Q355E Steel Plate GB/T 1591 Supplier
What is GB/T 1591 Q355E Steel?
Q355E, also searched as GB/T 1591 Q355E, Q355E steel plate, Q355E plate, Q355 E and the older name Q345E, is the 355 MPa quality-grade-E grade in GB/T 1591-2018. That standard covers high-strength low-alloy structural steels. Q is the yield symbol, 355 is the thin-plate minimum yield in MPa, and E is the quality letter for Charpy impact at −40°C.
The 2018 edition replaced Q345 with Q355 and cancelled quality grade A. A drawing that still says Q345E is usually reviewed against Q355E, but the yield name, impact letter and thickness band still have to match the purchase order. Q355E on this page is the hot-rolled grade. It has no N and no M suffix.
Q355NE is normalized or normalizing-rolled. Q355ME is thermomechanical rolled. Those are different delivery conditions, different carbon-equivalent windows and different thickness limits. A hot-rolled Q355E certificate cannot be stamped NE or ME. Grade B is +20°C. C is 0°C. D is −20°C. F exists on some M grades, not on hot-rolled Q355E.
EN 10025-2 has no exact −40°C letter at 355 MPa. S355J2 is −20°C and is the usual warmer comparison. S355K2 is also −20°C, with a higher energy. S355NL is normalized and tested colder, so it is a process comparison, not a twin. On the US side, A572 Gr.50 is 50 ksi / 345 MPa and is not an E-letter twin. JIS G3106 SM490B is the usual Japanese comparison. Dual mark only when both books are fully met. See EN 10025-2 and high strength low alloy plates.
SHH STEEL is a global steel mill sourcing partner and steel manufacturer and exporter, mill-direct, China origin. We source Q355E from first-line structural mills, print heat analysis and product analysis when ordered, and ship plate to fabricators in the United States, Europe, the Middle East, Southeast Asia, Africa and South America. Related pages include structural steel plates and the products index.
Material Specification
| Specification Element | Requirement | SHH STEEL Compliance |
|---|---|---|
| Plate book | GB/T 1591-2018 Q355E | Confirmed |
| Other search names | Q355E steel plate, Q345E | Covered, not a silent swap |
| Delivery condition | Hot rolled | Confirmed |
| Yield, ≤ 16 mm | 355 MPa min | Confirmed |
| Quality grade | E, impact at −40°C | Confirmed |
| EN comparison | S355J2 is −20°C | Warmer, not a swap |
| US comparison | A572 Gr.50 is 345 MPa | Not a twin |
| Product analysis | GB/T 222 column when ordered | Confirmed |
| Not the same condition | Q355NE or Q355ME | Do not substitute |
| Supply role | Global steel mill sourcing partner | SHH STEEL |
| Certification | EN 10204 3.1 or 3.2 | As ordered |
Nearby pages that buyers compare, but must not swap blindly, include S355J2, S355NL and A572 Gr.50.
Chemical Composition
Heat analysis is the mill ladle table in GB/T 1591-2018 for hot-rolled Q355. Product analysis, when ordered, follows GB/T 222. Q355E is a carbon-manganese HSLA plate. Grade E is the tightest cleanliness letter on hot-rolled Q355, because the impact test is at −40°C. Mills may add Nb, V or Ti for grain refinement. The certificate shows the elements actually used.
Heat Analysis and Product Analysis — GB/T 1591 Q355E, hot rolled
| Element | Heat analysis (%) | Product analysis (%) |
|---|---|---|
| Carbon (C), max | 0.18 | 0.20 |
| Silicon (Si), max | 0.50 | 0.55 |
| Manganese (Mn), max | 1.60 | 1.70 |
| Phosphorus (P), max | 0.025 | 0.030 |
| Sulfur (S), max | 0.020 | 0.025 |
| Niobium (Nb), max | 0.05 | 0.06 |
| Vanadium (V), max | 0.15 | 0.16 |
| Titanium (Ti), max | 0.20 | 0.21 |
| Chromium (Cr), max | 0.30 | 0.35 |
| Nickel (Ni), max | 0.50 | 0.55 |
| Copper (Cu), max | 0.40 | 0.45 |
| Molybdenum (Mo), max | 0.10 | 0.11 |
| Nitrogen (N), max | 0.015 | 0.017 |
| Aluminium (Als), min when used | 0.015 | 0.010 |
Carbon equivalent is limited by thickness in the standard. A thick flange can have a lower CEV cap than a 12 mm web. If the purchase order writes product analysis, SHH STEEL prints both columns and the thickness band used for the tensile test. Do not treat this chemistry as weathering plate. Do not treat it as quenched-and-tempered Q460E under GB/T 16270.
