Stainless steel SUS420J1 is a type of martensitic stainless steel, which is a material specified by the Japanese Industrial Standard (JIS). Martensitic stainless steels are characterized by their high hardness and ability to be heat-treated to achieve even higher hardness levels.

SUS420J1 is known for its excellent wear resistance and corrosion resistance, making it a popular choice for various applications. It is commonly used for manufacturing cutting tools, surgical instruments, springs, and other components that require high hardness and resistance to wear and corrosion.

What is the chemical composition of Stainless steel SSUS420J1?

Stainless steel SSUS420J1 is a type of martensitic stainless steel designated by the Japanese Industrial Standards (JIS). It is known for its high hardness, wear resistance, and corrosion resistance, making it suitable for manufacturing knives, surgical instruments, springs, and more.

The chemical composition of SSUS420J1 is defined by the JIS G4303-2005 standard, which specifies the following elements and their respective percentage ranges:

C：0.16-0.25

Si：≤1.00

Mn ：≤1.00

P ：≤0.04

S： ≤0.03

Cr ：12.0-14.0

Ni：≤0.60

What are the mechanical properties of Stainless steel SSUS420J1?

LThe mechanical properties of Stainless steel SSUS420J1 include tensile strength, yield strength, elongation, reduction of area, impact strength, and hardness. According to JIS G4303-2005 standard, the typical mechanical properties of SSUS420J1 are:

Tensile strength: ≥686 MPa

Yield strength: ≥490 MPa

Elongation: ≥15%

Reduction of area: ≥40%

SSUS420J1 is known for its high hardness, wear resistance, and corrosion resistance, making it suitable for applications such as making knives, surgical instruments, springs, and other high-wear components. The mechanical properties of SSUS420J1 can be improved through heat treatment, such as annealing, quenching, and tempering, to achieve the desired balance of properties for specific applications.

What are the physical properties of Stainless steel SUS420J1？

Density:

The density of SUS420J1 is around 7.72 g/cm³. This is a relatively high density compared to some other materials, which can affect its overall weight and volume in applications.

Elastic modulus:

The elastic modulus, or Young’s modulus, of SSUS420J1 is approximately 200 GPa. This is a measure of the stiffness of the material, and is an important factor in determining how it will respond to applied stresses.

Thermal expansion coefficient:

The thermal expansion coefficient of SSUS420J1 is about 10.4 × 10^-6/℃. This value represents how much the material will expand or contract in response to changes in temperature, and is an important consideration in applications where temperature changes may occur.

Thermal conductivity:

The thermal conductivity of SSUS420J1 is approximately 24.9 W/m·℃. This indicates how well the material can conduct heat, and is an important factor in determining its performance in high temperature applications.

Specific heat capacity:

The specific heat capacity of SSUS420J1 is around 460 J/kg·℃. This value represents the amount of heat required to raise the temperature of a given mass of the material by 1 degree Celsius.

Electrical resistivity:

The electrical resistivity of SSUS420J1 is approximately 0.55 Ω·mm²/m. This value represents how well the material can conduct electricity, and is an important consideration in applications where electrical conductivity is required.

What is the processing method of Stainless steel SSUS420J1?

The processing methods of Stainless steel SSUS420J1 include annealing, quenching, and tempering.

Annealing involves heating SSUS420J1 to 800-900°C, holding it for a certain period, and then slowly cooling it to obtain a uniform softening structure. The hardness of the material after annealing is approximately 200 HBW.

Quenching involves heating SSUS420J1 to 950-1050°C, holding it for a certain period, and then rapidly cooling it to obtain a martensitic structure. The hardness of the material after quenching is approximately 500 HBW.

Tempering is a process that follows quenching and involves heating SSUS420J1 to a temperature below the critical point, holding it for a certain period, and then cooling it to obtain a desired combination of strength, toughness, and ductility. The tempering temperature typically ranges from 150-300°C, with higher temperatures resulting in lower hardness and higher toughness.

Tempering temperature (℃)Tempering time (h)Hardness (HRC)Tensile strength (MPa)
1501521620
2001511580
2501481470
3001461400
3501421270
4001381100

What are the characteristics of stainless steel SUS420J1?

Stainless steel SUS420J1 is a martensitic stainless steel that is known for its high hardness, wear resistance, and corrosion resistance. It has a relatively low carbon content, which gives it good weldability and machinability compared to other martensitic stainless steels.

Additionally, SUS420J1 has good heat resistance and dimensional stability, making it suitable for use in applications that involve high temperatures or require tight tolerances. It is often used to make cutting tools, surgical instruments, springs, and other high-stress components. However, it is important to note that SUS420J1 may be susceptible to corrosion in certain environments, such as those containing chlorides or other halides.

What is the application of Stainless steel SUS420J1?

Stainless steel SUS420J1 has a high hardness, wear resistance, and corrosion resistance, making it suitable for various applications that require these properties. Some common applications of SUS420J1 include:

Manufacturing of cutting tools: SUS420J1 is often used in the production of cutting tools such as blades and knives due to its high hardness and wear resistance.

Medical instruments: SUS420J1 is also suitable for manufacturing medical instruments such as surgical scissors and forceps due to its corrosion resistance and ease of sterilization.

Springs and mechanical parts: SUS420J1 is used in the production of springs and mechanical parts due to its high strength and resistance to deformation.

Mold making: SUS420J1 is also used in the manufacturing of molds for plastic injection molding and die-casting due to its high surface hardness and wear resistance.

Overall, SUS420J1 is a versatile stainless steel grade that can be used in a wide range of applications where hardness, wear resistance, and corrosion resistance are required.