Boiler Tube

ASTM A335 Seamless Alloy Pipes

ASTM A 335/A 335M Standard Specification for Seamless Ferritic Alloy-Steel Pipe for High-Temperature ServiceASTM A335 P9 Seamless Ferritic Alloy-Steel Pipe cover nominal wall seamless alloy-steel pipe intended for high-temperature service.

Standard:ASTM A 335/A 335M
Standard Specification for Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service
 
ASTM A335 P9 Seamless Ferritic Alloy-Steel Pipe cover nominal (average) wall seamless alloy-steel pipe intended for high-temperature service.
Pipe ordered to ASTM A 335 specification shall be suitable for bending,flanging (vanstoning), and similar forming operations, and for fusion welding. Selection will depend upon design, service conditions, mechanical properties, and high-temperature characteristics.

Manufacture:Seamless process ,Hot-finished or Cold-finished
Wall thickness(WT): 2.1mm——20 mm.
Outer diameter (OD): 21 mm——509mm
Length: 6M or specified length as required.
Ends: Plain End, Beveled End, Threaded

Materials and Manufacture
Grade P5 Pipe may be either hot finished or cold drawn with the finishing treatment.
 
Heat Treatment:

P5 Seamless Ferritic Alloy-Steel Pipe will be reheated and furnished in the full-annealed, isothermal annealed, or normal-ized and tempered condition. If furnished in the normalized and tempered condition, the minimum tempering temperature are 1250°F [675°C].

Chemical Composition of ASTM A335 P5

GradeChemical Composition(%)
CMnPSSiCrMo
 P5≤0.0150.30-0.60≤0.025≤0.025≤0.504.00-6.000.45-0.65


Mechanical Properties of ASTM A335 P5

GradeMechanical property
Tensile Strength(MPa)Yield Strength(MPa)Elongation(%)
 P5≥415≥205≥30

 
Outside diameter tolerances of ASTM A335 Seamless Ferritic Alloy-Steel Pipe

NPS DesignatorOverUnder
in.mmin.mm
1⁄8 to 1 1⁄2 , incl.1 ⁄ 64 (0.015)0.401 ⁄ 64 (0.015)0.40
Over 1 1⁄2 to 4, incl.1 ⁄ 32 (0.031)0.791 ⁄ 32 (0.031)0.79
Over 4 to 8, incl.1 ⁄ 16 (0.062)1.591 ⁄ 32 (0.031)0.79
Over 8 to 12, incl.3 ⁄ 32 (0.093)2.381 ⁄ 32 (0.031)0.79
Over 12± 1 %

 
Hydrostatic Test
Each length of pipe shall be subjected to the hydrostatic test or nondestructive examination.

Mechanical Tests Required
Transverse or Longitudinal Tension Test and Flattening Test, Hardness Test, or Bend Test—For material heat treated in a batch-type furnace, tests shall be made on 5 % of the pipe from each treated lot.
For small lots, at least 1 pipe shall be tested. For material heat treated by the continuous process, tests shall be made on a sufficient number of pipe to constitute 5 % of the lot, but in no case less than 2 pipe.

Marking
In addition to the marking prescribed in Specification A 999/A 999M, the marking shall include the length, the ANSI schedule number and the heat number or manufacturer’s number by which the heat can be identified.
 
Ordering Information
Orders for material includes the following, as required, to describe the desired material adequately:
(1) Quantity (feet, centimetres, or number of lengths),
(2) Name of material (seamless alloy steel pipe),
(3) Grade (P5),
(4) Manufacture (hot-finished or cold-drawn),
(5) Size (NPS or outside diameter and schedule number or average wall thickness),
(6) Length (specific or random),
(7) End finish (Ends Section of Specification A 999/A 999M),
(8) Test report required (Certification Section of Specification AA 999/A 999M)

ASME_SA335_P5_Seamless_Ferritic_Alloy_Steel_Pipe

ASTM A335 P9 Seamless Pipe for High-Temperature Service,A335 P9 Seamless Pipe reheated and furnished in the full-annealed, isothermal annealed, or normal-ized and tempered condition. the minimum tempering temperature are 1250°F [675°C].

