300 Series Stainless Steel: Performance, Application, Grades & Comparison

We will analyze the chemical composition, mechanical properties and physical properties of 300 series stainless steel in detail, and compare it with other series such as 400 series, 200 series and Duplex stainless steel to help you fully understand its advantages and disadvantages. In addition, this article will also provide maintenance tips for 300 series stainless steel to ensure that it stays in optimal condition in various environments.

What Is 300 Series Stainless Steel?

300 series stainless steel is a chromium-nickel austenitic stainless steel, mainly characterized by high Cr (16-20%) and high Ni (8-14%) content, sometimes including other alloying elements. With excellent  properties, they are widely used in various fields.

How 300 Series Stainless Steel Is Produced?

Smelting and Casting

The 300 series stainless steel production begins with electric arc furnace smelting, using high-purity iron ore, chromium ore, nickel ore and alloying elements. The raw materials are mixed, heated to a molten state and cast into a preliminary billet, with strict control of temperature and alloy composition to ensure quality. Subsequently, the billet is heat treated to optimize the internal structure and improve performance. It may be further processed into products of desired shapes and specifications.

Hot Rolling and Cold Rolling

The billet after casting is hot rolled, which is a process in which the billet is heated to a high temperature and then pressed into the desired thickness through a rolling mill. Hot rolling not only improves the surface quality of the steel, but also improves its mechanical properties. The thickness and width of the steel can be precisely controlled through the hot rolling process to meet the requirements of different applications.

Cold rolling is a manufacturing process conducted at room temperature, enabling steel to be transformed into thinner, more precise plates or strips. Cold-rolled stainless steel has higher strength and a smoother surface, and is often used for precision machining and decorative purposes.

Heat Treatment and Surface Treatment

Heat treatment improves the mechanical and physical properties of stainless steel, including annealing, quenching and tempering. Annealing enhances plasticity and toughness, quenching increases hardness and strength, and tempering adjusts brittleness. Surface treatments such as polishing make the surface smooth, and electroplating enhances corrosion resistance.  These treatments improve the quality and performance of stainless steel together.

Performance of 300 Series Stainless Steel 

Chemical Composition

The main chemical components of 300 series stainless steel include.

Chromium (Cr): 16%~20% content, forming an anti-corrosion passivation film, enhancing the corrosion resistance of stainless steel.

Nickel (Ni): 8%~12% content, improving the toughness and corrosion resistance of stainless steel, stabilizing the austenite structure.

Molybdenum (Mo): 2%~3% in 316 stainless steel, enhancing the corrosion resistance of 316 in chlorides.

Manganese (Mn): The content of manganese is higher in 200 series stainless steel, which is mainly used to improve the strength and hardness of steel.

Mechanical Properties

Yield Strength

• Yield strength is a reflection of the practical use limit of the material. The yield strength of 300 series stainless steel is usually in the range of 210-250 MPa, which is moderate compared with other stainless steel series, but due to its good ductility and machinability, it is widely used in various structures and equipment.

Tensile Strength

• Tensile strength indicates the maximum load a material can bear before breaking. 300 series stainless steels excel at withstanding mechanical loads and impact forces, with tensile strengths typically in the 500-700 MPa range, making them suitable for applications requiring strength and durability.

Ductility and Elongation

• Ductility refers to a material’s ability to extend under pressure without breaking. 300 series stainless steel has excellent ductility, with an elongation usually between 40-60%. This makes 300 series stainless steel easy to cold work into complex shapes and less prone to cracking.

Hardness

• Hardness is the resistance of a material to local deformation. The hardness of 300 series stainless steel is usually between 80-90 HRB (Rockwell B scale). Although 300 series stainless steel is not as hard as some martensitic stainless steels, its excellent overall properties make up for this.

Impact Toughness

• Impact toughness measures a material’s ability to resist impact at low temperatures without damage.300 series stainless steel exhibits excellent impact toughness at low temperatures. For example, 304 stainless steel can still maintain good toughness at -196°C (-320°F).

Physical Properties

Density

• Density is the mass per unit volume and affects the weight of the material and design choices. The density of 300 series stainless steel is usually between 7.90-8.00 g/cm³. The higher density provides a stable physical structure for 300 series stainless steel, making it excellent in structural applications.

