Description: BBN steel is a well-known steel manufacturer and service provider in China, GB/T1591 Q345D steel plate,GB/T1591 Q345D low alloy steel plate is our superior product, we are favored by customers with high quality, competitive price and excellent service
Payment Terms: L/C, T/T, D/P, Western Union, Paypal, Money Gram
Premium Low-Temperature ToughnessQ345D is a high-strength low-alloy steel with guaranteed -20°C Charpy V-notch impact performance, ideal for offshore containers and deep-sea structures.
Stable Stock & Flexible CustomStock plates 3–500mm thick available; custom production 10–40 working days. Cut-to-length up to 18000mm and width up to 4200mm.
Strict Quality CertificationEN 10204 3.1 / 3.2 MTC available, third-party inspection supported, multi-standard UT and low-temperature impact verification.
01Product Overview & Execution Standards
GB/T 1591 Q345D is a premium high-strength low-alloy structural steel manufactured in accordance with the GB/T 1591 national standard. It is characterized by exceptional low-temperature toughness, stable mechanical properties and outstanding weldability.
Featuring high tensile strength and excellent adaptability to extreme environments, Q345D is widely used by container manufacturers for offshore deep-sea containers and various marine engineering structural components. A mandatory -20°C Charpy V-notch impact test is performed on all Q345D plates to guarantee reliable low-temperature service performance.
Item
Specification
Executive Standard
GB/T 1591
Steel Grade
Q345D
Steel Category
High-Strength Low-Alloy Structural Steel
Thickness Range
3mm – 500mm
Width Range
1000mm – 4200mm
Length Range
3000mm – 18000mm, Custom Cut
Heat Treatment
As Rolled, Control Rolled, Normalised
MOQ
1 PC
Delivery Time
Promptly (Stock); Custom production: 10–40 working days
Stock Status
Available
Certification
EN 10204 3.1 / 3.2 MTC available; third-party inspection supported
Payment Terms
T/T, L/C At Sight
Impact Test
-20°C Charpy V-notch (mandatory)
02Plate Size & Dimension Specifications
Q345D is supplied as steel plates covering an extensive dimension range, suitable for offshore containers, deep-sea marine structures and heavy engineering fabrication.
3 – 500 mmThickness RangeHot-rolled & normalised
1000 – 4200 mmWidth RangeMill edge or slit
3000 – 18000 mmLength RangeCustom cut available
1 PCMinimum OrderStock & custom
01
As Rolled / Control Rolled
Hot-rolled Q345D plates with controlled rolling process for improved toughness and uniform properties across the plate.
02
Normalised
Normalising heat treatment option to enhance low-temperature impact toughness for critical marine service.
03
Custom Cutting
Cut-to-length, cut-to-width and profile cutting per client drawings, length up to 18000mm.
04
Stock Availability
Common thicknesses kept in stock for prompt shipment; full range available via custom production.
Note: Dimension tolerances follow GB/T 1591 and relevant rolling standards. Non-standard sizes and special heat treatment states are available on request — send your drawing or size list for feasibility and lead time.
03Equivalent International Steel Grades
GB/T 1591 Q345D corresponds to the following international standard grades, enabling flexible material selection for global offshore and structural projects.
Standard System
Approximate Grade
EN Standard
S355J2 (1.0577)
ASTM Standard
A572 Grade 50
JIS Standard
SPFC590
Note: Equivalent grades match in general strength level; minor differences may exist in impact temperature requirements and tolerances. Q345D's mandatory -20°C impact requirement should be verified when substituting grades for low-temperature service.
04Chemical Composition (Heat Analysis, Max %)
Strict chemical composition control ensures the high toughness and structural stability of Q345D low alloy steel plate.
Element
C
Si
Mn
P
S
V
Nb
Ti
Al (min)
Content (%)
0.18
0.55
1.00–1.60
0.030
0.030
0.02–0.15
0.015–0.060
0.02–0.20
0.015
Note: Values are maximum percentages (heat analysis) per GB/T 1591 unless stated as a range or minimum. The micro-alloying elements V, Nb and Ti, together with Al, refine grain structure and secure the required low-temperature toughness.
05Mechanical Properties
Mechanical performance parameters of GB/T 1591 Q345D low alloy steel plate (room temperature condition), with mandatory -20°C impact verification.
≥345 MPaYield (thickness ≤16mm)Min. per GB/T 1591
470 – 630 MPaTensile StrengthAll thicknesses
-20°CCharpy V-notch ImpactMandatory on all plates
≥275 MPaYield (thickness >50mm)Min. per GB/T 1591
Plate Thickness (mm)
Yield Strength (≥ MPa)
Tensile Strength (MPa)
≤ 16
345
470 – 630
> 16 ≤ 35
325
470 – 630
> 35 ≤ 50
295
470 – 630
> 50
275
470 – 630
Note: Yield strength decreases with increasing plate thickness as specified above; tensile strength remains 470–630 MPa across all thicknesses. A mandatory -20°C Charpy V-notch impact test is performed on every plate to guarantee reliable low-temperature service.
06Quality Assurance, Custom Service & Applications
We provide comprehensive customized technical solutions and strict quality inspection services for Q345D steel plates to meet high-standard engineering requirements.
1
Low-Temp Impact Certification
Professional -20°C Charpy V-notch impact test certification to verify low-temperature toughness performance.
2
Custom Cutting & Welding
Custom cutting and welding processing according to client drawings and technical requirements.
3
Chemical Composition Control
Precise chemical composition control to ensure high toughness and structural stability.
4
Mill Test Certificate
Original mill test certificate compliant with EN 10204 3.1 / 3.2 standards.
Widely used by container manufacturers for offshore deep-sea containers requiring reliable low-temperature toughness.
Deep-Sea Marine Engineering
Marine engineering structural components exposed to extreme environments and low-temperature service.
Heavy Mechanical Manufacturing
Heavy machinery and equipment structures demanding high strength and outstanding weldability.
Large-Scale Structural Engineering
Key projects requiring extreme environmental adaptability and stable structural performance.
Note: All Q345D plates are supplied with full official test certificates. We support customized heat treatment, precision cutting, professional low-temperature impact testing and multi-standard ultrasonic inspection.
Get Your Q345D Steel Official Quotation
Send us your thickness, width, length, quantity and processing requirements. We will reply with the latest stock status, competitive factory price and technical support within 24 hours. Sufficient stock and flexible customization services fully meet the procurement demands of marine, mechanical and structural engineering projects.
BBN Steel has established a complete set of production and supplier management system processes to ensure the improvement of product quality and better service to users.
Production Control
BBN Steel has established a complete production quality control process to ensure every link from research and development to mass production.
Supplier management
Our supplier selection will consider factors such as health and safety, ethics, environmental protection, price and quality to better serve customers.
Certification & Patent
We have successively won various international authoritative certifications, GB /T19001-ISO9001: 2000 quality management system was implemented.
After sales service
We provide booking space, shipping tracking service and after-sales service, we will always be first-class products and perfect pre-sale and after-sales service.
Get in Touch
Welcome to contact us through online consulting, emails and hotline if you are interested in our company or products. Our staff will reply you within 24 hours.
Address: HIGH-TECH DEVELOPMENT ZONE, ZHENGZHOU, CHINA
