Products Features

Excellent low-temperature impact toughness (core advantage)

The core advantage of ASTM A333 lies in its excellent low-temperature impact toughness. This specification mandates Charpy V-notch impact testing of the material at specified low temperatures, ensuring sufficient resistance to brittle fracture under low-temperature service conditions. Grade 6 has an average impact energy of ≥ 18J and a minimum single value of ≥ 13J at -46°C, effectively mitigating the risk of brittle fracture in materials at low temperatures and ensuring the safety and reliability of pipelines during low-temperature service.

Good welding performance

The low carbon equivalent design of ASTM A333 ensures good weldability with a mature welding process, making it suitable for large-scale on-site installation. When welding low-temperature steel, strict control of heat input is required to prevent a decrease in the toughness of the heat-affected zone. Preheating is generally not necessary before welding (except for thick-walled pipes or in low-temperature environments), and post-weld heat treatment at 600-650°C can be optionally performed after welding to relieve residual stresses.

Good machinability

It can undergo various forming processes such as hot bending, cold bending, and forging, making it suitable for manufacturing pipe fittings like elbows, tees, and reducers. It can also be machined using conventional machining methods. It should be noted that Grades 3 (3.5% Ni) and 8 (9% Ni), due to their higher nickel content, have a slightly higher tendency for work hardening compared to Grade 6.

Mature technology and long-term reliability

It exhibits good organizational stability during long-term service within their respective applicable temperature ranges (Grade 6 ≤ -46°C / Grade 3 ≤ -101°C / Grade 8 ≤ -196°C). Delivered in normalized or normalized plus tempered condition, it achieves a uniform and fine microstructure, ensuring organizational stability and reliability under low-temperature service conditions.

Technical Specifications

Chemical Composition(ASTM A333 / ASME SA333)

Element	Grade 1	Grade 3	Grade 4	Grade 6	Grade 7	Grade 8	Grade 9	Note
C	≤ 0.30%	≤ 0.19%	≤ 0.12%	≤ 0.30%	≤ 0.19%	≤ 0.13%	≤ 0.20%	Ensure low-temperature toughness and weldability
Mn	0.40-1.06%	0.31-0.64%	0.50-1.05%	0.29-1.06%	≤ 0.90%	≤ 0.90%	0.40-1.06%	Solid solution strengthening, improve strength
P	≤ 0.035%	≤ 0.035%	≤ 0.035%	≤ 0.035%	≤ 0.035%	≤ 0.035%	≤ 0.035%	Harmful elements, strictly controlled
S	≤ 0.035%	≤ 0.035%	≤ 0.035%	≤ 0.035%	≤ 0.035%	≤ 0.035%	≤ 0.035%	Harmful elements, strictly controlled
Si	0.10-0.35%	0.13-0.32%	0.18-0.37%	≥ 0.10%	0.13-0.32%	0.13-0.32%	0.13-0.32%	Deoxidizer
Ni	-	3.18-3.82%	0.47-0.98%	-	2.03-2.57%	8.40-9.60%	1.60-2.24%	Elements of Low-Temperature Toughness
Cr	-	-	0.44-1.01%	-	-	-	-	Improve hardenability
Cu	-	-	0.40-0.70%	-	-	-	-	Improve corrosion resistance
Mo	-	-	0.40-0.75%	-	-	-	-	Enhance high-temperature strength
Fe	Remaining quantity	Remaining quantity	Remaining quantity	Remaining quantity	Remaining quantity	Remaining quantity	Remaining quantity	Matrix element

Physical Properties

Performance	Numerical Value/Range	Test conditions
Density	≈ 7.85 g/cm³	Room temperature (20°C)
Melting Point	≈ 1420-1460°C	-
Elastic modulus	≈ 200 GPa	Room temperature
Thermal Conductivity	≈ 50 W/(m·K)	Room temperature
Coefficient of thermal expansion (20-100°C)	≈ 11.7 × 10⁻⁶ /K	-
Poisson's ratio	≈ 0.28	Room temperature
Magnetism	Ferromagnetic	Carbon steel/ low-alloy steel, which is magnetic

Mechanical Properties (Typical value, ASTM A333)

