Alloy Steel Plate

Product Introduction

Alloy steel plate supplied to EN 10083-3 and GB/T 3077 for engineering machinery, automotive components, pressure and power equipment, and general engineering.

StandardsEN 10083-3 · GB/T 3077

Grades105 designations

Alloy familiesMn · Cr · CrMo · CrNiMo · MnB

ConditionsHot rolled · Annealed · Normalized · Q&T

DocumentationMill test certificate · Heat number traceable · Third-party inspection on request

Two standard systems, one source — the EN 10083-3 range (Cr / CrMo / CrNiMo / MnB) and the full GB/T 3077 range, supplied from the same mill programme.
Low alloy through high alloy — from manganese and chromium-molybdenum engineering steels to more heavily alloyed grades; the usual dividing line is about 8% total alloying elements.
Heat treated to your drawing — annealed, normalized or quenched and tempered to the condition your specification calls for, with the condition and test results stated on the MTC.

01What Alloy Steel Plate Is

Steel is a metal alloy consisting mostly of iron together with a small amount of carbon. Alloy steel is any steel to which one or more elements besides carbon have been intentionally added, in order to produce a desired physical property or characteristic. The elements most commonly added are molybdenum, manganese, nickel, silicon, boron, chromium and vanadium.

Alloy steel is usually subdivided into two groups: low alloy steel and high alloy steel. The dividing line is defined somewhat arbitrarily, but most agree that steel alloyed with more than about eight percent of its weight in elements other than iron and carbon is high alloy steel. Low alloy steels are the more common group. The physical properties of these steels are modified by the added elements to give greater hardness, durability, corrosion resistance or toughness compared with carbon steel — and to develop those properties these alloys usually require heat treatment.

2Standard SystemsEN 10083-3 · GB/T 3077

105Grade Designations28 EN · 77 GB

7Alloying ElementsMn · Cr · Mo · Ni · V · B · Si

4Supply ConditionsHot rolled · Annealed · Normalized · Q&T

02Specifications & Condition of Supply

Item	Specification
Standards	EN 10083-3 · GB/T 3077 (other standards on request)
Product	Alloy steel plate; sheet and coil supply reviewed against the rolling programme
Alloy families	Manganese · chromium · chromium-molybdenum · chromium-nickel-molybdenum · boron treated · silicon-manganese
Delivery condition	Hot rolled Annealed Normalized Quenched & tempered
Surface	As rolled · shot blasted · machined or ground on request
Dimensions	Thickness, width and length confirmed per order against mill capability
Testing	Chemical analysis · tensile · hardness · impact · ultrasonic examination on request
Documentation	Mill test certificate with heat number, cast analysis and test results
Processing	Cutting to size, heat treatment, machining and processing to drawing

On dimensions and properties: alloy plate is produced to order and the achievable thickness, width and length depend on the grade, the rolling programme and the required heat treatment, so sizes are confirmed against each enquiry rather than quoted from a fixed stock list. Mechanical values likewise depend on grade, thickness and delivery condition — for project orders we state the applicable limits on the MTC against the standard and your specification.

03Available Grades & Standards

The full grade range of both standards is listed below. Click any linked grade to open its dedicated page with composition, mechanical properties and supply details.

Standard	Steel Grade
EN 10083-3	38Cr2	41CrS4	50CrMo4	51CrV4
	46Cr2	25CrMo4	30CrNiMo8	20MnB5
	34Cr4	25CrMoS4	34CrNiMo6	30MnB5
	34CrS4	34CrMo4	35NiCr6	38MnB5
	37Cr4	34CrMoS4	36NiCrMo16	27MnCrB5-2
	37CrS4	42CrMo4	39NiCrMo3	33MnCrB5-2
	41Cr4	42CrMoS4	30NiCrMo16-6	39MnCrB6-2
GB/T 3077	20Mn2	20MnVB	12CrMoV	20CrNi
	30Mn2	40MnVB	35CrMoV	40CrNi
	35Mn2	20MnTiB	12Cr1MoV	45CrNi
	40Mn2	25MnTiBRE	25Cr2MoVA	50CrNi
	45Mn2	15Cr	25Cr2Mo1VA	12CrNi2
	50Mn2	15CrA	38CrMoAl	12CrNi3
	20MnV	20Cr	40CrV	20CrNi3
	27SiMn	30Cr	50CrVA	30CrNi3
	35SiMn	35Cr	15CrMn	37CrNi3
	42SiMn	40Cr	20CrMn	12Cr2Ni4
	20SiMn2MoV	45Cr	40CrMn	20Cr2Ni4
	25SiMn2MoV	50Cr	20CrMnSi	20CrNiMo
	37SiMn2MoV	38CrSi	25CrMnSi	40CrNiMoA
	40B	12CrMo	30CrMnSi	18CrNiMnMoA
	45B	15CrMo	30CrMnSiA	45CrNiMoVA
	50B	20CrMo	35CrMnSiA	18Cr2Ni4WA
	40MnB	30CrMo	20CrMnMo	25Cr2Ni4WA
	45MnB	30CrMoA	40CrMnMo
	20MnMoB	35CrMo	20CrMnTi
	15MnVB	42CrMo	30CrMnTi

Grades not shown with a link are supplied to order — send the standard, grade, dimensions, quantity and required delivery condition and we will confirm availability, heat treatment and lead time. Certification and third-party inspection (SGS, BV, DNV or your nominated inspector) can be arranged on request.

