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4340 steel is a versatile alloy widely used in various industries due to its excellent mechanical properties. Apart from its mechanical characteristics, understanding the physical properties of 4340 steel is essential.

Understanding the Significance of Physical Properties

Physical properties provide valuable information about how a material behaves under specific conditions. They help engineers and designers make informed decisions regarding material selection and application suitability. By exploring the physical properties of 4340 steel, we can gain insights into its behavior in different environments and its potential applications.

Density of 4340 Steel

Density refers to the mass per unit volume of a material and is an important property to consider when evaluating its weight and size requirements. The density of 4340 steel is approximately 7.85 grams per cubic centimeter (g/cm³). This moderate density allows for a balance between strength and weight, making it suitable for various structural and load-bearing applications.

Melting Point of 4340 Steel

The melting point of a material indicates the temperature at which it transitions from a solid to a liquid state. In the case of 4340 steel, its melting point is around 1427-1517 degrees Celsius (2600-2750 degrees Fahrenheit). This relatively high melting point ensures that 4340 steel can withstand elevated temperatures during processing and application, making it suitable for applications that involve heat exposure.

Thermal Conductivity of 4340 Steel

Thermal conductivity refers to a material’s ability to conduct heat. For 4340 steel, the thermal conductivity is relatively low compared to other metals, with values ranging from 29 to 50 watts per meter-kelvin (W/m·K). This property makes 4340 steel a good choice for applications that require controlled heat transfer, such as heat-resistant components in engines or machinery.

Electrical Conductivity of 4340 Steel

The electrical conductivity of a material determines its ability to conduct electricity. In the case of 4340 steel, it has a relatively low electrical conductivity. This property makes it suitable for applications where electrical insulation is required.

The moderate thermal conductivity allows for controlled heat transfer, and the low electrical conductivity makes it suitable for applications requiring electrical insulation. （physical properties of 4340 steel）

Introduction to 4340 Steel: In the world of engineering and manufacturing, selecting the right material for a specific application is crucial. 4340 steel is a versatile alloy that has gained significant popularity due to its exceptional properties and wide range of applications.

Composition of 4340 Steel

4340 steel belongs to the category of nickel-chromium-molybdenum (Ni-Cr-Mo) steels, which are known for their high strength and toughness. The composition of 4340 steel typically includes the following elements:

• Iron (Fe): The primary element, forming the base of the steel.
• Carbon (C): Provides strength and hardness to the alloy.
• Nickel (Ni): Enhances toughness and impact resistance.
• Chromium (Cr): Improves hardenability and corrosion resistance.
• Molybdenum (Mo): Contributes to high temperature strength and creep resistance.

The specific percentages of these elements may vary slightly depending on the manufacturing process and desired properties.

Physical Properties

4340 steel exhibits several notable physical properties that make it suitable for various applications. Some of the key physical properties of 4340 steel are:

• Density: The density of 4340 steel is approximately 7.85 g/cm³, which is relatively high compared to some other alloys.
• Melting Point: The melting point of 4340 steel is around 1427°C (2600°F), enabling it to withstand high-temperature environments.
• Thermal Conductivity: The thermal conductivity of 4340 steel is moderate, allowing for efficient heat transfer when required.

Mechanical Properties

The mechanical properties of 4340 steel make it a preferred choice for applications where high strength and toughness are crucial. Here are some key mechanical properties of 4340 steel:

• Tensile Strength: 4340 steel typically has a tensile strength ranging from 930 to 1080 MPa (135,000 to 157,000 psi), making it highly resistant to deformation under tension.
• Yield Strength: The yield strength of 4340 steel is approximately 785 MPa (114,000 psi), indicating its ability to withstand significant loads without permanent deformation.
• Hardness: 4340 steel can achieve a hardness of around 28 to 32 HRC (Rockwell C scale) after appropriate heat treatment.

Heat Treatment of 4340 Steel

4340 steel can be heat treated to enhance its mechanical properties further. The most common heat treatment processes applied to 4340 steel include:

• Quenching and Tempering: This process involves heating the steel to a specific temperature, followed by rapid cooling (quenching) and subsequent tempering to achieve the desired hardness and toughness.
• Annealing: Annealing is performed to relieve internal stresses and improve machinability. It involves heating the steel to a specific temperature and then slowly cooling it.

The choice of heat treatment process depends on the desired properties and application requirements.

