Wingate Alloys Inc. > Products > Pressure Vessel > A335 Chrome Alloy Steel Pipe

A335 Chrome Alloy Steel Pipe

A335 Chrome Alloy Steel Pipe, Fittings & Flanges

Scope

This specification covers nominal wall and minimum wall seamless ferritic alloy-steel pipe intended for high temperature service. Pipe ordered to this specification shall be suitable for bending, flanging and similar forming operations, and for fusion welding.

Material & Manufacture

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

Chemical Requirements

Grade

P-5

P-9

P-11

P-22

P-91

P-91 shall also include the following:

Element

UNS Designation

K41545

S50400

K11597

K21590

K91560

Carbon

0.15 max

0.15 max

0.05 – 0.15

0.05 – 0.15

0.08 – 0.12

V at 0.18 – 0.25

Manganese

0.30 – 0.60

0.30 – 0.60

0.30 – 0.60

0.30 – 0.60

0.30 – 0.60

N at 0.030 – 0.070

Phosphorous, max

0.025

0.025

0.025

0.025

0.020

Ni at 0.40 max

Sulfur, max

0.025

0.025

0.025

0.025

0.010

Al at 0.02 max

Silicon

0.50 max

0.25 – 1.00

0.50 – 1.00

0.50 max

0.20 -0.50

Cb at 0.06 – 0.10

Chromium

4.00 – 6.00

8.00 – 10.00

1.00 – 1.50

1.90 – 2.60

8.00 – 9.50

Ti at 0.01 max

Molybdenum

0.45 -0.65

0.90 – 1.10

0.44 – 0.65

0.87 – 1.13

0.85 – 1.05

Zr at 0.01 max

Tensile Requirements

Seamless

P-5

P-9

P-11

P-22

P-91

P91 shall not have a hardness not exceeding 250 HB/265 HV [25HRC].
Tensile Strength, min., psi
ksi

60

60

60

60

85

MPa

415

415

415

415

585

Yield Strength, min., psi
ksi

30

30

30

30

60

MPa

205

205

205

205

415

Permissible Variation in Wall Thickness

NPS [DN] Designator

Tolerance, % from Specified

Over
Under
1/8 to 2 1/2 [6 to 65] incl., all t/D ratios
20.0%
12.5%
Above 2 1/2 [65], t/D < or = 5%
22.5%
12.5%
Above 2 1/2 [65], t/D > 5%
15.0%
12.5%
(t = Specified Wall Thickness; D = Specified Outside Diameter)

Elongation Requirements

Calculated Minimum Elongation Values
Elongation in 2 in. or 50 mm, min %

Wall Thickness

P5, P9, P11, P22

P91

in.

mm

Longitudinal

Transverse

Longitudinal

5/16 (0.312)

8

30

20

20

9/32 (0.281)

7.2

28

19

19

1/4 (0.250)

6.4

27

18

18

7/32 (0.219)

5.6

26

17

3/16 (0.188)

4.8

24

16

5/32 (0.156)

4

22

15

7/8 (0.125)

3.2

21

14

3/32 (0.094)

2.4

20

13

1/18 (0.062)

1.6

18

12

Permissible Variations in Outside Diameter

Outside Diameter at any point shall not vary from standard specified more than:

NPS [DN] Designator

Over

Under

in.

mm

in.

mm

1/8 to 1 1/2 [6 to 40], incl.

1/64 (0.015)

0.40

1/64 (0.015)

0.40

Over 1 1/2 to 4 [40 to 100], incl.

1/32 (0.031)

0.79

1/32 (0.031)

0.79

Over 4 to 8 [100 to 200], incl.

1/16 (0.062)

1.59

1/32 (0.031)

0.79

Over 8 to 12 [200 to 300], incl.

3/32 (0.093)

2.38

1/32 (0.031)

0.79

Over 12 [300]

+/- 1% of the specified outside diameter

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]