Q345R Steel Plate for Pressure Vessels (GB/T 713)

Q345R is a grade designation for pressure vessel steel plate under the Chinese national standard. The manufacturing specification is GB/T 713.2-2023 (previous version: GB/T 713-2014), and the ultrasonic testing standard is NB/T 47013.3-2015.

This grade is equivalent to SA516GR70 in the ASME standard and A516GR70 in the ASTM standard.

Q345R steel plates typically undergo impact testing at 0°C, but custom impact testing at -20°C is also available upon request.

Q345R designation explanation: Q stands for Yield Strength, 345 represents 345 MPa, R denotes Pressure Vessel Steel.

Yield Strength

≥345 MPa

Tensile Strength

510–640 MPa

Impact (0°C)

≥34 J

Standard

GB/T 713.2-2023

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Product Overview

Q345R Steel Plate is a carbon–manganese pressure vessel steel manufactured in accordance with GB/T 713. It is specifically designed for boilers, pressure vessels, and pressure-retaining equipment where material reliability, weldability, and operational safety are critical.

Compared with ordinary structural steel, Q345R offers more stable mechanical properties, controlled chemical composition, and improved weldability, reducing the risk of brittle fracture under specified service conditions.

Yield 345MPa Fine-grain Weldable Impact tested

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Core Advantages

Professional technical support (GB/ASME/EN)
Zero communication errors at order stage
Customizable: HIC/SSC, high-temp properties
Fast delivery: 15 days hot-rolled / 30 days normalized

Professional Technical Support & Customization

Comprehensive Knowledge Base: Our sales team is proficient in mainstream domestic and international pressure vessel standards. Whether it's the Chinese national standard Q345R, the American ASME standard SA516GR70, or the European standard P355GH, we can provide accurate technical communication.

Zero Communication Errors: With solid product knowledge, we can avoid all basic errors during the order technical condition confirmation stage, ensuring the accuracy of your order.

Flexible Customization Capabilities: The Q345R standard does not have mandatory requirements for hardness and high-temperature performance. If your design has special requirements (e.g., specific hardness, high-temperature mechanical properties, simulated post-weld heat treatment, HIC/SSC testing), we support customized production.

Hot-rolled ≈15 days

Normalized ≈30 days

Max thickness 140mm

📋 Applications

Boilers & boiler drums

Pressure vessels & reactors

Heat exchangers & condensers

LPG storage tanks

Industrial gas storage

Pressure shells & heads

📦 Stock Resources

Hot-rolled plates: 6–36mm (W:1800–2500, L:11000–12500)

Normalized plates: 12–120mm (W:2000–2500, L:11000–12500)

Hot-rolled coils: 5–16mm (W:1500–2000)

Click to check Q345R inventory

Spot stock size range and supply conditions

Hot Rolled (AR)

Thickness (mm)	Width (mm)	Length (mm)
6–36	1800/2000/2200/2500	11000–12500

Normalized (N/N+T)

Thickness (mm)	Width (mm)	Length (mm)
12–120	2000/2200/2500	11000–12500

Hot-Rolled Coils

Thickness (mm)	Width (mm)
5–16	1500/1800/2000

Supply Condition: HR, NR, N, N+T

Q345R Chemical Composition (max %)

C	Si	Mn	Cu	Ni	Cr	Mo	Nb	V	Ti	P	S
≤0.20	≤0.55	1.20–1.70	≤0.30	≤0.30	≤0.30	≤0.08	≤0.050	≤0.050	≤0.030	≤0.025	≤0.010

Q345R · alloying elements & roles

per GB 713

C Carbon ≤0.18%

Influences strength and hardness.

Si Silicon ≤0.50%

Increases strength, deoxidizer.

Mn Manganese 0.90–1.60%

Enhances strength and toughness, desulfurizer.

P Phosphorus ≤0.035%

Harmful element, reduces toughness.

S Sulfur ≤0.035%

Harmful element, causes hot shortness.

Cu Copper ≤0.35%

Improves corrosion resistance.

Cr Chromium ≤0.20%

Improves corrosion resistance and hardness.

Ni Nickel ≤0.40%

Enhances toughness and low-temperature properties.

Nb Niobium 0.02–0.05%

Refines grain structure, improves strength.

V Vanadium 0.05–0.10%

Refines grain structure, improves toughness.

Ti Titanium ≤0.02%

Refines grain, fixes carbon and nitrogen.

Mo Molybdenum ≤0.08%

Improves high-temperature strength and corrosion resistance.

Al Aluminum ≥0.015%

Deoxidizer, refines grain structure.