Common Applications

4340 steel finds applications in various industries and sectors due to its excellent combination of strength, toughness, and wear resistance. Some common applications of 4340 steel include:

• Aerospace Components: 4340 steel is used in the manufacturing of critical aerospace components, such as landing gear, shafts, and gears, where high strength and reliability are essential.
• Automotive Industry: The automotive industry utilizes 4340 steel in components like crankshafts, connecting rods, and gears, thanks to its high fatigue strength and impact resistance.
• Oil and Gas Sector: 4340 steel is employed in the oil and gas industry for components like drill collars, shafts, and valves due to its ability to withstand harsh operating conditions.
• Tooling and Machinery: The exceptional strength and toughness of 4340 steel make it an ideal choice for tooling applications, including punches, dies, and molds.

Advantages of Using 4340 Steel

The use of 4340 steel offers several advantages, making it a popular choice in various industries:

• High Strength: 4340 steel exhibits remarkable strength, allowing it to withstand heavy loads and high-stress environments.
• Toughness: The toughness of 4340 steel enables it to resist fracture under impact or shock loading, making it suitable for demanding applications.
• Versatility: 4340 steel can be heat treated to achieve a wide range of mechanical properties, making it adaptable to different application requirements.
• Machinability: With proper heat treatment and machining techniques, 4340 steel can be easily machined into complex shapes and precise components.

By understanding the composition, properties, and applications of 4340 steel, engineers and manufacturers can make informed decisions when selecting materials for their projects. (Introduction to 4340 Steel)

Heat treatment and process of 4340 steel round bar&plate

AISI 4340 alloy steel can be cold worked in the annealed condition using all conventional methods. It is highly malleable.

Annealing & Temper

Full annealing may be done at 844°C (1550 F), followed by controlled (furnace) cooling to 315°C (600 F) at a rate not to exceed 10°C (50 F) per hour. It can be air-cooled from 315°C to 600F.

AISI 4340 alloy steel shall be in the heat-treated or normalized heat-treated condition before tempering. The tempering temperature depends on the desired strength level. For strength levels in the 260 – 280 ksi range, temper at 232°C (450 F). Temper at 510°C (950 F) for strengths in the range of 125 – 200 ksi. Do not temper 4340 steel if it is in the 220 – 260 ksi strength range as tempering will result in reduced impact resistance at that strength level. Tempering in the range of 250 °C – 450 °C should be avoided where possible due to temper brittleness.

4340 steel heat treatment

AISI 4340 alloy steel is heat treated at 830°C (1525°F) and quenched in oil.

*Machinability

It can be processed using all conventional techniques. Processing can be carried out in the annealed or normalized and tempered condition.

*Welding

Welding of steels in the quenched and tempered condition (commonly supplied) is not recommended and should be avoided if possible due to the risk of quench cracking as the mechanical properties change in the weld heat-affected zone.

If soldering is necessary, preheat to 200 to 300°C and maintain this temperature while soldering. Stress is relieved immediately after welding at 550 to 650°C, followed by quenching and tempering.

If it is indeed necessary to weld in the quenched and tempered condition, the workpieces should be stress relieved as far as possible at a temperature 15°C below the original tempering temperature, after cooling immediately to hand temperature.

Something about 4340 alloy steel

*What is 4340 alloy steel?

4340 Alloy Steel is an iron-based alloy containing nickel, chromium, and molybdenum. The relatively high carbon content provides this alloy with superior strength in applications where severe service conditions exist. 4340 Alloy Steel has high strength, superior toughness, and good ductility.

*Is 4340 a low alloy steel?

AISI 4340 is a low alloy steel containing nominally 0.4% C, 0.8% Cr, 0.25% Mo, and 1.8% Ni. Higher strength levels up to 150 KSI 0.2% PS may be achieved by suitable heat treatment. Often used in preference to AISI 4140 at the higher strength levels because of its better hardenability and improved CVN impact toughness.

*How hard is 4340 annealed?

AISI 4340 is stocked in the heat treated and stress-relieved condition at approximately 150,000 psi (1034 N/mm2) and in the annealed condition at HB 235 max.

*What is 4340 steel used for?

AISI 4340 alloy steel is mainly used in power transmission gears and shafts, aircraft landing gear, and other structural parts.

