ASTM A333

Product introduction

ASTM A333/A333M Steel: Material Analysis and Mechanical Properties

1. Material Overview

ASTM A333/A333M is the standard specification for seamless and welded steel pipe for low-temperature service. This specification covers wall seamless and welded carbon and alloy steel pipe intended for use at low temperatures where notch toughness is required. The pipes are suitable for bending, flanging, and similar forming operations.

2. Chemical Composition by Grade

Grade	C (%) max	Mn (%)	P (%) max	S (%) max	Si (%)	Ni (%)	Other Elements	Key Feature
Grade 1	0.30	0.40-1.06	0.025	0.025	0.10-0.50	-	Cu ≤ 0.40	Lowest temp: -50°F (-45°C)
Grade 3	0.19	0.31-0.64	0.025	0.025	0.18-0.37	3.18-3.82	-	Nickel steel for low temp
Grade 4	0.12	0.50-1.05	0.025	0.025	0.18-0.37	-	-	Killed carbon steel
Grade 6	0.30	0.29-1.06	0.025	0.025	0.10-0.50	-	-	Similar to Grade 1
Grade 7	0.19	0.90 max	0.025	0.025	0.13-0.32	2.03-2.57	-	2.25% Nickel steel
Grade 8	0.13	0.90 max	0.025	0.025	0.13-0.32	3.18-3.82	-	3.5% Nickel steel
Grade 9	0.20	0.40-1.06	0.025	0.025	0.10-0.50	1.60-2.24	-	2.0% Nickel steel
Grade 10	0.20	1.15-1.50	0.025	0.025	0.10-0.50	-	-	High manganese
Grade 11	0.10	0.30-0.70	0.025	0.025	0.10-0.50	-	Al min 0.02	Aluminum killed

3. Mechanical Properties and Temperature Ratings

Grade	Tensile Strength min	Yield Strength min	Elongation min	Minimum Test Temperature	Charpy Impact Energy Requirement
Grade 1	55,000 psi (380 MPa)	30,000 psi (205 MPa)	35%	-50°F (-45°C)	13 ft-lb (18 J) avg
Grade 3	65,000 psi (450 MPa)	35,000 psi (240 MPa)	30%	-150°F (-101°C)	13 ft-lb (18 J) avg
Grade 4	60,000 psi (415 MPa)	35,000 psi (240 MPa)	30%	-75°F (-59°C)	13 ft-lb (18 J) avg
Grade 6	60,000 psi (415 MPa)	35,000 psi (240 MPa)	30%	-50°F (-45°C)	13 ft-lb (18 J) avg
Grade 7	65,000 psi (450 MPa)	40,000 psi (275 MPa)	30%	-100°F (-73°C)	13 ft-lb (18 J) avg
Grade 8	65,000 psi (450 MPa)	40,000 psi (275 MPa)	30%	-150°F (-101°C)	13 ft-lb (18 J) avg
Grade 9	63,000 psi (435 MPa)	46,000 psi (315 MPa)	30%	-100°F (-73°C)	13 ft-lb (18 J) avg
Grade 10	65,000 psi (450 MPa)	50,000 psi (345 MPa)	30%	-75°F (-59°C)	13 ft-lb (18 J) avg
Grade 11	60,000 psi (415 MPa)	35,000 psi (240 MPa)	35%	-325°F (-198°C)	13 ft-lb (18 J) avg

4. Low-Temperature Toughness Characteristics

Charpy Impact Energy vs. Temperature (Schematic - Grade 3 & 8)
↑ Impact Energy (ft-lb)
|
|50 ┼∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙
|   |∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙
|40 ┼∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙
|   |∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙ [Grade 8 (3.5% Ni)]
|30 ┼∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙
|   |∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙
|20 ┼∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
|   |∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
|10 ┼∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓ [Grade 3 (3.5% Ni)]
|   |∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
|   |∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
| 0 ┼──────────────────────────────────────░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░
|   |                                      ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░
|   |                                      ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ [Carbon Steel Grade 1]
|-10┼──────────────────────────────────────░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░
|   |                                      ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░
    └──────────────────────────────────────────────────────────────────────────────────────────────────→
     -200°F   -150°F   -100°F   -50°F     0°F     +50°F
     (-129°C) (-101°C) (-73°C)  (-45°C)  (-18°C) (+10°C)
     
∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙ = Nickel steel maintains toughness at lower temperatures
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓ = Nickel steel impact transition range
░░░░░░░░░░░░░░░ = Carbon steel rapid toughness decline

5. Key Characteristics

Low-Temperature Toughness: Primary feature - maintains ductility and impact resistance at sub-zero temperatures
Nickel Alloying: Grades with nickel (3, 7, 8, 9) provide superior low-temperature properties
Fine Grain Practice: Required to ensure consistent low-temperature performance
Normalized Condition: Typically supplied normalized to optimize toughness
Notch Toughness: Verified through Charpy V-notch impact testing at specified temperatures
Weldability: Generally good with proper procedures, especially for cryogenic grades

6. Common Applications

LNG (Liquefied Natural Gas) facilities and pipelines
Cryogenic storage tanks and transfer lines
Refrigeration systems and cold storage facilities
Chemical plants processing gases at low temperatures
Oil & gas industry in arctic environments
Ammonia and ethylene processing equipment
Industrial gas production (oxygen, nitrogen, argon)

7. Comparison with Similar Pipe Materials

Property	ASTM A333 (Low-Temp)	ASTM A53 (General)	ASTM A106 (High-Temp)	ASTM A312 (Stainless)
Service Temperature	Down to -325°F (-198°C)	Ambient to 400°F (204°C)	Up to 750°F (399°C)	Cryogenic to 1500°F (816°C)
Key Element	Nickel (in some grades)	Carbon	Carbon-Manganese	Chromium-Nickel
Impact Testing	Required (Charpy V-notch)	Not required	Not required	Required for low-temp
Typical Cost	Medium-High	Low	Low-Medium	High
Corrosion Resistance	Low (carbon steel)	Low	Low	Excellent
Common Grades	1, 3, 6, 8	A, B	A, B, C	304, 304L, 316, 316L

8. Heat Treatment Requirements

Grade	Required Heat Treatment	Purpose	Typical Process
All Grades	Normalizing or Normalizing & Tempering	Grain refinement, toughness optimization	Heat to 1600-1700°F (871-927°C), air cool
Welded Pipe	Full body normalization or Q&T	HAZ toughness restoration	After welding, re-normalize entire pipe
Thick Wall	Quench & Temper	Through-thickness properties	For wall thickness > specified limit
Grade 11	Double Normalize & Temper	Ultra-low temp toughness	Special cycle for -325°F service

9. Fabrication & Welding Considerations

Welding Processes: SMAW (stick), GTAW (TIG), GMAW (MIG), SAW (sub-arc) with low-hydrogen procedures
Preheat Requirements: 200-400°F (93-204°C) depending on thickness and grade
Filler Metals: Must match or exceed base metal toughness (E7018, E8018-C3, etc.)
Post-Weld Heat Treatment: Often required for stress relief, especially for thick sections
Bending & Forming: Can be cold or hot formed with proper procedures
Weld Qualification: Essential - welds must pass impact testing at design temperature

10. Limitations and Special Requirements

Impact Testing Mandatory: Each heat and each pipe size must be impact tested
Temperature Specific: Each grade rated for specific minimum temperature
Not for High Temperatures: Strength decreases significantly above 400°F (204°C)
Corrosion Vulnerability: Requires protection in corrosive environments
Cost Premium: Nickel-alloyed grades significantly more expensive than carbon steel
Quality Assurance: Extensive testing and documentation required
Special Handling: Protection against moisture contamination during storage

*Note: ASTM A333 pipe is commonly specified for ASME B31.3 Process Piping and other pressure piping codes. Design must consider not only pressure but also thermal contraction stresses at low temperatures. Grade selection depends on the specific minimum design temperature and required toughness. For LNG service (-260°F/-162°C), stainless steel (A312) or aluminum pipes are typically used instead of A333.*

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