N Nitrogen controlled by process

Controlled by production process; affects aging and grain refinement.

Q345R typical ranges (wt%): C ≤0.18, Si ≤0.50, Mn 0.90–1.60, P≤0.035, S≤0.035, Cu≤0.35, Cr≤0.20, Ni≤0.40, Mo≤0.08, Al≥0.015. Microalloying: Nb 0.02–0.05, V 0.05–0.10, Ti≤0.02. N controlled per process.

Q345R Mechanical Properties & Impact Test

Thickness (mm)	YS (MPa)	TS (MPa)	Elong (%)	Impact 0°C (J)
3–16	≥345	510–640	21	≥34
>16–36	≥325	500–630	21	≥34
>36–60	≥315	490–620	21	≥34

Q345R vs SA516Gr70 vs P355GH

Item	Q345R	SA516Gr70	P355GH
Standard	GB/T 713	ASTM A516	EN 10028-2
Impact mandatory	Yes (0°C, ≥34J)	Project dependent	Yes (0°C, ≥40J)
Specified temp	0°C	Not specified	0°C
Avg. impact energy	≥34 J	Project specified	≥40 J
Min single value	≥27 J	Project specified	≥27 J

Scenario-Based Recommendation · GB Grade Comparison

Q345R

General pressure vessels, boilers, no special low temp

Yield ≥345 MPa · Tensile 510-640 MPa
Charpy: 0°C ( -20°C optional )

vs Q245R: higher strength, broader applicability

Current Grade

Q245R

Low‑pressure tanks, non‑critical, budget sensitive

Yield ≥245 MPa · Tensile 400-520 MPa

vs Q345R: cost saving when ≤245 MPa is sufficient

Q245R details

Q370R

High‑pressure vessels, lightweight design

Yield ≥370 MPa · Tensile 530-630 MPa
Charpy -20°C

vs Q345R: 25 MPa higher yield, allows thickness reduction

Q370R details

16MnDR

Cryogenic tanks, cold regions, LPG

Yield ≥315 MPa · Tensile 490-620 MPa
Charpy -40°C guaranteed

vs Q345R: Q345R usually not certified for -40°C, 16MnDR is purpose‑built

16MnDR details

09MnNiDR

Ethylene, chemical, extreme‑cold equipment

Yield ≥280 MPa · Tensile 430-570 MPa
Charpy -70°C (Ni alloyed)

vs 16MnDR: 16MnDR stops at -40°C, 09MnNiDR reaches -70°C

09MnNiDR details

Quick selection path: Q245R (economy) → strength/temp increases → Q345R (standard) → Q370R (higher strength) ; Low‑temp branch: 16MnDR (-40°C) → 09MnNiDR (-70°C)

Quality Control & Inspection

Mill Test Certificate 3.1 Chemical analysis Mechanical testing Charpy V-notch UT optional Third-party inspection

📐 Customizable Specification Range for Q345R

Thickness

6–140 mm

(custom rolling)

Width

1500–5200 mm

(adjustable per order)

Length

≤ 18000 mm

(max. single length)

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Delivery Condition

AR CR TMCP N+T N

AR as rolled · CR controlled rolled · TMCP thermo‑mechanical · N+T normalized + tempered · N normalized

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Additional Requirements

Simulated post‑weld heat treatment (PWHT)
Brinell hardness requirements (specify range)
HIC / SSC testing on request
High‑temperature tensile properties

📋 Other customized technical conditions (impact temperature, UT grade, etc.) are also negotiable.

✅ The above ranges represent our standard customizing capability — dimensions, delivery conditions, and supplementary tests can be further adjusted to meet your project specifications.

Frequently Asked Questions

What is Q345R steel plate used for?

Q345R steel plate is mainly used for boilers, pressure vessels, heat exchangers, reactors, and other pressure-retaining equipment manufactured according to GB/T 713.

Is Q345R equivalent to SA516 Grade 70?

Q345R is not officially equivalent to SA516 Grade 70. Substitution requires design approval and compliance with applicable pressure vessel codes.

Can Q345R be used for low-temperature applications?

Q345R is suitable for normal to moderate low-temperature service. For cryogenic applications, steels such as 16MnDR or 09MnNiDR are recommended.

Does Q345R steel plate require impact testing?

Yes. Impact testing is a mandatory requirement under GB/T 713 for Q345R pressure vessel steel plates.

Can you provide Q345R steel plates with custom sizes?

Yes. Custom rolling up to 140mm thick, 5400mm wide, 15000mm long. Delivery: 10-15 days hot-rolled, 30-35 days normalized.