Which is better, 316 stainless steel or 304?

Stainless steel 316 and stainless steel 304 each have their own advantages and disadvantages. Which one is better depends on the specific usage scenario and requirements. Here is a detailed comparison of them:

Component differences:

304 stainless steel: The main alloying elements are chromium and nickel. The chromium content is approximately 18%-20%, and the nickel content is approximately 8%-10.5%. The Chinese designation is 06Cr19Ni10.

316 stainless steel: Based on the composition of 304 stainless steel, the chromium content is reduced, the nickel content is increased, and 2% - 3% of molybdenum element is added. The Chinese brand name is 0Cr17Ni12Mo2.

Corrosion Resistance:

304 stainless steel: In general environments such as air, water and steam, it has excellent corrosion resistance and can meet the requirements of most daily and industrial applications. However, in environments containing chloride ions, its corrosion resistance is relatively weak.

316 stainless steel: Due to the addition of molybdenum, it can better resist the damage caused by chloride ions to the passivation film on the surface of stainless steel, thereby effectively reducing the risks of pitting and crevice corrosion. In environments containing chloride ions such as seawater and high-salinity industrial wastewater, its corrosion resistance is even better.

High temperature strength:

304 stainless steel: Its high-temperature resistance is approximately 800 degrees.

316 stainless steel: It has superior high-temperature strength compared to 304 stainless steel. Its ability to withstand high temperatures can reach 1200 to 1300 degrees Celsius, making it more suitable for use in high-temperature environments.

Mechanical properties:

304 stainless steel: The tensile strength is 520 MPa, the yield strength under specified conditions is 205 MPa, and the elongation rate is 40%. It has excellent cold and hot processing and forming properties, and can be processed to produce various products such as plates, tubes, wires, strips, and profiles. It is suitable for manufacturing parts for cold heading, deep drawing, and deep stretching forming.

316 stainless steel: The tensile strength is not less than 620 MPa, the yield strength is not less than 310 MPa, and the elongation rate is not less than 30%. It also has good strength and toughness, and excellent work hardening property.

Price:

304 stainless steel: The production process is relatively simple, the cost is low, and the price is also quite affordable.

316 stainless steel: Due to the addition of molybdenum and the relatively high nickel content, along with the stricter production process requirements, its manufacturing cost is higher and its price is also more expensive than that of 304 stainless steel.

In general daily usage scenarios, such as household kitchenware and architectural decoration, 304 stainless steel usually meets the requirements and offers better cost-effectiveness; while in marine engineering, chemical equipment, and high-temperature environments where corrosion resistance and high-temperature strength are highly demanded, 316 stainless steel is a better choice.