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Martensitic Stainless Steel (SUS420J2,RB-S)

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Main applications

Knitting needles, loom reeds, spinning machines, doctor blades, blades, rulers, soldering irons, scrapers, HDD drive components, bearings, and various springs


Product size range

Thickness: 0.050~2.5mm  

  Width: 3.0~300mm

 
Manufacturing sites

JAPAN、SHANGHAI(Quenching is possible)


  • Product overview Features
  • Standards & Chemical composition
  • Tokkin Advantages
  • Physical Properties Mechanical properties

Product overview

SUS420J2, RB-S are classified as martensitic stainless steels, and their most notable feature is that they can be quenched.

They have a high carbon content and can acquire extremely high strength if quenched after purchase. By fine tuning the tempering process, it is possible to endow them with a wide range of mechanical properties.

At the same time, they have the drawback of being the most rust-prone stainless steels.

However, thanks to their ability to acquire high heat resistance and work hardening, they are used in a variety of applications such as those listed above.

As their high percentage of carbon makes them prone to rust, it is best to think of these stainless steels as being closer to iron.

 

Features

Features of each grade are described in the table below.

Grade

Features

SUS420J2

SUS420J2 is classified as a martensitic stainless steel. Thanks to its marketability, price, and other features, it is used in a wide range of fields. When shipped with an annealed finish, it contains completely spheroidized carbides, making it easily processed.

RB-S

RB-S is classified as a martensitic stainless steel. It has a higher carbon content than SUS420J2, giving it good quench hardening properties. It provides one of the highest levels of hardness of any stainless steel, and is used for blades and other applications. It is quite hard even with an annealed finish, which makes it unsuitable for complex processing, but ideal for blade applications.

Standard

TOKKIN

Designation

International Standard

USA

Europe

UK

Germany

France

Russia

China

 Japan

ISO

UNS

AISI

EN

BS

DIN

NF

ΓOCT

 GB  JIS

SUS420J2

5

S42000

420

X30Cr13

420S45

X30Cr13

Z33C13

30X13

 X30Cr13  SUS420J2

RB-S

TOKKIN's original material

 

Chemical composition

TOKKIN

Designation

Chemical composition(%)

C

Si

Mn

P

S

Cr

Ni

Mo

SUS420J2

0.26~0.40

≦1.00

≦1.00

≦0.040

≦0.030

12.00~14.00

RB-S

0.58~0.70

≦1.00

≦1.00

≦0.040 *1

≦0.015 *2

12.50~14.50

*1  Less than 0.030  *2  about 0.002

Tokkin Advantages

 Excellent hardenability

By controlling carbide grain diameter, we are able to improve hardenability.

 

 Reduced load on heat treatment furnace

Material can be quenched at a lower temperature or in a shorter time than normal, making it possible to reduce the load placed on the heat treatment furnace.

 

 Custom-made thickness

Tokkin can provide micron-level customization of thickness for special applications such as razors and utility knife blades.

 

 Excellent sharpenability

Our proprietary structure control provides improved sharpenability.

 

 Made-to-order product that can be manufactured in small lots

We can supply custom-made products top suit your processing conditions.

Other manufacturers typically accept custom-made orders in one-ton units, but we are able to provide small lots starting from 300 kg.

Physical propaties

TOKKIN

Designation

Density

 

g/cm3

Specific heat

 

J(kg·K)

Coefficient of

 

thermal expansion

 

(0~100℃)10-6/K

Thermal

 

conductivity

 

W/(m·K)

Electric

resistance

 

μΩ·cm

Young's modulus

 

N/mm2

SUS420J2

7.75

460

10.3×10-6/K

24.7

55

200,000

RB-S

7.70

430

-

25.0

60

220,000

 

Mechanical properties 

TOKKIN

Designation

Finishing condition

Hardness

Tensile strength   Elongation

HV

N/mm2

%

SUS420J2

Annealed

150~200

540~655

20~30

Full hard

280~320

880~1030

1~3

 

 

    Fig. (Left) Cold rolling reduction and hardness            (Right) Quenching tempering

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