304 vs 316 Stainless Steel
The main difference between 304 vs 316 stainless steel is the composition and corrosion resistance, SS304 doesn’t contain molybdenum while SS316 contains 2-3% molybdenum. The addition of molybdenum provides pitting resistance in phosphoric acid, acetic acid and dilute chloride solutions and provides corrosion resistance in sulfurous acid. In addition, AISI 304 has a 18% Cr and 8% Ni and therefore known as 18-8 stainless steel, while AISI 316 has a 16% Chromium and 10% Nickel.
Difference Between 304 and 316 Stainless Steel in Chemical Composition
The following table shows the difference between 304 and 316 stainless steel in composition.
|SS304 vs SS316 Composition (%)|
|Steel Grade||C, ≤||Si ≤||Mn ≤||P ≤||S ≤||Cr||Ni||Mo|
SS304 vs SS316 Mechanical Properties
304 vs 316 stainless steel properties
|SS304 vs SS316 Mechanical Properties|
|ASTM||UNS||AISI||Tensile Strength, MPa (ksi), ≥||0.2% Yield Strength, MPa (ksi), ≥||Elongation in 50 mm, %, ≥||Reduction in area, %, ≥||Brinell Hardness (HBW) ≤||Rockwell Hardness (HRBW) ≤||Condition|
|ASTM A276/A276M||UNS S30400||304||515 (75)||205 (30)||40||50||–||–||Annealed, Hot finished|
|UNS S30400||304||620 (90)||310 (45)||30||40||–||–||Annealed, Cold finished, ≤ 0.5 in. (12.7 mm)|
|ASTM A240/A240M||UNS S30400||304||515 (75)||205 (30)||40||–||201||92|
304 vs 316 Stainless Steel Strength and Hardness
304 vs 316 stainless steel strength and hardness can be found in the above table.
304 vs 316 Stainless Steel Cost
AISI 304 vs 316 stainless steel cost: Taking steel plates as an example, the cost of 316 is about 1.5 times the cost of 304. The price of stainless steel depends on the price of the alloying element and the amount of the alloy (eg Ni, Cr and Mo). The price of molybdenum (Mo) is about twice that of nickel (Ni), six times that of chromium (Cr), 316 nickel content is higher than 304, and 316 contains molybdenum, while 304 does not contain it, so the cost of 316 is higher than 304.
SS304 vs SS316 Corrosion
Since Mo is added to SS316, Mo can improve the pitting resistance and is therefore more resistant to corrosion than SS304.