04How to Read the Grade Designation

Both standards encode the chemistry in the grade name, so the designation already tells you what the steel is built on.

EN 10083-3: Carbon First

The leading number is the nominal carbon content in hundredths of a percent — 42CrMo4 is a 0.42% carbon steel. The element symbols that follow name the principal alloying additions, and the trailing digit is a code for their content level. In 50CrMo4, chromium and molybdenum are the alloying pair.

GB/T 3077: Carbon in Ten-Thousandths

The leading two digits give the carbon content in ten-thousandths — 40Cr is 0.40% carbon, 15CrMo is 0.15% carbon. An element symbol with no number after it means that element is below about 1.5%.

The “A” Suffix

A trailing A marks a higher-purity grade with tighter limits on phosphorus and sulphur — for example 30CrMoA, 15CrA and 40CrNiMoA. These are specified where toughness or fatigue performance matters more than cost.

The “S” for Free Cutting

Grades such as 41CrS4, 25CrMoS4, 34CrMoS4 and 42CrMoS4 carry an increased sulphur content for improved machinability in high-volume turned parts.

B for Boron Hardenability

A B in the name — 20MnB5, 40B, 40MnB, 27MnCrB5-2, 39MnCrB6-2 — means a small boron addition used to raise hardenability without adding large amounts of other alloys.

EN/GB

Counterparts, Not Automatic Substitutes

42CrMo4 (EN 10083-3) and 42CrMo (GB/T 3077) sit on the same chromium-molybdenum design, as do 34CrMo4 / 35CrMo and 25CrMo4 / 20CrMo. Limits and test requirements still differ between the two standards, so always confirm the substitution against the MTC and your design code.

05Alloying Elements & What They Contribute

Each element is added for a reason. The table below shows what the principal additions do and where they appear in our grade range.

Element	What It Contributes	Typical Grades in This Range
Mn Manganese	Raises strength and hardenability, improves wear resistance, and is present in almost every grade as a deoxidiser	20Mn2 · 35Mn2 · 50Mn2 · 40MnB · 20MnVB
Cr Chromium	Increases hardness, wear resistance and hardenability, and contributes corrosion and oxidation resistance	15Cr · 20Cr · 40Cr · 50Cr · 38CrSi
Mo Molybdenum	Holds strength at elevated temperature, resists temper softening and reduces the risk of temper embrittlement	15CrMo · 30CrMo · 35CrMo · 42CrMo · 25Cr2MoVA
Ni Nickel	Improves toughness, particularly at low temperature, and supports through-hardening of large sections	20CrNi · 40CrNi · 12CrNi3 · 30CrNi3 · 40CrNiMoA
V Vanadium	Refines the grain and adds precipitation strengthening, giving a better strength–toughness balance after tempering	20MnVB · 40MnVB · 50CrVA · 35CrMoV · 12Cr1MoV
B Boron	A trace addition that markedly raises hardenability, letting leaner chemistries reach the same as-quenched hardness	40B · 45B · 50B · 20MnB5 · 27MnCrB5-2
Si Silicon	Raises strength and the elastic limit, acts as a deoxidiser, and improves resistance to tempering	27SiMn · 35SiMn · 42SiMn · 20SiMn2MoV
Al Aluminium	Grain refinement and, in nitriding grades, a hard wear-resistant surface layer after nitriding	38CrMoAl

Selection note: the contribution of each element depends on the full chemistry, the section thickness and the heat treatment, not on the element alone. Where a design code sets composition or property limits, those limits govern — send us the specification and we confirm the grade and condition against it.

06Heat Treatment & Mechanical Response

Alloy steel is specified as much by its heat treatment as by its chemistry — the same grade can be supplied soft for machining or hardened for service.

