Martensitic stainless steel is a kind of stainless steel with high strength, high hardness and excellent corrosion resistance produced by heat treatment process. Its main component is chromium, and an appropriate amount of nickel, molybdenum, copper and other alloying elements are added at the same time, and a martensitic structure is formed after quenching, tempering and other heat treatment processes. Martensitic stainless steel can be divided into low-carbon type and high-carbon type, which are used to manufacture different high-strength and high-hardness parts. The advantage is that it has good corrosion resistance and high mechanical properties. The disadvantage is that it is prone to hydrogen embrittlement, difficult to process, and relatively high in price. In general, martensitic stainless steels are widely used in fields requiring high strength, high hardness and corrosion resistance.

What are the basic characteristics of martensitic stainless steel?

Martensitic stainless steel is a type of stainless steel that is known for its high strength, hardness, and good corrosion resistance. The main characteristics of martensitic stainless steel are as follows:

High strength and hardness: Martensitic stainless steel is known for its high strength and hardness, making it ideal for applications where these properties are important. It is often used to make cutting tools, bearings, and other high-stress components.

Good corrosion resistance: Although not as corrosion-resistant as austenitic stainless steel, martensitic stainless steel still has good corrosion resistance, especially in low-chloride environments. It is often used in applications where both strength and corrosion resistance are important.

Magnetic properties: Martensitic stainless steel is magnetic, which makes it useful in applications where magnetic properties are required.

Poor weldability: Martensitic stainless steel has poor weldability, and is prone to cracking during welding. Preheating and post-weld heat treatment may be necessary to avoid cracking.

Hardenability: Martensitic stainless steel can be hardened through heat treatment, which allows it to achieve even higher levels of strength and hardness.

What is martensite?

Martensite is a type of microstructure that can form in certain types of metals, particularly those that have been rapidly cooled from a high temperature. It is a hard, brittle, and crystalline phase that forms in the solid state during the cooling process.

Martensite is typically found in steel alloys, such as those used in the manufacture of knives, springs, and other high-strength components. It is characterized by its high strength and hardness, but also its brittleness, which can make it difficult to work with in certain applications.

The formation of martensite occurs when the temperature of the metal is rapidly reduced, typically through quenching in a liquid such as oil or water. This rapid cooling prevents the metal from transitioning to its normal crystalline state, and instead locks it into a distorted, crystalline structure. The resulting martensitic microstructure can be further transformed through heat treatment, such as tempering, to achieve desired mechanical properties.

Can martensitic stainless steel withstand high temperature?

Martensitic stainless steel has a relatively high temperature resistance, but its ability to withstand high temperatures depends on several factors such as the specific grade of steel, the temperature and duration of exposure, and the surrounding environment.

Generally speaking, martensitic stainless steel can withstand temperatures up to around 600-700°C (1112-1292°F) without losing its strength or suffering significant deformation. However, prolonged exposure to high temperatures can cause the steel to lose its toughness and eventually become brittle. This is known as "temper embrittlement."

In addition, the corrosion resistance of martensitic stainless steel can be significantly reduced at high temperatures, especially in the presence of certain chemicals such as chlorides.

Are martensitic stainless steels magnetic?

Yes, martensitic stainless steels are generally magnetic. This is because martensitic stainless steels contain higher levels of carbon and lower levels of nickel than austenitic stainless steels, which makes them more susceptible to magnetism.

When the carbon content in martensitic stainless steel is high enough, the steel can form a magnetic body-centered tetragonal crystal structure. This structure is different from the face-centered cubic structure in non-magnetic austenitic stainless steels.

However, the magnetic properties of martensitic stainless steels vary depending on factors such as the specific alloy composition, level of cold working or heat treatment, and temperature. For example, if a martensitic stainless steel is heat treated above its critical temperature, it loses its magnetism and becomes nonmagnetic. Additionally, martensitic stainless steels can improve their magnetic properties if they are cold worked or strain hardened.

What are the uses of martensitic stainless steel?

Martensitic stainless steel has a wide range of uses across various industries due to its high strength, hardness, and good corrosion resistance. Here are some common applications of martensitic stainless steel:

Industrial and construction equipment: Martensitic stainless steel is often used in the manufacture of industrial equipment such as pumps, valves, and fittings, as well as construction equipment such as bolts and fasteners.

