Q420ME TMCP Steel Plate GB/T 1591 Supplier

Q420ME, also searched as GB/T 1591 Q420ME, Q420ME steel plate, Q420ME TMCP plate and Q420 ME, is the 420 MPa quality-grade-E grade delivered by thermomechanical controlled process in GB/T 1591-2018. Q is the yield symbol, 420 is the thin-plate minimum yield in MPa, M is the delivery letter, and E is the quality letter for Charpy impact at −40°C.

The M is the point of this page. Normalized GB/T 1591 Q420NE has an N. A normalized certificate cannot be stamped ME. Grade B on the TMCP route is GB/T 1591 Q420MB. Grade C is GB/T 1591 Q420MC. Grade D is GB/T 1591 Q420MD. Hot-rolled GB/T 1591 Q420E has neither M nor N. The 390 MPa TMCP sister at the same temperature is GB/T 1591 Q390ME. The full family sits on GB/T 1591. Do not drop a 420 MPa drawing onto a 390 MPa plate, and do not upgrade it to GB/T 1591 Q460E without a price check.

The closest European TMCP comparison is EN 10025-4 S420ML, tested colder than −20°C. EN 10025-4 S420M is only −20°C. EN 10025-3 S420NL is normalized. On the US side, ASTM A572 Grade 60 is 60 ksi / 415 MPa, one step lower, and it is not an ME twin. ASTM A572 Gr.55 is 55 ksi. JIS G3106 SM570 is the usual Japanese comparison. Dual mark only when both books are fully met. See EN 10025-4 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 Q420ME from first-line structural mills that can actually run the TMCP schedule and hold −40°C impact, 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.

Nearby pages that buyers compare, but must not swap blindly, include GB/T 1591 Q420ND, GB/T 1591 Q390ME and ASTM A572 Gr.55.

Heat analysis is the mill ladle table in GB/T 1591-2018 for TMCP Q420. Product analysis, when ordered, follows GB/T 222. Q420ME is a microalloyed HSLA plate. Grade E is the tightest cleanliness letter on this TMCP family, because the impact test is at −40°C. Mills may add Nb, V or Ti. The certificate shows the elements actually used. TMCP chemistry is often leaner than a normalized heat of the same yield, because the rolling schedule does part of the grain refinement.

Heat Analysis and Product Analysis — GB/T 1591 Q420ME, TMCP

Carbon equivalent is limited by thickness in the standard. The M route often has a lower CEV window than normalized GB/T 1591 Q420NE. 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 quenched-and-tempered GB/T 16270 Q460E. A 390 MPa file is GB/T 1591 Q390ME, not this grade.

Buyers search Q420ME mechanical properties, Q420ME yield strength, GB/T 1591 Q420ME tensile and Q420ME impact −40°C.

Tensile and impact — GB/T 1591 Q420ME, TMCP

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 TMCP heat will hold E on very thick plate. SHH STEEL confirms the thickness before promising the letter.

Yield steps down with thickness. A 420 MPa name on 12 mm plate is not the minimum on a 40 mm flange. 420 MPa is about 61 ksi. ASTM A572 Grade 60 is 60 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.

A warmer hot-rolled file is GB/T 1591 Q420B. A 355 MPa file is GB/T 1591 Q355ME.

There is no official one-to-one substitute for Q420ME. What buyers compare is a 420 MPa TMCP plate tested at −40°C.

EN 10025-4 S420ML is the closest process comparison and is tested colder. EN 10025-4 S420M is only −20°C. EN 10025-3 S420NL is normalized. EN 10025-2 S355JR is +20°C and only 355 MPa. In the United States, ASTM A572 Grade 60 is 60 ksi / 415 MPa. ASTM A572 Gr.55 is 55 ksi. ASTM A36 is 36 ksi and is well below this yield. In Japan, JIS G3106 SM570 is the usual comparison. SHH STEEL will not stamp EN 10025-4 S420ML or ASTM A572 Gr.60 on a Q420ME certificate unless the purchase order names both books and both tables are met.

Buyers pick Q420ME when a bridge, building member or welded fabrication wants about 420 MPa yield, a TMCP condition, and impact at −40°C. Search phrases such as Q420ME steel plate and GB/T 1591 Q420ME all point here. The family index is GB/T 1591.

It is the wrong plate when the drawing says normalized. That work is GB/T 1591 Q420NE. It is the wrong plate when the drawing says hot rolled. That work is GB/T 1591 Q420E. It is the wrong plate for a −20°C file. That work is GB/T 1591 Q420MD, and the normalized sister is GB/T 1591 Q420ND. It is the wrong plate for a 0°C file. That work is GB/T 1591 Q420MC. It is the wrong plate for a +20°C file. That work is GB/T 1591 Q420MB. It is the wrong plate for a 390 MPa file. That work is GB/T 1591 Q390ME or GB/T 1591 Q390NE. It is the wrong plate for a 460 MPa file. That work is GB/T 1591 Q460NC or GB/T 1591 Q460NE. 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, quality grade E, and the M condition at 420 MPa.

