ASTM A335 P91 Alloy Steel Seamless Pipes and Tubes

ASTM A335 /A335M ASME SA335 pipes shall be made by the seamless process and shall be either hot-finished or cold drawn with the finishing treatment.

ASTM A335 /A335M covers nominal wall and minimum wall seamless ferritic alloy-steel pipe intended for high-temperature service.

ASTM A 999/A999M specification for general requirements for alloy and stainless-steel pipe

E92 Test method for Vickers hardness of metallic materials

E213 practice for ultrasonic testing of metal pipe and tubing

E309 practice for Eddy-Current examination of steel tubular products using magnetic saturation

E381 method of macro etch testing steel bars, billets, blooms, and forgings

Grade

C

Mn

P

S

Si

Cr

Mo

V

Nb

N

Al

Others

P11

0.05-0.15

0.30-0.60

≤0.025

≤0.025

0.50-1.00

1.0-1.50

0.44-0.65

/

/

/

/

/

P12

0.05-0.15

0.30-0.61

≤0.025

≤0.025

≤0.50

0.80-1.25

0.45-0.65

/

/

/

/

/

P22

0.05-0.15

0.30-0.60

≤0.025

≤0.025

≤0.50

1.90-2.60

0.87-1.13

/

/

/

/

/

P91

0.08-0.12

0.30-0.60

≤0.020

≤0.010

0.20-0.50

8.0-9.50

0.85-1.05

0.18-0.25

0.030-0.070

≤0.40

≤0.02

Cb 0.06-0.10 Ti 0.01max Zr 0.01max

Grade	P11	P12	P22	P91
UNS Number	K11597	K11562	K21590	K91560
Heat Treat Type	full or isothermal anneal normalize and temper	full or isothermal anneal normalize and temper subcritical anneal	full or isothermal anneal normalize and temper	normalize and temper quench and temper
Austenitizing/ Solutioning Temperature, min or range °F [°C]	…	…	…	1900-1975[1040-1080] 1900-1975[1040-1080]
Subcritical Annealing or Tempering Temperature, Min or range °F [°C]	1200 [650]	1200 [650] 1200-1300 [650 to 705]	1250 [675]	1350-1470[730-800] 1350-1470[730-800]

Grade	Tensile	Yield	Elongation	Hardness
	Strength (Mpa)	Strength (Mpa)	(%)
P11 P12	≥415	≥220	≥30	≤89HRB
P22	≥415	≥200	≥30	≤89HRB
P91	≥585	≥415	≥20	91HRB-25HRC

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 Electric Test—Each tube 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.