Standard:ASTM A 335/A 335M
Standard Specification for Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service
 
ASTM A335 P9 Seamless Ferritic Alloy-Steel Pipes cover nominal (average) wall seamless alloy-steel pipe intended for high-temperature service.

A335 P9 is a high temperature chromium molybdenum alloy heat-resistant steel. Because of its good oxidation resistance, high temperature strength and sulfide corrosion resistance, A335 P9 is widely used in high temperature, high pressure, flammable and explosive pipelines of petroleum refining and chemical equipment, especially the direct heating pipes of heating furnace. The medium temperature can reach 550-600 ℃.
 
Equivalent grade
GradeStandardCountry
STBA26JIS G3462Japan
T9ASTM A213U.S.A
HT7SAVDNIKSweden
Manufacture:Seamless process ,Hot-finished or Cold-finished
Wall thickness(WT): 2.1mm——20 mm.
Outer diameter (OD): 21 mm——509mm
Length: 6M or specified length as required.
Ends: Plain End, Beveled End, Threaded
 
Materials and Manufacture
Grade P9 Pipe may be either hot finished or cold drawn with the finishing treatment.
 
Heat Treatment:
P9 Seamless Ferritic Alloy-Steel Pipe will be reheated and furnished in the full-annealed, isothermal annealed, or normal-ized and tempered condition. If furnished in the normalized and tempered condition, the minimum tempering temperature are 1250°F [675°C].

Chemical Composition of ASTM A335 P9
GradeChemical Composition(%)
CMnPSSiCrMo
 P9≤0.0150.30-0.60≤0.025≤0.025≤0.504.00-6.000.45-0.65
Mechanical Properties of ASTM A335 P9
GradeMechanical property
Tensile Strength(MPa)Yield Strength(MPa)Elongation(%)
 P9≥415≥205≥30

Outside diameter tolerances of ASTM A335 Seamless Ferritic Alloy-Steel Pipe
NPS DesignatorOverUnder
in.mmin.mm
1⁄8 to 1 1⁄2 , incl.1 ⁄ 64 (0.015)0.401 ⁄ 64 (0.015)0.40
Over 1 1⁄2 to 4, incl.1 ⁄ 32 (0.031)0.791 ⁄ 32 (0.031)0.79
Over 4 to 8, incl.1 ⁄ 16 (0.062)1.591 ⁄ 32 (0.031)0.79
Over 8 to 12, incl.3 ⁄ 32 (0.093)2.381 ⁄ 32 (0.031)0.79
Over 12± 1 %

Hydrostatic Test
Each length of pipe shall be subjected to the hydrostatic test or nondestructive examination.
 
Mechanical Tests Required
Transverse or Longitudinal Tension Test and Flattening Test, Hardness Test, or Bend Test—For material heat treated in a batch-type furnace, tests shall be made on 5 % of the pipe from each treated lot.
For small lots, at least 1 pipe shall be tested. For material heat treated by the continuous process, tests shall be made on a sufficient number of pipe to constitute 5 % of the lot, but in no case less than 2 pipe.

Marking
In addition to the marking prescribed in Specification A 999/A 999M, the marking shall include the length, the ANSI schedule number and the heat number or manufacturer’s number by which the heat can be identified.
 
