GB/T 713.3 Q420DR Steel Plate | Q420DR Low Temp Vessel Plate

Q420DR is a strength-named grade. GB/T 713.3 explains the letters: Q = yield, 420 = minimum yield in MPa, DR = low-temperature vessel. Buyers search GB/T 713.3 Q420DR, Q420DR steel plate and Q420DR low temp vessel plate. It is one of the four grades added when GB/T 713.3-2023 replaced GB/T 3531-2014. The other three additions are Q460DR, 13MnNiDR and 11MnNiMoDR.

Yield is 420 MPa at 6–20 mm. Tensile is 590–720 MPa. Delivery is normalized or normalized and tempered. Impact is −40 °C, 60 J, and this grade also requires a lateral expansion of not less than 0.53 mm. That extra impact rule applies to Q420DR and Q460DR only. SHH STEEL is a global steel mill sourcing partner and steel manufacturer & exporter (mill-direct, China origin) for this grade.

Do not ship Q420R against Q420DR. Q420R is GB/T 713.2 room/elevated-temperature plate, usually tested at −20 °C. Q420DR is GB/T 713.3 −40 °C plate with required nickel and niobium. Do not ship 16MnDR against Q420DR. 16MnDR is also −40 °C, but yield is 315 MPa, not 420 MPa. Do not ship 11MnNiMoDR against Q420DR. That grade is QT and −70 °C.

Company scope: global steel mill sourcing partner – SHH STEEL.

This plate sits in pressure vessel steel plates. ASME comparisons belong on ASME SA537 and ASME SA516, not as automatic substitutes.

Heat analysis follows GB/T 713.3 Table 1. Product analysis follows GB/T 713.1. Write both on the PO if the destination file needs finished-plate chemistry.

Heat Analysis and Product Analysis — GB/T 713.3 Q420DR

Nickel, vanadium and niobium are part of the strength package. That is why Q420DR is not a stamp-over of Q420R or 16MnDR. Nitrogen is limited to 0.020%. SHH STEEL reports heat analysis on every certificate and product analysis when the order names it.

Strength sits with Q420R, but the impact rule is the GB/T 713.3 rule, not the GB/T 713.2 rule.

Tensile and Yield — GB/T 713.3 Q420DR

Elongation is 19% min. Impact is −40 °C, 60 J. Lateral expansion shall not be less than 0.53 mm. Bend is 180°, D=3a. Delivery is N or N+T.

Do not quote 420 MPa yield on a 25 mm plate. The 20–30 mm column drops to 400 MPa. Do not treat 590–720 MPa tensile as permission to stamp SA537 Cl.1 or SA516 Gr.70 without checking impact temperature, energy and lateral expansion.

Comparison names help a buyer search. They do not authorize substitution.

Buyers pick Q420DR when they want GB/T 713.3 low-temperature plate at the 420 MPa step, not the 315 MPa step of 16MnDR. Impact stays at −40 °C. If the file needs −50 °C or −70 °C, look at 15MnNiNbDR, 13MnNiDR, 09MnNiDR or 11MnNiMoDR instead.

It is not an ASME Section VIII plate by default. An ASME file should name SA537 Cl.1 or SA516 Gr.70 and then write the extras.

SHH STEEL supplies this plate to fabricators in the United States, Mexico, South America, Europe, the Middle East, Africa and Asia. Stainless inquiries belong on ASME SA240 or ASTM A240.

Q420DR is killed Ni-Nb high-strength low-temperature vessel plate. Treat welding as production welding, and as Code welding when the equipment is a vessel.

Qualify to the applicable code. ASME dual-name work uses ASME Section IX. Match consumables to the 590–720 MPa tensile band and the −40 °C toughness target, including lateral expansion when the WPS needs it. A 16MnDR procedure is not automatically valid. A Q420R procedure is the wrong book. Preheat follows thickness and hydrogen control. The fabricator owns the WPS. SHH STEEL can share mill heat data for that review.

Usual delivery from SHH STEEL is normalized or normalized-and-tempered GB/T 713.3 Q420DR. As-rolled is not the default.

If the vessel will see PWHT, say so. Test coupons then follow a simulated cycle. Extra simulation, 3.2 hold points or special NDE add time. Plan about two months when those extras are on the order.

The certificate lists GB/T 713.3 Q420DR; heat number; heat analysis; product analysis when ordered; tensile to the correct thickness column; N or N+T; impact at −40 °C; lateral expansion. Certificates may be EN 10204 3.1 or EN 10204 3.2.

Usual supply range from SHH STEEL for Q420DR low temp vessel plate:

• Thickness: commonly 6 mm – 30 mm per Table 2. Confirm any request above 30 mm against mill capability
• Width: 1500 mm – 4000 mm
• Length: 3000 mm – 12000 mm
• Cut-to-length plates and nest sizes inside those limits

Ship plate inquiries belong on shipbuilding steel plates or BV Rules. Weathering plate belongs on EN 10025-5 or Corten A/B. TMCP fine-grain structural belongs on EN 10025-4. QT structural belongs on EN 10025-6. Ordinary structural belongs on EN 10025-2 or JIS G3106.