Mechanical Properties
Buyers search Q355E mechanical properties, Q355E yield strength, GB/T 1591 Q355E tensile and Q355E impact −40°C.
Tensile and impact — GB/T 1591 Q355E, hot rolled
| Thickness | Yield min | Tensile | Elongation min | Impact |
|---|---|---|---|---|
| ≤ 16 mm | 355 MPa | 470–630 MPa | 22% | −40°C, grade E |
| > 16–40 mm | 345 MPa | 470–630 MPa | 21% | −40°C, grade E |
| > 40–63 mm | 335 MPa | 470–630 MPa | 20% | −40°C, grade E |
| > 63–80 mm | 325 MPa | 470–630 MPa | 19% | −40°C, grade E |
| > 80–100 mm | 315 MPa | 470–630 MPa | 19% | −40°C, grade E |
| > 100–150 mm | 295 MPa | 450–600 MPa | 18% | −40°C, grade E |
| > 150–200 mm | 285 MPa | 450–600 MPa | 17% | −40°C, grade E |
| > 200–250 mm | 275 MPa | 450–600 MPa | 17% | −40°C, grade E |
Impact energy is the average of three longitudinal Charpy V-notch specimens, commonly 27 J to 34 J minimum at −40°C, depending on the ordered edition and thickness. One value may fall below the table, but not below 70% of that value. Write a higher energy on the order if the owner requires it. Not every hot-rolled heat will hold E on very thick plate. SHH STEEL confirms the thickness before promising the letter.
Yield steps down with thickness. A 355 MPa name on 12 mm plate is not the minimum on a 40 mm flange. 355 MPa is about 51.5 ksi. A572 Gr.50 is 50 ksi and is not this book. Density is 7.85 g/cm³. Hardness is not a design value for this grade. Z15, Z25 or Z35 through-thickness tensile is an extra, not part of the E letter.
Material Comparison
| Grade | Book | Delivery | Yield, thin plate | Impact | Swap? |
|---|---|---|---|---|---|
| Q355B | GB/T 1591-2018 | Hot rolled | 355 MPa | +20°C | No |
| Q355C | GB/T 1591-2018 | Hot rolled | 355 MPa | 0°C | Warmer sister |
| Q355D | GB/T 1591-2018 | Hot rolled | 355 MPa | −20°C | Warmer sister |
| Q355E | GB/T 1591-2018 | Hot rolled | 355 MPa | −40°C | This page |
| Q355NE | GB/T 1591-2018 | Normalized | 355 MPa | −40°C | Different process |
| Q355ME | GB/T 1591-2018 | TMCP | 355 MPa | −40°C | Different process |
| S355J2 | EN 10025-2 | As rolled | 355 MPa | −20°C | Warmer comparison |
| A572 Gr.50 | ASTM A572 | As rolled | 345 MPa | Different | Lower yield |
Equivalent Material Grades
There is no official one-to-one substitute for Q355E. What buyers compare is a 355 MPa plate tested at −40°C.