Cutting tools: Due to its high hardness and wear resistance, martensitic stainless steel is commonly used to make cutting tools such as knives, blades, and surgical instruments.

Bearings: Martensitic stainless steel is also used in the manufacture of bearings and other components that require high strength and wear resistance.

Aerospace and defense: Martensitic stainless steel is used in a variety of aerospace and defense applications due to its high strength, durability, and resistance to corrosion.

Oil and gas industry: Martensitic stainless steel is used in the oil and gas industry to make drill bits, casing, tubing, and other equipment that must withstand high pressures and corrosive environments.

Automotive industry: Martensitic stainless steel is used in the automotive industry to make engine components such as valves, camshafts, and exhaust systems due to its high strength and resistance to corrosion and heat.

If you are considering selecting a suitable martensitic stainless steel supplier for your project, take a look at Hengqiao(Shanghai) International Trading Limited. Our company's stainless steel is very strong and durable, with excellent wear and corrosion resistance, ideal for use in harsh environments. In addition, it has good machinability, weldability and formability, making it easy to use in the manufacturing process. Finally, our martensitic stainless steels are priced competitively, making them an affordable choice for many businesses. Whether you're looking for materials for tools, cutlery, or other industrial applications, our martensitic stainless steels are a reliable and high-quality choice. We are confident that our products will meet and exceed your expectations and we invite you to try our martensitic stainless steels for your next project.

631 stainless steel, also known as SUS 631 or 17-7PH, is a type of stainless steel that is hardened through precipitation. It was developed from 18-8CrNi, an austenitic stainless steel, and has an unstable eat austenite structure after undergoing a solution . This makes it ductile and easy to process. After adjusting the components through precipitation and carbonization, it undergoes martensite transformation treatment to achieve a low-carbon tempered martensite structure with improved toughness. temperatures. Additionally, it has better corrosion resistance than most martensitic stainless steels.

631 stainless steel is commonly used in the manufacturing of high-strength springs, bearings, high-pressure gas cylinders, aircraft parts, and spacecraft parts, among others.

Chemical composition

Element%	C	Si	Mn	P	S	Cr	Ni	Al
min	-	-	-	-	-	16	6.5	0.75
max	0.09	1	1	0.035	0.03	18	7.7	1.5

Note: These values are approximate

Mechanical properties

Tensile strength		Yield strength		Elongation		Hardness
≥1035  MPa		≥930 MPa		≥10%		30-32 HRC

Note: These values are approximate

Physical properties

Property	Value
Density	7.85 g/cm³
Melting point	1398-1446°C
Coefficient of thermal expansion	16.5 μm/m-K
Thermal conductivity	16.3 W/m-K
Specific heat capacity	475 J/kg-K

Note: These values are approximate

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630 stainless steel is also known as 17-4PH stainless steel, It is a precipitation hardening stainless steel.
630 stainless steel is extremely strong and tough, especially at high temperatures. It also has good corrosion resistance, especially in corrosive environments such as seawater. After proper heat treatment, 630 stainless steel can obtain a tensile strength as high as 1100MPa and a high yield strength.
Because 630 stainless steel has good mechanical properties and corrosion resistance, it is widely used in aviation, aerospace, petrochemical, pharmaceutical, food processing and other fields.

Chemical composition

Element%	C	Si	Mn	P	S	Cr	Ni	Cu	Nb
min	0.07	-	-	-	-	15	3	3	-
max	0.15	1	1	0.04	0.03	17	5	5	0.3

Note: These values are approximate

Mechanical properties

Tensile strength		Yield strength		Elongation		Impact toughness
1100-1350  MPa		1000-1250 MPa		8-15%		50-60 J

Note: These values are approximate

Physical properties

Property	Value
Density	7.8 g/cm³
Melting Point	1398℃
Coefficient of Thermal Expansion	11.7×10^-6/℃
Thermal Conductivity	14.6 W/(m·K)
Specific Heat Capacity	477 J/(kg·K)
Electrical Resistivity	72 μΩ·cm

Note: These values are approximate

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440F stainless steel is a type of martensitic stainless steel that boasts high carbon and chromium content, resulting in exceptional strength, hardness, and resistance to wear, corrosion, and high temperatures. Due to its outstanding properties, it is a favored material for creating parts that require robust hardness and corrosion resistance, such as valves, bearings, and blades. Furthermore, this stainless steel is straightforward to machine, making it a popular choice in the manufacturing industry. With a maximum hardness of approximately 60 HRC, 440F stainless steel is considered an exceptionally hard material.

