1.2714/L6/5kt4/5CrNiMo Hot Work Tool Steel Forged and Rolled High Quality Steel

• Type: Round
• Standard: AISI, ASTM, DIN, JIS, GB, BS
• Composition: Stainless Steel Scrap
• Technique: Forged
• Shape: Bar
• Surface Treatment: Black/Milled/Machined
• Model NO.: round bar
• Special Use: High-strength Steel Plate, Wear Resistant Steel, Silicon Steel, Cold Heading Steel, Free Cutting Steel
• Application: Tool Steel Bar
• Transport Package: Wooden
• Specification: 6-400mm
• Trademark: Smooth
• Origin: China
• HS Code: 7214100000

Product Description

1.2714/L6/5KT4/5CrNiMo
Brief Description
L6 steel has good toughness, strength and high wear resistance.It has almost the same mechanical properties at room temperature and between 500 to 600°C.When heated to 500 °C, the hardness of HB300 can still be maintained.Because of the molybdenum in steel, it is not sensitive to temper brittleness.After slow cooling from 600 °C, the impact toughness has only decreased slightly.
L6 steel has good hardenability.300mm x 400mm x 300mm of large steel material, the hardness of the section is almost the same since 820°C oil quenching and 560°C tempering.
This steel is used to make all kinds of large and medium forging dies.
This kind of steel is easy to form white point, and it needs to control the smelting process and the cooling system after forging.
1.Size Range for L6 Tool Steel
L6 Steel Round Bar: diameter 80mm~330mm
L6 Steel Plate: thickness 25mm~400mm x width 200mm~800mm
Delivery Condition:
Tured Round Bar,Milling Plate,Black,requiremts for customers.
Spheroidizing Annealing,ESR material.
2.L6 Tool Steel Equivalent Grades

Country	USA	German		Japan	China
Standard	ASTM A681	W-nr.	DIN	JISG4404	GB/T1299-2000
Grades	L6	1.2713	55NiCrMoV6	5KT4	5CrNiMo

3.L6 Tool Steel Chemical Composition

Grades	C%	Si%	Mn%	P%	S%	Cr%	Mo%	V%	Ni%
L6	0.65~0.75	0.10~0.50	0.25~0.80	≤0.03	≤0.03	0.60~1.20	≤0.50	--	1.25~2.00
1.2713	0.50~0.60	0.10~0.40	0.65~0.95	≤0.03	≤0.03	0.60~0.80	0.25~0.35	0.07~0.12	1.50~1.80
5CrNiMo	0.50~0.60	≥0.35	0.50~0.80	≤0.03	≤0.03	0.50~0.80	0.15~0.30	--	1.40~1.80

4.L6 Tool Steel Physical Properties
L6 critical temperature

Critical point	Ac1	Ac3	Ar1
Temp.(approx.)	1310°F(710°C)	1418°F(770°C)	1256°F(680°C)

Coefficient of linear thermal expansion(at 55-57HRC)

Temperature (°F)	in/in(°F x10^-6)	Temperature (°C)	mm/mm(°C x10^-6)
70~200	6.25	21~93	11.24
70~300	6.57	21~149	11.81
70~400	7.01	21~204	12.60
70~500	7.25	21~260	13.03
70~600	7.35	21~316	13.21
70~700	7.50	21~371	13.48
70~800	7.68	21~427	13.81
70~900	7.74	21~482	13.91
70~1000	7.99	21~538	14.36

5.Forging of L6 Tool Steel
L6 hot working technology

Items	Heating temperature	Starting forging temperature	Final forging temperature	Cooling
Ingot	2084~2156°F (1140~1180°C)	2012~2102°F (1100~1150°C)	1472~1616°F (800~880°C)	Slow cooling, cooling in hole or sand
Billet	2012~2102°F (1100~1150°C)	1922~2012°F (1050~1100°C)	1472~1508°F (800~850°C)	Slow cooling, cooling in hole or sand

L6 steel can be hardened by cooling in the air and can easily form white spots.Therefore,it should be cooled slowly after forging.For large forgings which must be put in the furnace of heated to 1110°F(600°C),stay after its temperature is the same,and slowly cooled to 302~392°F(150~200°C),then cooled in the air.For large forgings,tempering immediately after cooling to the temperature of 302~392°F(150~200°C).
6.Heat treatment of L6 Tool Steel
  Hardening
  Critical Temperature: Ac1: 1325°F (719°C)
  Preheating
  Heat at a rate not exceeding 400°F per hour (222°C per hour) to 1150-1250°F (621-677°C) and equalize.
Austenitizing
Heat slowly from the preheat.
Furnace or Salt: 1450-1500°F (788-816C)
Soak for 30 minutes for the first inch (25.4 mm) of thickness, plus 15 minutes for each additional inch (25.4 mm).
Quenching
Oil to 150-125°F (66-51°C).
Note: Sizes under 3 inches (76.2mm) in cross section will achieve moderate hardness by cooling in a blast of air or pressurized gas.
Tempering
Temper immediately after quenching. Hold at temperature for 1 hour per inch (25.4 mm) of thickness, 4 hours minimum, then air cool to ambient temperature.
To minimize internal stresses in cross sections greater than 6 inches (152.4 mm) and to improve stability in tools that will be EDM'd after heat treatment, a soaking time of 8 to 10 hours at the tempering temperature is strongly recommended.
Annealing
Annealing must be performed after hot working and before re-hardening.
Heat at a rate not exceeding 400°F per hour (222°C per hour) to 1400°F (760°C), and hold at temperature for 1 hour per inch (25.4mm) of maximum thickness; 2 hours minimum. Then cool slowly with the furnace at a rate not exceeding 50°F per hour (28°C per hour) to 1000°F (538°C). Continue cooling to ambient temperature in the furnace or in air. The resultant hardness should be a maximum of 235 HBW.
For improved machinability, hold at 1400°F (760°C) for1 hour per inch (25.4mm) of maximum thickness; 2 hours minimum. Then cool slowly with the furnace cool from 1400°F (760°C) to 1250°F (677°C), hold for 8 hours, then air cool to ambient temperature. The resultant hardness should be a maximum of 192 HBW.
7.Applications of L6 Steel
  Use for general purpose tools and dies where greater toughness is required, but with some sacrifice of abrasion-resistance. The following are some of the applications:
· Forming rolls
· punches
· blanking and forming dies
· trimmer dies
· clutch parts
· pawls
· knuckle pins
· clutch pins
· shear blades
· spindles