ASTM A225 Grade D Steel Plate | A225 Gr.D Mn-V-Ni Vessel Plate

ASTM A225 Grade D is the mid-strength grade in the current ASTM A225/A225M. The specification covers manganese-vanadium-nickel alloy steel plates intended primarily for welded layered pressure vessels. The live standard has two grades only: Grade C and Grade D. Older talk about Grade A or Grade B belongs to withdrawn editions. As a China mill Agent, SHH STEEL supplies this plate to ASTM A225/A225M.

The same plate is written A225 Gr.D, A225GRD, A225 GR D, A225 Grade D, ASTM A225 Gr.D, ASME SA225 Grade D, SA225 Gr.D, SA225GRD, SA225 GR D and A/SA225 Grade D. They all mean Grade D. ASME SA-225/SA-225M is the Code companion used when the vessel will be stamped to ASME Section VIII.

Grade D is not the high-strength line. Grade C takes 725–930 MPa tensile and 485 MPa yield at all thicknesses. Grade D takes 550–725 MPa through 75 mm and 515–690 MPa over 75 mm. If the drawing says Grade C, do not ship Grade D and call it “close.” If the drawing says Grade D, do not ship Grade C as a silent upgrade. Carbon caps are also different: Grade C 0.25% max, Grade D 0.20% max.

This is not carbon vessel plate. If the drawing says SA516 Gr.70 or A516 Gr.70, open that page. If it says SA285 Gr.C or A285 Gr.C, that is low-to-intermediate tensile carbon. ASTM A225 Grade D is a Mn-V-Ni alloy.

It is not nickel cryogenic plate like SA203 Gr.D or A203 Gr.D. Those plates live on 3.5% nickel. A225 Grade D lives on manganese, vanadium and 0.40–0.70% nickel. The two “Grade D” names are easy to mix in a search box. They are not the same steel.

It is not Mn-Mo plate like SA302 Gr.B or A302 Gr.B. It is not Cr-Mo like SA387 Gr.22 Cl.2. It is not QT 690 like SA517 Gr.Q or A517 Gr.Q. SA517 / A517 is quench and temper. ASTM A225 Grade D is normalized at all thicknesses. That sentence is in the heat-treatment clause, not in a mill brochure.

The steel shall be killed and shall conform to the fine austenitic grain size requirement of ASTM A20 / ASME SA-20. Maximum thickness is limited only by the ability of the chemistry to meet the tensile table. Mills commonly offer about 8–150 mm; heavier sizes are an enquiry.

For Code work the plate is dual-marked ASTM A225 Grade D / ASME SA225 Grade D. Certificates can be EN 10204 3.1 or EN 10204 3.2.

When a project is still choosing alloy vessel plate, a China mill Distributor path through SHH STEEL puts A225GRD next to SA302 Gr.C, SA387 Gr.11 Cl.2 and SA537 Cl.1. Mn-Mo, Cr-Mo, carbon heat-treated and Mn-V-Ni are four different purchases.

This plate is a vessel product. It is not structural ASTM A36 steel plate. It is not silicon-killed high-temp carbon like SA515 Gr.70 or A515 Gr.70.

Chemistry for ASTM A225 Grade D is reported as heat analysis and product analysis under ASTM A225/A225M Table 1. Carbon is lower than Grade C. Manganese is allowed higher.

Heat Analysis — ASTM A225 Grade D / A225 Gr.D

Product Analysis — A225GRD / SA225 Grade D

Carbon 0.20% max applies to both heat and product analysis. That is tighter than Grade C (0.25% max). Manganese is a maximum, not a min–max band: 1.70% heat, 1.84% product. Vanadium is 0.10–0.18% heat. Nickel is the same window as Grade C, 0.40–0.70% heat.

Compare that ladle with nearby alloys before anyone tries a silent swap. SA203 Gr.A and A203 Gr.A live on nickel, not vanadium. SA302 Gr.A and A302 Gr.D live on molybdenum. SA387 Gr.12 Cl.2 lives on chromium-molybdenum. Grade D in A225 is none of those ladles.

