What is 347 stainless steel?

Type 347 stainless steel is a niobium stabilized chromium-nickel austenitic stainless steel with corrosion resistance similar to 304/304L. In the temperature range of 800-1500°F, the material stabilizes chromium carbide precipitates by the addition of niobium and forms niobium carbide precipitates. After exposure to this temperature range, Type 347 stainless steel exhibits excellent resistance to intergranular corrosion, is resistant to oxidation up to 1500°F, and has higher creep and stress rupture characteristics than Type 304/304L. In addition, it has good low temperature toughness and is nonmagnetic in the annealed state.

Chemical composition of 347 stainless steel

347 stainless steel is a high temperature corrosion resistant stainless steel, its main chemical composition includes:

material

347

chemical composition

Carbon

Chromium

Nickel

Manganese

Silicon

Phosphorus

Sulfur

Niobium

 

0.08

17.0-19.0

9.0-13.0

2.00

0.75

0.045

0.030

10 x C min / 1.00 max

These chemical components endow 347 stainless steel with excellent corrosion resistance and high temperature resistance. It has good oxidation resistance in high temperature environment, and can resist the erosion of strong corrosive media such as sulfuric acid, nitric acid and chloride.

What are the mechanical properties of 347 stainless steel?

347 stainless steel has good mechanical properties, and its typical mechanical properties are as follows:

material

347

mechanical properties

Yield Strength, min. (ksi)

Tensile Strength, min. (ksi)

Elongation, min. (%)

Hardness, max. (Rb)

30

75

40

92

These mechanical properties make 347 stainless steel suitable for applications in high temperature environments and corrosive media, such as chemical equipment, oil and gas processing equipment, nuclear power plants and refineries, etc. In addition, 347 stainless steel also has good welding performance, which can be easily manufactured and installed.

Physical properties of 347 stainless steel

347 stainless steel has the following characteristics in terms of physical properties:

material

347

Physical Properties

Density, lb/in3

Modulus of Elasticity, psi

Coefficient of Thermal Expansion, 68-212˚F, /˚F

Thermal Conductivity, Btu/ft hr ˚F

Specific Heat, Btu/lb ˚F

Electrical Resistivity, Microohm-in

0.288

28.0 x 106

9.3 x 10-6

9.2

0.12

28.4

These physical properties indicate that 347 stainless steel has certain thermal conductivity and electrical conductivity, and is suitable for applications that need to withstand high temperatures and currents. In addition, its linear expansion coefficient is comparable to that of common metal materials, which can reduce thermal stress caused by temperature changes.

Is 347 stainless steel magnetic?

347 stainless steel belongs to austenitic stainless steel and is usually non-magnetic. Austenitic stainless steel is non-magnetic in solid solution state. However, when 347 stainless steel undergoes a certain degree of processing deformation or cold working, it may cause changes in the lattice structure, resulting in magnetization in some areas. This magnetization is called stress-induced magnetism and can be restored to a non-magnetic state during stress-relieving annealing.

Therefore, for normal 347 stainless steel material, when it is not processed or cold worked, it is generally non-magnetic. However, it should be noted that if 347 stainless steel is subjected to large processing stress or cold processing, it may produce a certain degree of magnetism.

Performance characteristics of 347 stainless steel

347 stainless steel is an austenitic stainless steel with the following performance characteristics:

Corrosion resistance: 347 stainless steel has good corrosion resistance, especially in high temperature environments. It has high corrosion resistance to many organic and inorganic acids, such as sulfuric acid, nitric acid and hydrochloric acid.

Oxidation resistance: Due to the stable element tantalum (Ta), 347 stainless steel has excellent oxidation resistance, which can effectively prevent the oxidation of the metal surface in a high temperature environment.

High temperature strength: 347 stainless steel has good strength and heat resistance at high temperature. It can withstand stress and deformation under high temperature conditions and maintain the stability of the structure.

Welding performance: 347 stainless steel has good welding performance and can be welded by conventional welding methods. The welded joint area has similar corrosion resistance and mechanical properties to the base material.

Plasticity: 347 stainless steel has good plasticity and processing properties, and can be formed and processed by cold working or hot working.

Falling film ability: 347 stainless steel has the ability to reduce carbide deposition and precipitation under high temperature conditions, and can effectively resist intergranular corrosion and carbide deposition in the welding heat-affected zone.

In summary, 347 stainless steel has good corrosion resistance, oxidation resistance, high temperature strength, weldability and plasticity, and is suitable for many applications in high temperature and corrosive environments.

Disadvantages of 347 stainless steel

While 347 stainless steel has many advantages, it also has some disadvantages. One of its major disadvantages is reduced toughness compared to other stainless steel alloys. This can make it more likely to break under certain conditions.

Another disadvantage of 347 stainless steel is its higher cost compared to some other stainless steel options. Production costs are generally higher due to the addition of tantalum and niobium, which help to increase its resistance to intergranular corrosion.

