China Origin Carbon Steel 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 characterized by its superior hardness and the presence of numerous, large, chromium-rich alloy carbides within its microstructure. These carbides offer excellent resistance to wear from sliding contact with other metals and abrasive materials. While other steels may provide enhanced toughness or wear resistance, D2 stands out due to its balanced blend of wear resistance, toughness, performance, cost-effectiveness, and availability in various forms. The remelting process further enhances its chemical homogeneity, refines carbide size, and improves both the 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, Milling 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
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 uniformly to 1560°F (850°C). Then cool slowly in the furnace at a rate of 20°F (10°C) per hour to 1200°F (650°C), followed by cooling freely in air.
Stress Relieving
After rough machining, heat the tool uniformly to 1200°F (650°C) and hold for 2 hours. Cool slowly to 930°F (500°C), then allow 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 after the tool has been fully heated through.
Protect the part against decarburization and oxidation during the hardening process.
Quenching
Quench in air or pressurized gas to 150-125ºF (66-51ºC). Sizes up to 4 inches (101.6 mm) in thickness will through-harden when air-cooled from 1575ºF (857ºC). Sizes up to 6 inches (152.4 mm) in thickness will through-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 minimum of 2 hours, then allow to air-cool to ambient temperature. The typical tempering range is 350 to 400ºF (177 to 204ºC).
For superior wear resistance, temper between 300-350°F (149-177°C) to achieve a hardness of 62-64 HRC. For an optimal balance of wear resistance and toughness, temper within the range of 500-550°F (260-288°C). This process will yield a hardness of 58-60 HRC.
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For maximum toughness, perform a double tempering treatment: first for 2 hours, then for an additional 2 hours at temperatures exceeding 950°F (510°C). This method will result in a hardness level below 58 HRC.
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7. D2 Tool Steel Applications
D2 tool steel is commonly utilized in various applications including blanking, forming, and trim dies, 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, scrap choppers, among others.

With over a decade of expertise in producing D2 Tool Steel, we at Huangshi Smooth Industry and Trade Co., Ltd. are committed to pursuing the highest quality standards. Our D2 Tool Steels are all ESR products, ensuring premium quality. D2 Tool Steel is our top-selling product, so if you have any questions, please don't hesitate to contact us. We are here to assist you in every way possible!