A Grade C heat cannot be recertified as Grade D if carbon sits above 0.20% or if the tensile result sits in the Grade C window only. If the drawing says ASTM A225 Grade D or A225GRD, the ladle must sit in the Grade D table. SHH STEEL reports heat analysis on every certificate and adds product analysis when A20 / SA-20 or the vessel specification requires it.

Tighter phosphorus, sulfur or residuals are supplementary. Vacuum treatment is available when written on the order.

Grade D uses two tensile lines by thickness. That is the first thing a designer should read.

Tensile Requirements — ASTM A225 Grade D per ASTM A225/A225M

Yield is determined by the 0.2% offset method or the 0.5% extension-under-load method. A 70 mm plate is tested to the 415 MPa line. An 80 mm plate is tested to the 380 MPa line. Do not apply the thin-line yield to a 90 mm plate and call the heat compliant.

Grade C in the same specification is 725–930 MPa tensile and 485 MPa yield at all thicknesses. That is why Grade C is the high-pressure choice and Grade D is the mid-strength layered-vessel choice.

Density is 7.85 g/cm³. Hardness is not a default line in A225. A special HBW window is supplementary.

Charpy impact is not a hidden default at −20 °C or −46 °C. If the vessel needs a stated test temperature and energy, that is a supplementary requirement under A20 / SA-20. Write the temperature on the purchase order.

Compare strength class carefully. SA537 Cl.2 is carbon QT. SA517 Gr.F is QT 690 MPa class with a 65 mm ceiling. SA516 Gr.70 is fine-grain carbon at 485–620 MPa. A225 Grade D is not a substitute for those pages.

Order ASTM A225 Grade D when the drawing names Grade D. SHH STEEL does not swap A225GRD for A516 Gr.70 or SA517 Gr.P without a written revision.

ASTM A225 Grade D exists because layered vessels need a weldable Mn-V-Ni plate that is stronger than ordinary carbon and more formable than Grade C. Vanadium refines grain. Nickel at 0.40–0.70% helps toughness. Manganese carries hardenability for the normalized condition. Lower carbon than Grade C is the weldability argument.

Allowable stress for Code work comes from ASME Section II Part D for SA-225 Grade D after dual marking. Impact temperature is an order number.

Typical use is layered shells, intermediate-pressure drums specified to A225 / SA225, and other fusion-welded equipment written as Mn-V-Ni vessel plate. It is not a replacement for SA387 Gr.91 Cl.2 creep service and not a replacement for SA203 Gr.A nickel low-temp service.

A225GRD is a vanadium-bearing alloy vessel plate. Welding is not the same job as welding SA516 Gr.60 or SA285 Gr.B.

Procedures for Code work are qualified to ASME Section IX. Consumables should match the required joint strength and toughness. Low-hydrogen practice is mandatory thinking. Grade D carbon is 0.20% max, which is kinder than Grade C, but vanadium and manganese still raise hardenability enough that a cold, restrained start can crack.

Preheat depends on thickness, restraint, hydrogen and the qualified WPS. After welding, many shops want to PWHT. Simulated PWHT of mill coupons should be on the purchase order whenever the vessel specification includes PWHT.

Do not copy a SA387 Gr.22 Cl.1 Cr-Mo procedure or a SA517 Gr.A QT procedure onto ASTM A225 Grade D. The fabricator owns the qualified WPS.

Heat treatment of ASTM A225 Grade D is explicit in the specification:

Grade D plates of all thicknesses shall be normalized.

That is not optional language. As-rolled Grade D is not ASTM A225 Grade D. Grade C plates 50 mm and under are usually supplied as-rolled and may be ordered normalized; Grade D does not get that option.

Holding time follows mill practice and A20 / SA-20 thickness rules. If the purchaser fixes a normalizing temperature band or a subsequent stress relief because later PWHT is planned, those limits go on the mill instruction and onto the certificate.

Do not apply the quench-and-temper route used for SA517 Gr.E or A517 Gr.E and call the plate A225 Gr.D.

SHH STEEL reports the actual heat-treatment condition on the MTC for every A225 Gr.D plate.

Usual delivery is normalized alloy vessel plate. Additional stress relieving is supplied when specified.

The certificate lists ASTM A225 Grade D and, when dual certified, ASME SA225 Grade D; heat number; heat analysis; product analysis when ordered; tensile results by thickness line; heat-treatment temperatures; Charpy results when ordered; and supplementary tests.

