Q355E seamless steel pipe is a type of low-alloy, high-strength structural steel designed for demanding engineering applications. The letter "Q" denotes the minimum yield strength, meaning Q355 indicates a yield strength of 355 MPa.
The suffix "E" signifies that the steel maintains a minimum impact energy of 27 J at –40°C, demonstrating its outstanding resistance to brittle fracture under low-temperature conditions.
In terms of mechanical performance, Q355E seamless steel pipes possess a tensile strength range of 470–630 MPa, ensuring exceptional tensile capability and increasing the safety and durability of components in service.
Advantages of Q355E Seamless Steel Pipes
1. Superior Strength and Toughness
Q355E seamless pipes combine high yield strength with excellent tensile strength while maintaining reliable impact toughness in low-temperature environments. These properties enable the pipes to perform well under heavy loads and harsh conditions.
2. Excellent Low-Temperature Performance
Engineered for cold-region applications, Q355E seamless steel pipes remain stable when operating between –40°C and –60°C. Owing to optimized chemical composition and controlled production processes, the pipes resist brittle cracking and stress corrosion in extreme cold environments.
3. Adequate Corrosion Resistance
Although not classified as a corrosion-resistant alloy, Q355E provides sufficient resistance against general atmospheric corrosion. Its performance can be significantly enhanced through hot-dip galvanizing or other protective surface coatings.
Specifications
| Item | Description |
|---|---|
| Product name | Q355E Seamless Steel Pipe for Low-Temperature Service |
| Origin | China |
| Standards | GB/T 6479, GB/T 8163, GB/T 8162 |
| Related standards | GB/T 18984, ASTM A333 |
| Material grade | Q355E |
| Outer diameter | 10.3 mm – 914.4 mm |
| Wall thickness | 1 mm – 30 mm |
| Length | 3 m – 12 m or customized |
| Technique | Hot rolled |
| Surface treatment | Black paint, varnish, hot-dip galvanizing, or as required |
| Pipe ends | Plain end, beveled end |
| Delivery condition | Normalized |
Chemical Composition (%)
| Grade | C max | Si max | Mn | P max | S max | Nb | V | Ti | Cr max | Ni max | Mo max | N max |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Q355E | 0.18 | 0.50 | 0.90–1.65 | 0.025 | 0.020 | 0.005–0.05 | 0.01–0.12 | 0.006–0.05 | 0.30 | 0.50 | 0.10 | 0.015 |
Mechanical Properties
| Grade | Yield Strength (min, MPa) | Tensile Strength (MPa) | Elongation (%) |
|---|---|---|---|
| Q355E | 355 | 470–630 | 22 |
Applications of Q355E Seamless Steel Pipes
Q355E seamless pipes are applicable across numerous industries, particularly where both strength and low-temperature resistance are essential.
1. Construction and Structural Engineering
Widely used for building frames, supports, beams, and load-bearing components. Its high strength allows structures to resist heavy forces, enhancing overall safety and stability.
2. Low-Temperature Service
Ideal for storing or transporting cryogenic and low-temperature fluids, thanks to its reliable impact toughness at –40°C and below.
3. Petroleum and Chemical Industries
Because of its satisfactory corrosion resistance and strong mechanical performance, Q355E is suitable for pipelines, processing equipment, and medium-corrosive service environments.