Ordering Information
Orders for material includes the following, as required, to describe the desired material adequately:
(1) Quantity (feet, centimetres, or number of lengths),
(2) Name of material (seamless alloy steel pipe),
(3) Grade (P9),
(4) Manufacture (hot-finished or cold-drawn),
(5) Size (NPS or outside diameter and schedule number or average wall thickness),
(6) Length (specific or random),
(7) End finish (Ends Section of Specification A 999/A 999M),
(8) Test report required (Certification Section of Specification AA 999/A 999M)
ASME_SA335_P9_Seamless_Ferritic_Alloy_Steel_Pipe

ASTM A335 Grade P11 Pipe are either hot finished or cold drawn with the finishing treatment. P11 Seamless Ferritic Alloy-Steel Pipe are reheated and furnished in the full-annealed, isothermal annealed, or normal-ized and tempered condition.

Standard:ASTM A 335/A 335M
Standard Specification for Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service

ASTM A335 P11 Seamless Ferritic Alloy-Steel Pipes cover nominal (average) wall seamless alloy-steel pipe intended for high-temperature service.
Pipe ordered to ASTM A 335 specification shall be suitable for bending,flanging (vanstoning), and similar forming operations, and for fusion welding. Selection will depend upon design, service conditions, mechanical properties, and high-temperature characteristics.

ASTM A335 P11 Seamless Ferritic Alloy-Steel Pipe Quick Details
Manufacture:Seamless process ,Hot-finished or Cold-finished
Wall thickness(WT): 2.1mm——20 mm.
Outer diameter (OD): 21 mm——509mm
Length: 6M or specified length as required.
Ends: Plain End, Beveled End, Threaded

Materials and Manufucture
Grade P11 Pipe may be either hot finished or cold drawn with the finishing treatment.

Heat Treatment:
P11 Seamless Ferritic Alloy-Steel Pipe are reheated and furnished in the full-annealed, isothermal annealed, or normal-ized and tempered condition. If furnished in the normalized and tempered condition,the minimum tempering temperature for Grades P11are 1200°F [650°C].
 
Chemical Composition of ASTM A335 P11

GradeChemical Composition(%)
CMnPSSiCrMo
P110.05-0.0150.30-0.60≤0.025≤0.0250.50-1.001.00-1.500.44-0.65

 
Mechanical Properties of ASTM A335 P11

GradeMechanical property
Tensile Strength(MPa)Yield Strength(MPa)Elongation(%)
P11≥415≥205≥30


Outside diameter tolerances of ASTM A335 Seamless Ferritic Alloy-Steel Pipe

NPS DesignatorOverUnder
in.mmin.mm
1⁄8 to 1 1⁄2 , incl.1 ⁄ 64 (0.015)0.401 ⁄ 64 (0.015)0.40
Over 1 1⁄2 to 4, incl.1 ⁄ 32 (0.031)0.791 ⁄ 32 (0.031)0.79
Over 4 to 8, incl.1 ⁄ 16 (0.062)1.591 ⁄ 32 (0.031)0.79
Over 8 to 12, incl.3 ⁄ 32 (0.093)2.381 ⁄ 32 (0.031)0.79
Over 12± 1 %

 
Hydrostatic Test
Each length of pipe shall be subjected to the hydrostatic test or nondestructive examination.
 
Mechanical Tests Required
Transverse or Longitudinal Tension Test and Flattening Test, Hardness Test, or Bend Test—For material heat treated in a batch-type furnace, tests shall be made on 5 % of the pipe from each treated lot.
For small lots, at least 1 pipe shall be tested. For material heat treated by the continuous process, tests shall be made on a sufficient number of pipe to constitute 5 % of the lot, but in no case less than 2 pipe.
 
Marking
In addition to the marking prescribed in Specification A 999/A 999M, the marking shall include the length, the ANSI schedule number and the heat number or manufacturer’s number by which the heat can be identified.
 
Ordering Information
Orders for material includes the following, as required, to describe the desired material adequately:
(1) Quantity (feet, centimetres, or number of lengths),
(2) Name of material (seamless alloy steel pipe),
(3) Grade (P11),
(4) Manufacture (hot-finished or cold-drawn),
(5) Size (NPS or outside diameter and schedule number or average wall thickness),
(6) Length (specific or random),
(7) End finish (Ends Section of Specification A 999/A 999M),
(8) Test report required (Certification Section of Specification AA 999/A 999M)

ASTM A335 Grade P12—The steel shall be made by coarsegrain melting practice.ASTM A335 Grade P12 Seamless Ferritic Alloy-Steel Pipe are either hot finished or cold drawn with the finishing treatment.