EN 10025-2 stops at −20°C for the J2 and K2 letters. S355J2 is the usual warmer comparison. S355NL is normalized and colder, so the process is not the same. In the United States, A572 Gr.50 is 50 ksi / 345 MPa. A36 is 36 ksi and is well below this yield. In Japan, SM490B is the usual comparison. Old DIN St52-3 still appears on legacy drawings. SHH STEEL will not stamp S355J2 or A572 on a Q355E certificate unless the purchase order names both books and both tables are met.
| Designation | Country / region | Standard | Notes |
|---|---|---|---|
| Q355E | China | GB/T 1591-2018 | Name on this page |
| Q345E | China | Old GB/T 1591 | Replaced name, review only |
| Q355B / Q355C / Q355D | China | GB/T 1591-2018 | Warmer impact letters |
| Q355NE / Q355ME | China | GB/T 1591-2018 | Normalized / TMCP, not this page |
| S355J2 | Europe | EN 10025-2 | −20°C, warmer comparison |
| S355NL | Europe | EN 10025-3 | Normalized, colder comparison |
| A572 Gr.50 | USA | ASTM A572 | 50 ksi, lower yield |
| SM490B | Japan | JIS G3106 | Usual Japanese comparison |
Structural Service
Buyers pick Q355E when a bridge, building member, equipment frame or welded fabrication wants about 355 MPa yield, hot-rolled delivery and impact at −40°C. Search phrases such as Q355E steel plate, GB/T 1591 Q355E and Q345E all point here after the 2018 revision is checked.
It is the wrong plate for a +20°C file that can use Q355B. It is the wrong plate for a −20°C file that can use Q355D. It is the wrong plate when the drawing says normalized. That work is Q355NE. It is the wrong plate when the drawing says TMCP. That work is Q355ME. It is the wrong plate for a quenched-and-tempered 460 MPa boom. That work is Q460E under GB/T 16270. It is the wrong plate for a pressure vessel. That work sits on ASTM A516 or pressure vessel steel plates.
SHH STEEL supplies this plate when the drawing names GB/T 1591 and quality grade E at 355 MPa, hot rolled.
Weldability
Q355E is a weldable HSLA structural plate. Carbon is controlled, and many heats use Nb, V or Ti. A procedure written for mild A36 can be a starting point on thin plate, but it is not a finished WPS for thick Q355E. Carbon equivalent rises with thickness, and the standard caps CEV by band. A procedure qualified only at −20°C may miss the −40°C coupon.
Typical consumables are matching 50 ksi / 355 MPa low-hydrogen electrodes or wires. E7018-class electrodes are common on shop joints that do not need full plate strength in the weld metal. A procedure written for S355J2 is a useful strength reference after the test temperature is lowered to −40°C. Preheat follows thickness, hydrogen and the approved WPS. Thick plate and restrained joints need more preheat than a 10 mm web.
The fabricator owns the WPS. SHH STEEL can share mill heat data, product analysis and carbon equivalent for that review. Do not use a Q355E procedure on Q355ME without checking the TMCP carbon equivalent.
Heat Treatment and Delivery Condition
Usual delivery from SHH STEEL for Q355E is hot rolled. The plate is not normalized and not thermomechanical rolled unless the order changes the grade to Q355NE or Q355ME.
Do not order Q355E as quenched and tempered. That route belongs to GB/T 16270, not to this page. Stress relief after fabrication, if used, should be agreed before cutting, because a high temper can move yield on a controlled-rolled heat.
The certificate lists GB/T 1591 Q355E, heat number, heat analysis, product analysis when ordered, tensile by thickness band, and −40°C impact. Certificates may be EN 10204 3.1 or EN 10204 3.2. Dual marking to S355J2 is available only when both books are fully met, and that still does not create a −40°C European letter.
Dimensions
Usual supply range from SHH STEEL for Q355E steel plate:
- Thickness: commonly 8 mm – 80 mm, heavier plate to 120 mm by mill confirmation
- Width: 1500 mm – 3000 mm, wider by enquiry
- Length: 3000 mm – 12000 mm
Cut-to-size webs, flanges, base plates and gussets are available. Browse more sizes on structural steel plates.
Tolerances
Dimensional limits for Q355E follow GB/T 709 unless the purchase order names EN 10029 or another table.