Surface is vessel-plate quality. Shot blasting and shop primer are available.

Certificates may be EN 10204 3.1 or EN 10204 3.2. BV, LR, DNV, TUV, SGS or the buyer’s agency can witness rolling, normalizing and testing when the order says so.

Usual supply range from SHH STEEL for A225 Gr.D Mn-V-Ni vessel plate:

• Thickness: 8 mm – 150 mm (heavier sizes by mill enquiry; thickness is limited by chemistry meeting the tensile table)
• Width: up to about 4000 mm
• Length: up to about 12000 mm

State thickness clearly. At 75 mm the tensile table changes. An 80 mm plate is ordered and tested to the lower yield line.

Dimensional limits follow ASTM A20 / ASME SA-20. Thickness, width, length, flatness and camber are vessel-plate tolerances.

Ultrasonic testing to A435, A577 or A578 is commonly added on layered-vessel plate. Extra-flatness is a negotiated item.

Most export ASTM A225 Grade D orders add tests beyond the base tensile table. SHH STEEL does not assume these extras.

Simulated PWHT. Same-heat coupons follow the vessel cycle. Tensile and Charpy are run after that cycle.

Charpy details. Temperature, energy, specimen orientation and location as agreed. Not a hidden default.

NDE. UT to A435 / A577 / A578; edge MT/PT after cutting. Layered-vessel work often writes UT on the mill order.

Hardness survey. Surface or through-thickness HBW/HV after normalize or after simulated PWHT.

Restricted chemistry. Tighter P, S, residuals or vacuum treatment per A20.

HIC / NACE. Only when TM0284 or MR0175 / ISO 15156 is cited. Grade D is not automatically sour-service plate.

Z-direction. A770 or Z15/Z25/Z35 for nozzles and strained joints.

Third-party. Witness of normalizing, testing and documents. Output can be EN 10204 3.2.

If an item is not on the purchase order, it is not assumed, not tested and not printed as if it were.

These names are used for project comparison. They are not automatic substitutes.

For stamping, write ASTM A225 Grade D or dual A225 / SA225 Grade D. Nearby comparison pages also include A302 Gr.B and A517 Gr.S.

ASTM A225 Grade D / A225 Gr.D is selected when a Section VIII or layered vessel needs Mn-V-Ni alloy strength below the Grade C tensile window.

Do not use this grade as a silent stand-in for SA387 Gr.5 Cl.2 or SA517 Gr.S. Those drawings name different alloys and different heat treatments.

SHH STEEL works as a China Mill Direct Exporter for plates to ASTM A225/A225M. On ASTM A225 Grade D that means mill pricing, dual A225/SA225 marking, heat and product analysis including the 0.10–0.18% vanadium band and 0.20% carbon cap, normalizing on every thickness, thickness-correct tensile lines at 75 mm, 3.1 as standard and 3.2 when specified.

We keep the order on the right grade. Grade D is not Grade C. A225 is not SA285 Gr.A. A225 is not SA516 Gr.55. A225 Gr.D is not SA517 Gr.Q. If the drawing is nickel low-temp, we point the inquiry to SA203 / A203. If it is Cr-Mo elevated-temp, we point it to SA387. If it is QT 690, we point it to SA517 / A517. If the drawing is Grade C, we will not ship Grade D.

Company scope: China steel Mill Agent-SHH STEEL.

ASTM A225 Grade D Steel Plate is the mid-strength manganese-vanadium-nickel vessel grade in the current ASTM A225/A225M, which lists only Grade C and Grade D. Whether the inquiry says A225 Gr.D, A225GRD, A225 Grade D, SA225 Gr.D or ASME SA225 Grade D, SHH STEEL supplies plate with heat and product analysis, mandatory normalizing, thickness-correct tensile lines at 75 mm, agreed extras, and EN 10204 3.1 or 3.2 certification.

As Direct Mill Supply by SHH STEEL, we provide ASTM A225 Grade D / A225 Gr.D Mn-V-Ni Vessel Plate for ASME Section VIII layered-vessel fabrication.

Contact SHH STEEL for mill rolling, dual A225/SA225 marking, 3.2 inspection or a quotation.

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