Chemical composition

Element%	C	Si	Mn	P	S	Cr	Mo	Ni
min	0.95	-	-	-	-	16	-	-
max	1.2	1	1	0.04	0.03	18	0.75	0.5

Note: These values are approximate

Mechanical properties

Tensile strength		Yield strength		Elongation		Hardness
1170-1310  MPa		1050-1180 MPa		10-20%		57-60 HRC

Note: These values are approximate

Physical properties

Property	Value
Density	7.7 g/cm³
Coefficient of thermal expansion	10.4 x 10^-6 /K (20-100°C)
Thermal conductivity	24 W/(m·K) (100°C)
Specific heat capacity	460 J/(kg·K) (0-100°C)
Electrical resistivity	0.60 x 10^-6 Ω·m
Magnetic properties	High magnetic permeability,

Note: These values are approximate

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440C stainless steel is a high-grade martensitic stainless steel commonly used in the manufacture of highly wear-resistant mechanical parts such as high-quality knives and bearings. It is a member of the 400 series of stainless steels and is ideal for high-performance knives due to its high hardness, high corrosion resistance, and high toughness.

Specifically, 440C stainless steel is mainly composed of elements such as carbon, chromium and molybdenum, among which the carbon content is as high as 0.95%, which makes it have extremely high hardness and wear resistance. At the same time, the chromium element makes it extremely resistant to corrosion and can be used in various harsh environments. Molybdenum contributes to the corrosion resistance and toughness of the alloy.

Chemical composition

Element%	C	Si	Mn	P	S	Cr	Mo
min	0.95	-	-	-	-	16	-
max	1.2	1	1	0.04	0.03	18	0.75

Note: These values are approximate

Mechanical properties

Tensile strength		Yield strength		Elongation		Hardness
1700-1900  MPa		1300-1500 MPa		2-10%		58-62HRC

Note: These values are approximate

Physical properties

Property	Value
Density	7.75 g/cm³
Melting Point	1480-1530°C
Coefficient of Thermal Expansion	10.4×10⁻⁶/°C
Thermal Conductivity	24 W/(m·K)
Electrical Resistivity	60-70 nΩ·m
Magnetic Permeability	1.25×10⁻⁶ H/m
Specific Heat Capacity	460 J/(kg·K)

Note: These values are approximate

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440B stainless steel is a type of martensitic stainless steel that is often used in various applications that require high hardness, toughness, and corrosion resistance.

440B stainless steel is also commonly used in the manufacture of bearings, valves, and other components that require excellent resistance to wear, fatigue, and corrosion.

Compared to SUS440A steel, 440B stainless steel has a higher hardness. On the other hand, 440B stainless steel has a higher toughness than SUS440C steel.

Chemical composition

Element%	C	Si	Mn	P	S	Cr	Mo
min	0.75	-	-	-	-	16	-
max	0.95	1	1	0.04	0.03	18	0.75

Note: These values are approximate

Mechanical properties

Tensile strength		Yield strength		Elongation		Hardness
1310-1450 MPa		1140-1240 MPa		8-14%		58-60 HRC

Note: These values are approximate

Physical properties

Property	Value
Density	7.7 g/cm³
Thermal Expansion Coefficient	10.4 x 10^-6 /K (20-100 °C)
Thermal Conductivity	24 W/(m·K)
Specific Heat Capacity	460 J/(kg·K)
Electrical Resistivity	0.60 x 10^-6 Ω·m

Note: These values are approximate

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440A stainless steel is a martensitic stainless steel that is known for its high chromium content, which gives it excellent corrosion resistance in harsh environments. It is often used in the manufacture of bearing parts that are exposed to corrosive environments and do not require lubrication.

In addition to its excellent corrosion resistance and hardness, 440A stainless steel also has good high-temperature dimensional stability. This means that it can maintain its shape and size even when exposed to high temperatures, which makes it suitable for use in high-temperature applications such as furnace parts and cutting tools.

