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Q620ME STRUCTURAL STEEL (TMCP)

TMCP Delivery | Grade Q620ME | Yield 620MPa | Impact -40°C 31J | Extreme Low-Temperature Ultra-High Strength Steel 🔍 Q620ME Grade Lookup →

Product Overview

Q620ME is a Chinese grade low-alloy high-strength structural steel conforming to GB/T 1591-2018 standard. Delivered in thermomechanically rolled (TMCP) condition, it offers refined grain structure, excellent weldability, and guaranteed extreme low-temperature toughness. The quality grade E provides impact properties at -40°C (longitudinal min. 31J, transverse min. 20J). With minimum yield strength of 620MPa (≤16mm), it delivers superior strength for arctic engineering, offshore structures, and critical building applications requiring exceptional performance in severe cold environments.

Equivalent grades: Q620ME ↔ Q620E (previous domestic grade), EN 10025-4 S620MC (Europe), ASTM A656 Grade 90 (USA).

International Grade Comparison

Europe (EN 10025-4)

S620MC

Impact: 0°C (40J)

Yield: 620MPa

C: ≤0.16%

Si: ≤0.60%

Mn: ≤2.00%

P: ≤0.025%

S: ≤0.020%

China (GB/T 1591)

Q620ME

Impact: -40°C (31J)

Yield: 620MPa

C: ≤0.18%

Si: ≤0.60%

Mn: ≤2.00%

P: ≤0.025%

S: ≤0.020%

TMCP Delivery | Grade E -40°C Impact

USA (ASTM A656)

Gr.90

Impact: -20°C (optional)

Yield: 620MPa min

C: ≤0.18%

Si: ≤0.60%

Mn: ≤1.80%

P: ≤0.025%

S: ≤0.020%

Note: Q620ME is delivered in TMCP condition, offering refined grain structure and guaranteed impact toughness at -40°C. S620MC offers similar yield strength with 0°C impact (40J); ASTM A656 Grade 90 provides comparable strength (620MPa min) with optional -20°C impact.

China Grade Comparison: Q620E vs Q620ME

Q620E (Previous)

As-rolled / Normalized

Yield: 620MPa (≤16mm)

Impact -40°C: 31J (Longitudinal)

C: ≤0.20%

P: ≤0.025%

S: ≤0.020%

Delivery: As-rolled or normalized

Q620ME (TMCP)

TMCP

Yield: 620MPa (≤16mm)

Impact -40°C: 31J (Longitudinal) / 20J (Transverse)

C: ≤0.18% (lower carbon)

Mn: ≤2.00%

Cr: ≤1.00%

P: ≤0.025%

S: ≤0.020%

Delivery: TMCP, refined grain, superior weldability, guaranteed -40°C toughness

Key Advantages

Ultra-High Strength

Min yield 620MPa, tensile 710-880MPa (≤40mm).

-40°C Impact Toughness

Guaranteed KV2 31J at -40°C (Longitudinal).

Excellent Weldability

Optimized TMCP process, low carbon equivalent.

Applications

Heavy Machinery & Arctic

Cranes, mining equipment, excavators, arctic infrastructure requiring ultra-high strength and -40°C impact toughness.

Engineering Structures

Bridge girders, transmission towers, offshore platforms, polar infrastructure, extreme cold environments.

Q620ME Chemical Composition

Chemical element composition of Chinese grade Q620ME low alloy high strength structural steel
Current manufacturing execution standard: GB/T 1591-2018

Grade Quality C ≤ Si ≤ Mn ≤ P ≤ S ≤
Q620M E 0.18 0.60 2.00 0.025 0.020
Nb V Ti Cr ≤ Ni ≤ Cu ≤ Mo ≤ N ≤ B ≤ Als ≥
0.01-0.11 0.01-0.12 0.006-0.05 1.00 0.80 0.80 0.30 0.025 0.004 0.015

Notes: The steel shall contain at least one grain-refining element (Al, Nb, V, Ti) with content not less than lower limit. All-aluminum (Alt) min 0.02% if substituted. For structural steel and bars, P/S can increase by 0.005%. Ti can be as high as 0.2%.

Mechanical Properties

Upper yield strength ReH (MPa, min)

≤16mm 16-40mm 40-63mm 63-80mm 80-100mm 100-120mm
620 610 600 580 — —

Tensile strength Rm (MPa)

≤40mm 40-63mm 63-80mm 80-100mm 100-120mm
710-880 690-880 670-860 — —

Elongation A% (min): 15%

Impact KV2 (J) min – Quality E (-40°C)

Direction -40°C
Longitudinal 31
Transverse 20
Note: Thermomechanically rolled (TMCP) condition includes TMCP + tempered condition. If yield not obvious, use Rp0.2. For thickness >80mm, consult technical specifications.

Size & Specification

Product Thickness (mm) Width (mm) Length (mm)
Plate 3-80 1000-4000 3000-18000
Sheet/Coil 1.5-20 900-2000 Coil or cut length

Custom sizes and cutting available upon request.

Customizable Options

Laser/plasma cutting, edge beveling, shot blasting, priming, third-party inspection, custom marking.

Quality Assurance

Full Testing
Spectral analysis, tensile & impact, ultrasonic
MTC 3.1/3.2
Full traceability & EN10204 docs

Packaging & Logistics

Bundled with steel straps, waterproof wrapping, clear marking. FOB, CIF, CFR from major Chinese ports. Lead time: 25-35 days.

Request a Quote

Direct email: customize@cehesteel.com – reply within 2 hours.

Frequently Asked Questions

What is Q620ME?

TMCP low-alloy high-strength steel per GB/T 1591-2018, min yield 620MPa, grade E guarantees impact 31J at -40°C (longitudinal).

Equivalent to S620MC?

Yes, comparable to EN 10025-4 S620MC and ASTM A656 Grade 90.

Difference Q620ME vs Q620E?

Q620ME features TMCP delivery for refined grain structure, superior weldability, and guaranteed -40°C impact with transverse requirements (20J).

Typical applications?

Heavy-duty engineering structures (cranes, mining equipment, bridges), arctic infrastructure requiring ultra-high strength and -40°C toughness.