China Origin Steel Round Bar

• 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 Steel is a versatile, high-carbon, high-chromium, air-hardening tool steel that boasts exceptional hardness and numerous large, chromium-rich alloy carbides. These carbides ensure superior wear resistance against sliding contact with metals and abrasive materials. While other steels might offer improved toughness or wear resistance, D2 strikes a perfect balance between wear resistance, toughness, tool performance, and cost, available in a broad array of product forms. The remelting process enhances chemical uniformity, refines carbide size, and improves mechanical and fatigue properties, making it an excellent choice for various applications.
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1. Size Range for D2 Tool Steel
D2 Steel Round Bar: Diameter 80mm to 330mm
D2 Steel Plate: Thickness 25mm to 400mm, Width 200mm to 800mm
Delivery Condition:
Turned Round Bar, Milled Plate, Black, customized 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
The physical properties of D2 Tool Steel are detailed in the tables below. Its 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 it uniformly to 1560°F (850°C). Then cool inside the furnace at a rate of 20°F (10°C) per hour down to 1200°F (650°C), followed by free air cooling.
Stress Relieving
Post rough machining, heat the tool uniformly to 1200°F (650°C) for 2 hours. Cool slowly to 930°F (500°C), then allow it to cool freely in the air.
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: Duration at the hardening temperature once the tool is uniformly heated.
Protect the part against decarburization and oxidation during the hardening process.
Quenching
Use air or pressurized gas to 150-125ºF (66-51ºC). Thicknesses up to 4 inches (101.6 mm) will fully harden when air-cooled from 1575ºF (857ºC). Thicknesses up to 6 inches (152.4 mm) will fully harden when air-cooled from 1625ºF (885ºC).
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Tempering
Temper immediately after quenching. Hold at the tempering temperature for 1 hour per inch (25.4 mm) of thickness, with a 2-hour minimum. Then, allow the part to air cool to ambient temperature. Typical tempering range is 350 to 400ºF (177 to 204ºC).
For unparalleled wear resistance, temper the China Origin Steel Round Bar between 300-350°F (149-177°C) to achieve a formidable hardness of 62-64 HRC. For the perfect synergy of wear resistance and toughness, tempering between 500-550°F (260-288°C) will yield a balanced hardness of 58-60 HRC.
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To maximize toughness, employ a double tempering process: two hours plus another two hours at temperatures exceeding 950°F (510°C). This meticulous process will result in a hardness of less than 58 HRC.
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7. D2 Tool Steel Applications
The versatility of D2 tool steel makes it indispensable for a myriad of applications including blanking, forming, and trim dies, gages, slitting cutters, wear parts, lamination dies, thread rolling dies, and drawing dies. The steel excels in rotary cutting dies, knurls, bending dies, shear blades, burnishing tools, and machine parts. It's also ideal for master parts, injection screw and tip components, seaming rolls, extrusion dies, tire shredders, and scrap choppers, among others.

For over a decade, Huangshi Smooth Industry and Trade Co., Ltd has been at the forefront of producing superior D2 Tool Steel. With a commitment to excellence, all our D2 Tool Steels are ESR products, ensuring unmatched quality. Our D2 Tool Steel stands as our flagship product. Should you have any inquiries, do not hesitate to contact us—we are dedicated to providing exceptional assistance!