Chemical composition

Element%	C	Si	Mn	P	S	Cr	Mo
min	0.6	-	-	-	-	16	-
max	0.75	1	1	0.04	0.03	18	0.75

Note: These values are approximate

Mechanical properties

Tensile strength		Yield strength		Elongation		Hardness
760-1310 MPa		590-1140 MPa		10-25%		55-57 HRC

Note: These values are approximate

Physical properties

Property	Value
Density	7.75 g/cm³
Melting Point	1371-1508 ℃
Coefficient of Thermal Expansion	10.4 × 10^-6/K
Thermal Conductivity	24.2 W/mK
Specific Heat Capacity (0-100℃)	0.16 J/(g·K)
Magnetism	Can be magnetized

Note: These values are approximate

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Austenitic stainless steel is a type of stainless steel mainly composed of austenite. This steel is known for its high corrosion resistance, good formability and excellent toughness at both low and high temperatures. Austenitic stainless steels contain high levels of chromium and nickel, which provide corrosion resistance and ductility. The chromium in steel forms a passivating layer on the metal surface, protecting the metal from corrosion. The nickel in the steel helps increase its ductility, making it easier to shape.

What is austenite?

Austenite refers to a solid solution in steel consisting of iron, carbon and other alloying elements. It is a crystalline structure formed at high temperatures and plays an important role in iron and steel metallurgy. Its lattice structure is a face-centered cubic structure. It forms at high temperatures, cools slowly, and usually requires heating to a high temperature state. Then cool quickly. Austenite, whose properties depend on its carbon content and the presence of other alloying elements, generally has good ductility, toughness and strength. When the austenite in the steel cools below room temperature, it gradually transforms into other crystal structures such as martensite and bainite. Therefore, controlling the proportion and structure of austenite in steel is of great significance for the preparation of steel.

What is the composition of austenitic stainless steel?

The composition of austenitic stainless steels usually includes high levels of chromium and nickel, and small amounts of other elements such as carbon, manganese, nitrogen and molybdenum. The exact composition may vary depending on the specific grade of austenitic stainless steel. The high levels of chromium and nickel give austenitic stainless steels excellent corrosion resistance while keeping the carbon content low to prevent carbide precipitation and maintain the ductility of the steel. Manganese is added to improve the machinability and strength of the steel, while nitrogen is sometimes added to improve the steel's resistance to pitting corrosion. Molybdenum is often added to improve the steel's resistance to localized corrosion and to increase its overall strength.

Are austenitic stainless steels magnetic?

Austenitic stainless steels are generally non-magnetic or only slightly magnetic. This is because they contain a high content of nickel, which stabilizes the austenitic structure and reduces the magnetic permeability of the steel. In fact, the non-magnetic nature of austenitic stainless steel is one of its key properties, making this steel suitable for a variety of applications where magnetic interference may be an issue. However, it is worth noting that certain grades of austenitic stainless steels can become slightly magnetic when cold worked or exposed to high temperatures. This is known as "cold-work-induced" or "temperature-induced" magnetism, and it occurs when the austenite structure deforms or chromium carbides form at grain boundaries. Generally speaking, this kind of magnetism is relatively weak and will not significantly affect the overall non-magnetic properties of austenitic stainless steel.

What are the advantages of austenitic stainless steel?

Austenitic stainless steel has several important properties that make it a popular material for a wide range of applications. Some of the main properties of austenitic stainless steels include: 1.Excellent corrosion resistance: Austenitic stainless steel has very high corrosion resistance, thanks to the high content of chromium and nickel in its composition. This makes it ideal for harsh environments such as marine or chemical applications. 2.Good formability: Austenitic stainless steel is highly formable and easily weldable, making it a versatile material that can be formed and joined in many different ways. It can also be easily formed into complex shapes or sheets without losing its strength. 3.High Toughness: Austenitic stainless steels have excellent toughness even at low temperatures, making them ideal for applications where impact resistance is important. 4.High-temperature strength: Austenitic stainless steels retain their strength at high temperatures, making them a common material for high-temperature applications such as heat exchangers and furnace components. 5.Sanitation: Austenitic stainless steels are easy to clean and sanitize, making them ideal for use in industries such as food processing and medical equipment.

How to judge whether the stainless steel you buy is austenitic?