Thermal Conductivity

• Thermal conductivity refers to a material’s ability to conduct heat. The thermal conductivity of 300 series stainless steel is relatively low, usually between 15-25 W/(m·K). Low thermal conductivity allows 300 series stainless steel to effectively insulate heat and reduce heat loss in high temperature environments.

Thermal Expansion Coefficient

• The thermal expansion coefficient refers to the degree to which a material expands in volume when heated. The thermal expansion coefficient of 300 series stainless steel is typically 16-17 × 10⁻⁶ /K. This property allows 300 series stainless steel to remain structurally stable in environments with large temperature changes.

Resistivity

• Resistivity reflects a material’s ability to conduct electricity. 300 series stainless steels have high resistivity (0.7-0.8 µΩ·m ), making them suitable for use as electrical insulators.

Magnetism

• 300 series stainless steel is usually non-magnetic, but may show slight magnetism after cold working, such as 304 stainless steel may be slightly magnetic after cold rolling. This property makes 300 series stainless steel an ideal choice for non-magnetic applications such as precision instruments and electronic equipment.

Chemical Properties

Corrosion Resistance

• The corrosion resistance of 300 series stainless steel is one of its most notable properties. With high chromium and nickel content, these stainless steels are resistant to a wide range of chemical media.

Oxidation Resistance

• 300 series stainless steels exhibit excellent oxidation resistance at elevated temperatures. The oxide film formed by chromium can protect the steel from oxidation.

Chemical Resistance

• 300 series stainless steels show different resistance capabilities in various chemical media. For example, 304 stainless steel has good resistance to weak acids (such as acetic acid) and some organic acids, while 316 stainless steel can better withstand strong acids and chlorides.

Resistance to Ammonia and Ammonia Water

• 300 series stainless steels have good resistance to ammonia and ammonia water. Due to the role of nickel and chromium, these stainless steels can maintain good chemical stability in an ammonia or ammonia environment to avoid corrosion or damage.

Applications of 300 Series Stainless Steel

Medical device field: 304 and 316 stainless steel are ideal for surgical instruments, medical devices and implants due to their excellent corrosion resistance and biocompatibility. They can resist the erosion of body fluids and disinfectants, ensuring the long-term stability and safety of medical devices.

Food and beverage industry: 304 stainless steel is widely used in kitchen utensils, food processing machinery and beverage storage containers due to its corrosion resistance and easy cleaning properties.

Construction and decoration field: 300 series stainless steel also performs well in construction and decoration, and is often used to create building exteriors, door and window frames and railings. Its beautiful appearance and excellent corrosion resistance add unique charm and long-term value to architectural design.

Chemical and petroleum industry: In chemical processing and petroleum production equipment, 316 stainless steel stands out for its excellent corrosion resistance. It can withstand harsh chemical environments and ensure the stable operation of equipment under complex working conditions.

Automobile industry: 300 series stainless steel meets the strict requirements for high temperature and corrosion resistance, and is often used in key parts such as automobile exhaust systems and body structures.

Advantages and Disadvantages of 300 Series Stainless Steel

Advantages

• Excellent corrosion resistance: With a high proportion of nickel and chromium, the 300 series stainless steel forms a tough chromium oxide protective layer, which effectively resists a wide range of acid, alkali and salt corrosion. In particular, the 316 series has stronger pitting resistance in chlorine-containing environments due to the addition of molybdenum.

• Flexible and diverse processing: This series of stainless steel exhibits excellent plasticity and welding performance, easily copes with complex processes such as stamping, bending, and welding, and provides convenience for manufacturing diversified and refined product structures.

• Stable mechanical properties: Even under high temperature conditions, the 300 series stainless steel can maintain high strength and hardness to meet the stringent requirements of high-intensity working environments.

• Beautiful and durable: Its unique metallic luster and good decorative properties make it an ideal choice for products that pursue high-quality appearance. At the same time, its excellent corrosion resistance ensures the long service life of the product.

Disadvantages

• Higher cost: Due to the high proportion of chromium and nickel contained in 300 series stainless steel, its cost is relatively high. This may affect projects or applications with limited budgets.

• Poor low temperature performance: At very low temperatures, some 300 series stainless steels may become brittle. This may make them not perform as well as some other materials in extremely cold environments.

• Intergranular corrosion may occur at high temperatures: At high temperatures or in welding conditions, carbon (C) in 300 series stainless steel may form chromium carbide compounds with chromium (Cr), resulting in a decrease in the chromium content at the grain boundaries, forming the so-called “chromium-poor zone”, thereby losing corrosion resistance and causing intergranular corrosion. However, this can usually be avoided by controlling the carbon content and using appropriate heat treatment processes.