Q420ME is a weldable TMCP HSLA structural plate. Carbon is controlled, and many heats use Nb, V or Ti. A procedure written for ASTM A36 is not a finished WPS for thick Q420ME. Carbon equivalent on the M route is often lower than normalized GB/T 1591 Q420NE, which helps the root pass, but the TMCP microstructure still needs a qualified procedure. A procedure qualified only at −20°C may miss the −40°C coupon.

Typical consumables are matching 60 ksi low-hydrogen electrodes or wires. E7018-class electrodes are under-matched if the joint must develop full plate strength. A procedure written for ASTM A572 Gr.55 is a useful strength reference after chemistry and the −40°C coupon are checked, but it does not cover 420 MPa. Preheat follows thickness, hydrogen and the approved WPS. Heat input should stay inside the mill window. A very high heat input can soften the TMCP zone next to the weld.

The fabricator owns the WPS. SHH STEEL can share mill heat data, product analysis and carbon equivalent for that review. Do not use a Q420ME procedure on GB/T 1591 Q355MB without checking the lower-yield carbon equivalent. Do not use it on GB/T 1591 Q460ND either.

Usual delivery from SHH STEEL for Q420ME is thermomechanical controlled process. The plate is not normalized as GB/T 1591 Q420NE and not hot rolled as GB/T 1591 Q420E.

TMCP combines controlled rolling and accelerated cooling. Finish rolling is held in the non-recrystallization range, then the plate is cooled on the run-out table to a finish temperature the mill records. Do not order Q420ME as quenched and tempered. That route belongs to GB/T 16270. Stress relief after fabrication, if used, should be agreed before cutting, because a high temper can move the TMCP properties.

The certificate lists GB/T 1591 Q420ME, heat number, delivery condition, 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 EN 10025-4 S420ML is available only when both books are fully met.

Usual supply range from SHH STEEL for Q420ME steel plate:

• Thickness: commonly 8 mm – 60 mm, heavier plate to 80 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.

Dimensional limits for Q420ME follow GB/T 709 unless the purchase order names EN 10029 or another table.

Typical thickness tolerance idea for Q420ME plate

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 Q420ME unless the order says so.

Q420ME already defines 420 MPa yield, TMCP delivery and −40°C impact. Extra items still have to be written on the purchase order.

Book name. Write GB/T 1591 Q420ME. Do not write only Q420, and do not write Q420NE if the mill must stamp M. The family page is GB/T 1591.

Impact. Grade E is −40°C. Write a higher energy if the owner requires it. Do not expect this result from GB/T 1591 Q420MD.

Delivery condition. Write thermomechanical controlled process. Write GB/T 1591 Q420NE if normalized is required.

EN or US comparison. Write EN 10025-4 S420ML or ASTM A572 Gr.60 only if dual mark is required and both tables are met. Do not treat EN 10025-4 S420M 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, Q420ME, thickness and mill logo.

Third-party witness. EN 10204 3.2 with SGS, TÜV, BV, ABS or the inspector named.

Q420ME is the plate for a 420 MPa TMCP 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 under GB/T 16270. A 460 MPa normalized file is GB/T 1591 Q460ND.

SHH STEEL sources Q420ME 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. 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.

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 TMCP with −40°C test about 30–45 days; 3.2 inspection about 40–50 days.

SHH STEEL is a global steel mill sourcing partner and steel manufacturer and exporter, mill-direct, China origin. For Q420ME that means mill-direct structural price, not a multi-layer stockist mark-up. We buy from mills that can actually run the TMCP schedule and test at −40°C, so the M and the E are both on the certificate.

Delivery is short when the size is in rolling range: ex-stock 5–7 days, standard ME 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 Q420ME, keep the TMCP route, and do not ship GB/T 1591 Q420NE or GB/T 1591 Q420MD as ME. We will not drop the M to save a cooling cycle, and we will not change E to D to save a cold test. If the drawing only needs −20°C, we will move the inquiry to Q420MD. If the drawing needs 460 MPa, we will move it to GB/T 1591 Q460C or GB/T 1591 Q460NC.

Q420ME steel plate to GB/T 1591 is 420 MPa TMCP structural plate with impact at −40°C. It is not normalized GB/T 1591 Q420NE. EN 10025-4 S420ML is the closest TMCP comparison. ASTM A572 Grade 60 is 415 MPa and is not a substitute. Whether the inquiry says Q420ME, GB/T 1591 Q420ME or Q420ME TMCP plate, SHH STEEL as a global steel mill sourcing partner supplies plate with Q420ME chemistry, heat and product analysis as ordered, GB/T 709 tolerances and EN 10204 3.1 or 3.2 certification.

SHH STEEL supplies Q420ME Steel Plate to the United States, Europe, the Middle East, Africa, Asia and the Americas for work that actually names the M condition. The grade family is listed on GB/T 1591.

Contact SHH STEEL for mill rolling, −40°C impact, cutting, UT, 3.2 inspection or a worldwide quotation.

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