Smooth Finish Alloy Steel Flat 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 SteelD2 Tool Steel is a versatile high-carbon, high-chromium, air-hardening tool steel renowned for its high hardness potential and the presence of numerous, large, chromium-rich alloy carbides in its microstructure. These carbides offer excellent wear resistance from sliding contact with other metals and abrasive materials. While other steels may offer enhanced toughness or wear resistance, D2 stands out for its balanced combination of wear resistance, toughness, tool performance, cost-effectiveness, and diverse product forms. The remelting process enhances chemical homogeneity, refines carbide size, and provides significant improvements in 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, 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 207000MPa, and the specific heat at constant pressure Cp is 461J/(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 through to 1560°F (850°C). Allow it to cool in the furnace at a rate of 20°F (10°C) per hour down to 1200°F (650°C), then freely in air.
Stress Relieving
After rough machining, the tool should be heated through to 1200°F (650°C) and held for 2 hours. Cool slowly to 930°F (500°C), then 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 = Duration at the hardening temperature after the tool is thoroughly heated.
Protect the part against decarburization and oxidation during hardening.
Quenching
Use air or pressurized gas cooling 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 air cool to ambient temperature. The typical tempering range is 350 to 400ºF (177 to 204ºC).
For maximum wear resistance, temper between 300-350°F (149-177°C) to achieve a hardness of 62-64 HRC. For an optimal balance between wear resistance and toughness, temper between 500-550°F (260-288°C), which will yield a hardness of 58-60 HRC.
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For achieving unparalleled toughness, undergo a double tempering process: 2 hours plus an additional 2 hours at temperatures above 950°F (510°C). This meticulous procedure will yield a hardness lower than 58 HRC, ensuring superior durability and performance.
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7. D2 Tool Steel Applications
D2 Tool Steel finds extensive use in a variety of critical applications, including but not limited to: 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, and more.

With over a decade of expertise in producing D2 Tool Steel, Huangshi Smooth Industry and Trade Co., Ltd specializes in providing high-quality ESR products. D2 Tool Steel is our flagship product, renowned for its superior quality. Should you have any inquiries, please do not hesitate to contact us, and we will be dedicated to assisting you with the utmost diligence.