Also, 347 stainless steel may not be suitable for applications requiring high tensile strength or extreme temperatures. It has a lower yield strength than some other stainless steels and begins to lose its mechanical properties at temperatures above about 800°C (1472°F).

Also, while 347 stainless steel has excellent resistance to aqueous environments containing acidic compounds, it may not perform well in highly oxidizing environments or strong reducing acids such as hydrochloric acid.

Despite these disadvantages, it’s important to note that each material has its own advantages and disadvantages. It is critical for engineers and designers to carefully consider the specific requirements of their application before selecting any material.

While there are some disadvantages to using 347 stainless steel, such as reduced toughness and higher cost compared to other options, it still offers valuable advantages, such as increased resistance to intergranular corrosion. Choosing the right material depends on weighing these factors according to the requirements of the project.

What is the difference between 347 stainless steel and 304 stainless steel?

347 stainless steel and 304 stainless steel are two common stainless steel materials, they have some differences in chemical composition, corrosion resistance and application.

chemical composition:

347 stainless steel contains 17-20% chromium (Cr), 9-13% nickel (Ni), and 0.5-1.0% molybdenum (Mo) and other elements. In addition, it also contains small amounts of elements such as carbon (C) and titanium (Ti).

304 stainless steel contains 18-20% chromium (Cr) and 8-10.5% nickel (Ni), but does not contain molybdenum (Mo). In addition, it also contains a small amount of elements such as carbon (C) and manganese (Mn).

Corrosion resistance:

347 stainless steel has better high temperature corrosion resistance than 304 stainless steel, and has better resistance to strong corrosive media such as sulfuric acid, nitric acid and chloride.

304 stainless steel has good corrosion resistance in general environment, but corrosion problems may occur in high temperature and strong acid environment.

Application field:

347 stainless steel is often used in applications in high temperature environments, such as chemical equipment, oil and gas processing equipment, nuclear power plants and refineries, etc.

304 stainless steel is widely used in food processing, architectural decoration, medical equipment, furniture manufacturing and other fields.

It should be noted that the above is only a general description of the difference, and the specific application needs to be selected according to the actual situation and requirements.

What is the difference between 347 stainless steel and 304 stainless steel?

347 stainless steel and 304 stainless steel are two common stainless steel materials, they have some differences in chemical composition, corrosion resistance and application.

chemical composition:

347 stainless steel contains 17-20% chromium (Cr), 9-13% nickel (Ni), and 0.5-1.0% molybdenum (Mo) and other elements. In addition, it also contains small amounts of elements such as carbon (C) and titanium (Ti).

304 stainless steel contains 18-20% chromium (Cr) and 8-10.5% nickel (Ni), but does not contain molybdenum (Mo). In addition, it also contains a small amount of elements such as carbon (C) and manganese (Mn).

Corrosion resistance:

347 stainless steel has better high temperature corrosion resistance than 304 stainless steel, and has better resistance to strong corrosive media such as sulfuric acid, nitric acid and chloride.

304 stainless steel has good corrosion resistance in general environment, but corrosion problems may occur in high temperature and strong acid environment.

Application field:

347 stainless steel is often used in applications in high temperature environments, such as chemical equipment, oil and gas processing equipment, nuclear power plants and refineries, etc.

304 stainless steel is widely used in food processing, architectural decoration, medical equipment, furniture manufacturing and other fields.

It should be noted that the above is only a general description of the difference, and the specific application needs to be selected according to the actual situation and requirements.

Application fields of 347 stainless steel

Due to its special properties, 347 stainless steel is widely used in the following fields:

Petroleum and chemical industry: 347 stainless steel has excellent corrosion resistance and high temperature resistance in the fields of petroleum, chemical industry, natural gas processing and storage. It is often used in the manufacture of petroleum refining units, chemical reactors, pipelines, storage tanks and heat exchangers and other equipment.

Application in high temperature environment: Because 347 stainless steel has good high temperature strength and oxidation resistance, it is widely used in high temperature heating equipment, such as burners, furnaces and heat treatment furnaces.

Nuclear energy industry: 347 stainless steel plays an important role in nuclear power plants. It is used to make critical components such as nuclear reactor pressure vessels, steam generators, cooling ducts and nuclear fuel storage.

Medical device field: 347 stainless steel has good biocompatibility and corrosion resistance, and is widely used in the manufacture of medical devices and implants, such as surgical instruments, orthopedic implants and artificial heart valves.

High-temperature stoves and barbecue equipment: Due to the high-temperature strength and corrosion resistance of 347 stainless steel, it is used to manufacture high-temperature stoves, ovens, grills, and gas stoves.

Food processing industry: 347 stainless steel meets hygienic standards and has good corrosion resistance to acidic and alkaline substances in food. Therefore, it is widely used in food processing equipment, food storage tanks and piping systems, etc.

In short, 347 stainless steel has excellent performance in corrosive environments and high temperature conditions, so it is widely used in petrochemical, high temperature equipment, nuclear energy, medical equipment, food processing and other fields.