Performance	Grade 1	Grade 3	Grade 4	Grade 6	Grade 7	Grade 8	Grade 9	Specification
Tensile Strength	≥ 380 MPa	≥ 450 MPa	≥ 415 MPa	≥ 415 MPa	≥ 450 MPa	≥ 690 MPa	≥ 435 MPa	ASTM A333
Yield strength	≥ 205 MPa	≥ 240 MPa	≥ 240 MPa	≥ 240 MPa	≥ 205 MPa	≥ 515 MPa	≥ 315 MPa	ASTM A333
Elongation	≥ 35%	≥ 30%	≥ 30%	≥ 30%	≥ 30%	≥ 22%	≥ 28%	ASTM A333
Impact test temperature	-46°C	-101°C	-46°C	-46°C	-73°C	-196°C	-73°C	ASTM A333
Impact Toughness (Average Value)	≥ 18J	≥ 18J	≥ 18J	≥ 18J	≥ 18J	≥ 18J	≥ 18J	ASTM A333

Note: Note: Grade 6 is the most widely used grade in the ASTM A333 standard, offering an excellent balance between strength, weldability, low-temperature toughness, and cost, suitable for low-temperature service conditions down to -46°C. Grade 3 (3.5% Ni) is applicable for -101°C, and Grade 8 (9% Ni) for -196°C.

Low-temperature Impact Performance (Core Indicator)

Grade	Minimum operating temperature	Impact test temperature	Minimum Impact Energy (Average Value)	Minimum impact energy (single value)	Typical applications
Grade 1	-46°C	-46°C	≥ 18J	≥ 13J	General low-temperature conditions
Grade 3	-101°C	-101°C	≥ 18J	≥ 13J	LNG, air separation unit
Grade 4	-46°C	-46°C	≥ 18J	≥ 13J	Low-temperature sulfur-containing environment
Grade 6	-46°C	-46°C	≥ 18J	≥ 13J	Most commonly used, preferred for -46°C low-temperature conditions
Grade 7	-73°C	-73°C	≥ 18J	≥ 13J	Lower temperature requirements
Grade 8	-196°C	-196°C	≥ 18J	≥ 13J	LNG storage tanks, liquid nitrogen/ liquid oxygen pipelines
Grade 9	-73°C	-73°C	≥ 18J	≥ 13J	Petrochemical deep cryogenic equipment

Heat treatment system

The final performance of ASTM A333 is highly dependent on the heat treatment regime:

Normalizing

Heat to 845-925°C, hold for sufficient time, then air cool. This results in a uniform and fine-grained microstructure, improving low-temperature toughness. The normalizing temperature for Grade 8 is typically 845-900°C, slightly higher than other grades.

Normalizing + Tempering (Recommended for Grade 8)

After normalizing, heat to 565-650°C for tempering, then air cool. This eliminates normalizing stresses and further optimizes low-temperature toughness.

Full Annealing (Optional)

Heat to 815-870°C, hold at temperature, then furnace cool to approximately 650°C, followed by air cooling to room temperature. Used to eliminate cold working stresses or improve cold working formability.

Post-Weld Heat Treatment (PWHT, selected based on wall thickness and operating conditions)

Heat to 600-650°C, hold at temperature, then cool slowly to eliminate residual welding stresses.

Applicable Media

Liquefied Natural Gas (LNG)

LNG receiving terminals, low-temperature pipelines of liquefaction plants (≤ -162°C)

Air separation unit

liquid oxygen, liquid nitrogen, liquid argon pipelines and cold box pipelines

Low-temperature liquids

Transportation of low-temperature media such as liquid ethylene, liquid ammonia, and liquid hydrogen

Petrochemical Deep Cryogenics

Deep Cryogenic Separation of Ethylene Plants, Low-Temperature Process Piping

Low-Temperature Storage Tanks

LNG storage tank pipelines, low-temperature spherical tanks

Note: Each grade of ASTM A333 has different applicable minimum temperature limits. Grade 6 is suitable for temperatures above -46°C, Grade 3 for above -101°C, and Grade 8 for above -196°C. When selecting materials, the appropriate grade should be chosen based on the minimum design temperature. It is not applicable to high-temperature conditions (above 350°C) and strongly corrosive media such as strongly oxidizing acids.

