CARBON STEEL · LOW ALLOY HIGH STRENGTH PLATE

Q355B Low Alloy High Strength Steel Plate
国标/T 1591 Structural Steel Plate

Higher yield than Q235 with micro-alloyed toughness — the weight-saving choice for bridges, buildings, machines and heavy structures.

STANDARD: 国标/T 1591 GRADE: Q355B THICKNESS 2–100 mm

YIELD STRENGTH

≥355 MPa

TENSILE STRENGTH

470–630 MPa

IMPACT ENERGY

≥34 J @ −20°C

01 · 产品概述

Q355B is a low-alloy high-strength structural steel to GB/T 1591, micro-alloyed with niobium, vanadium and titanium. It delivers about 50 % higher yield strength than Q235B, allowing lighter sections and reduced welding, while keeping good weldability and excellent low-temperature toughness.

WHY CHOOSE Q355B

One material, one grade — Q355B only. Micro-alloyed chemistry, guaranteed 355 MPa yield, certified impact toughness and full traceability via mill certificate.

02 · 主要特点

High Yield Strength

≥355 MPa yield enables thinner, lighter sections — up to ~30 % weight saving versus Q235 designs.

Excellent Weldability

Low carbon equivalent (CEV) keeps HAZ hardness low — weldable without pre-heat in most shop conditions.

Low-Temperature Toughness

Guaranteed ≥34 J at −20 °C (grade B) for safe service in cold climates and dynamic loading.

Weight Saving

Higher design stress cuts plate thickness and tonnage, reducing material, freight and fabrication cost.

Certified Quality

Mill test certificate with full chemistry and mechanicals supplied for every batch; third-party inspection available.

Cut-to-Size

Plasma and flame cutting to drawing — plates, blanks and profiled parts ready for use.

03 · 化学成分 (Cast Analysis, %) — Q355B (国标/T 1591)

元素	C	和	锰	磷	S	Nb	V	的
Max / 范围	0.24	0.55	1.60	0.035	0.035	0.015–0.060	0.020–0.120	0.020–0.100

笔记: Micro-alloy elements Nb, V, Ti added singly or in combination per GB/T 1591. Cu ≤ 0.40 %, N ≤ 0.012 %, Al ≥ 0.015 %. Mill test certificate supplied with every batch.

04 · 机械性能 (Plate Thickness ≤ 16 毫米)

财产	价值	Test Method
屈服强度 (ReH)	≥ 355 兆帕	国标/T 228.1
抗拉强度 (Rm)	470 – 630 兆帕	国标/T 228.1
伸长 (A)	≥ 22 %	国标/T 228.1
Charpy Impact (Grade B, −20 °C)	≥ 34 J	国标/T 229
Bend Test (180°)	No cracking, d = 2t	国标/T 232

YIELD STRENGTH — COMMON GRADES COMPARISON

Q235B (≥235兆帕)BASE

Q355B (≥355 MPa)+51%

Q460C (≥460 MPa)HIGHER

05 · 物理性能

DENSITY

7.85 g/cm³

MELTING POINT

≈ 1510 ℃

MODULUS OF ELASTICITY

200 – 210 GPa

THERMAL EXPANSION

≈ 12×10⁻⁶ /K

06 · 通用规格

厚度 (毫米)	宽度 (毫米)	长度 (毫米)	Typical Weight
6	1500 / 2000 / 2200 / 2500	6000 / 9000 / 12000	47.1 kg/m²
8	1500 / 2000 / 2200 / 2500	6000 / 9000 / 12000	62.8 kg/m²
10	1500 / 2000 / 2200 / 2500	6000 / 9000 / 12000	78.5 kg/m²
12	1500 / 2000 / 2200 / 2500	6000 / 9000 / 12000	94.2 kg/m²
16	2000 / 2200 / 2500	6000 / 9000 / 12000	125.6 kg/m²
20 – 100	1500 – 3000	6000 – 12000	157 – 785 kg/m²
表面	Hot-rolled, mill scale surface; shot-blasted & primed, or oiled, available on request

Custom width, 长度, edge preparation and profiling available — specify your requirement in the inquiry.

07 · 应用领域

Steel bridges & gantry structures
Building frames & high-rise columns
Engineering machinery & cranes
造船 & 海洋结构
压力容器 & 储罐
Wind power towers & 重型设备

08 · 加工 & 包装

Flame / plasma cutting, shot blasting, edge milling and painting available. Plates packed on steel or wooden pallets, steel-banded and protected for ocean shipment.

DELIVERY

Sea freight with full export documentation (CI, PL, CO, MTC, third-party inspection if required) and loading supervision.

Need Q355B plate for your structure?

Tell us thickness, 宽度, length and quantity — we will confirm stock, price and delivery within 24 hours.

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