ASTM A268/A268M-20 - 1.3.2020
 
1. Scope

1.1 This specification2 covers a number of grades of nominal-wall-thickness, stainless steel tubing for general corrosion-resisting and high-temperature service. Most of these grades are commonly known as the “straight-chromium” types and are characterized by being ferromagnetic. Two of these grades, TP410 and UNS S 41500 (Table 1), are amenable to hardening by heat treatment, and the high-chromium, ferritic alloys are sensitive to notch-brittleness on slow cooling to ordinary temperatures. These features should be recognized in the use of these materials.

TABLE 1  Continued

Grade

TP439

. . .

. . .

TP430 Ti

TP
XM-27

TP
XM-33A

18Cr-2Mo

29-4

29-4-2

26-3-3

25-4-4

...

. . .

. . .

. . .

. . .

TP468

UNS
Designation

S43035

S43932

S41500B

S43036

S44627

S44626

S44400

S44700

S44800

S44660

S44635

S44735

S32803

S40977

S43940

S42035

S46800

Element

Composition, %

C, max

0.07

0.030

0.05

0.10

0.01A

0.06

0.025

0.010

0.010

0.030

0.025

0.030

0.015C

0.03

0.03

0.08

0.030

Mn, max

1.00

1.00

0.5–1.0

1.00

0.40

0.75

1.00

0.30

0.30

1.00

1.00

1.00

0.5

1.50

1.00

1.00

1.00

P, max

0.040

0.040

0.03

0.040

0.02

0.040

0.040

0.025

0.025

0.040

0.040

0.040

0.020

0.040

0.040

0.045

0.040

S, max

0.030

0.030

0.03

0.030

0.02

0.020

0.030

0.020

0.020

0.030

0.030

0.030

0.005

0.015

0.015

0.030

0.030

Si, max

1.00

1.00

0.60

1.00

0.40

0.75

1.00

0.20

0.20

1.00

0.75

1.00

0.50

1.00

1.00

1.00

1.00

Ni

0.50 max

0.50

3.5–5.5

0.75 max

0.5D max

0.50 max

1.00 max

0.15 max

2.0–2.5

1.0–3.50

3.5–4.5

1.00 max

3.0–4.0

0.30–1.00

. . .

1.0–2.5

0.50

Cr

17.00–

17.0–19.0

11.5–14.0

16.00–

25.0–27.5

25.0–27.0

17.5–19.5

28.0–30.0

28.0–30.0

25.0–28.0

24.5–26.0

28.00–

28.0–
29.0

10.50–
12.50

17.50–
18.50

13.5–
15.5

18.00–
20.00

 19.00

 

 19.50

 30.00

 

 

 

 

Mo

...

...

0.5–1.0

...

0.75–1.50

0.75–1.50

1.75–2.50

3.5–4.2

3.5–4.2

3.0–4.0

3.5–4.5

3.60–4.20

1.8–2.5

. . .

. . .

0.2–1.2

. . .

Al, max

0.15

0.15

. . .

...

...

...

...

...

...

...

...

...

. . .

. . .

. . .

. . .

. . .

Cu, max

...

...

. . .

...

0.2

0.20

...

0.15

0.15

...

...

...

. . .

. . .

. . .

. . .

. . .

N, max

0.04

0.030 (Ti + Cb) {0.20 + 4 (C + N)} min.; 0.75 max

. . .

...

0.015

0.040

0.035

0.020E

0.020E

0.040

0.035

0.045

0.020

0.030

. . .

. . .

0.030

Ti

0.20 + 4 (C

 

. . .

5 × C min;

...

7 × (C + N)

(Ti + Cb)

...

...

(Ti + Cb) =

(Ti + Cb) =

(Ti + Cb) =

. . .

. . .

0.10–0.60

0.30–0.50

0.07–0.30

 

 + N) min;

 

 

 0.75 max

 

 but no less

 0.20 + 4

 

 

 0.20–1.00

 0.20 + 4

 0.20–1.00

 

 

 

 

 

 

 1.10 max

 

 

 

 

 than 0.20

 (C + N)

 

 

 and 6 ×

 (C + N)

 and 6 ×

 

 

 

 

 

 

 

 

 

 

 

 min; 1.00

 min; 0.80

 

 

 (C + N)

 min to

 (C+ N)

 

 

 

 

 

 

 

 

 

 

 

 max

 max

 

 

 min

 0.80 max

 min

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Cb

...

 

. . .

...

0.05–0.20

...

...

...

...

...

...

...

0.15–
0.50F

. . .

(3 × %C + 0.30) min

. . .

0.10–0.60

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(Ti + Cb) =

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.20 +4(C+N)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

min;0.80 max

1.2 An optional supplementary requirement is provided, and when desired, shall be so stated in the order.

1.3 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. The inch-pound units shall apply unless the “M” designation of this specification is specified in the order.

1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

 
2. Referenced Documents

E213-22

Standard Practice for Ultrasonic Testing of Metal Pipe and Tubing

A1016/A1016M-23

Standard Specification for General Requirements for Ferritic Alloy Steel, Austenitic Alloy Steel, and Stainless Steel Tubes

A763-15(2021)

Standard Practices for Detecting Susceptibility to Intergranular Attack in Ferritic Stainless Steels

A480/A480M-23b

Standard Specification for General Requirements for Flat-Rolled Stainless and Heat-Resisting Steel Plate, Sheet, and Strip (Includes all amendments and changes 11/7/2023).

E273-20

Standard Practice for Ultrasonic Testing of the Weld Zone of Welded Pipe and Tubing