Standard:ASTM A 335/A 335M
Standard Specification for Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service
 
ASTM A335 P12 Seamless Ferritic Alloy-Steel Pipes cover nominal (average) wall seamless alloy-steel pipe intended for high-temperature service.
Pipe ordered to ASTM A 335 specification shall be suitable for bending,flanging (vanstoning), and similar forming operations, and for fusion welding. Selection will depend upon design, service conditions, mechanical properties, and high-temperature characteristics.

Manufacture:Seamless process ,Hot-finished or Cold-finished
Wall thickness(WT): 2.1mm——20 mm.
Outer diameter (OD): 21 mm——509mm
Length: 6M or specified length as required.
Ends: Plain End, Beveled End, Threaded

Materials and Manufacture
Grade P12—The steel shall be made by coarsegrain melting practice.
Grade P12 Pipe may be either hot finished or cold drawn with the finishing treatment
 
Heat Treatment:
Pipe of Grades P12, either hot finished or cold drawn, may be given a final heat treatment at 1200°F [650°C] to 1300°F [705°C] .
 
Chemical Composition of ASTM A335 P12

GradeChemical Composition(%)
CMnPSSiCrMo
P12≤0.0150.30-0.60≤0.025≤0.025≤0.500.80-1.250.45-0.65


Mechanical Properties of ASTM A335 P12

GradeMechanical property
Tensile Strength(MPa)Yield Strength(MPa)Elongation(%)
P12≥415≥205≥30

 
Outside diameter tolerances of ASTM A335 Seamless Ferritic Alloy-Steel Pipe

NPS DesignatorOverUnder
in.mmin.mm
1⁄8 to 1 1⁄2 , incl.1 ⁄ 64 (0.015)0.401 ⁄ 64 (0.015)0.40
Over 1 1⁄2 to 4, incl.1 ⁄ 32 (0.031)0.791 ⁄ 32 (0.031)0.79
Over 4 to 8, incl.1 ⁄ 16 (0.062)1.591 ⁄ 32 (0.031)0.79
Over 8 to 12, incl.3 ⁄ 32 (0.093)2.381 ⁄ 32 (0.031)0.79
Over 12± 1 %

 
Hydrostatic Test
Each length of pipe shall be subjected to the hydrostatic test or nondestructive examination.
 
Mechanical Tests Required
Transverse or Longitudinal Tension Test and Flattening Test, Hardness Test, or Bend Test—For material heat treated in a batch-type furnace, tests shall be made on 5 % of the pipe from each treated lot.
For small lots, at least 1 pipe shall be tested. For material heat treated by the continuous process, tests shall be made on a sufficient number of pipe to constitute 5 % of the lot, but in no case less than 2 pipe.

Marking
In addition to the marking prescribed in Specification A 999/A 999M, the marking shall include the length, the ANSI schedule number and the heat number or manufacturer’s number by which the heat can be identified.

Ordering Information
Orders for material includes the following, as required, to describe the desired material adequately:
(1) Quantity (feet, centimetres, or number of lengths),
(2) Name of material (seamless alloy steel pipe),
(3) Grade (P12),
(4) Manufacture (hot-finished or cold-drawn),
(5) Size (NPS or outside diameter and schedule number or average wall thickness),
(6) Length (specific or random),
(7) End finish (Ends Section of Specification A 999/A 999M),
(8) Test report required (Certification Section of Specification AA 999/A 999M)

ASTM A335 P12 Seamless Ferritic Alloy-Steel Pipe

ASTM A335 P22 Seamless Ferritic Alloy-Steel Pipes cover nominal wall seamless alloy-steel pipe intended for high-temperature service.