30crnimo8 steel data sheet–30CrNiMo8 steel is used for automotive | OTAI

What is 30crnimo8 steel

30crnimo8 steel is one structural steel with medium hardenability designed for heavy-duty components, characterized by high elasticity and strength properties reaching over 1560 N/mm2 at small diameters. When it is softened, the hardness reaches max. 248 HRB.

It is also characterized by its resistance to variable loads and impacts.

However, it is not good for welding and it ultimately requires additional preheating.

Why Choose OTAI

1)All year round, Otai can guarantee 30crnimo8 steel’ stock in different thicknesses and lengths, which can be customized.

2)After placing an order, shipment can be arranged immediately.

3)Otai is a leading China supplier of 30crnimo8 steel, working with Uddeholm, and Thyssenkrupp, with ISO9001 certified.

Customer’s story

We would like to share a real case of our customer with you. Stacy from Indonesia send us an inquiry about the 30crnimo8 steel alloy, which required a lot of specifications and a small quantity. Stacy asked many suppliers who were unwilling to cooperate and finally found us. We are the source manufacturer so that we can meet the needs of customers to customize the specifications of goods. Then Stacy placed the order successfully. After receiving the goods, she said that he would seek our cooperation for a long time. (30crnimo8 steel data sheet)

Steel News

There are conditions for improvement in steel demand in September, but it should not be expected to be too high for the strength of demand. In the short term, more demand will be based on moderate release, and it is unlikely that a concentrated outbreak will be released. In September, the fundamental rebound of the steel market is insufficient, and the steel price will be mainly adjusted by shocks.

30crnimo8 steel composition–It is usually supplied with Q+T condition| OTAI

What is 30crnimo8 steel

30crnimo8 steel is one structural steel with medium hardenability designed for heavy-duty components, characterized by high elasticity and strength properties reaching over 1560 N/mm2 at small diameters. When it is softened, the hardness reaches max. 248 HRB.

It is also characterized by its resistance to variable loads and impacts.

However, it is not good for welding and it ultimately requires additional preheating.

Why Choose OTAI

1)All year round, Otai can guarantee 30crnimo8 steel stock in different thicknesses and lengths, which can be customized.

2)After placing an order, shipment can be arranged immediately.

3)Otai is a leading China supplier of 30crnimo8 steel, working with Uddeholm, and Thyssenkrupp, with ISO9001 certified.

Customer’s story

We would like to share a real case of our customer with you. Stacy from Indonesia send us an inquiry about the 30crnimo8 steel alloy, which required a lot of specifications and a small quantity. Stacy asked many suppliers who were unwilling to cooperate and finally found us. We are the source manufacturer so we can meet the needs of customers to customize the specifications of goods. Then Stacy placed the order successfully. After receiving the goods, she said that he would seek our cooperation for a long time. (30crnimo8 steel composition)

Steel News

In the first half of 2022, under the circumstance of frequent uncertainties in global economic development, the economic development expectations of the major economies weakened. The World Bank lowered its global economic growth forecast for this year to 2.9% on June 7; the OECD lowered its economic forecast to 3% on June 8; the Institute of International Finance lowered its forecast to 2.3% in early May, and the IMF The (International Monetary Fund) lowered its economic forecast three times in a row in six months, the latest results will be released in July and the expected value will not exceed 3%.

steel grade 30crnimo8 – It is made for forming wrought product | OTAI

What is 30crnimo8 steel

30crnimo8 steel is one structural steel with medium hardenability designed for heavy-duty components, characterized by high elasticity and strength properties reaching over 1560 N/mm2 at small diameters. When it is softened, the hardness reaches max. 248 HRB.

It is also characterized by its resistance to variable loads and impacts.

However, it is not good for welding and it ultimately requires additional preheating.

Why Choose OTAI

1)All year round, Otai can guarantee 30crnimo8 steel’ stock in different thicknesses and lengths, which can be customized.

2)After placing an order, shipment can be arranged immediately.

3)Otai is a leading China supplier of 30crnimo8 steel, working with Uddeholm, and Thyssenkrupp, with ISO9001 certified.

