.
The quality of pipes is ensured by manufacturing process and non-destructive test.
Hardness of metal not less than 100 HB.
Length tolerance of measured pipes not greater than +10 mm.
Monitoring of continuity of metal by pneumotest with pressure of 6 bar is available.
Intergranular corrosion test in accordance with ASTM A262, Practice E is available.