Standard:ASTM A 335/A 335M
Standard Specification for Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service
 
ASTM A335 P22 Seamless Ferritic Alloy-Steel Pipes cover nominal (average) wall seamless alloy-steel pipe intended for high-temperature service.


ASTM A335 P22 Steel

P22 is the steel grade in ASTM A335 alloy seamless steel pipe standard. P22 is 2.25cr-mo high temperature ferritic steel for boiler and superheater. 
 
The thermal strength of ASTM A335 P22 steel is relatively high, and its creep rupture strength and allowable stress at the same temperature (temperature ≤ 580 ℃) are even higher than that of 9Cr Mo steel, and it has good processability and weldability, and good durable plasticity. Therefore, it has been widely used in the harsh working environment, such as in thermal power, nuclear power and some hydrogen equipment, such as various heating pipe belts and high-pressure vessels. ASTM A335 P22 steel has been widely used in the United States, Japan and Europe. ASTM A335 P22 steel is a mature steel with stable performance and good process performance.

 

Equivalent steel grade

GradeStandardCountry
STBA24JIS G3462Japan
10CrMo910DIN 17175Germany
12Cr2MoGGB/T 5310China

Manufacture:Seamless process ,Hot-finished or Cold-finished
Wall thickness(WT): 2.1mm——20 mm.
Outer diameter (OD): 21 mm——509mm
Length: 6M or specified length as required.
Ends: Plain End, Beveled End, Threaded

Materials and Manufacture
Grade P22 Pipe may be either hot finished or cold drawn with the finishing treatment.
 

Heat Treatment:
Grade P22 Seamless Ferritic Alloy-Steel Pipe will be reheated and furnished in the full-annealed, isothermal annealed, or normal-ized and tempered condition. If furnished in the normalized and tempered condition, the minimum tempering temperature are 1250°F [675°C].
 

Chemical Composition of ASTM A335 P22

GradeChemical Composition(%)
CMnPSSiCrMo
P22≤0.0150.30-0.60≤0.025≤0.025≤0.501.90-2.600.87-1.13


Mechanical Properties of ASTM A335 P22

GradeMechanical property
Tensile Strength(MPa)Yield Strength(MPa)Elongation(%)
P22≥415≥205≥30

 

Outside diameter tolerances of ASTM A335 Seamless Ferritic Alloy-Steel Pipe

NPS DesignatorOverUnder
in.mmin.mm
1⁄8 to 1 1⁄2 , incl.1 ⁄ 64 (0.015)0.401 ⁄ 64 (0.015)0.40
Over 1 1⁄2 to 4, incl.1 ⁄ 32 (0.031)0.791 ⁄ 32 (0.031)0.79
Over 4 to 8, incl.1 ⁄ 16 (0.062)1.591 ⁄ 32 (0.031)0.79
Over 8 to 12, incl.3 ⁄ 32 (0.093)2.381 ⁄ 32 (0.031)0.79
Over 12± 1 %

 
Hydrostatic Test
Each length of pipe shall be subjected to the hydrostatic test or nondestructive examination.
 
Mechanical Tests Required
Transverse or Longitudinal Tension Test and Flattening Test, Hardness Test, or Bend Test—For material heat treated in a batch-type furnace, tests shall be made on 5 % of the pipe from each treated lot.
For small lots, at least 1 pipe shall be tested. For material heat treated by the continuous process, tests shall be made on a sufficient number of pipe to constitute 5 % of the lot, but in no case less than 2 pipe.
 

Marking
In addition to the marking prescribed in Specification A 999/A 999M, the marking shall include the length, the ANSI schedule number and the heat number or manufacturer’s number by which the heat can be identified.

