9

403 stainless steel is a kind of martensitic stainless steel with good processability and good heat resistance. 403 stainless steel contains 11.5%-13% chromium and basically does not contain nickel, so its corrosion resistance is relatively poor. 403 is a A hardenable stainless steel commonly used in gas turbine blades and highly stressed components.

What is the chemical composition of 403 stainless steel?

The chemical composition of 403 stainless steel mainly includes:

material

403（%）

chemical composition

Fe

Cr

Mn

Si

C

P

S

86

12.3

1.0

0.50

0.15

0.040

0.030

The above is the general chemical composition range of 403 stainless steel, and the specific composition may vary according to different standards and requirements.

Mechanical properties of 403 stainless steel

material

403

Mechanical Properties

Tensile strength

Yield strength

Fatigue Strength

Poisson’s ratio

Elongation at break (in 50 mm)

485 MPa

310 MPa

275 MPa

0.27-0.30

25.00%

Physical properties of 403 stainless steel

material

403

Physical Properties

Density

Izod impact (tempered)

Hardness, Brinell (converted from Rockwell B hardness)

7.80 g/cm3

102 J

139

Thermal properties of 403 stainless steel

material

403

Thermal Properties

 

Thermal expansion co-efficient (@0-100°C/32-212°F)

Thermal conductivity (@500°C/932°F)

9.90 µm/m°C

21.5 W/mK

Corrosion resistance of 403 stainless steel

The surface of 403 stainless steel can form a closely adhered oxide film, so it has a high degree of atmospheric corrosion resistance. 403 stainless steel can resist common atmospheric corrosion, such as moisture and slightly oxidizing media.

Water corrosion resistance: 403 stainless steel has good corrosion resistance to general water media such as tap water, steam, and fresh water at room temperature. However, its corrosion resistance may be reduced in high temperature, high salinity or strong oxidizing water environments.

Resistance to organic acid corrosion: 403 stainless steel has certain corrosion resistance to some organic acids, such as acetic acid and acetic acid.

Alkali corrosion resistance: 403 stainless steel has good alkali resistance and can withstand the alkali solution of general concentration.

It should be noted that the corrosion resistance of 403 stainless steel is relatively low, and its resistance to strong corrosive media such as strong acid, hydrochloric acid, and hydrofluoric acid is weak. When using it, it is necessary to select appropriate materials according to the specific environment and media.

Oxidation resistance of 403 stainless steel

403 stainless steel has a certain degree of oxidation resistance, but compared with other stainless steels, its oxidation resistance is weaker. The following are some characteristics of the oxidation resistance of 403 stainless steel:

Resistant to oxidation up to 1400°F (760°C).

Temperatures in continuous use should not exceed 1200-1300°F (649-704°C).

Low chromium content: The chromium content in 403 stainless steel is low, usually between 11.5-13.5%. Compared with other stainless steels, the chromium content is low and the oxidation resistance is relatively weak.

Susceptible to high-temperature oxidation: 403 stainless steel is susceptible to oxidation in high-temperature environments, which may lead to the formation of an oxide layer on the surface, fading, and oxidation damage.

Heat treatment of 403 stainless steel

403 stainless steel can be heat treated to improve its performance and structure. Common heat treatment methods include annealing treatment and solution treatment.

Annealing treatment: During the annealing treatment, 403 stainless steel is heated to an appropriate temperature (usually 800-900°C), and then slowly cooled. Annealing can eliminate work hardening and stress, and improve the plasticity and machinability of steel. In addition, annealing also helps to adjust the structure, reduce the formation of grain boundaries, precipitation and carbides, and improve the corrosion resistance of steel.

Solution treatment: Solution treatment is done by heating 403 stainless steel to a high enough temperature (usually 1000-1100°C) and then rapidly cooling to dissolve carbides and other components in the steel. Solution treatment can increase the hardness and strength of steel and improve corrosion resistance. However, it should be noted that too high temperature and too long solution treatment may lead to intergranular corrosion and the formation of precipitation, which will affect the performance of steel.

High temperature resistance of 403 stainless steel

403 stainless steel has certain high temperature resistance, but compared with some high temperature alloys and other stainless steels, its high temperature resistance is weaker. The following are some characteristics of the high temperature resistance of 403 stainless steel:

Mechanical properties: 403 stainless steel maintains good strength and hardness at high temperatures, and can maintain the original mechanical properties to a certain extent.

Oxidation resistance: 403 stainless steel is prone to oxidation in high temperature environment and forms an oxide layer, which can provide certain anti-oxidation protection. However, due to its low chromium content, the oxide layer of 403 stainless steel is relatively thin and not dense enough, so its oxidation resistance is relatively weak and it is easily affected by high temperature oxidation.

Thermal expansion coefficient: The thermal expansion coefficient of 403 stainless steel is relatively high, and it is prone to thermal expansion when heated, so it is necessary to pay attention to the stress and deformation caused by thermal expansion at high temperatures.

To sum up, 403 stainless steel has weak high temperature resistance and is suitable for some applications in low and medium temperature environments. When used in a high temperature environment, it is necessary to select a more suitable high temperature alloy or high temperature resistant stainless steel material according to the specific working temperature, stress and environmental factors.

Is 403 stainless steel magnetic?

403 stainless steel is a kind of magnetic stainless steel. The magnetism of stainless steel mainly depends on its crystal structure and chemical composition. Generally speaking, austenitic stainless steel (such as 304, 316, etc.) is non-magnetic, while martensitic stainless steel (such as 403, 410, etc.) has certain magnetic properties.

403 stainless steel belongs to martensitic stainless steel, which is caused by the ferrite matrix (Alpha ferromagnetic phase), so it has certain magnetic properties. However, for 403 stainless steel with higher purity or under some specific conditions, its magnetism may be weaker. It should be noted that magnetism cannot be used as the only criterion for judging the quality of stainless steel, and it needs to be comprehensively evaluated in combination with other properties and characteristics.

Application of 403 stainless steel

403 stainless steel is suitable for many applications due to its certain corrosion resistance and strength. Here are some common 403 stainless steel applications:

Food processing equipment: Because 403 stainless steel has good corrosion resistance to food acidic and alkaline environments, it is often used in the manufacture of food processing equipment and containers, such as food mixers, mortar pots and coffee machines.

Chemical industry equipment: Due to its certain corrosion resistance, 403 stainless steel is used in some chemical industry equipment, such as storage tanks, seals and pipes.

Medical Devices: 403 stainless steel is commonly used in the manufacture of medical devices and surgical tools such as surgical instruments, dental equipment, and orthopedic implants due to its corrosion resistance and low allergy-causing properties.

Knives and blades: 403 stainless steel has a certain hardness and wear resistance, and is often used in the manufacture of knives and blades, such as blades, screwdrivers, and can openers.

Household Utensils: Due to its good corrosion resistance and appearance, 403 stainless steel is widely used in household products such as locks, door handles and kitchen utensils.