Carbon Steel Flat Bar Specification

• Customization: Available
• Type: Special Steel Bar
• Standard: AISI, ASTM, DIN, JIS, GB, BS
• Model NO.: round bar
• Composition: Stainless Steel Scrap
• Technique: Forged
• Shape: Bar
• Surface Treatment: Polished
• 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 SteelD2 Tool Steel is an exceptionally versatile, high-carbon, high-chromium, air-hardening tool steel renowned for its high attainable hardness. Its microstructure is rich with large, chromium-rich alloy carbides, offering excellent resistance to wear from both sliding contact with metals and abrasive materials. While other steels may offer superior toughness or wear resistance, D2 strikes a perfect balance between wear resistance, toughness, tool performance, affordability, and availability in various product forms. The remelting process further enhances D2 by improving chemical homogeneity and refining carbide size, resulting in superior 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
The physical properties of D2 Tool Steel are detailed in the tables below. The elastic modulus is 207000 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 thoroughly to 1560°F (850°C). Cool in the furnace at a rate of 20°F (10°C) per hour to 1200°F (650°C), then allow to cool freely in air.
Stress Relieving
After rough machining, heat the tool thoroughly to 1200°F (650°C) for 2 hours. Cool slowly to 930°F (500°C), then allow to cool freely in 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 refers to the duration at hardening temperature after the tool is thoroughly heated.
Protect the part from decarburization and oxidation during hardening.
Quenching
Quench in air or pressurized gas to 150-125ºF (66-51ºC). Sections up to 4 inches (101.6 mm) in thickness will harden through when air-cooled from 1575ºF (857ºC). Sections up to 6 inches (152.4 mm) in thickness will harden through when air-cooled from 1625ºF (885ºC).
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Tempering
Temper immediately after quenching. Maintain 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 unparalleled wear resistance, temper between 300-350°F (149-177°C) to achieve a remarkable hardness of 62-64 HRC. For an optimal balance between wear resistance and toughness, temper between 500-550°F (260-288°C), resulting in a robust 58-60 HRC.
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To maximize toughness, undertake a double tempering process: 2 hours plus an additional 2 hours at temperatures exceeding 950°F (510°C). This rigorous method will yield a hardness of less than 58 HRC.
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7. D2 Tool Steel Applications
Typical applications for D2 tool steel include a diverse array of demanding tasks such as blanking, forming, and trimming 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 and master parts; injection screw and tip components; seaming rolls; extrusion dies; tire shredders; scrap choppers, and more.

With over a decade of expertise in producing D2 Tool Steel, we are committed to upholding the highest quality standards. Our D2 Tool Steels are exclusively ESR products, a testament to their superior quality. As our flagship product, D2 Tool Steel represents our dedication to excellence. Should you have any inquiries, please do not hesitate to reach out to us. We are here to assist you with any questions you may have!