Ordering Information
Orders for material includes the following, as required, to describe the desired material adequately:
(1) Quantity (feet, centimetres, or number of lengths),
(2) Name of material (seamless alloy steel pipe),
(3) Grade (P22),
(4) Manufacture (hot-finished or cold-drawn),
(5) Size (NPS or outside diameter and schedule number or average wall thickness),
(6) Length (specific or random),
(7) End finish (Ends Section of Specification A 999/A 999M),
(8) Test report required (Certification Section of Specification AA 999/A 999M)

ASME_SA335_P22_Seamless_Ferritic_Alloy_Steel_Pipe

ASTM A335 Grade P91 Seamless Ferritic Alloy-Steel Pipes will be normalized at 1900°F [1040°C] minimum, and tempered at 1350°F [730°C] minimum as a final heat treatment.

Standard: ASTM A 335/A 335M
Standard Specification for Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service
 
ASTM A335 P91 Seamless Ferritic Alloy-Steel Pipes cover nominal (average) wall seamless alloy-steel pipe intended for high-temperature service.

ASTM A335 P91 steel
ASTM A335 P91 steel is an improved 9Cr-1Mo steel. When V, Nb and other alloy elements are added into the original 9Cr-1Mo martensitic steel, the allowable stress at 550-650 ℃ is significantly higher than that of 10CrMo910 and TP304 steel. Compared with 10CrMo910 steel, under the same temperature and pressure conditions, the pipe wall thickness can be reduced by 50%. The recommended use temperature of A335 P91 steel is below 650 ℃, A335 P91 steel has good high temperature resistance and resistance Corrosion and creep resistance,
 
ASTM A335 P91 steel pipe can be used in high pressure environment with steam temperature over 600 ℃.
 
Material properties of ASTM A335 P91:
At present, A335 P91 material has been widely used in reheater, superheater header, nozzle seat and steam pipeline of subcritical and supercritical power station boilers. A335 P91 belongs to martensitic heat strength steel. The pipe made of P91 steel has good mechanical properties, high temperature resistance and creep resistance.
 
Manufacture:Seamless process ,Hot-finished or Cold-finished
Wall thickness(WT): 2.1mm——20 mm.
Outer diameter (OD): 21 mm——509mm
Common specifications:25mm*7mm,  141.3mm*6.55mm,  323.9mm*25.4mm,
Length: 6M or specified length as required.
Ends: Plain End, Beveled End, Threaded
 
Materials and Manufacture
Grade P91 Pipe may be either hot finished or cold drawn with the finishing treatment.
 
Heat Treatment:
Grade P91 Seamless Ferritic Alloy-Steel Pipes will be normalized at 1900°F [1040°C] minimum, and tempered at 1350°F [730°C] minimum as a final heat treatment.
Alternatively, liquid quenching and tempering is allowed for thicknesses above 3 in. when we mutually agreed with the purchaser.
 
Chemical Composition of ASTM A335 P91

GradeCMnPSSiCr
A335 P910.08-0.120.3-0.6≤0.02≤0.010.2-0.58.0-9.5
MoVNNiAlNb
0.85-1.050.18-0.250.03-0.07≤0.4≤0.040.06-0.10
Mechanical Properties of ASTM A335 P91
GradeMechanical property
Tensile Strength(MPa)Yield Strength(MPa)Elongation(%)
P91≥510≥400≥20

Analysis of welding performance of ASTM A335 P91
In alloy steel, in addition to carbon elements, other elements also play an important role in the strength and weldability of steel pipes. The carbon equivalent of A335 P91 refers to the welding carbon equivalent, which is calculated according to the following formula:
 
Ceq=C+Mn/6+(Cr+V+Mo)/5+(Cu+Ni)/15
Where CEQ is carbon equivalent
 
Therefore, the carbon equivalent of A335 P91 pipe CEQ = C + Mn / 6 + (Cr + V + Mo) / 5 + (Cu + Ni) / 15 = 0.08 + 0.30 / 6 + (8.0 + 0.18 + 0.85) / 5 + 0.4 / 15 = 1.9627
The middle value of carbon equivalent is 0.45. The smaller the corresponding carbon equivalent value is, the better the welding performance is. On the contrary, when the carbon equivalent value is larger, the worse the welding performance is. From the above calculation results of carbon equivalent of A335 P91 pipeline, it can be seen that 1.9627 is much larger than 0.45, so the welding performance of A335 P91 pipeline is poor.
 
