Product Details

ASTM A335 is a ASTM standard specifies Seamless Ferritic Alloy Steel Pipe for High-Temperature Service. ASTM A335 pipe ordered to this specification shall be suitable for bending and similar forming operations, and for fusion welding. Selection will depend upon design, service conditions, mechanical properties, and high-temperature characteristics.

This specification covers seamless ferritic alloy-steel pipe for high-temperature service. The pipe shall be suitable for bending, flanging, and similar forming operations, and for fusion welding. The steel material shall conform to chemical composition, tensile property, and hardness requirements. Each length of pipe shall be subjected to the hydrostatic test. Also, each pipe shall be examined by a non-destructive examination method in accordance to the required practices. The range of pipe sizes that may be examined by each method shall be subjected to the limitations in the scope of the respective practices. The different mechanical test requirements for pipes, namely, transverse or longitudinal tension test, flattening test, and hardness or bend test are presented.

Mainly Grade of ASTM A335:

ASTM A335 P11, P22, P5, P9, P91, P92

Chemical Composition (%) for the main grade

Grade	C	Mn	P, S, max	Si	Cr	Mo
P11	0.05-0.15	0.30-0.60	0.025	0.50-1.00	1.00-1.50	0.44-0.65
P22	0.05-0.15	0.30-0.60	0.025	0.50 max	1.90-2.60	0.87-1.13
P5	0.15 max	0.30-0.60	0.025	0.50 max	4.00-6.00	0.45-0.65
P9	0.15 max	0.30-0.60	0.025	0.25-1.00	8.00-10.00	0.90-1.10
P91	0.08-0.12	0.30-0.60	0.020/0.010	0.20-0.50	8.00-9.50	0.85-1.05
	V 0.18-0.25	N 0.03-0.07	Ni 0.40 max	Al 0.02 max	Nb 0.06-0.10	Ti 0.01 max
P92	0.07-0.13	0.30-0.60	0.020/0.010	0.50 max	8.50-9.50	0.30-0.60
	V 0.15-0.25	N 0.03-0.07	Ni 0.40 max	Al 0.02 max	Nb 0.04-0.09	W 1.50-2.00
				B 0.001-0.006	Ti 0.01 max	Zr 0.01 max

Mechanical Properties

	Grade P11, P22, P5, P9	Grade P91	Grade P92
Tensile strength, min, (MPa)	415	585	620
Yield strength, min, (MPa)	205	415	440
Elongation, min, (%), L/T	30/20	20/…	20/…

Heat Treatment

A / N+T

N+T / Q+T

N+T

Material & Manufacture

Pipe may be either hot finished or cold drawn with the finishing heat treatment noted below.

Heat Treatment Requirements

	P5, P9, P11, and P22
Grade	Heat Treatment Type	Normalizing Temperature Range F [C]	Subcritical Annealing or Tempering Temperature Range F [C]

P5 (b,c)	Full or Isothermal Anneal
	Normalize and Temper	*****	1250 [675]
	Subcritical Anneal (P5c only)	*****	1325 – 1375 [715 - 745]
P9	Full or Isothermal Anneal
	Normalize and Temper	*****	1250 [675]
P11	Full or Isothermal Anneal
	Normalize and Temper	*****	1200 [650]
P22	Full or Isothermal Anneal
	Normalize and Temper	*****	1250 [675]
P91	Normalize and Temper	1900-1975 [1040 - 1080]	1350-1470 [730 - 800]
	Quench and Temper	1900-1975 [1040 - 1080]	1350-1470 [730 - 800]

Mechanical Tests Specified

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 one 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.

Notes for Hardness Test

P91 shall not have a hardness not exceeding 250 HB/265 HV [25HRC].

Notes for Bend Test

For pipe whose diameter exceeds NPS 25 and whose diameter to wall thickness ratio is 7.0 or less shall be subjected to the bend test instead of the flattening test.
Other pipe whose diameter equals or exceeds NPS 10 may be given the bend test in place of the flattening test subject to the approval of the purchaser.
The bend test specimens shall be bent at room temperature through 180 without cracking on the outside of the bent portion.

Hydrostatic Test

The inside diameter of the bend shall be 1 inch [25 mm].
Each length of pipe shall be Hydro tested, at option of manufacture nondestructive electric testing can be used.