The difference between 304 stainless steel and 316 stainless steel

Stainless steel has penetrated into all aspects of everyone’s life. 304 stainless steel is also widely known as food-grade stainless steel. Now businesses often promote 316 stainless steel. What is the difference between them.



Stainless steel is a kind of alloy steel

We usually say “stainless steel”, the full name is “stainless acid-resistant steel”. To make the steel not rust, it is actually very simple, just add some metal impurities to make alloy steel (such as adding chromium). But not rusting, it only means that it will not be corroded by air, and the ability is still too poor. So we also need it to be resistant to chemical corrosion, so “stainless acid-resistant steel” appeared. To make stainless acid-resistant steel, many kinds of metals need to be added, and different metal formulas form different stainless steels.

304 and 316 are both austenitic stainless steels

Stainless steel is often divided into: martensitic steel, ferritic steel, austenitic steel, austenitic-ferritic (duplex) stainless steel and precipitation hardening stainless steel according to the structure state. In addition, it can be divided into: chromium stainless steel, chromium-nickel stainless steel and chromium-manganese-nitrogen stainless steel according to the composition. Among them, austenitic stainless steel has the best comprehensive performance and no magnetism, so it is the most widely used in our daily life. 304 and 316 belong to austenitic stainless steel.

Several common models
304: ie 18/8 stainless steel. Products such as: corrosion-resistant containers, tableware, furniture, railings, medical equipment. 
       The standard composition is 18 % chromium plus 8 % nickel. It is a stainless steel that is non-magnetic and cannot be changed by heat treatment. The GB grade is 06Cr19Ni10.

304 L: The same characteristics as 304, low carbon, so it is more resistant to corrosion and easy to heat treatment, but has poor mechanical properties.

316: After 304, the second most widely used steel grade, mainly used in the food industry, watch accessories, pharmaceutical industry and surgical equipment, adding molybdenum to obtain a special structure that is resistant to corrosion.
 Because of its better resistance to chloride corrosion than 304, it is also used as "marine steel". SS316 is usually used in nuclear fuel recovery units.

316 L: Low carbon, so it is more resistant to corrosion and easy to heat treatment. Products such as chemical processing equipment, nuclear power generators, and refrigerant storage tanks.

Comprehensive consideration of cost performance

For food steel, 304 is enough, and there are almost no defects; the use of 316 in this regard is purely overkill, and the aspect that 316 is stronger than 304 is not reflected at all. Therefore, when consumers choose products, they can make comprehensive judgments according to their needs and cost-effectiveness, and choose suitable products.


Post time: Mar-18-2022

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