Welding precautions:
1.The structure of A335 P9 steel is martensite, and the supply state is generally normalizing + tempering. It belongs to high alloy steel, which has poor weldability and is prone to cold cracks, embrittlement of welded joints, softening of HAZ area and other problems. Only in strict accordance with the process specification can satisfactory welded joints be obtained.
2. Welding and heat treatment temperature shall be strictly controlled, and welding with smaller parameters is the key point to ensure complete penetration of weld root.
3. The preheating temperature of heat treatment is moderate, and it should be controlled in the range of 150-200 ℃ as far as possible, which is conducive to the flow of molten iron in the weld pool, and overcomes the phenomenon of incomplete fusion and incomplete penetration at the root of weld due to the high Cr alloy is not easy to feed wire.

Outside diameter tolerances of ASTM A335 Seamless Ferritic Alloy-Steel Pipe
NPS DesignatorOverUnder
in.mmin.mm
1⁄8 to 1 1⁄2 , incl.1 ⁄ 64 (0.015)0.401 ⁄ 64 (0.015)0.40
Over 1 1⁄2 to 4, incl.1 ⁄ 32 (0.031)0.791 ⁄ 32 (0.031)0.79
Over 4 to 8, incl.1 ⁄ 16 (0.062)1.591 ⁄ 32 (0.031)0.79
Over 8 to 12, incl.3 ⁄ 32 (0.093)2.381 ⁄ 32 (0.031)0.79
Over 12± 1 %

Hydrostatic Test
Each length of pipe shall be subjected to the hydrostatic test or nondestructive examination.
 
Mechanical Tests Required
Transverse or Longitudinal Tension Test and Flattening Test, Hardness Test, or Bend Test—For material heat treated in a batch-type furnace, tests shall be made on 5 % of the pipe from each treated lot.
For small lots, at least 1 pipe shall be tested. For material heat treated by the continuous process, tests shall be made on a sufficient number of pipe to constitute 5 % of the lot, but in no case less than 2 pipe.
 
Marking

In addition to the marking prescribed in Specification A 999/A 999M, the marking shall include the length, the ANSI schedule number and the heat number or manufacturer’s number by which the heat can be identified.
ASme_SA335_P91_Seamless_Ferritic_Alloy_Steel_Pipe

ASTM A335 P92 Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service,Application of ASTM A335 P92,Heat Treatment,Chemical Composition,Physical Properties.

Standard:ASTM A335/A 335M
Standard Specification for Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service
 

ASTM A335 P92 Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service

P92 Steel
A335 P92 alloy tube, P92 material is American steel number ASTM A335 P92, which is martensitic heat-resistant steel.
92 steel is based on P91 steel, and the content of Mo element is appropriately reduced. At the same time, a certain amount of W is added to increase the molybdenum equivalent (Mo + 0.5W) of the material from 1% of P91 steel to about 1.5%. The steel is also added with a small amount of boron. After the above alloying improvement, compared with other commonly used heat-resistant steels of 9% Cr series, its high temperature corrosion resistance and oxidation resistance are similar, but the high temperature strength and creep performance are greatly improved. Improvement.
 
Compared with P91 steel, P92 steel has a 30% higher endurance strength at 600 ℃. In order to improve the thermal efficiency of modern coal-fired generating units, the generating units must be operated at higher temperature and pressure parameters, and a large number of P92 seamless steel pipes are required.