Typical thickness tolerance idea for Q355E plate
| Nominal thickness (mm) | Usual minus (mm) | Usual plus (mm) |
|---|---|---|
| 8 – 15 | −0.3 | +0.8 |
| 15 – 25 | −0.4 | +0.9 |
| 25 – 40 | −0.5 | +1.1 |
| 40 – 60 | −0.6 | +1.3 |
| 60 – 80 | −0.7 | +1.5 |
| 80 – 100 | −0.8 | +1.6 |
Width on 1500–3000 mm plate is commonly held to about +20 / 0 mm or ±25 mm unless a tighter extra is named. Length on 3000–12000 mm plate is commonly held to about +50 / 0 mm. Flatness follows the agreed class. SHH STEEL will not assume a zero-minus extra on Q355E unless the order says so.
Supplementary Requirements
Q355E already defines 355 MPa yield, hot-rolled delivery and −40°C impact. Extra items still have to be written on the purchase order.
Book name. Write GB/T 1591 Q355E. Do not write only Q355, and do not write Q345E if the mill must stamp the 2018 grade.
Impact. Grade E is −40°C. Write a higher energy if the owner requires it.
Delivery condition. Write hot rolled. Write Q355NE or Q355ME if normalized or TMCP is required.
EN or US comparison. Write S355J2 or A572 Gr.50 only if dual mark is required and both tables are met. Do not treat S355J2 as a −40°C grade.
Product analysis. Write it if the file needs the second chemistry column.
Through-thickness. Z15, Z25 or Z35 when the joint is loaded through the thickness.
NDE. UT to GB/T 2970 or the named class.
Identification. Heat number, Q355E, thickness and mill logo.
Third-party witness. EN 10204 3.2 with SGS, TÜV, BV, ABS or the inspector named.
Applications
| Industry | Typical components |
|---|---|
| Cold-region bridges | Q355E webs and flanges from SHH STEEL |
| Outdoor structures | Q355E columns and base plates tested at −40°C |
| Construction machinery | Q355E frames where −40°C impact is specified |
| General fabrication | Q355E gussets and connection plates |
| Comparison vs S355J2 | Q355E next to S355J2 |
| Comparison vs S355NL | Q355E next to S355NL |
| Comparison vs A572 Gr.50 | Q355E next to A572 Gr.50 |
Q355E is the plate for a 355 MPa hot-rolled file tested at −40°C. It is the wrong plate for a painted weathering facade that needs corten. It is the wrong plate for a 690 MPa QT boom.
Supply Capability
SHH STEEL sources Q355E from first-line Chinese structural mills and ships it on worldwide terms. Partner mills include Wuyang (Wugang), Angang, Shougang, Hanye, Anyang Iron and Steel, Baosteel, Xinyu, Xingcheng and other qualified mills when the size requires it.
Mill test certificates are issued to EN 10204 3.1 as standard. EN 10204 3.2 is arranged when the order names a third-party hold point.
Usual rolling thickness: 8 mm, 10 mm, 12 mm, 16 mm, 20 mm, 25 mm, 30 mm, 40 mm, 50 mm, 60 mm, 80 mm. Heavier plate is confirmed before order.
Processing: CNC or flame cutting, bevel, flattening, shot blast, UT to the named class.
Trade terms: FOB Shanghai main, CIF destination available. Payment: TT, LC, or TT + LC.
Ocean time from Shanghai: US West 14–18 days; US Gulf 28–35 days; Rotterdam / Antwerp 28–35 days; Jebel Ali 18–25 days; Singapore 7–12 days; other ports quoted.
Third-party: SGS, TÜV, BV, ABS, CCS, GL, VL, DNV, RINA, NK, KR, or the inspector named.
Global Delivery and Markets
SHH STEEL is a global steel mill sourcing partner with mill partnerships in China. We supply GB, ASTM, ASME, EN, DIN and JIS steel to buyers in the United States, Europe, the Middle East, Southeast Asia, Africa and South America. Origin is mill-direct, China origin.
