Comparison Of 201 And 316 Stainless Steel: Economic Austenitic Vs Standard Austenitic Grade

201 and 316 are both austenitic stainless steels, with the core difference lying in alloying elements (nickel, chromium, molybdenum) and corrosion resistance. 201 is an economic nickel-saving grade, while 316 is a standard molybdenum-containing corrosion-resistant grade. This comparison clarifies the selection balance between cost and corrosion resistance.

Core Parameter Comparison

Parameter	201 Stainless Steel	316 Stainless Steel
Chemical Composition (wt%)	C≤0.15, Si≤1.00, Mn≤5.50-7.50, P≤0.060, S≤0.030, Cr=16.00-18.00, Ni=3.50-5.50, N≤0.25, Fe=Balance	C≤0.08, Si≤1.00, Mn≤2.00, P≤0.045, S≤0.030, Cr=16.00-18.00, Ni=10.00-14.00, Mo=2.00-3.00, Fe=Balance
Mechanical Properties (Annealed)	Tensile Strength ≥520MPa, Yield Strength ≥275MPa, Elongation ≥40%, Hardness ≤210HB	Tensile Strength ≥515MPa, Yield Strength ≥205MPa, Elongation ≥40%, Hardness ≤217HB
Service Temperature	-20℃ to 600℃ (continuous service)	-196℃ to 870℃ (continuous service)
Equivalent Grades	SUS201 (JIS), EN 1.4372, UNS S20100	SUS316 (JIS), EN 1.4401, UNS S31600

Key Performance Differences: 1. Corrosion resistance: 316 contains molybdenum (2-3%) and high nickel (10-14%), with excellent resistance to pitting, crevice corrosion and chloride corrosion; 201 has low nickel (3.5-5.5%) and no molybdenum, poor corrosion resistance, prone to rust in humid or chloride environments. 2. Low-temperature performance: 316 can withstand ultra-low temperature (-196℃) without embrittlement; 201 is brittle below -20℃. 3. Cost: 201 is 40-50% cheaper than 316, with obvious cost advantages. 4. High-temperature performance: 316's high nickel content improves high-temperature oxidation resistance, service temperature 270℃ higher than 201. 5. Weldability: Both have good weldability, but 201 is prone to grain coarsening after welding, while 316 has stable welding performance.

Applicable Scenario Distinction: 201 is suitable for low-cost, low-corrosion indoor scenarios, such as decorative pipes, furniture accessories, indoor storage tanks (dry environment), and mid-to-low-end kitchen utensils. 316 is suitable for medium-corrosion environments, such as chemical equipment (weak acid/alkali), marine hardware, food processing machinery (saline food), and heat exchangers (industrial water).

Practical Q&A

Q1: Why is 201 not suitable for coastal areas? A1: Its low nickel and no molybdenum make it poor in chloride corrosion resistance; seawater vapor contains high chloride ions, which will cause 201 to rust within 3-6 months; 316 can be used in coastal atmospheric environments for 5-8 years.

Q2: Can 201 replace 316 in food processing? A2: Only suitable for dry food processing (such as flour, grain); not suitable for saline, acidic food (such as seafood, pickles) processing, as it is prone to rust and contaminates food; 316 is the standard material for food contact with corrosive ingredients.

Q3: What is the difference in weldability between 201 and 316? A3: Both use ER308L welding wire; 201 needs to control low heat input to avoid intergranular corrosion; 316 has better welding stability, no strict heat input control for thin plates, and no post-weld heat treatment required.

Q4: How to improve the corrosion resistance of 201? A4: Surface electroplating (chrome, nickel) or passivation treatment can be used; avoid long-term exposure to moisture and corrosive gases; it is not recommended to use in outdoor or industrial pollution areas.

Q5: What is the selection principle of 201 and 316? A5: Choose 201 if cost is the priority and the environment is dry and low-corrosion; choose 316 if corrosion resistance (especially chloride corrosion) is required, even if the cost is higher.