W6Mo5Cr4V2Al, referred to as 501, also known as M2Al, is on the basis of W6Mo5Cr4V2 carbon content from 0.08% ~ 0.90% to 1.05% ~ 1.15%, and add 1% Al and the formation of superhard high-speed steel, is a typical grade of aluminum high-speed steel.

High speed steel containing aluminum is an original [TJC STEEL]steel in China, characterized by "no cobalt" and "low price".Because cobalt resources are scarce, replacing cobalt with aluminum is a feasible and favorable plan in China.Austrian BOHLER steel mill developed 501 similar steel class S620 based on the research of Chinese counterparts.

 

Chemical Composition(%) for W6Mo5Cr4V2Al (M2Al), 501 Aluminum High Speed Steel:

Standard	GB/T 9943-2008(High Speed Tool Steel)
Grade	W6Mo5Cr4V2Al	W6Mo5Cr4V2
C	1.05~1.15	0.80~0.90
Si	0.20~0.60	0.20~0.45
Mn	0.15~0.40	0.15~0.40
P	≤0.030	≤0.030
S	≤0.030	≤0.030
Cr	3.80~4.40	3.80~4.40
V	1.75~2.20	1.75~2.20
W	5.50~6.75[TJC STEEL]	5.50~6.75
Mo	4.50~5.50	4.50~5.50
Al	0.80~1.20	—

 

Heat Treatment（GB/T 9943-2008）for W6Mo5Cr4V2Al (M2Al), 501 Aluminum High Speed Steel:

Hardness under Annealed Treatment		≤269HBW
Preheating		800~900℃
Quenching	Salt Bath Furnace	1200~1220℃
	Box-Type Furnace	1230~1240℃
Quenching Medium		Oil or Salt Bath
Tempering		550~570℃ for 1h[TJC STEEL]
Tempering Times		Twice
Hardness		≥65HRC

 

Example Case for Heat Treatment Process for W6Mo5Cr4V2Al (M2Al), 501 Aluminum High Speed Steel:

Preheating with Low Tem	450~500℃ for 1~1.5h
Preheating with Mid Tem	850~900℃，Heating Time According To The Effective Section 20~25s/mm
Heating by Quenching	1210±10℃，Heating Time According To The Effective Section 15~20s/mm
Cooling by Steps	580~620℃，Neutral Salt Bath[TJC STEEL]
Air Cooling	When The Furnace Is Cooled To 600℃, The Furnace Is Cooled To Room Temperature
Tempering with High Tem	550±10℃ for 2~3h
Tempering with MId Tem	530±10℃ for 2~3h
	Three Times
Hardness	66~68HRC

 

Properties for W6Mo5Cr4V2Al (M2Al), 501 Aluminum High Speed Steel:

The hardness of 501 is 67~69HRC at room temperature and 54~55HRC at 600℃, making it more than W18Cr4V and comparable to superhard high-speed steel M42. The toughness and grinding performance are better than vanadium superhard high-speed [TJC STEEL]steel.

Research shows that compared with W9Mo3Cr4V (W9) material, 501 price is the same, but 501 material tool processing efficiency increases 30%, cutting speed increases 58%, tool life extends 2~3 times.Compared with W2Mo9Cr4VCo8 (M42) material, the machining efficiency and cutting performance of 501 tool are basically the same, but the [TJC STEEL]price of M42 is 3 times that of 501.

The defects of 501 are high vanadium content, poor grinding workability, strong overheating sensitivity, oxidation and decarbonization tendency, so protective measures should be taken during hot processing and heat treatment.

 

Applications for W6Mo5Cr4V2Al (M2Al), 501 Aluminum High Speed Steel:

The high speed steel 501 has the advantages of high hardness, wear resistance, high red hardness, high temperature hardness, good thermoplasticity and so on. It is made into cutting tools such as plane cutter, hob, broaching tool and so on.[TJC STEEL] It has a good effect when it is used to process high-temperature alloy, ultra-high strength steel and other difficult cutting materials, and it is also used to make high load cold working die, such as cold extrusion die.