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Q390D STRUCTURAL STEEL

Chemical element composition – Chinese grade Q390D low alloy high strength structural steel 🔍 Q390D Grade Lookup →

Product Overview

Q390D is a Chinese grade low-alloy high-strength structural steel conforming to GB/T 1591-2018 standard. Grade D provides guaranteed impact toughness at -20°C. With minimum yield strength of 390MPa, it provides higher strength than Q355 series and is widely used in bridges, buildings, pressure vessels, and engineering structures requiring enhanced load-bearing capacity in low-temperature conditions.

Equivalent grades: Q390D ↔ Q355D (lower strength domestic), EN 10025 S420J2 (Europe), ASTM A572 Grade 65 (USA).

International Grade Comparison

Europe (EN 10025-2)

S420J2

Impact: -20°C (27J)

Yield: 420MPa

C: ≤0.22%

Si: ≤0.55%

Mn: ≤1.70%

P: ≤0.025%

S: ≤0.025%

Nb: ≤0.05%

V: ≤0.12%

Ti: ≤0.05%

USA (ASTM A572)

Gr.65

Impact: Not specified

Yield: 450MPa

C: ≤0.26%

Si: ≤0.40%

Mn: ≤1.35%

P: ≤0.025%

S: ≤0.025%

Nb: ≤0.05%

V: ≤0.15%

Ti: ≤0.05%

China (GB/T 1591)

Q355D

Impact: -20°C (34J)

Yield: 355MPa

C: ≤0.20%

Si: ≤0.55%

Mn: ≤1.60%

P: ≤0.025%

S: ≤0.025%

Nb: ≤0.05%

V: ≤0.12%

Ti: ≤0.05%

Note: Q390D offers higher strength than Q355D and is comparable to S420J2 and ASTM A572 Grade 65; always verify specific requirements before substitution.

China Grade Comparison: Q390B vs Q390C vs Q390D

Q390B

Grade B

Impact: +20°C

KV2 (L): 34J

P: ≤0.035%

S: ≤0.035%

Q390C

Grade C

Impact: 0°C

KV2 (L): 34J

P: ≤0.030%

S: ≤0.030%

Q390D

Grade D

Impact: -20°C

KV2 (L): 34J

P: ≤0.030%

S: ≤0.025%

Note: Q390 series grades share similar tensile properties. The key differences are impact test temperature and impurity limits: B (+20°C, 34J, P≤0.035%, S≤0.035%), C (0°C, 34J, P≤0.030%, S≤0.030%), D (-20°C, 34J, P≤0.030%, S≤0.025%).

Key Advantages

Higher Strength

Minimum yield strength of 390MPa (≤16mm) and tensile strength 490-650MPa, ideal for high-stress structural applications.

Good Weldability

Controlled carbon content and micro-alloying elements ensure good weldability for most fabrication processes.

-20°C Impact Toughness

Grade D provides guaranteed impact energy of 34J at -20°C (longitudinal), suitable for low-temperature applications.

Applications

Building Structures

High-rise buildings, industrial plants, stadiums, steel frameworks requiring higher strength in cold regions.

Heavy Machinery

Construction machinery, crane booms, mining equipment, heavy vehicles for arctic conditions.

Q390D Chemical Composition (GB/T 1591-2018)

Grade Quality C Si Mn P S
Q390 D ≤0.20 ≤0.55 ≤1.7 ≤0.030 ≤0.025
Nb V Ti Cr Ni Cu Mo N Als (min)
≤0.05 ≤0.13 ≤0.05 ≤0.3 ≤0.5 ≤0.4 ≤0.1 ≤0.015 ≥0.015

Notes:

a. For bars, P/S upper limit +0.005%.

b. V+Nb+Ti ≤0.22%, Mo+Cr ≤0.30%.

c. Ti up to 0.20% maximum.

d. Alt (total aluminum) can substitute Als with minimum 0.020%. When Nb/V/Ti added at specified levels, Als lower limit not required.

e. Steel must contain at least one grain-refining element (Al, Nb, V, Ti) with content not less than specified minimum.

Q390D Tensile Properties (GB/T 1591-2018)

Upper yield strength ReH/MPa ≥
Grade ≤16mm 16-40mm 40-63mm 63-80mm 80-100mm 100-150mm 150-200mm 200-250mm
Q390D 390 380 360 340 340 320 310 300
Property Thickness Range Value
Tensile Strength Rm ≤100mm 490-650 MPa
100-200mm 470-620 MPa
200-250mm 470-620 MPa
Elongation A % ≤16mm 20%
16-40mm 20%
40-63mm 20%
63-80mm 19%
80-200mm 19%
200-250mm 19%
Impact Temperature 20°C 0°C -20°C
KV2 (J) ≥ Longitudinal 55 47 34
Transverse 31 27 27

Notes: When yield not obvious, use Rp0.2.

Size & Specification

Product Form Thickness (mm) Width (mm) Length (mm)
Plate 3 - 250 1000 - 4000 3000 - 18000
Sheet / Coil 1.5 - 20 900 - 2000 Coil or cut to length

Other sizes can be produced upon request. Custom cutting available.

Customizable Options

We offer comprehensive customization services to meet your specific project requirements:

Custom Dimensions
Non-standard sizes, laser cutting		 Surface Treatments
Shot blasting, priming		 Edge Preparation
Beveling, machining
Custom Heat Treatment
Normalizing, stress relieving		 Special Testing
Third-party inspection		 Custom Marking
Special labeling

Quality & Manufacturing Assurance

Modern Production

Advanced continuous casting and controlled rolling technology

In-process Inspection

Rigorous testing at each stage, including spectral analysis and impact testing at -20°C

Full Documentation

Mill Test Certificate (MTC) compliant with EN 10204 3.1/3.2

Packaging & Logistics

  • Packaging: Steel plates bundled with steel straps on wooden skids. Coils wrapped with waterproof paper and steel covers.
  • Marking: Each bundle/coil marked with grade, size, heat number, weight.
  • Logistics: FOB, CIF, CFR from main Chinese ports. Lead time 25-35 days after order.

Request a Quote

Emails go directly to customize@cehesteel.com — reply within 2h.

Frequently Asked Questions

What is Q390D?

Q390D is a hot-rolled low-alloy structural steel per GB/T 1591-2018 with 390MPa min yield and 34J impact at -20°C.

What are the equivalents of Q390D?

Q390D is comparable to Q355D (domestic), EN 10025 S420J2 (Europe), and ASTM A572 Grade 65 (USA).

Weldability?

Good weldability with appropriate procedures due to controlled chemistry and low carbon content.

Available thickness?

3mm to 250mm plates, 1.5-20mm coils/sheets with custom cutting available.

Mill certificates?

Yes, EN 10204 3.1 MTC with full data including -20°C impact test results.

Difference between B, C, D?

Impact temperature: B (+20°C), C (0°C), D (-20°C) with tightening impurity limits.