Dimensional limits follow GB/T 713.1 and the mill rolling standard named on the order. Do not apply ASTM A36/A36M structural tolerances to a Chinese vessel plate without writing them. UT to GB/T 2970, JB/T 4730 / NB/T 47013.3, EN 10160 or ASTM A435 / A577 / A578 is added when the order names it.

Most export Q420DR orders add extras. SHH STEEL does not assume them.

Charpy details. Temperature, energy, location, orientation and lateral expansion ≥0.53 mm.

Product analysis. Add this when the destination file wants finished-plate chemistry.

Simulated PWHT. When the equipment will be stress-relieved.

NDE. UT per the named method.

Z-direction. Z15 / Z25 / Z35 when the drawing names it.

HIC / NACE / SSC. Only when written.

Third-party. EN 10204 3.2, with inspectors arranged for US, Mexican, European, Middle East, Japanese or Korean documentation packages.

Stainless inquiries belong on stainless steel products, JIS G4305 or AISI stainless. Other vessel comparisons: SA203 Gr.B, SA302 Gr.B, A516 Grade 70, SA533 Type C Cl.1, SA517 Gr.P, SA738 Gr.C.

SHH STEEL is a global steel mill sourcing partner with mill partnerships in China. We supply ASTM, ASME, EN, DIN, JIS and GB steel to buyers outside a single region. Origin is mill-direct, China origin.

SHH STEEL has supplied steel plates to:

• North America: USA, Mexico
• South America: Argentina, Peru and other South American ports
• Central America: El Salvador
• Europe: Spain, Netherlands, Germany and surrounding ports
• Middle East: UAE, Saudi Arabia and nearby Gulf ports
• Africa: South Africa
• South / Southeast Asia: India, Thailand, Singapore, Vietnam, Philippines
• East Asia: Japan, Korea

Typical trade terms on this grade: FOB Shanghai, CIF Port Klang, CIF Santos, CIF Gioia Tauro, plus Houston, Rotterdam, Jebel Ali, Singapore, Antwerp, Manzanillo, Busan, Hamburg, Durban, Laem Chabang, Mumbai, Callao, Ho Chi Minh, Barcelona and Yokohama.

Typical lead time for GB/T 713.3 Q420DR:

• Ex-stock: about 5–7 days
• Mill rolling, standard N or N+T: about 45 days
• Simulated PWHT, 3.2 or extra NDE: about 2 months

Documents travel with the cargo: mill certificate, packing list, commercial invoice, bill of lading, and EN 10204 3.1 or 3.2 as ordered. Third-party inspection can be arranged before loading. Packing is seaworthy, with edge protection and marking in English as specified on the order.

SHH STEEL is a global steel mill sourcing partner and steel manufacturer & exporter (mill-direct, China origin). We supply ASTM / ASME / EN / DIN / JIS / GB steel to the USA, Mexico, South America, Europe, the Middle East, Africa and Asia. On GB/T 713.3 Q420DR that means mill pricing, Q420DR chemistry reported as heat analysis and as product analysis when ordered, recorded N or N+T, tensile results to the correct thickness column, −40 °C impact with lateral expansion, 3.1 as standard and 3.2 when specified.

We keep the grade on the order. Q420DR is not Q420R. Q420DR is not Q460DR. Q420DR is not 16MnDR. Q420DR is not 11MnNiMoDR. Q420DR is not SA537 Cl.1 unless both books are met. If the drawing says Q420R, we will not roll Q420DR and call the names close.

Company scope: global steel mill sourcing partner – SHH STEEL.

GB/T 713.3 Q420DR Steel Plate is a 2023-added Chinese −40 °C high-strength pressure-vessel plate at the 420 MPa yield step, 590–720 MPa tensile at 6–20 mm, N or N+T delivery, with lateral expansion not less than 0.53 mm. Whether the inquiry says GB/T 713.3 Q420DR or Q420DR Low Temp Vessel Plate, SHH STEEL as a global steel mill sourcing partner and steel manufacturer & exporter (mill-direct, China origin) supplies plate with Q420DR chemistry, heat and product analysis when ordered, recorded N or N+T, −40 °C impact, and EN 10204 3.1 or 3.2 certification.

SHH STEEL supplies GB/T 713.3 Q420DR Low Temp Vessel Plate to the USA, Mexico, South America, Europe, the Middle East, Africa and Asia for work that actually names this grade. FOB Shanghai / CIF Port Klang / Santos / Gioia Tauro.

Contact SHH STEEL for mill rolling, stock inquiry, N or N+T, 3.2 inspection or a quotation.

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