1. The chemical composition is different:
316 has 2-3 more nickels than 304. The standard composition of 304 stainless steel is 18% chromium plus 8% nickel. It is a stainless steel that is non-magnetic and cannot be changed by heat treatment. GB grade is 0Cr18Ni9.
2. Different performance:
The strength and hardness of 304 and 316 are similar. The difference between the two is that the corrosion resistance of 316 is much better than that of 304. More importantly, molybdenum metal is added to 316, which improves the heat resistance.
3. Different scope of application
Common curtain walls, side walls, and roofs use 304 stainless steel, but in some severely corrosive industrial or marine atmospheres, 316 stainless steel is a good choice.
The addition of molybdenum gives it a special structure that resists corrosion. Because of its better resistance to chloride corrosion than 304, it is also used as "marine steel".