There are several ways to judge whether the stainless steel you buy is austenitic: Check the material grade: Austenitic stainless steels are usually identified by their grade, which is a number that represents the specific alloy composition of the steel. The most common austenitic grades include 304, 316 and 321. You can check the material grade on the product label or spec sheet to confirm it is an austenitic stainless steel. Magnetic test: Austenitic stainless steel is not magnetic or only slightly magnetic. You can use a magnet to test whether steel is magnetic. If the magnet is strongly attracted to the steel, it is probably not austenitic. Check Corrosion Resistance: Austenitic stainless steels are highly resistant to corrosion, especially in harsh environments such as marine or chemical applications. You can check corrosion resistance by performing a simple salt spray test, exposing a small sample of steel to salt spray and observing its performance over time. Hengqiao(Shanghai) International Trading Limited is a reliable and reputable stainless steel supplier, and I highly recommend you to buy from us. We offer a wide range of high quality stainless steel products for a variety of applications from kitchen appliances to industrial machinery. Our supplied stainless steel materials undergo strict quality control measures to ensure that they meet the highest standards of performance and durability. In addition, our knowledgeable and experienced team is ready to answer any questions you may have and provide technical support and advice. With our competitive prices, fast delivery time and excellent customer service, we are confident that you will be satisfied with the products you purchase from our company.

431 stainless steel is a high hardness, high strength martensitic stainless steel. The corrosion resistance and mechanical strength of 431 stainless steel can be improved by adding molybdenum and chromium. This stainless steel has excellent mechanical properties, grinding and wear resistance, and has good corrosion resistance and heat treatment performance. Therefore, it is often used in the manufacture of high-strength, high wear-resistant parts, such as bearings, valves, threads, bolts and connections. In addition, 431 stainless steel is also suitable for the manufacture of high wear-resistant knives, molds and clamps. It should be noted that the welding performance of 431 stainless steel is poor, so it is necessary to handle it carefully and choose suitable welding materials when welding.

Chemical composition

Element%	C	Si	Mn	P	S	Cr	Ni
min	-	-	-	-	-	15	1.25
max	0.2	1	1	0.04	0.03	17	2.5

Note: These values are approximate

Mechanical properties

Tensile strength		Yield strength		Elongation
≥690 MPa		≥345 MPa		≥20%

Note: These values are approximate

Physical properties

Property	Value
Density	7.8 g/cm³
Elastic modulus	200 GPa
Thermal expansion coefficient	10.4 × 10^-6/K
Thermal conductivity	24 W/(m·K)
Magnetic	Yes, can be magnetic depending on processing

Note: These values are approximate

Our company: Hengqiao(Shanghai) International Trading Limited

As a premium supplier of stainless steel, we offer a wide range of grades, sizes and finishes to suit your needs.
Size: according to customer requirements
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SUS420F is a kind of stainless steel, also known as 420F stainless steel, which is a kind of martensitic stainless steel. It is a steel alloyed by elements such as chromium and molybdenum, which has high hardness and strength, and also has certain corrosion resistance.

SUS420F stainless steel is mainly used in the manufacture of knives, instruments, valves, bearings, pumps and pneumatic components. It has good processing performance, easy to cut and shape, and can be processed into various shapes. In addition, SUS420F stainless steel also has high magnetic permeability, which can be applied to the manufacture of electronic equipment and motors.

It should be noted that the welding performance of SUS420F stainless steel is poor, and appropriate welding processes and measures should be taken. In addition, it is not suitable for use in high temperature or strong corrosive environment.

Chemical composition

Element%	C	Si	Mn	P	S	Cr	Ni	Mo
min	0.26	-	-	-	0.15	12	-	-
max	0.4	1	1.25	0.06	-	14	0.6	0.6

Note: These values are approximate

Mechanical properties

Tensile strength		Yield strength		Elongation
≥700 MPa		≥460 MPa		≥15%

Note: These values are approximate

Physical properties

Property	Value
Density	7.7 g/cm³
Melting Point	1450-1520℃
Coefficient of Thermal Expansion	11.5 × 10^-6 / ℃
Thermal Conductivity	24.9 W/(m·K)
Electrical Conductivity	25.2 × 10^6 / (Ω·m)

Note: These values are approximate

Our company: Hengqiao(Shanghai) International Trading Limited

As a premium supplier of stainless steel, we offer a wide range of grades, sizes and finishes to suit your needs.
Size: according to customer requirements
Standards: GB, ASTM, EN, JIS, etc.
Coil/Tube/Pipe/Sheet/Strip/wire/Bar/Channel
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