ASTM A333 Grade 7 Seamless Pipes

ASTM A333 Standard covers seamless and welded steel pipe for low temperature service. The ASTM A333 Grade 7 steel involved is similar to AISI 4032 low alloy steel. ASTM A333 Grade 7 pipe shall be made by the seamless or welding process with the addition of no filler metal in the welding operation.

Seamless and Welded Steel Pipe size for Low-Temperature Service:

  • Outer Dimensions: 19.05mm-114.3mm
  • Wall Thickness:2.0mm-14 mm
  • Length: max 16000mm

Application: Seamless and Welded Steel Pipe for Low-Temperature Service.
Steel grade: ASTM A333 Grade 7
Inspection and Test:

  • Chemical Composition Inspection, Mechanical Properties Test
  • Tensile Strength,Yield Strength, Elongation, Flaring, Flattening, Bending, Hardness, Impact Test
  • Surface and Dimension Test,No-destructive Test, Hydrostatic Test.

 

Crade The lowest temperature for strike test
ASTM A333 Grade 7 -100 -75

ASTM A333 Gr. 7 Chemical Compositions(%)

Grade Chemical Composition (%)
C(max) Si Mn P(max) S(max) Cr Ni
Grade 7 0.19 0.13-0.32 0.9 0.025 0.025 2.03-2.57

ASTM A333 Gr.7 Mechanical Properties

Grade Tensile Strength (MPa) Yield Point (MPa) Elongation (%)
Y X
ASTM A333 Grade 7 ≥450 ≥240 ≥30 ≥22

Impact temperature

Minimum Impact Test Temperature -45 C(-50 F)

Impact requirements

 Size Minimum Average Notched Bar Impact Value of Each Set of Three Specimens Minimum Notched Bar Impact Value of One Specimen Only of a Set
Size of Specimen, mm
ft-lbf
J
ft-lbf
J
10 by 10
13
18
10
14
10 by 7.5
10
14
8
11
10 by 6.67
9
12
7
9
10 by 5
7
9
5
7
10 by 3.33
5
7
3
4
10 by 2.5
4
5
3
4

Straight line interpolation for intermediate values is permitted.

Impact temperature reduction

Specimen Width Along Notch or Actual Material Thickness mm Temperature Reduction,Degrees Colder C
10 (standard size) 0
9 0
8 0
7.5 (3/4 standard size) 3
7 4
6.67 (2/3 standard size) 5
6 8
5 (1/2 standard size) 11
4 17
3.33 (1/3 standard size) 19
3 22
2.5 (1/4 standard size) 28

P Number/ Group Number

ASTM A333
Grade 6
P Number
1
Group
1

Machinability

Machinability is good, similar to law alloy 4032 steel.

Forming

The product comes in piping form but may be formed readily by conventional methods.

Welding

Weldable by conventional methods.

Heat Treatment

Product is supplied in the normalized, 1500 f and air cooled, condition. It may be quenched and tempered by heating to 1475 F, quench in circulating water and then temper by re-heating to 1100 F and rapid air cooling.

Forging

Product is supplied in pipe form and not normally forged from that shape.

Hot Working

Hot working may be done qt 2000 F down to 1600 F if need be. Do not hot work below 1550 F and immediately following hot working cool in a controlled atmosphere furnace from a temperature above 1550 F.

Cold Working

Cold working may be done by conventional methods.

Annealing

Anneal, or normalize, at 1600 F and air cool.

Strike Temperature Condition

Grade The lowest temperature for strike test
ASTM A333 Gr.6 -150 -100

Packing:

  • Packed in wooden crates, wrapped in plastic, and suitably protected for sea-worthly delivery or as requested.
  • Both ends of each crate will indicate the order no., heat no., dimensions, weight and bundles or as requested.

Delivery:

Pipes are supplied in hexagonal bundles or round bundles tied with steel strip.
Weight of bundle – up to 5000 kg upon request of customer.
Each bundle is furnished with three tags.

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