d2

D2 Mold Steel

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Product Description

Products: Round bar, Flat bar, Plates.
D2 Tool Steel
Equivalent grades: SKD11 Mold Steel/DC53 Mould Steel/1.2379 Tool Steel/Cr12Mo1V1 Die Casting Steel
D2 is a high carbon – high chromium air hardening tool steel, heat treatable to 60-62 Rc. D2 offers excellent wear and abrasion resistance, due to large volumes of carbides in the microstructure. D2 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 is available in de-carb free rounds, flats, and squares, as well as ground flat stock and drill rod.

ANALYSIS

A.I.S.I. D2 conforms to ASTM A681, DIN 1.2379, SAE J437, J438

 Typical chemical composition of AISI D2 Steel
 C  SI  Cr  Mo  V
 1.50%  0.30%  12.00%  0.80% 0.90%

APPLICATIONS

Typical applications for D2 tool 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, etc

HEAT TREATING

FORGING
Heating for forging must be done slowly and uniformly. Soak through at 1850°-1950°F and reheat as often as necessary, stopping work when the temperature drops below 1700°F. After forging, cool slowly in lime, mica, dry ashes or furnace. D2 should always be annealed after forging.
ANNEALING
Heat slowly to 1550°-1600°F, hold until entire mass is heated through, and cool slowly in the furnace (40°F per hour) to about 1000°F, after which cooling rate may be increased. Suitable precautions must be taken to prevent excessive carburization or decarburization.
STRESS RELIEVING
When desirable to relieve the strains of machining, heat slowly to 1050°-1250°F, allow to equalize, and then cool in still air (Strain Relieving).
PREHEAT PRIOR TO HARDENING
Preheat slowly to 1350°-1450°F and hold at this temperature until material is uniformly heated.
HARDENING
After thorough preheating, heat to 1800°-1850°F. Hold the work piece at the hardening temperature until it is completely and uniformly heated.
QUENCHING
D2 is an air hardening steel and will develop hardness on cooling in still air. To avoid scaling and prevent decarburization of the work piece surface, controlled atmosphere or vacuum furnaces are recommended. If these furnaces are not available, pack hardening, salt baths or wrapping the piece in stainless steel foil will provide some degree of surface protection in the hardening process. Parts should be allowed to cool to 150F, or to where they can be held in the bare hand, and then temper immediately.
TEMPERING
The tempering temperature may be varied according to the desired hardness. If maximum hardness is desired, tempering should be in the range 300°-400°F, but if a lower hardness is acceptable, tempering at 950°F will give the optimum combination of hardness and toughness.

 Tempering Temperature F  1850F Air-Quenched Rockwell C
 None  64
 400  60
 500  58
 600  58
 700  58
 800  57
 900*  58/60
 960*  58/60
 1000  56
 1100  48
 1200  40
 * Secondary Hardening Range

TOLERANCES

D2 de-carb free rounds are produced .015-.035 oversize. D2 de-carb free flats and squares are produced .015-.035 oversize on thickness, and widths are milled or cut oversize sufficiently to clean to nominal size.
D2 ground flat stock, produced in standard 18″ and 36″ lengths, is available in standard precision ground (+/-.001″ on thickness, +.005/-.000″ on width), and oversize ground (+.010/+.015 on thickness and width).