Manufacture:Seamless process ,Hot-finished or Cold-finished
Wall thickness(WT): 2.1mm——35 mm.
Outer diameter (OD): 23 mm——509mm
Common specifications:25mm*7mm,  141.3mm*6.55mm,  323.9mm*25.4mm,
Length: 6M or specified length as required.
Ends: Plain End, Beveled End, Threaded

Manufacture
ASTM A335 P91 Seamless Ferritic Alloy-Steel Pipe may be either hot finished or cold drawn with the finishing treatment.
 
ASTM A335 P92 Seamless Alloy Steel Pipe Chemical Composition(%)

GradeCMnPSSiCrMo
A335 P910.07-0.130.3-0.6≤0.02≤0.01≤0.58.5-9.500.3-0.6
VNNiAlNbWB
0.15-0.250.03-0.07≤0.4≤0.040.04-0.091.5-2.00.001-0.006

ASTM A335 P92 Seamless Alloy Steel Pipe Mechanical & Physical Properties

Tensile Strength(MPa)Yield Strength(MPa)Elongation(%)
≥620≥440≥20

 
Size Tolerances of ASTM A335 P92 Alloy Steel Pipe

Tolerance Of Outside Diameter

ASTM A450Hot rolledOutside Diameter(mm)Tolerance(mm)
OD≤101.6+0.4 / -0.8
101.6<OD≤190.5+0.4 / -1.2
190.5<OD≤228.6+0.4 / -1.6
Cold DrawnOD<25.4±0.10
25.4≤OD≤38.1±0.15
38.1<OD<50.8±0.20
50.8≤OD<63.5±0.25
63.5≤OD<76.2±0.30
76.2≤OD≤101.6±0.38
101.6<OD≤190.5+0.38 / -0.64
190.5<OD≤228.6+0.38 / -1.14
ASTM A530,ASTM A335NPSOutside Diameter(inch)Tolerance(mm)
1/8≤OD≤1-1/2±0.40
1-1/2<OD≤4±0.79
4<OD≤8+1.59 / -0.79
8<OD≤12+2.38 / -0.79
12<OD±1%


Tolerance Of Wall Thickness

ASTM A450Hot rolledOutside Diameter(mm)Tolerance(%)
OD≤101.6,WT≤2.4+40 / -0
OD≤101.6,2.4<WT≤3.8+35 / -0
OD≤101.6,3.8<WT≤4.6+33 / -0
OD≤101.6,4.6<WT+28 / -0
101.6<OD,2.4<WT≤3.8+35 / -0
101.6<OD,3.8<WT≤4.6+33 / -0
101.6<OD,4.6<WT+28 / -0
Cold DrawnOD≤38.1+20 / -0
OD>38.1+22 / -0
ASTM A530NPSOutside Diameter(inch)Tolerance(%)
1/8≤OD≤2-1/2+22 / -12.5
3≤OD≤18,WT/OD≤5%+22.5 / -12.5
3≤OD≤18,WT/OD>5%+15 / -12.5
20≤OD,WT/OD≤5%+22.5 / -12.5
20≤OD,WT/OD>5%+15 / -12.5

 
Tests Required
Hydrostatic Test
Transverse or Longitudinal Tension Test and Flatten- ing Test, Hardness Test, or Bend Test
 
Heat Treatment:
ASTM A335 P91 Seamless Ferritic Alloy-Steel Pipe shall be normalized at 1900°F [1040°C] minimum and tempered at 1350°F [730°C] minimum as a final heat treatment.

Application of ASTM A335 P92 Seamless Ferritic Alloy-Steel Pipe
A335 P92 Seamless Ferritic Alloy-Steel Pipes are widely used in high-temperature components such as main steam pipelines, reheater pipes and headers of ultra-supercritical thermal power generating units;
The use of A335 P92 Seamless Ferritic Alloy-Steel Pipes greatly reduces the wall thickness and structural weight of the pipeline, and improves the flexibility and effectiveness of the generator set.