ASTM A333 is suitable for low-temperature service ranging from -46°C to -196°C and is recommended for use in the following areas:

Application Fields

LNG receiving terminals and liquefaction plants (core applications, Grade 3 / Grade 8)
● LNG unloading pipelines, vapor (BOG) pipelines
● LNG transportation pipelines (≤ -162°C)
● LNG Tank Accompanying Pipeline System
Air Separation and Industrial Gases (Core Applications, Grade 6 / Grade 3)
● Liquid Oxygen, Liquid Nitrogen, and Liquid Argon Piping Systems (-183°C ~ -196°C)
● Cold Box Piping Systems for Air Separation Units
● Low-Temperature Piping for Industrial Gas Separation Equipment
Petrochemical Deep Cryogenics (Core Applications, Grade 6 / Grade 7 / Grade 9)
● Deep Cryogenic Separation Pipelines for Ethylene Cracking Units (-100°C ~ -160°C)
● Low-temperature transportation pipelines for propylene and butadiene
● Low-temperature methanol wash (Rectisol) process piping
Low-temperature storage and transportation
● Piping system for low-temperature liquid storage tanks
● Filling pipeline system for low-temperature tank trucks
● Pipelines for liquefied gas transport ships
Low-temperature pipe fittings
● Low-temperature elbows, tees, reducers
● Low-temperature forged pipe fittings, flanges

Delivery and Customization

We offer flexible and reliable supply chain solutions to ensure you receive ASTM A333 low-temperature seamless steel pipes that perfectly match your project requirements.
Customizable material forms
We support producing various basic and special shapes according to drawings or specifications.

Form	Hot-rolled seamless steel pipe	Cold-drawn seamless steel pipe	Large-diameter thick-walled pipe
Conventional Range	Diameter: 60.3 - 1067 mm; Wall Thickness: 3 - 150 mm	Outer Diameter: 10.3 - 114.3 mm; Wall Thickness: 1 - 15 mm	Outer Diameter: 219 - 1067 mm; Wall Thickness: 20 - 150 mm
Customization Capability	Fixed-length cutting, bevel processing, pipe end threads, normalized/ annealed condition	Precision Dimension Control, Bright Annealing, Fixed-Length Cutting	Hot expansion of tubes, fixed-length cutting, bevel machining

Why Choose Us? - Reliable Engineering Technology. Dependable Delivery.

We are not just a supplier, but a trusted materials partner for you in China.

Vertically Integrated Production

Own 20,000㎡ facility with 10+ automated lines (8,000+ tons/year). In-house tooling & die center enables rapid customization and effective cost control - no middleman markup.

Strict Quality Control at Every Stage

Full traceability across key QC checkpoints throughout production. 100% compliant with ASTM/ASME, EN, and GB standards. Material test reports available with every shipment.

Reliable Delivery & Export Packaging

10+ years exporting to Europe, North America, Southeast Asia & Middle East with waterproof and anti-rust protection, combined with flexible shipping options ensures safe and on-time arrival.

Sample Validation Before Mass Production

We provide free samples for quality verification, allowing you to place bulk orders only after approval. We ensure consistency from sample to mass production by accurate dimensional measurement and transparent manufacturing.

FAQ

Q: What are the main advantages of ASTM A333 Grade 6?

Q: What is the difference between ASTM A333 Grade 6 and ASTM A106 Grade B? How to choose between them?

Q: How to select the commonly used grades of ASTM A333?

Q: What is the minimum service temperature for ASTM A333 Grade 6?

Q: What is the welding performance of ASTM A333 Grade 6?

Q: What is the corrosion resistance of ASTM A333 Grade 6?

Hot Tags: astm a333, China astm a333 manufacturers, suppliers, factory

Comparison Item	ASTM A333 Gr.6	ASTM A106 Gr.B
Core purpose	Low-temperature process pipelines (LNG, air separation units)	High-temperature operating condition pipelines (power plants, refineries)
Design temperature	Lowest -46°C	Up to 427°C
Impact Toughness Requirements	Mandatory requirement (-46°C impact energy ≥ 18J)	No mandatory impact requirements
Product form	Seamless or welded	Limited to seamless steel pipes
Selection suggestions	Low-temperature conditions should be given priority	High-temperature operating conditions should be prioritized for

Grade	Minimum operating temperature	Core Features	Typical applications	Selection suggestions
Grade 6	-46°C	Carbon steel, which offers the best cost-performance ratio and is the most commonly used	General low-temperature operating conditions, pipeline in cold regions	Preferred for low-temperature conditions above -46°C
Grade 3	-101°C	3.5% Ni, excellent low-temperature toughness (-101°C)s	LNG receiving terminal, air separation unit	-46°C to -101°C operating conditions
Grade 8	-196°C	Ni, ultra-low temperature toughness	LNG storage tanks, liquid oxygen/liquid nitrogen pipelines	-101°C to -196°C ultra-low temperature conditions

ASTM A333

Products Features

Technical Specifications

Application Fields

Delivery and Customization

Why Choose Us? - Reliable Engineering Technology. Dependable Delivery.

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