How to Maintain 300 Series Stainless Steel?

In order to maintain the performance of 300 series stainless steel, the following maintenance measures should be taken.

Regular Cleaning: Use neutral cleaners and water to clean stainless steel surfaces regularly. Do not use strong acid or alkaline cleaners as they may corrode the stainless steel.

Preventing Corrosion (Continued): Regularly inspect equipment and structures, and promptly address possible corrosion spots. For stainless steel used in chemical environments, apply appropriate protective layers or coatings to enhance its corrosion resistance.

Removing Dirt and Rust: When dirt or rust appears on the surface of stainless steel, it can be cleaned with a chloride-free cleaner. Use a soft cloth or sponge to wipe gently, and avoid using wire brushes or sandpaper, which may scratch the surface and cause more severe corrosion.

Preventing Scratches and Wear: Avoid scratching the surface of stainless steel with hard objects. For areas that require frequent friction, you can use protective pads or consider ways to reduce friction in the design.

Regular Inspection: For important structural parts or equipment, regular professional inspections and maintenance are carried out to ensure the integrity and functionality of stainless steel parts.

What Is the Difference between 300 Series, 400 Series and 200 Series?

300 series, 400 series and 200 series stainless steel each have different characteristics and applications, and understanding their differences will help you choose the most suitable material.

300 Series Stainless Steel

Main features: high corrosion resistance, high toughness, good processing. 300 series stainless steel includes grades such as 304 and 316, which are widely used in medical, food, construction and other fields.

Chemical composition: It mainly contains a high proportion of chromium and nickel, and the nickel content increases its corrosion resistance and high temperature resistance.

Application scenarios: It is suitable for occasions with high requirements for corrosion resistance and high strength, such as food processing equipment, medical equipment, architectural decoration, etc.

400 Series Stainless Steel

Main characteristics: 400 Series stainless steels contain less nickel and are generally harder and stronger than 300 Series, but have less corrosion resistance.

Chemical composition: The main component is chromium, and the nickel content is low, usually between 12% chromium and 0-1% nickel. Common grades include 410, 420, 430, etc.

Application scenarios: It is suitable for occasions with high requirements for hardness and wear resistance, such as knives, automotive exhaust systems, home appliances, etc. It is not as corrosion resistant as the 300 series and is suitable for milder environmental conditions.

200 Series Stainless Steel

Main Characteristics: 200 series stainless steel usually contains higher manganese and nitrogen, and lower nickel content. Although the corrosion resistance is worse than that of the 300 series, it has higher strength and lower cost.

Chemical Composition: It mainly contains chromium, manganese and nitrogen, and the nickel content is relatively low. Common grades include 201, 202, etc.

Application Scenarios: It is suitable for cost-sensitive occasions that do not require extremely high corrosion resistance, such as building materials, household goods, etc. The 200 series is usually used for applications that are low in cost but still require certain corrosion resistance.

300 Series vs Duplex

300 Series Stainless Steel

Features: Austenitic stainless steel; good corrosion resistance, processability and toughness; common grades are 304 and 316.

Application: Because of its excellent corrosion resistance, it is widely used in various environments.

Duplex Stainless Steel

Features: With high strength and good corrosion resistance, duplex stainless steel combines the structure of austenite and ferrite, like 2205 and 2507.

Advantages: Compared with the 300 series, Duplex stainless steel has higher strength and also performs well in corrosion resistance, especially in chloride environments. 

Application: Widely used in fields with high strength and corrosion resistance requirements such as petrochemicals, marine engineering, and fertilizer production.

Grade 304 vs Grade 316

304 Stainless Steel

Features: Excellent corrosion resistance, processability, and formability. Widely used in household equipment and architectural decoration.

Application: Suitable for food processing equipment, medical equipment, kitchen utensils, etc. It has high corrosion resistance, but does not perform as well as 316 in chloride environments.

316 Stainless Steel

Features: 2-3% molybdenum is added to 304, making it more corrosion resistant in chloride environments.

Application: Suitable for marine environments, chemical processing equipment, pharmaceutical industries, and other occasions with extremely high corrosion resistance requirements. 316 stainless steel is generally pricier than 304.

Click to read more about 304 vs 316.

Common Grades of 300 Series Stainless Steel

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