7 Types of High Speed Steel Tool Materials You Should Know

High speed steel is a kind of high alloy tool steel with good toughness, which is suitable for manufacturing broach, hob and other complex tools.

At that time, its emergence greatly improved the cutting speed, so it is called high speed steel.

When the cutting temperature is higher than about 600 ℃, the hardness does not decrease significantly, and good cutting performance can still be maintained.

The carbon content of high-speed steel is 0.7% ~ 1.65%, and the steel contains alloying elements such as W, Mo, Cr, V and Co, with a total amount of more than 10%.

Due to the high carbon content of steel and a large number of alloy elements, there are fishbone like carbides in the as cast billet, which can only be broken by forging and distributed evenly.

The classification of high-speed steel tool materials is shown in Fig. 2-3, mainly including ordinary high-speed steel, high-performance high-speed steel and powder metallurgy high-speed steel.

classification of high speed steel

Fig. 2-3 classification of high speed steel

(1) Classification and characteristics of ordinary high speed steel

1. Tungsten high speed steel (W18 for short)

Due to the small vanadium content, the grinding process is good. The tendency of overheating during quenching is small, and the heat treatment control is easy.

Steel has good grinding performance and comprehensive performance and strong universality.

However, the distribution of carbides is often uneven, the strength and toughness are not strong enough, and the thermoplasticity is poor, so it is not suitable to make large section tools.

The sample diagram of tungsten high-speed steel is shown in Fig. 2-4, and its chemical composition and characteristics are shown in table 2-3.

tungsten high speed steel

Fig. 2-4 tungsten high speed steel

Table 2-3 chemical composition and characteristics of tungsten high speed steel

classification

Code

Chemical composition

Chemical composition (mass fraction,%)

Characteristic

Purpose

C

W

Mo

Cr

V

Co

Wear resistance

High temperature hardness

Primary sex

W series

SKH2

18-4-1

0.78

18.00

 

4.15

1.00

 

 

Water home

 

For ordinary cutting

SKH3

19-4-1-5

0.78

18.00

 

4.15

1.00

5.00

 

Meters*

*

For high speed heavy cutting

SKH4

18-4-1-10

0.78

18.00

 

4.15

125

10.00

*Meters

 

 

Machining of difficult cutting materials

SKH5

20-4-1-16

0.30

19.50

 

4.15

1.25

16.50

**

 

 

 

SKH10

13-4-5-5

1.53

12.50

 

4.15

4.70

4.70

 

 

 

For machining highly difficult cutting materials

Note: * indicates the strength of the feature, and the more * indicates the stronger its performance.

2. Tungsten molybdenum high speed steel

This kind of steel is made by replacing part of tungsten with molybdenum to reduce the non-uniformity of carbide quantity and distribution.

The addition of molybdenum can improve the grinding processability and improve the thermoplastic, bending strength and toughness.

However, its quenching temperature range is narrow and its decarburization overheating sensitivity is large.

Therefore, its high-temperature cutting performance is slightly worse than W18.

The chemical composition and characteristics of tungsten high speed steel are shown in table 2-4.

Table 2-4 chemical composition and characteristics of tungsten molybdenum high speed steel

classification

Code

Chemical composition

Chemical composition (mass fraction,%)

Characteristic

Purpose

C

W

Mo

Cr

V

Co

Wear resistance

High temperature hardness

toughness

Mo system

SKH51

6-5-4-2

0.85

6.10

5.00

4.15

1.90

**

*

******

For ordinary cutting

SKH52

6-5-4-2

1.05

6.10

5.50

4.15

2.55

***

**

****

High hardness materials with certain initial properties are required for cutting

SKH53

6-5-4-3

1.18

6.20

4.95

4.15

3.05

***

**

***

SKH54

6-5-4-4

1.33

5.90

5.00

4.15

4.20

 

****

**

***

SKH55

6-5-4-2-5

0.90

6.20

4.95

4.15

1.95

5.00

***

***

***

It needs high-speed heavy material cutting with certain toughness

SKH56

6-5-4-2-8

0.90

6.20

4.95

4.15

1.95

8.00

***

****

***

SKH57

10-4-4-3-10

1.28

10.00

3.50

4.15

3.35

10.00

****

******

**

SKH 58

2-9-4-2

1.00

1.80

8.70

4.15

1.95

 

***

*

**

For ordinary cutting

SKH59

1.5-10-4-1-8

1.08

1.55

9.50

4.15

1.15

8.00

***

***

**

For high speed heavy cutting

Note: * indicates the strength of the feature, and the more * indicates the stronger its performance.

(2) Classification and characteristics of high performance high speed steel

High performance high speed steel is a new type of steel in which alloying elements such as carbon, vanadium, cobalt or aluminum are added to general-purpose high speed steel.

1. High carbon high speed steel

The carbon content of high-speed steel is 20% ~ 0.0%, which is higher than that of general-purpose steel.

However, the strength and toughness decreased slightly and could not withstand large impact.

2. High vanadium high speed steel

With the increase of vanadium carbide content, the wear resistance of high speed steel is improved, the grain can be refined and the overheating sensitivity of steel can be reduced.

The grinding performance is poor, and the cutting edge is easy to burn and anneal, so it is not suitable to manufacture complex tools such as thread tools.

3. Cobalt high speed steel

Adding cobalt to high-speed steel can improve the thermal stability of steel, promote the precipitation of carbide during tempering, increase the dispersion hardness effect and improve the tempering hardness, so as to improve the high-temperature hardness and oxidation resistance.

