D2 Tool Steel Chemical Component Analysis

What is steel?

Steel is an alloy made up of iron with typically a few tenths of a percent of carbon to improve its strength and fracture resistance compared to iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant need typically an additional 11% chromium. Because of its high tensile strength and low cost, steel is used in buildings, infrastructure, tools, ships, trains, cars, machines, electrical appliances, and weapons.

What is too steel?

Tool steel is a type of carbon alloy steel that is well-matched for tool manufacturing, such as hand tools or machine dies. Its hardness, resistance to abrasion and ability to retain shape at increased temperatures are the key properties of this material. Tool steel is typically used in a heat treated condition which provides increased hardness.

Types of Tool Steel. The different tool steel grades include:

Water Hardening

Air Hardening

D Type

Oil Hardening

Shock resisting types

Hot-Working.

What is D type tool steel?

D Type (D-Grades) This is a high carbon, high chromium (air hardening) tool steel. It was formulated to combine both the abrasion resistance and air-hardening characteristics. Common applications for these tool steels include forging dies, die-casting die blocks, and drawing dies. Typical Applications of D-Grade tool steel include Burnishing Tools, File Cutting, Paper Cutters, Die Bending, Blanking, Coining, Cold Heading Die Inserts, Embossing, Cold Extrusion, Cold Forming, Lamination, Cold Swaging, Thread Roll, Cold Trimming, Wire Drawing, Gages, Paper Knives, Rotary Slitters, Cold Shear Knives, Woodworking Knives, Knurling tools and Lathe Center Knives.

What is D2 steel?

D2 steel is a high carbon – high chromium air hardening tool steel, heat treatable to 60-62 HRC. D2 offers excellent wear and abrasion resistance, due to large volumes of carbides in the micro-structure. D2 steel is widely used in long production cold work applications requiring very high wear resistance and high compression strength. It is machinable in the annealed condition, and, like other air hardening tool steels, exhibits minimal distortion in heat treat. D2 steel is available in de-carb free rounds, flats, and squares, as well as ground flat stock and drill rod.

What D2 steel used?

Typical applications for D2 steel are blanking, forming, and trim dies, gages, slitting cutters, wear parts, lamination dies, thread rolling dies, drawing dies, rotary cutting dies, knurls, bending dies, gages, shear blades, burnishing tools, rolls, machine parts, master parts, injection screw and tip components, seaming rolls, extrusion dies, tire shredders, scrap choppers, Stamping dies, Forming Dies, Punches, Forming Rolls, Knives, slitters, shear blades, Tools, Scrap choppers, Tyre shredders, etc.

D2 Steel Chemical Composition Standard:

ASTM A681 – 08 Standard Specification for Tool Steels Alloy.

D2 Steel Grade All Grades Comparison:

ASTM;Material No.;DIN;EN

D2;1.2379;X155CrVMo12-1;X160CrMoV121

D2 Steel Chemical Composition(%)

D2 Steel Elements Analysis:

Carbon-C

Carbon is inseparable from steel and is therefore usually not defined as alloying constituent. Carbon is the most important element for the majority of steels and has the strongest influence on their properties.

Vanadium-V

Vanadium refines the primary grain and thus the as cast structure. It is a strong carbide forming element, thus causing an increase in wear resistance, edge holding properly and high-temperature strength. It is therefore a preferred alloying constituent in high-speed steels, hot work tool steels and high-temperature steels.

Chromium-Cr

Chromium makes steel oil and air hardenable. By lowering the critical cooling rate necessary for the formation of martensite, it increases hardenability and thus improves heat treating properties while at the same time it reduces impact strength. Chromium is a strong carbide former.

Manganese-Mn

Manganese has a deoxidizing effect. It combines with sulphur to form manganese sulphides and hus lowers the untavourable effect of iron sulphides. This is of particular importance for free- cuting steels because itreduces the risk of red shortness.

Molybdenum-Mo

Molybdenum is mostly added together with other alloying elements. By reducing the critical cooling rate, it improves hardenability Mn reduces to a large extent temper brittleness, e.g. in CrNi and Mn steels, and promotes fine-grain formation.

Nickel-Ni

In constructional steels, Ni causes an increase of impact strength, even at subzero temperatures is therefore added to case-hardening steels, heat treatable steels and steels intended for low temperature service to increase theirtoughness properties All transformation points (A1-A4) are lowered by nickel.

Aluminum-Al

Aluminum is the strongest and most common used deoxidizing and dentriding agent. It has therefor a favorable effect on the intensivity to ageing and it promotes a fine grain formation, when added in small amounts.

Copper-Cu

Copper is only added to a few steel grades, because it builds up below the oxide layer and produces high surface sensitivity in hot forming operations due to penetration into the grain boundary.

Silicon – Si

Silicon has a deoxidizing effect. It promotes graphite precipitation and narrows subtantially the gamma-range. It increases strength and wear resistance (heat treatable Si-Mn steels). Silicon causes a considerable increase of the elastic limit and is therefore most suitable as alloying constituent in spring steels. Owing to its ability to improve substantially the resistance to scaling, Si is added to heat resisting steels. Its contents are, however, limited, as it impairs the hot and cold forming properties.

Sulphur – S

Among all trace elements, sulphur produces the most serious segregations. Iron sulphide leads to red shortness because the low melting sulphide eutectics surround the grains like a net, resulting in a low coherence of the latter and in breaking up of grain boundaries during hot forming. This phenomenon is intensified by the effect of oxygen.

How D2 steel produce?

Electric Arc Furnace (EAF) Melting: This process is also known as primary melting. It is based on the melting of metal chips which are obtained from milling processes and suppliers. Basically, EAF melting uses leftovers of different metal processing methods. Electric arc furnace melting is widely used because the production costs are low. Still some extra treatment may be needed to achieve the highest possible quality and properties. An example of this is annealing to prevent cracking.

Electroslag Refining (ESR): Electroslag refining is also known as electroslag remelting. Throughout the process, the metal is melted progressively. The resulting ingots have good surface quality without notable imperfections.