Customer’s story

We would like to share a real case of our customer with you. Stacy from Indonesia send us an inquiry about the 30crnimo8 steel alloy, which required a lot of specifications and a small quantity. Stacy asked many suppliers who were unwilling to cooperate and finally found us. We are the source manufacturer so that we can meet the needs of customers to customize the specifications of goods. Then Stacy placed the order successfully. After receiving the goods, she said that he would seek our cooperation for a long time. (steel grade 30crnimo8)

Steel News

There are conditions for improvement in steel demand in September, but it should not be expected to be too high for the strength of demand. In the short term, more demand will be based on moderate release, and it is unlikely that a concentrated outbreak will be released. In September, the fundamental rebound of the steel market is insufficient, and the steel price will be mainly adjusted by shocks.

30crnimo8 astm equivalent-4340, 1.6580 Hardened Alloy Steel| OTAI

What is 30crnimo8 steel

30crnimo8 steel is one structural steel with medium hardenability designed for heavy-duty components, characterized by high elasticity and strength properties reaching over 1560 N/mm2 at small diameters. When it is softened, the hardness reaches max. 248 HRB.

It is also characterized by its resistance to variable loads and impacts.

However, it is not good for welding and it ultimately requires additional preheating.

Why Choose OTAI

1)All year round, Otai can guarantee 30crnimo8 steel stock in different thicknesses and lengths, which can be customized.

2)After placing an order, shipment can be arranged immediately.

3)Otai is a leading China supplier of 30crnimo8 steel, working with Uddeholm, and Thyssenkrupp, with ISO9001 certified.

Customer’s story

We would like to share a real case of our customer with you. Stacy from Indonesia send us an inquiry about the 30crnimo8 steel alloy, which required a lot of specifications and a small quantity. Stacy asked many suppliers who were unwilling to cooperate and finally found us. We are the source manufacturer so we can meet the needs of customers to customize the specifications of goods. Then Stacy placed the order successfully. After receiving the goods, she said that he would seek our cooperation for a long time. (30crnimo8 astm equivalent)

Steel News

In the first half of 2022, under the circumstance of frequent uncertainties in global economic development, the economic development expectations of the major economies weakened. The World Bank lowered its global economic growth forecast for this year to 2.9% on June 7; the OECD lowered its economic forecast to 3% on June 8; the Institute of International Finance lowered its forecast to 2.3% in early May, and the IMF The (International Monetary Fund) lowered its economic forecast three times in a row in six months, the latest results will be released in July and the expected value will not exceed 3%.

30crnimo8 steel application-for automotive and mechanical engineering | OTAI

What is 30crnimo8 steel

30crnimo8 steel is one structural steel with medium hardenability designed for heavy-duty components, characterized by high elasticity and strength properties reaching over 1560 N/mm2 at small diameters. When it is softened, the hardness reaches max. 248 HRB.

It is also characterized by its resistance to variable loads and impacts.

However, it is not good for welding and it ultimately requires additional preheating.

Why Choose OTAI

1)All year round, Otai can guarantee 30crnimo8 steel’ stock in different thicknesses and lengths, which can be customized.

2)After placing an order, shipment can be arranged immediately.

3)Otai is a leading China supplier of 30crnimo8 steel, working with Uddeholm, and Thyssenkrupp, with ISO9001 certified.

Customer’s story

We would like to share a real case of our customer with you. Stacy from Indonesia send us an inquiry about the 30crnimo8 steel alloy, which required a lot of specifications and a small quantity. Stacy asked many suppliers who were unwilling to cooperate and finally found us. We are the source manufacturer so that we can meet the needs of customers to customize the specifications of goods. Then Stacy placed the order successfully. After receiving the goods, she said that he would seek our cooperation for a long time. (30crnimo8 steel application)

Steel News

There are conditions for improvement in steel demand in September, but it should not be expected to be too high for the strength of demand. In the short term, more demand will be based on moderate release, and it is unlikely that a concentrated outbreak will be released. In September, the fundamental rebound of the steel market is insufficient, and the steel price will be mainly adjusted by shocks.

30crnimo8 steel equivalent-It is considered a structural steel | OTAI

What is 30crnimo8 steel

30crnimo8 steel is one structural steel with medium hardenability designed for heavy-duty components, characterized by high elasticity and strength properties reaching over 1560 N/mm2 at small diameters. When it is softened, the hardness reaches max. 248 HRB.

It is also characterized by its resistance to variable loads and impacts.

However, it is not good for welding and it ultimately requires additional preheating.

Why Choose OTAI

1)All year round, Otai can guarantee 30crnimo8 steel stock in different thicknesses and lengths, which can be customized.