SHH STEEL has supplied steel plates to the USA, Mexico, Argentina, Peru, El Salvador, Spain, Netherlands, Germany, UAE, Saudi Arabia, South Africa, India, Thailand, Singapore, Vietnam, the Philippines, Japan and Korea.
Typical lead time: ex-stock 5–7 days when an E heat is in yard; standard rolling with −40°C test about 30–45 days; 3.2 inspection about 40–50 days.
Why Choose SHH STEEL
SHH STEEL is a global steel mill sourcing partner and steel manufacturer and exporter, mill-direct, China origin. For Q355E that means mill-direct structural price, not a multi-layer stockist mark-up. We buy from mills that can actually test at −40°C, so the letter E is on the certificate and not only in the enquiry.
Delivery is short when the size is in rolling range: ex-stock 5–7 days, standard E heat about 30–45 days, 3.2 inspection about 40–50 days. Cutting, bevel and UT can run in the same window. FOB Shanghai is the main term. CIF to US West, US Gulf, Rotterdam, Jebel Ali and Singapore is quoted on the same file.
Experience on this grade is simple: print GB/T 1591 Q355E, keep the hot-rolled route, and do not ship Q355D or Q355ME as E. We will not change E to D on the certificate to save a cold test, and we will not treat Q355E as A36. If the drawing needs normalized plate, we will move the inquiry to Q355NE and keep the price on the right grade.
FAQ
- What is Q355E steel plate?
- Q355E in GB/T 1591-2018 is hot-rolled high-strength low-alloy plate with 355 MPa minimum yield on thin plate and Charpy impact at −40°C. SHH STEEL supplies this plate worldwide as a global steel mill sourcing partner.+
- Is Q355E the same as Q355D?
- No. Both yield at 355 MPa and both are hot rolled. Q355D is tested at −20°C. Q355E is tested at −40°C.
- Is Q355E the same as Q345E?
- Q355E replaced Q345E in the 2018 edition. The yield name changed. SHH STEEL does not stamp Q345E on a 2018 certificate unless the purchase order still requires the old book and the mill can issue it.
- Is Q355E the same as Q355NE or Q355ME?
- No. Q355E is hot rolled. Q355NE is normalized. Q355ME is thermomechanical rolled. Impact letter E is the same temperature. The process is not.
- What is the European equivalent of Q355E?
- There is no exact EN 10025-2 twin at −40°C. S355J2 is −20°C and is the usual warmer comparison. S355NL is normalized and colder. SHH STEEL does not dual-mark either grade unless both books are met.
- What is the US equivalent of Q355E?
- There is no official ASTM twin. A572 Grade 50 is 50 ksi / 345 MPa, slightly lower, and it does not carry an E letter. SHH STEEL does not dual-mark A572 unless both books are met.
- What thickness can SHH STEEL supply?
- Common rolling is 8 mm to 80 mm. Heavier plate is confirmed with the mill before order. Yield on plate over 16 mm is lower than the 355 MPa thin-plate number.
- Can SHH STEEL ship Q355E to the USA, Europe or the Middle East?
- Yes. SHH STEEL quotes FOB Shanghai and CIF to US West, US Gulf, Rotterdam, Jebel Ali, Singapore and other major ports.
Conclusion
Q355E steel plate to GB/T 1591 is 355 MPa hot-rolled structural plate with impact at −40°C. S355J2 is −20°C and is not a silent substitute. A572 Grade 50 is 345 MPa. Q355NE and Q355ME are different processes. Whether the inquiry says Q355E, GB/T 1591 Q355E, Q355E steel plate or Q345E, SHH STEEL as a global steel mill sourcing partner supplies plate with Q355E chemistry, heat and product analysis as ordered, GB/T 709 tolerances and EN 10204 3.1 or 3.2 certification.
SHH STEEL supplies Q355E Steel Plate to the United States, Europe, the Middle East, Africa, Asia and the Americas for work that actually names this grade.
Contact SHH STEEL for mill rolling, −40°C impact, cutting, UT, 3.2 inspection or a worldwide quotation.
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