What is 317L stainless steel?

317L stainless steel is a stainless steel material with high corrosion resistance, and its chemical composition contains a relatively high proportion of elements such as chromium, nickel and molybdenum. It is widely used in chemical, petroleum, pharmaceutical, food processing and other fields, and is often used in the manufacture of corrosion-resistant equipment and pipes. Compared with other stainless steels, 317L stainless steel has better acid and alkali resistance, better high temperature resistance and good processing performance.

What is the chemical composition of 317L stainless steel?

The chemical composition of 317L stainless steel is as follows:

Carbon (C): 0.03% max

Silicon (Si): 1.00% max

Manganese (Mn): 2.00% max

Phosphorus (P): 0.045% max

Sulfur (S): 0.030% max

Chromium (Cr): 18.00% - 20.00%

Nickel (Ni): 11.00% - 15.00%

Molybdenum (Mo): 3.00% - 4.00%

Vanadium (V): 0.20% max

Iron (Fe): balance

Among them, the high proportion of elements such as chromium, nickel and molybdenum in this material is the main reason for its corrosion resistance.

What are the physical properties of 317L stainless steel?

The physical properties of 317L stainless steel are as follows:

Density: 8.0 g/cm³;

Melting point: about 1400 - 1425°C;

Linear expansion coefficient: 16.5 μm/m-°C (20°C to 100°C);

Thermal conductivity: 14.6 W/(m K) (at 100°C);

Specific heat capacity: 502 J/(kg·K) (at 20°C).

When the temperature is higher than 1000 °C, the oxidation resistance of 317L stainless steel will be reduced, but it shows excellent corrosion resistance at room temperature and high temperature. In addition, the material has good toughness, weldability and processability, and is easy to manufacture into various shapes of equipment and components.

What are the mechanical properties of 317L stainless steel?

The mechanical properties of 317L stainless steel are as follows:

Tensile strength: ≥ 515 MPa;

Yield strength (0.2% offset): ≥ 205 MPa;

Elongation: ≥ 35%.

The material also has excellent creep resistance in high temperature environments and can be used to manufacture equipment and components that are heated for a long time. However, it should be noted that at low temperatures (below -20°C), its toughness will be reduced, so it is necessary to take into account the possible effects of low temperature conditions when using it. 

What is the welding performance of 317L stainless steel?

317L stainless steel has good welding performance and can be welded by common welding methods, such as manual arc welding, TIG argon arc welding and automatic submerged arc welding. Among them, TIG argon arc welding is one of the most commonly used welding methods because it can produce high-quality welds and make the welded materials have excellent corrosion resistance.

When welding 317L stainless steel, the following points need to be paid attention to:

In the selection of shielding gas, high-purity argon or nitrogen should be selected to avoid welding defects such as pores;

Correctly control the welding current and voltage to avoid deformation and cracks caused by overheating and cooling;

The surface of the material should be cleaned before welding to avoid the influence of pollution and oxidation on the welding quality;

For larger welds or where multi-layer welding is required, proper preheating and post-heat treatment should be carried out to improve the quality of the weld and the toughness of the material.

In short, under the premise of correctly mastering the welding technology, 317L stainless steel can achieve high-quality welding, and the welded material has good corrosion resistance and mechanical properties.

What is the corrosion resistance of 317 stainless steel?

317L stainless steel has good corrosion resistance, especially in harsh environments such as strong acid, strong alkali and high temperature, such as concentrated sulfuric acid, chloride solution, phosphoric acid, acetic acid, ammonia water, sea water and corrosive gases. The following are the corrosion resistance properties of this material:

Corrosion resistance: 317L stainless steel has excellent corrosion resistance and can resist the erosion of many organic and inorganic acids, including sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, etc. In addition, it is also resistant to attack by chloride ions.

High temperature resistance: 317L stainless steel still has excellent corrosion resistance at high temperatures, and can resist some highly corrosive oxidants, such as air, water vapor and monoxide and dioxide.

Resistance to intergranular corrosion: The material contains less carbon and titanium elements, so intergranular corrosion is not prone to occur.

In short, 317L stainless steel has strong corrosion resistance, so it is widely used in chemical, petroleum, pharmaceutical, food processing and other fields.

Is 317L stainless steel magnetic?

317L stainless steel is a non-magnetic stainless steel material. After processing, welding and cold treatment, the material can still remain non-magnetic, so it is widely used in fields where protection from magnetic field interference is required. Compared with other stainless steels, 317L stainless steel contains more elements such as nickel, molybdenum and chromium, and the addition of these elements helps to improve its corrosion resistance and non-magnetic properties.

Is 317L stainless steel hard enough?      

The hardness of 317L stainless steel depends on the specific process and heat treatment method. In general, 317L stainless steel after cold working can achieve higher hardness, but its hardness may decrease under high temperature or long-term use conditions. In addition, compared with other stainless steels, 317L stainless steel has relatively low strength and hardness, but has better mechanical properties such as toughness and ductility. If it is necessary to increase the hardness of 317L stainless steel, it can be treated by heat treatment and quenching.

What is the surface treatment of 317L stainless steel?

The surface treatment methods of 317L stainless steel include the following:

Polishing: Through mechanical polishing, chemical polishing and other methods, the surface of 317L stainless steel is smooth and smooth, and its aesthetics and corrosion resistance are improved.

Pickling: Use an acidic solution to treat the surface of 317L stainless steel to remove impurities such as scale and rust on the surface, and improve its surface finish and corrosion resistance.

Sandblasting: Use high-pressure gas or water to spray abrasives onto the surface of 317L stainless steel to remove oil, scale and burrs on the surface, and improve its surface quality and appearance.

Electroplating: A layer of metal or alloy is plated on the surface of 317L stainless steel to increase its surface hardness and corrosion resistance, and at the same time improve its appearance.

All of the above surface treatment methods can achieve certain improvements and improvements on 317L stainless steel. Which method should be chosen depends on factors such as the use, requirements and environment of the material.

What are the applications of 317L stainless steel?

Due to its excellent corrosion resistance and high temperature strength, 317L stainless steel is widely used in many fields, the main applications include the following:

Chemical industry: 317L stainless steel is widely used in the manufacture of chemical reactors, pipes, storage tanks, valves, heat exchangers and other equipment and components to resist the erosion of various corrosive media.

Oil and gas extraction: Because 317L stainless steel has excellent corrosion resistance and high temperature strength, it is widely used in pipelines, equipment and components in oil and gas extraction.

Pharmaceutical industry: 317L stainless steel is also a commonly used material in the pharmaceutical industry. It can be used to manufacture equipment and components such as liquid delivery systems, reactors and storage tanks.

Food processing: 317L stainless steel is widely used in the food processing industry, including containers, pipes and equipment for the production of milk, juice, beer and other foods.

Nuclear industry: Because 317L stainless steel has good corrosion resistance and high temperature strength, it is also widely used in the nuclear industry to manufacture reactor vessels, pipes and equipment.

In conclusion, 317L stainless steel can maintain its excellent performance in a variety of harsh environments, so it has been widely used in many industries.