Cold Work Die Steel Forging Process

• Type: Special Steel Bar
• Standard: AISI, ASTM, DIN, JIS, GB, BS
• Composition: Stainless Steel Scrap
• Technique: Forged
• Shape: Bar
• Surface Treatment: Polished
• Model NO.: round bar
• Special Use: High-strength Steel Plate, Wear Resistant Steel, Free Cutting Steel, Mold Steel
• Application: Die Steel Bar
• Transport Package: Wooden
• Specification: 6-400mm
• Trademark: Smooth
• Origin: China
• HS Code: 7214100000
• Production Capacity: 5000

Product Description

1.2379/D2/SKD11

Brief Description
D2 Tool Steelis a versatile high-carbon, high-chromium, air-hardening tool steel renowned for its high attainable hardness and the presence of numerous large, chromium-rich alloy carbides in its microstructure. These carbides ensure excellent resistance to wear from sliding contact with other metals and abrasive materials. While other steels might offer improved toughness or wear resistance, D2 strikes an exceptional balance of wear resistance, toughness, performance, pricing, and availability in a wide variety of product forms. The remelting process further enhances its chemical homogeneity, refines carbide size, and improves mechanical and fatigue properties.
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1. Size Range for D2 Tool Steel
D2 Steel Round Bar: Diameter 80mm~330mm
D2 Steel Plate: Thickness 25mm~400mm x Width 200mm~800mm
Delivery Condition:
Turned Round Bar, Milled Plate, Black finish, tailored to customer requirements.
Spheroidizing Annealing, ESR material.
2. D2 Tool Steel Equivalent Grades

Country	USA	German		Japan	China
Standard	ASTM A681	W-nr.	DIN	JISG4404	GB/T1299-2000
Grades	D2	1.2379	X155CrVMo121	SKD11	Cr12Mo1V1

3. D2 Tool Steel Chemical Composition

Grades	C%	Si%	Mn%	P%	S%	Cr%	Mo%	V%
D2	1.40~1.60	0.30~0.50	0.30~0.50	≤0.03	≤0.03	11.0~13. 0	0.70~1.20	0.80~1.10
1.2379/X155CrVMo121	1.50~1.60	0.10~0.40	0.15~0.45	≤0.03	≤0.03	11.0~12.0	0.60~0.80	0.90~1.10
SKD11	1.40~1.60	≤0.40	≤0.60	≤0.030	≤0.030	11.0~13. 0	0.80~1.20	0.20~0.50

4. D2 Tool Steel Physical Properties
Physical properties of D2 Tool Steel are detailed in the tables below. The elastic modulus is 207,000 MPa, and the specific heat at constant pressure (Cp) is 461 J/(kg·K).
Critical Temperature of D2 Tool Steel

Critical point	Ac1	Acm	Arcm	Ar1	Ms
Temp.(approximation)	1490°F (810°C)	1607°F (875°C)	1382°F (750°C)	1283°F (695°C)	374°F (190°C)

Coefficient of Linear Thermal Expansion

Temperature	68~212°F (20~100°C)	68~392°F (20~200°C)	68~572°F (20~300°C)	68~752°F (20~400°C)
Coefficient	10.5 x10^-6	11.5 x10^-6	11.9 x10^-6	12.2 x10^-6

5. Forging of D2 Tool Steel

Items	Heating temperature	Starting forging temperature	Final forging temperature	Cooling
Ingot	2048~2120°F (1120~1160°C)	1922~1994°F (1050~1090°C)	≥1562°F(850°C)	Hot charging annealing
billet	2048~2084°F (1120~1140°C)	1922~1958°F (1050~1070°C)	≥1562°F(850°C)	Hot charging annealing,cooling in hole or dust

6. Heat Treatment
Soft Annealing
Protect the steel and heat evenly to 1560°F (850°C). Allow it to cool in the furnace at a rate of 20°F (10°C) per hour to 1200°F (650°C), then cool freely in the air.
Stress Relieving
Post rough machining, heat the tool uniformly to 1200°F (650°C), hold for 2 hours, then cool slowly to 930°F (500°C) before allowing it to air cool freely.
Hardening
Preheating Temperature: 1110-1290°F (650-750°C). Austenitizing Temperature: 1810-1920°F (990-1050°C), typically 1830-1905°F (1000-1040°C).

Temperature		Soaking time (min)	Hardness before tempering
°F	°C
1815	990	60	approx. 63 HRC
1850	1010	45	approx. 64 HRC
1885	1030	30	approx. 65 HRC

*Soaking time refers to the duration at the hardening temperature once the tool has been uniformly heated through.
Protect the part against decarburization and oxidation during the hardening process.
Quenching
Air or pressurized gas cooling to 150-125ºF (66-51ºC). D2 steel up to 4 inches (101.6 mm) thick will fully harden when air cooled from 1575ºF (857ºC). Thicknesses up to 6 inches (152.4 mm) will harden when air cooled from 1625ºF (885ºC).
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Tempering
Temper immediately post-quenching. Maintain the temperature for 1 hour per inch (25.4 mm) of thickness, with a minimum of 2 hours, then air cool to ambient temperature. The typical tempering range is between 350 to 400ºF (177 to 204ºC).
For unsurpassed wear resistance, temper between 300-350°F (149-177°C) to achieve a hardness level of 62-64 HRC. For an optimal synergy between wear resistance and toughness, temper between 500-550°F (260-288°C), resulting in a hardness of 58-60 HRC.
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For superior toughness, employ a double tempering process: 2 hours plus an additional 2 hours at temperatures exceeding 950°F (510°C). This results in a hardness level below 58 HRC, ensuring maximum durability.
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7. D2 Tool Steel Applications
D2 tool steel is indispensable in numerous applications such as blanking, forming, and trim dies. It’s also essential for gages, slitting cutters, wear parts, lamination dies, thread rolling dies, drawing dies, rotary cutting dies, knurls, bending dies, shear blades, burnishing tools, rolls, machine parts, master parts, injection screw and tip components, seaming rolls, extrusion dies, tire shredders, and scrap choppers.

With over ten years of expertise in producing D2 Tool Steel and a commitment to achieving the highest quality standards, our D2 Tool Steels are all ESR products. As our top-selling item, D2 Tool Steel stands out for its excellent performance. Should you have any inquiries, please do not hesitate to reach out, and we will be delighted to assist you!