Condition	Purpose	Where It Is Used
As rolled / hot rolled	Supply condition for further processing; lowest cost, properties set by the rolling schedule	Plate intended for subsequent forming, machining or heat treatment by the buyer
Annealed	Softens the steel, relieves internal stress and improves machinability and cold formability	Heavily machined parts, complex blanks, plate that must be cut and formed before hardening
Normalized	Refines and homogenises the grain structure for a more uniform property profile through the section	General engineering parts, structural components, plate for welded fabrications
Quenched & tempered	Produces the high strength–toughness combination that alloy steel is normally chosen for	Gears, shafts, axles, connecting rods, high-duty structural and pressure parts
Carburising / nitriding	Hard wear-resistant case over a tough core, for low-carbon alloy grades	20Cr · 20CrMnTi · 20CrMnMo · 12Cr2Ni4 · 38CrMoAl

Mechanical values: yield, tensile, elongation, hardness and impact energy vary with grade, thickness, test direction and delivery condition, so we state the applicable figures on the MTC for each order rather than publishing a single set of numbers. Tell us the required condition and property limits and we confirm what the grade can meet.

07Typical Applications

Where alloy plate is chosen over carbon plate — higher duty, heat treatment, or a property carbon steel cannot reach.

Construction & Mining Machinery

Bucket and blade components, wear plates, boom and frame structures, pivot pins and high-duty fabricated parts where strength and wear resistance must come from heat-treated alloy plate.

Automotive & Commercial Vehicle

Gears, shafts, axle and steering components, connecting rods and transmission parts — typically quenched and tempered chromium, chromium-molybdenum or boron grades.

Pressure Vessels & Piping

Pressure and heat-resistant parts in chromium-molybdenum grades such as 15CrMo and 12Cr1MoV, where strength at elevated temperature and creep resistance govern the material choice.

Power Generation & Boilers

Boiler and turbine components, high-temperature fasteners and supports using vanadium and molybdenum alloyed grades such as 25Cr2MoVA and 25Cr2Mo1VA.

Tooling, Springs & Wear Parts

Spring and wear components in 50CrVA, nitrided parts in 38CrMoAl, dies, jigs and machine parts that must hold hardness and dimensional stability in service.

08Processing, Testing & Supply

Value-added services that shorten your fabrication cycle and keep the material traceable back to the heat.

Cutting to Size

Plate cut to your nesting plan or drawing, including profile cutting, to reduce scrap and handling in your workshop.

Heat Treatment

Annealing, normalizing or quenching and tempering carried out to the condition stated on your order and drawing.

Machining & Surface

Machining, grinding, shot blasting and priming so parts move straight into assembly or further processing.

Inspection & Certified Delivery

Chemical analysis, tensile, hardness and impact testing, ultrasonic examination on request, third-party inspection by your nominated agency, and an MTC carrying the heat number.

Ordering: payment terms L/C, T/T, D/P, Western Union, Paypal and Money Gram. Indicative lead time is 5 days for 1–10 tonnes and 10 days for 10–50 tonnes, with larger quantities negotiated — confirmed against the rolling programme and heat treatment route when you enquire.

09Frequently Asked Questions

Q1What is the difference between alloy steel plate and carbon steel plate?

Alloy steel has one or more elements besides carbon deliberately added — manganese, chromium, molybdenum, nickel, vanadium, boron or silicon — to obtain hardness, durability, corrosion resistance or toughness that carbon steel cannot reach. In practice the difference also shows in processing: alloy grades are usually supplied in a specified heat-treated condition, and their properties depend on that condition as much as on the chemistry.

Q2Can I substitute a GB/T 3077 grade for an EN 10083-3 grade?

Several grades sit on the same alloy design — 42CrMo4 and 42CrMo, 34CrMo4 and 35CrMo — but the two standards do not set identical composition limits, test requirements or delivery conditions. Treat them as counterparts and confirm the substitution against your design code and the MTC rather than assuming they are interchangeable.

Q3What sizes can you supply?

Alloy plate is produced to order, and the achievable thickness, width and length depend on the grade and the rolling programme. Send the standard, grade, required dimensions and quantity and we confirm what the mill can roll, together with the delivery condition you need.

Q4Which delivery conditions are available?

Hot rolled, annealed, normalized and quenched and tempered, with carburising or nitriding routes for the low-carbon alloy grades. Because mechanical properties vary with condition and thickness, we quote the figures that apply to the condition you order.

Q5What is the lead time and minimum quantity?

Indicative lead time is 5 days for 1–10 tonnes and 10 days for 10–50 tonnes, with quantities above 50 tonnes negotiable. Actual lead time depends on the grade, the heat treatment route and the rolling programme, and is confirmed with the quotation.

Q6What information do you need for a quotation?

The standard and grade, dimensions and quantity, required delivery condition and mechanical or hardness requirements, any inspection or certification needed (including third-party inspection), and the destination port. The more of this you send, the faster we can confirm availability and price.

Get Your Alloy Steel Plate Quotation

Send us your standard and grade, plate size, quantity, delivery condition and inspection requirements. We will reply with available sizes, heat treatment options, mill price and production lead time.

Get Price & Grade Availability E-mail: sales@bebonchina.com WhatsApp: +8617398960706

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Quantity(Metric Tons)	1 - 10	10 - 50	>50
Est. Time(days)	5	10	Negotiable

Alloy Steel Plate

Product Introduction