4. Aluminum high speed steel

Aluminum high-speed steel is a kind of high-performance high-speed steel containing Al without cobalt.

It does not contain cobalt, so it still has high strength and toughness.

Poor processability, high superheat sensitivity, narrow quenching heating temperature range and high tendency of oxidative decarburization.

(3) Classification and characteristics of powder metallurgy high speed steel

The classification of powder metallurgy high-speed steel is generally the same as that of ordinary high-speed steel, which is divided into tungsten system and molybdenum system.

However, the manufacturing process of powder metallurgy high-speed steel is different from that of traditional high-speed steel.

Powder metallurgy high-speed steel is the molten steel melted by high-frequency induction furnace and cooled by high-pressure gas jet to obtain crystalline powder, and then the obtained powder is pressed into a tool blank at high temperature and high pressure, or it is first formed into a steel blank, and then forged and rolled into a tool shape.

Powder metallurgy high speed steel has the following characteristics:

(1) No carbide segregation, improve the strength, toughness and hardness of the steel, and the hardness value is 69 ~ 70hrc.

(2) The microstructure is very fine, uniform and non directional, which reduces the internal stress and deformation of heat treatment.

(3) Continuous and stable heat treatment results and stable heat treatment size.

(4) The grinding performance is good, and the grinding efficiency is 2 ~ 3 times higher than that of smelting high-speed steel.

(5) Good wear resistance.

(6) The cost is high, and its price is equivalent to that of cemented carbide. Therefore, the main scope of application is to manufacture complex forming tools.

(7) It is suitable for manufacturing tools for cutting difficult materials, large-size tools (such as hob and gear shaper), precision tools and complex tools with large grinding capacity.

The main grades and components of powder metallurgy high speed steel are shown in table 2-5.

Table 2-5 main grades and components of powder metallurgy high speed steel (wt%)

Serial number

Chemistry

Purpose

Composition (mass Score,%)

 

Brand

 

Cr

W

Mo

V

Co

other

1

M2-PM

0.95~1.05

3.75~4.50

5.50~6.75

4.50~5.50

1.75~2.20

Max0.5

 

It is used to make tools and general tools that require good wear resistance and toughness and bear large impact force.

2

M3-PM

1.15~1.25

3.75~4.50

5.00~6.75

4.75~6.50

2.75~3.25

Max0.5

 

It can be used for cutting tools.

3

M4-PM

1.25~1.40

3.75~4.75

5.25~6.50

4.25~5.50

3.75~4.50

Max0.5

 

It is mainly used to manufacture cutting tools for cutting materials that are difficult to cut.

4

M35-PM

0.88~0.95

3.80~4.50

6.00~6.70

4.70~5.20

1.70~2.00

4.50~5.00

 

Wear resistant for manufacturing strong cutting. Impact resistant tools

5

M42-PM

1.05~1.15

3.50~4.25

1.15~1.85

9.00~10.0

0.95-~1.35

7.75~8.75

 

It is mainly used for high toughness precision wear-resistant hardware cold stamping die.

6

M61-PM

1.75~1.85

3.50~4.25

12.10~12.9

6.00~6.75

4.50-~5.25

max100

P≤0.02

It is used to make complex thin blade and impact resistant metal cutting tools

7

ASP2015

1.50-1.60

3.75~5.00

11.75~13.0

max1. 00

4.50~5.25

4.75~5.25

 

For high performance tools

8

ASP2017

0.80~0.85

380~4.50

2.85~3.25

3.90~4。20

0.95~1.35

7.75~8.75

Nb=1.00

It is suitable for cutting tools requiring high speed, high thermal hardness and long service life.

9

ASP2030

1.25~1.35

3.80~4.50

6.00~6.70

4.70~5.20

2.70~3.20

8.10~8.80

 

It is suitable for high-speed cutting and high thermal hardness. Long life tool

10

ASP2053

2.30-2.60

3.80~4.50

4.00~4.50

2.80~350

7.75~8.20

max0.50

 

For applications requiring extreme wear resistance

11

ASP2060

2.15-2.45

3.80~4.50

6.00~6.80

6.70~7.30

6.20~6.80

10.10~10.8

 

The utility model is suitable for manufacturing tools which are easy to collapse under the condition of intermittent cutting

12

ASP2080

2.30~2.60

3.8~4.30

10.50~11.5

4.80~5.30

5.80~6.20

15.50~16.5

 

It is suitable for high-speed and hard cutting tools with high service life

13

S390-PM

1.55~1.65

4.50~5.00

9.50~11.00

2.00~2.40

4.60~5.20

7.60~8.30

 

Small cutting tools with complex shapes and stamping dies

14

HS10-4-3-10PM

1.21~1.34

3.80~4.50

9.00~10.00

3.20~3.90

3.00~3.50

9.50~10.5

 

 

15

HS18-1-2-5-PM

0.75~0.83

3.80~4.50

17.5~18.50

0.50-0.80

1.40~1.70

450~5.00

 

 

16

HS12-1-4-PM

1.20~1.35

3.80~4.50

115~1250

0.70-1.00

3.50~450

max

50

 

17

CPM10V*

2.35~2.55

4.75~5.50

max0. 50

1.10~1.45

9.3~10.25

max0.50

S≤0.09

It is the first choice to replace cemented carbide and high wear-resistant materials, especially when the toughness of the tool cannot meet the requirements and considering the cost performance of the tool

Note:

It is generally required in the above table that P ≤ 0.03%, s ≤ 0.03%, n ≤ 0.08%, O ≤ 0.015%, AR ≤ 0.05ppm;

*Alloy tool steel

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