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Q500MD STRUCTURAL STEEL (TMCP)

TMCP Delivery | Grade Q500MD | Yield 500MPa | Impact -20°C 47J | Cold Climate Structural Steel 🔍 Q500MD Grade Lookup →

Product Overview

Q500MD 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 low-temperature toughness. The quality grade D provides impact properties at -20°C (longitudinal min. 47J, transverse min. 27J). With minimum yield strength of 500MPa (≤16mm), it delivers superior strength for cold climate engineering structures, offshore platforms, and demanding infrastructure projects in low-temperature environments.

Equivalent grades: Q500MD ↔ Q500D (previous domestic grade), EN 10025-4 S500ML (Europe), ASTM A656 Grade 80 (USA).

International Grade Comparison

Europe (EN 10025-4)

S500ML

Impact: -50°C (27J)

Yield: 500MPa

C: ≤0.16%

Si: ≤0.60%

Mn: ≤1.80%

P: ≤0.025%

S: ≤0.020%

China (GB/T 1591)

Q500MD

Impact: -20°C (47J)

Yield: 500MPa

C: ≤0.18%

Si: ≤0.60%

Mn: ≤1.80%

P: ≤0.030%

S: ≤0.025%

TMCP Delivery | Grade D -20°C Impact

USA (ASTM A656)

Gr.80

Impact: -20°C (optional)

Yield: 550MPa min

C: ≤0.18%

Si: ≤0.60%

Mn: ≤1.80%

P: ≤0.025%

S: ≤0.020%

Note: Q500MD is delivered in TMCP condition, offering refined grain structure and guaranteed impact toughness at -20°C. S500ML offers similar yield strength with -50°C impact; ASTM A656 Grade 80 provides higher strength (550MPa min) with optional -20°C impact.

China Grade Comparison: Q500D vs Q500MD

Q500D (Previous)

As-rolled / Normalized

Yield: 500MPa (≤16mm)

Impact -20°C: 47J (Longitudinal)

C: ≤0.20%

Delivery: As-rolled or normalized

Q500MD (TMCP)

TMCP

Yield: 500MPa (≤16mm)

Impact -20°C: 47J (Longitudinal) / 27J (Transverse)

C: ≤0.18% (lower carbon)

Delivery: TMCP, refined grain, superior weldability, guaranteed -20°C toughness

Key Advantages

Ultra-High Strength

Min yield 500MPa, tensile 610-770MPa.

-20°C Impact Toughness

Guaranteed KV2 47J at -20°C (Longitudinal).

Excellent Weldability

Optimized TMCP process, low carbon equivalent.

Applications

Building Structures

High-rise buildings, stadiums, industrial plants, cold-region construction requiring -20°C impact reliability.

Engineering Structures

Bridge girders, transmission towers, offshore platforms, heavy machinery in cold environments.

Q500MD Chemical Composition

Chemical element composition of Chinese grade Q500MD low alloy high strength structural steel
Current manufacturing execution standard: GB/T 1591-2018

Grade Quality C ≤ Si ≤ Mn ≤ P ≤ S ≤
Q500M D 0.18 0.60 1.80 0.030 0.025
Nb V Ti Cr ≤ Ni ≤ Cu ≤ Mo ≤ N ≤ B ≤ Als ≥
0.01-0.11 0.01-0.12 0.006-0.05 0.6 0.8 0.55 0.2 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
500 490 480 460 450 —

Tensile strength Rm (MPa)

≤40mm 40-63mm 63-80mm 80-100mm 100-120mm
610-770 600-760 590-750 540-730 —

Elongation A% (min): 17%

Impact KV2 (J) min – Quality D (-20°C)

Direction -20°C
Longitudinal 47
Transverse 27
Note: Thermomechanically rolled (TMCP) condition includes TMCP + tempered condition. If yield not obvious, use Rp0.2. For thickness >120mm, consult technical specifications.

Size & Specification

Product Thickness (mm) Width (mm) Length (mm)
Plate 3-100 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 Q500MD?

TMCP low-alloy high-strength steel per GB/T 1591-2018, min yield 500MPa, grade D guarantees impact 47J at -20°C (longitudinal).

Equivalent to S500ML?

Yes, comparable to EN 10025-4 S500ML and ASTM A656 Grade 80.

Difference Q500MD vs Q500D?

Q500MD features lower carbon (≤0.18%), TMCP delivery ensures refined grain structure, superior weldability, and guaranteed -20°C impact with transverse requirements.

Typical applications?

Engineering structures (bridges, offshore platforms, transmission towers) and building structures (high-rise buildings, cold-region infrastructure).