2)After placing an order, shipment can be arranged immediately.

3)Otai is a leading China supplier of 30crnimo8 steel, working with Uddeholm, and Thyssenkrupp, with ISO9001 certified.

Customer’s story

We would like to share a real case of our customer with you. Stacy from Indonesia send us an inquiry about the 30crnimo8 steel alloy, which required a lot of specifications and a small quantity. Stacy asked many suppliers who were unwilling to cooperate and finally found us. We are the source manufacturer so we can meet the needs of customers to customize the specifications of goods. Then Stacy placed the order successfully. After receiving the goods, she said that he would seek our cooperation for a long time. (30crnimo8 steel equivalent)

Steel News

In the first half of 2022, under the circumstance of frequent uncertainties in global economic development, the economic development expectations of the major economies weakened. The World Bank lowered its global economic growth forecast for this year to 2.9% on June 7; the OECD lowered its economic forecast to 3% on June 8; the Institute of International Finance lowered its forecast to 2.3% in early May, and the IMF The (International Monetary Fund) lowered its economic forecast three times in a row in six months, the latest results will be released in July and the expected value will not exceed 3%.

30crnimo8 steel chemical composition-Alloyed structural steel with medium hardenability | OTAI

What is 30crnimo8 steel

30crnimo8 steel is one structural steel with medium hardenability designed for heavy-duty components, characterized by high elasticity and strength properties reaching over 1560 N/mm2 at small diameters. When it is softened, the hardness reaches max. 248 HRB.

It is also characterized by its resistance to variable loads and impacts.

However, it is not good for welding and it ultimately requires additional preheating.

Why Choose OTAI

1)All year round, Otai can guarantee 30crnimo8 steel’ stock in different thicknesses and lengths, which can be customized.

2)After placing an order, shipment can be arranged immediately.

3)Otai is a leading China supplier of 30crnimo8 steel, working with Uddeholm, and Thyssenkrupp, with ISO9001 certified.

Customer’s story

We would like to share a real case of our customer with you. Stacy from Indonesia send us an inquiry about the 30crnimo8 steel alloy, which required a lot of specifications and a small quantity. Stacy asked many suppliers who were unwilling to cooperate and finally found us. We are the source manufacturer so that we can meet the needs of customers to customize the specifications of goods. Then Stacy placed the order successfully. After receiving the goods, she said that he would seek our cooperation for a long time. (30crnimo8 steel chemical composition)

Steel News

There are conditions for improvement in steel demand in September, but it should not be expected to be too high for the strength of demand. In the short term, more demand will be based on moderate release, and it is unlikely that a concentrated outbreak will be released. In September, the fundamental rebound of the steel market is insufficient, and the steel price will be mainly adjusted by shocks.

8620 steel gears-it is a low cost steel with good carburized properties. | OTAI

What is 8620 steel

8620 steel is a high-quality Quenched and Tempered Alloy Structural steel. It belongs to the high-quality low carbon, Low alloy chromium, molybdenum, nickel case hardening steel. Oil Quenched & Tempered Hardness is 28-34 HRc. AISI 8620 steel Annealing delivery hardness less than 250HB.

Why Choose OTAI

1)All year round, Otai can guarantee 8620 bars’ stock in different thicknesses and lengths, which can be customized.

2)After placing an order, shipment can be arranged immediately.

3)Otai is a leading China supplier of 8620 steel, working with Uddeholm, Thyssenkrupp, with ISO9001 certified.

Customer’s story

We would like to share a real case of our customer with you. Stacy from Indonesia send us an inquiry about the 8620 steel alloy, which required a lot of specifications and a small quantity. Stacy asked many suppliers who were unwilling to cooperate and finally found us. We are the source manufacturer so that we can meet the needs of customers to customize the specifications of goods. Then Stacy placed the order successfully. After receiving the goods, she said that he would seek our cooperation for a long time. (8620 steel gears)

Steel News

At present, nine counties and cities in Tangshan have lifted the management of regional blockade control.
The clustered epidemics in many places in China have dragged down the production and operation of the manufacturing and construction industries. In the short term, the demand for steel has been unstable, and the rise in steel prices is insufficient.
Once the social “dynamic clearing” is realized in various places, the demand for steel will be released retaliatory, the demand growth may be higher than the supply, the inventory will enter a stage of decline, and there may still be room for steel prices to rise.