304 vs 316 Stainless Steel - What's the Difference?
In the world of stainless steel, 304 stainless steel and 316 stainless steel are two common and widely used materials. Both are very popular and play an important role in many fields. Although they both belong to the stainless steel family, there are obvious differences in chemical composition, performance characteristics and scope of application.
In terms of chemical composition, 304 stainless steel is composed of 18% chromium (Cr) and 8% nickel (Ni). In addition to the two basic components, it also contains a small amount of carbon, manganese, silicon and other elements. This combination makes it have good oxidation resistance and corrosion resistance, and can maintain basic stability.
316 stainless steel adds about 2% molybdenum to 304 stainless steel. Chromium is about 2% less than 304 stainless steel. The increase of molybdenum improves the corrosion resistance of stainless steel, making the corrosion resistance of 316 stainless steel higher than that of 304 stainless steel!
The properties of the two alloys are roughly the same.
Introduction to 304 stainless steel
As one of the most widely used steels, it has good corrosion resistance and heat resistance. It is resistant to high temperatures of 800℃ and has the characteristics of good processing performance and high toughness. It is widely used in the industrial and furniture decoration industries as well as the food and medical industries.
Introduction to 316 stainless steel
Performance characteristics of 304 and 316
Corrosion resistance: As mentioned above, 316 stainless steel has better corrosion resistance due to its high content of molybdenum. It can better resist the corrosion of chloride ions. For equipment in coastal areas, marine engineering structures, etc., 316 stainless steel has a longer service life. While 304 stainless steel can meet the corrosion resistance requirements in general indoor and outdoor environments, its corrosion resistance is relatively weak in harsh corrosive environments.
Temperature: The performance of 316 stainless steel is more stable in high temperature environments. The strength and corrosion resistance of 304 stainless steel will decrease at high temperatures, and it is generally suitable for occasions where the temperature does not exceed 800℃.
Toughness and weldability: 304 stainless steel has good toughness, is easy to process and form, and has relatively good welding performance. Products of various complex shapes can be made through various processing techniques, and the joint strength after welding is high. 316 stainless steel also has good toughness, but due to its relatively complex alloy composition, some process details need to be paid attention to during welding.
Why is 304 stainless steel used more than 316 stainless steel?
This was also mentioned in the previous article. The molybdenum element in 316 stainless steel is about 2% more than that in 304 stainless steel, which greatly improves the corrosion resistance and acid and alkali resistance of 316 stainless steel, but it is this 2% difference. Make the cost of the two alloys different.
The cost price of 304 stainless steel is usually between 15,000 and 20,000 per ton, while 316 stainless steel is more than 2w per ton. And 304 has met most of the daily needs. Therefore, it is more popular.
304 stainless steel is widely used in tableware, kitchen and other equipment, but 316 stainless steel has stronger corrosion resistance, and is more used in medical equipment and industrial equipment in highly corrosive environments.
304 stainless steel is enough to meet the demand, so its market demand is greater. Although 316 stainless steel has better performance, it is mainly used in specific fields with higher material performance requirements due to its high cost.
Having said so much, the difference between the two is corrosion resistance. If what you are manufacturing is not so important and it is OK to use it, you can use 304 stainless steel. 316 stainless steel usually lasts a little longer than 304 stainless steel.